The findings identify groups with higher observed odds of iron deficiency anaemia, but the study design cannot establish that these factors caused the condition. Preterm infants are particularly vulnerable to iron deficiency because they generally have limited iron stores at birth, may lose blood through clinical procedures and undergo rapid growth when iron requirements are high. The study notes that iron deficiency anaemia can adversely affect neurodevelopment, immunity, growth and general health, with some consequences potentially becoming irreversible.

This makes early assessment of iron status relevant for infants born before 37 completed weeks of gestation, although the new findings concern a defined group of clinic attendees rather than all preterm births in Tanzania. Participants were recruited sequentially using convenience sampling until the required sample size of 190 was reached. The investigators initially assessed 202 preterm infants for eligibility.

Twelve were excluded because they had fever or had received a blood transfusion within the previous three months. The protocol also excluded infants with specified congenital anomalies, including cleft lip and palate, hydrocephalus and congenital heart disease with oxygen saturation below 90% and cyanosis, as well as infants who were acutely unwell, had tachycardia, tachypnoea or fever. Of the final sample, 139 infants came from Dodoma Regional Referral Hospital and 51 from Makole Health Centre.

Their mean age was 4.01 months, with a standard deviation of 0.99 months, and 109 of 190 were female. Information on the infants’ demographic characteristics, birth history, feeding practices, phlebotomy history, iron supplementation, clinical condition and maternal factors was gathered with a structured, pre-tested questionnaire, Reproductive and Child Health records, physical examinations and blood tests. The questionnaire was adapted from WHO STEPS instruments and relevant literature.

Its content validity was assessed by 10 experts, producing a scale-level content validity index of 0.90. Pretesting with 10% of the required sample produced a Cronbach’s alpha of 0.91, which the investigators described as excellent internal consistency. Data were entered in Microsoft Excel 2019 and analysed in IBM SPSS Statistics version 26 using descriptive statistics, chi-square tests and univariable and multivariable binary logistic regression.

Iron deficiency anaemia was identified through laboratory measures alone. Participants needed to meet at least three of five predefined criteria: haemoglobin below 10 g/dL, mean corpuscular volume below 80 fL, mean corpuscular haemoglobin concentration below 32 g/dL, serum ferritin below 12 micrograms per litre and C-reactive protein below 5 mg/L. Serum ferritin was used as the indicator of iron stores, while C-reactive protein was measured to account for the effect of inflammation on ferritin concentrations because ferritin is an acute-phase reactant. This operational definition is important when interpreting the prevalence because estimates can vary according to the criteria used to classify iron deficiency and anaemia, as well as the population, age at assessment, birth characteristics and supplementation practices.

The sample covered a range of preterm and low-birth-weight infants. Sixty-seven infants, or 35.26% of the sample, weighed less than 1.5 kg at birth, while 123 weighed between 1.5 kg and no more than 2.5 kg. Seventy-six infants were born before 32 weeks, 40 at 32–33 weeks and 74 at 34–36 weeks.

A total of 146 infants, or 76.84%, were exclusively breastfed, while 44 received mixed feeding with formula milk. Most infants received iron supplementation: 175 of 190, or 92.11%. Multiple gestation was reported for 33 mothers, and 22 infants had mothers whose haemoglobin before delivery was below 7 g/dL, which the study classified as severe anaemia.

In unadjusted comparisons, iron deficiency anaemia occurred in 19.4% of infants with a birth weight below 1.5 kg, compared with 7.3% among those weighing at least 1.5 kg. It was present in 60.0% of the 15 infants who had not received iron supplementation, compared with 7.4% of the 175 supplemented infants. Prevalence was 30.3% among infants born after multiple gestation and 7.6% among those born after singleton delivery.

Among infants whose mothers had haemoglobin below 7 g/dL before delivery, 50.0% had iron deficiency anaemia, compared with 6.6% when maternal haemoglobin was at least 7 g/dL. The bivariate analysis also found associations with gestational age and the duration of maternal iron supplementation. Infant age, phlebotomy history, feeding practices and maternal illness during pregnancy did not reach statistical significance in that analysis.

Multivariable analysis produced the strongest adjusted association for maternal severe anaemia. Infants whose mothers had haemoglobin below 7 g/dL before delivery had 12.00 times the adjusted odds of iron deficiency anaemia compared with infants whose mothers had haemoglobin of at least 7 g/dL, although the estimate was imprecise, with a 95% confidence interval of 2.70–53.34. Very low birth weight was associated with 6.91 times the adjusted odds of the condition, with a 95% confidence interval of 1.47–32.36.

Multiple gestation carried an adjusted odds ratio of 6.85, with a 95% confidence interval of 1.69–27.71, while absence of infant iron supplementation was associated with an adjusted odds ratio of 6.28, with a 95% confidence interval of 1.05–37.76. All four associations met the study’s statistical threshold of p below 0.05, but the wide confidence intervals indicate substantial uncertainty around the estimates. The 11.58% prevalence was similar to figures reported in other settings, including 9.9% in Sweden and 14.5% in Kenya, although the authors cautioned that comparisons are affected by differences in gestational age, birth weight, age at assessment, supplementation practices and eligibility criteria.

The Dodoma estimate was lower than reports from Turkey, at 42.8%, and Brazil, at 26.5%, and higher than a figure of 6% from Indonesia. The Indonesian study included infants born at 32–36 weeks, whereas the Dodoma study also included infants born before 32 weeks. The relatively high proportion of supplemented infants in the Dodoma sample may partly explain its lower prevalence compared with some studies, but the cross-sectional design does not allow the effect of supplementation to be isolated.

The comparison figures also come from different populations and definitions, so they do not establish a geographic trend. Several limitations constrain how far the findings can be generalised. Convenience sampling may have introduced selection bias because infants attending the two clinics may differ from other preterm infants, including those who did not attend these facilities.

Restricting recruitment to two health facilities in Dodoma also limits the applicability of the results to other regions and healthcare settings in Tanzania. In addition, some exposure categories contained relatively few participants, contributing to wide confidence intervals and reduced precision. The cross-sectional design prevents establishment of temporal or causal relationships between the identified factors and iron deficiency anaemia.

Within those boundaries, the measurements show that the condition occurred in a notable minority of these clinic attendees and that several maternal and infant characteristics were markers of higher observed odds. The authors identified strengthening iron supplementation, early recognition of high-risk infants and attention to maternal anaemia as priorities that may help reduce the burden, while noting that the study itself did not test an intervention or establish clinical effectiveness.

Subject of Research: Prevalence and associated factors of iron deficiency anaemia among preterm infants in Dodoma, Tanzania

Article Title: Prevalence of iron deficiency anaemia and associated factors among preterm infants aged 3–6 months attending clinics in Dodoma, Tanzania: a facility-based cross-sectional study

Article References: Mchwampaka, C., Mahamba, D., Jumanne, S., Msuya, M. A., & Matovelo, S. (2026). Prevalence of iron deficiency anaemia and associated factors among preterm infants aged 3–6 months attending clinics in Dodoma, Tanzania: a facility-based cross-sectional study. Frontiers in Pediatrics, 14, Article 1913886. https://doi.org/10.3389/fped.2026.1913886

Image Credits: AI Generated

DOI: 10.3389/fped.2026.1913886

Keywords: iron deficiency anaemia, preterm infants, Tanzania, Dodoma, birth weight, iron supplementation, maternal anaemia, multiple gestation, cross-sectional study, prevalence, iron, deficiency

The researchers began with public myocardial transcriptome data and found that Pik3r1 was significantly upregulated in diabetic cardiomyopathy. It was one of four genes shared among genes elevated in the disease, a curated inventory of mitochondrial genes and a set of ferroptosis-promoting genes. The same elevation appeared in three independent mouse datasets, while pathway analysis identified PI3K-Akt signaling as the most significantly enriched among upregulated pathways. These analyses supplied the rationale for testing PIK3R1 experimentally, although computational association alone could not establish a causal role.

To model diabetic cardiomyopathy, investigators fed male C57BL/6J mice a high-fat diet containing 60% fat and then administered three daily injections of low-dose streptozotocin. At week 24, model animals had elevated fasting glucose, impaired glucose tolerance, reduced left ventricular ejection fraction and fractional shortening, myocardial hypertrophy and fibrosis. Their cardiomyocytes also showed increased PIK3R1 expression. The experimental program included five cohorts of 10 mice per group, with separate tests of ferroptosis inhibition, mitochondrial fission inhibition, PI3K/Akt activation, cardiomyocyte-specific PIK3R1 knockout and a rescue involving the mitochondrial fission protein Drp1.

Two pharmacological experiments indicated that ferroptosis and excessive mitochondrial fission contribute to the phenotype in this model. Ferrostatin-1, a ferroptosis inhibitor, improved ejection fraction and fractional shortening, reduced myocardial remodeling and fibrosis, lowered serum cardiac injury markers and decreased TUNEL-positive apoptotic cells in diabetic mice. Mdivi-1, used to inhibit mitochondrial fission, produced similar improvements in cardiac performance, tissue injury and apoptosis. The study did not design an experiment to divide the relative contributions of ferroptosis, apoptosis and mitochondrial dysfunction, and it did not examine other regulated cell-death pathways.

Examination of the diabetic hearts linked altered mitochondrial dynamics with ferroptosis. Transmission electron microscopy showed atrophic mitochondria with increased membrane density, disrupted cristae and abnormal shapes. The hearts also accumulated iron, displayed elevated reactive oxygen species and had higher malondialdehyde, lower glutathione and a lower glutathione-to-oxidized-glutathione ratio. A fluorescent lipid probe shifted toward its oxidized form, while the ferroptosis-associated proteins ACSL4 and GPX4 moved in directions consistent with increased ferroptotic stress: ACSL4 increased and GPX4 decreased. After Mdivi-1 treatment, mitochondrial structure and these biochemical and molecular indicators improved together, though the reliance on one inhibitor means off-target effects cannot be excluded.

The central experiment used cardiomyocyte-specific PIK3R1 knockout mice generated with the Cre-LoxP system. Compared with wild-type diabetic mice, knockout mice had better left ventricular ejection fraction and fractional shortening, less hypertrophy and fibrosis, lower serum creatine kinase, creatine kinase-MB and lactate dehydrogenase, and fewer apoptotic cardiomyocytes. Knockout also preserved mitochondrial morphology, increased myocardial ATP content and mitochondrial DNA copy number, lowered reactive oxygen species, and shifted the balance of mitochondrial regulatory proteins toward fusion and autophagy rather than fission. Iron deposition and lipid peroxidation fell, GPX4 and SLC7A11 rose, and ACSL4 declined. These convergent measurements associate cardiomyocyte PIK3R1 deficiency with improved mitochondrial homeostasis and reduced ferroptosis in diabetic mice.

Signaling measurements followed a similar pattern. In wild-type diabetic mice, phosphorylation of PI3K and Akt decreased, as did nuclear Nrf2 and the downstream protein HO-1. The PI3K/Akt agonist 740 Y-P increased these signals and was accompanied by lower oxidative stress, higher ATP content, more active mitophagy and improved mitochondrial dynamics. PIK3R1-deficient mice showed greater pathway activation and better mitochondrial measures than corresponding wild-type groups. Because PIK3R1 encodes the p85α regulatory subunit that restrains PI3K, the increased PI3K and Akt phosphorylation after knockout was consistent with effective loss of the inhibitory subunit, although deletion efficiency was inferred rather than quantified directly in cardiac tissue.

A rescue experiment tested whether Drp1-driven mitochondrial fission could erase the cardiac protection associated with PIK3R1 loss. Researchers delivered an adeno-associated virus carrying Drp1 or an empty control vector to knockout diabetic mice. Drp1 overexpression reversed the knockout-associated improvements in ejection fraction and fractional shortening, worsened myocardial remodeling, raised serum cardiac injury markers and increased TUNEL-positive apoptosis. It also returned the expression of apoptosis-related proteins toward the diabetic wild-type pattern. These results place Drp1 downstream of PIK3R1 for cardiac function, remodeling and apoptosis. They do not show that Drp1 mediates the mitochondrial or ferroptotic effects, because those endpoints were not measured in the rescue cohort.

The findings offer a potentially useful research target, but they remain preclinical. The work included no cultured cardiomyocytes, no human myocardium and no clinical specimens, so cell autonomy and relevance to patients remain unknown. The investigators also did not disable PI3K, Akt or Nrf2 in PIK3R1-deficient animals, which would have been necessary to establish pathway dependence. Nuclear Nrf2 was evaluated by protein analysis without DNA-binding or antioxidant-response-element reporter tests, and several additional ferroptosis markers were absent. Only male mice were studied, all endpoints came from one 24-week time point, and group sizes followed comparable modeling practice rather than a prior power calculation. PIK3R1 therefore warrants further evaluation as a candidate therapeutic target, but the results do not establish a treatment for diabetic cardiomyopathy in people.

Subject of Research: Experimental mouse evidence linking cardiomyocyte PIK3R1 loss with improved mitochondrial dynamics, reduced ferroptosis and attenuated diabetic cardiomyopathy.

Article Title: Cardiomyocyte PIK3R1 deficiency attenuates mitochondrial dynamic imbalance and ferroptosis in diabetic cardiomyopathy in association with the PI3K/Akt/Nrf2 axis

Article References: Zhou, J., Xiao, Q., Zhang, F., Shen, X., Wu, S., Wang, L., & Huang, C. (2026). Cardiomyocyte PIK3R1 deficiency attenuates mitochondrial dynamic imbalance and ferroptosis in diabetic cardiomyopathy in association with the PI3K/Akt/Nrf2 axis. Frontiers in Cell and Developmental Biology, 14, Article 1953037. https://doi.org/10.3389/fcell.2026.1953037

Image Credits: AI Generated

DOI: 10.3389/fcell.2026.1953037

Keywords: PIK3R1, diabetic cardiomyopathy, ferroptosis, mitochondrial dynamics, PI3K/Akt/Nrf2, cardiomyocytes, Drp1, mice, oxidative stress, Cardiomyocyte, deficiency, attenuates

DADA2 is an autosomal recessive autoinflammatory disorder caused by biallelic loss-of-function pathogenic variants in the ADA2 gene. It is characterised by vasculopathy, immune dysregulation and haematological abnormalities, and its reported manifestations include recurrent fever, livedo racemosa, early-onset stroke, immunodeficiency and cytopenias. The paper cites an estimated global prevalence of approximately one in 222,000 people while noting that underdiagnosis is probably substantial. It also states that neurological manifestations affect about 50% of patients and that ischaemic and haemorrhagic strokes are among the most serious complications. The condition can therefore be consequential even when a child initially appears relatively well, as illustrated by the marked differences between two siblings in this series.

The first patient was a 3-year-old boy who developed progressive purpuric skin lesions, high-grade fevers every six to eight hours, drenching night sweats, lethargy, weight loss and joint inflammation. Emergency department visits initially attributed the symptoms to benign causes. A skin biopsy at the referring hospital showed perivascular lymphocytic inflammation with an occasional thrombus. After transfer to the Dublin centre, a multidisciplinary team identified livedoid vasculitic lesions and synovitis of both ankles, the right wrist and the left knee. His erythrocyte sedimentation rate was 33 mm/hr, above the reference range of 1–13 mm/hr, and C-reactive protein was 27 mg/L, compared with a reference range below 4 mg/L.

A repeat skin biopsy showed brisk arteritis in a small- to medium-calibre artery within the subcutaneous fat, together with mild superficial perivascular inflammation and mild neutrophilic panniculitis. This pattern prompted consideration of a monogenic cause of childhood-onset polyarteritis nodosa. ADA2 enzyme activity was 1.4 IU/L, below the reference range of 6.9–59.7 IU/L, and genetic testing confirmed compound heterozygous variants, c.140G>C, p.Gly47Ala, classified as pathogenic, and c.872C>T, p.Ser291Leu, classified as likely pathogenic. Adalimumab produced a rapid clinical response. In 2024, anti-adalimumab antibodies and subtherapeutic drug levels prompted a switch to etanercept with methotrexate, and the patient remained clinically stable thereafter. The case supports testing for DADA2 when a young child has livedo-like skin lesions, systemic inflammation and a polyarteritis nodosa-like biopsy pattern.

The second case demonstrates a 12-year diagnostic journey dominated initially by haematology. A male patient presented at 36 weeks’ gestation with hydrops fetalis and profound anaemia: his haemoglobin was 41 g/L, compared with a reference range of 140–240 g/L. A direct Coombs test was negative and the reticulocyte count was 0.2%, consistent with hypoproliferative anaemia. Clinicians made a working diagnosis of Diamond–Blackfan anaemia, and regular red-cell transfusions with iron chelation were initiated. By age five, the patient had developed recurrent aphthous stomatitis, arthralgia, joint stiffness, Raynaud’s phenomenon, erythema and dryness on the backs of his hands, and aseptic meningitis. Positive antinuclear, anti-dsDNA and anti-Ro antibodies later led to reclassification as atypical systemic lupus erythematosus, and azathioprine plus hydroxychloroquine was started. A renal biopsy in 2017 for intermittent proteinuria was normal.

Further complications included disseminated cytomegalovirus infection with pneumonitis and 10,000 copies/mL of viral DNA, persistent lymphopenia and hypogammaglobulinaemia. These findings prompted concern for an underlying inborn error of immunity, and whole-exome sequencing in 2021 identified a homozygous deletion of exons 4–5 in ADA2. The result supplied one genetic diagnosis for 12 years of apparently disparate findings. Family testing then showed that both parents and one sibling were heterozygous carriers. The case illustrates how unexplained symptoms, unusual complications and an inadequate response to an established diagnosis can justify revisiting the diagnostic formulation, but a single observation cannot establish how commonly such diagnostic revision is needed.

Adalimumab and intravenous immunoglobulin replacement improved this patient’s inflammatory markers, but his dependence on red-cell transfusions persisted. He therefore underwent a mismatched-unrelated-donor, T-cell receptor alpha-beta/CD19-depleted peripheral blood stem cell transplant with CD45RO-positive memory T-cell add-back in early 2024. The post-transplant course was complicated by Escherichia coli sepsis, donor-acquired G6PD deficiency, herpes zoster with post-herpetic neuralgia, and hepatic impairment with suspected portal hypertension. By 2025, he had achieved 100% donor chimerism, transfusion independence and clinical remission. The outcome supports consideration of transplantation in the severe, refractory haematological phenotype described by the authors, but the isolated case does not establish comparative benefit or generalise to all children with DADA2. His evolving illness also shows that an initial haematological presentation may not capture later inflammatory, vasculitic or immune manifestations.

The third patient, a 7-year-old Somali boy, was referred in July 2023 with poor oral intake, weight loss and fatigue. His family had recently arrived in Ireland as refugees and was living in emergency accommodation. Records from earlier evaluations in Sweden, including impressions of IgA vasculitis and possible Kawasaki disease, were unavailable, while language barriers initially limited the history. Interpreter-assisted sessions revealed that recurrent day-on, day-off fevers had begun in February 2023 and became progressively persistent. The rash was longstanding and widespread over the trunk, extremities and plantar surfaces, with hyperpigmentation suggesting chronicity. He also had marked fatigue, leg pain, vomiting, abdominal pain and severe weight loss; his admission weight was 20.9 kg, on the ninth centile.

Laboratory evaluation found a C-reactive protein of 104 mg/L, an erythrocyte sedimentation rate of 47 mm/hr, microcytic anaemia and a faecal calprotectin of 406 μg/g. Bone marrow examination excluded malignancy, while lymphocyte subset testing showed low numbers of T-helper, B and natural killer cells. After discussion across general paediatrics, rheumatology, infectious diseases, dermatology and haematology, the team concluded that IgA vasculitis did not explain the persistent fevers, rash distribution or constitutional severity, broadening the differential diagnosis to include inflammatory bowel disease, malignancy and autoinflammatory disease. ADA2 activity was 0.9 IU/L, and genetic testing confirmed a homozygous c.139G>T, p.Gly47Trp variant, establishing the diagnosis in August 2023. The paper does not claim that the family’s refugee status caused the diagnostic difficulty; instead, it identifies repeated, comprehensive history-taking with skilled interpreters as diagnostically important when communication barriers and fragmented records obscure clinical chronology.

Adalimumab resolved the boy’s fever, and nutritional rehabilitation with nasogastric feeding accompanied his treatment. His weight recovered to the 79th centile by 2025, and he maintained remission on adalimumab. Cascade genetic testing after his diagnosis offered another striking illustration of phenotypic variability. His 2-year-old sister carried the same homozygous p.Gly47Trp variant, and her ADA2 activity was 0.1 IU/L. Yet she had only occasional low-grade fevers, no rash, no significant joint symptoms and no constitutional features. Her growth and development were normal. Subtle laboratory abnormalities included a mildly elevated C-reactive protein of 8 mg/L, lymphocyte counts of 0.36–1.2 × 10⁹/L and IgM of 0.25 g/L, but none had independently prompted investigation before the family study.

Following multidisciplinary discussion and shared decision-making with the family, the younger girl began adalimumab at 20 mg subcutaneously every other week. The decision reflected the recognised risk of neurological complications and the established efficacy of TNF inhibition in reducing vascular events in symptomatic DADA2, while the authors acknowledge that prospective evidence on preventive treatment before a first clinical event is lacking. By 2025, she remained clinically well, her inflammatory markers had normalised and her development was normal. The sibling pair demonstrates that identical homozygous variants can be associated with markedly different clinical severity, but the observations do not identify why the phenotypes differ or establish a general treatment rule for asymptomatic children. The paper suggests that family screening can identify affected relatives before obvious symptoms, while concluding that current evidence is insufficient to support population-based newborn screening.

Across the four patients, diagnostic intervals ranged from three months to 12 years, and initial diagnoses included polyarteritis nodosa, Diamond–Blackfan anaemia, atypical systemic lupus erythematosus and IgA vasculitis. Features that the authors say should prompt consideration of DADA2 include unexplained transfusion-dependent anaemia with reticulocytopenia, cutaneous vasculitis with livedo-like features and subcutaneous nodules, a childhood polyarteritis nodosa-like presentation, recurrent or opportunistic infections, or a relevant family history. Coexisting findings across inflammatory, vascular, haematological and immune domains support measuring plasma ADA2 activity and pursuing ADA2 genetic testing, both of which the paper describes as widely accessible. The series also presents DADA2 as a pan-ethnic disorder that should not be excluded on ethnic grounds. However, it comprises only four patients treated at one tertiary centre, and its diagnostic observations and management outcomes require confirmation in larger multicentre cohorts.

Treatment responses differed with the dominant clinical problem in this series. The two patients with predominantly inflammatory or vasculitic manifestations achieved good control with TNF inhibitors, whereas the child whose disease was dominated by red-cell aplasia remained transfusion-dependent despite improved inflammatory markers and required transplantation. Anti-drug antibody development in the first case added a practical feature to long-term treatment: subtherapeutic adalimumab levels led to a successful switch to etanercept plus methotrexate. At the 2025 follow-up, the two patients continuing adalimumab were clinically stable or in remission, while the transplanted patient had full donor chimerism and transfusion independence. These individual outcomes under different treatment strategies are not comparative efficacy data. Overall, the case series supports early recognition, multidisciplinary review, reconsideration of an established diagnosis when a child’s course changes, careful interpreter-supported assessment and systematic family screening after an index DADA2 diagnosis.

Subject of Research: Clinical presentation, diagnosis and treatment of DADA2 in four paediatric patients

Article Title: Deficiency of adenosine deaminase 2 in paediatric patients: a case series from Ireland

Article References: Almubarak, R., Foley, C., Killeen, O. G., MacDermott, E., & Gallagher, K. (2026). Deficiency of adenosine deaminase 2 in paediatric patients: a case series from Ireland. Frontiers in Pediatrics, 14, Article 1878669. https://doi.org/10.3389/fped.2026.1878669

Image Credits: AI Generated

DOI: 10.3389/fped.2026.1878669

Keywords: DADA2, paediatric rare disease, autoinflammatory disease, diagnostic delay, paediatric vasculitis, TNF inhibitors, stem cell transplantation, family screening, haematological disease, Ireland, Deficiency, adenosine

Sirtuin 3, or Sirt3, is one of a family of NAD+-dependent deacetylases that reside inside mitochondria and remove chemical acetyl tags from metabolic enzymes. This deacetylation keeps enzymes involved in fatty acid oxidation, the respiratory chain, and antioxidant defense running at peak efficiency. Decades of work have linked Sirt3 loss to metabolic syndrome, fatty liver, cardiac lipid buildup, and pancreatic beta cell failure. Yet its role during adipogenesis, the process by which precursor cells mature into fat-storing adipocytes, remained poorly defined, particularly in light of well-documented biological sex differences in adipose tissue function and distribution.

To probe this question, the researchers turned to mouse embryonic fibroblasts, or MEFs, derived from both male and female Sirt3 wild-type and knockout mice. These cells were coaxed through a standard adipogenic differentiation protocol into lipid-rich, adipocyte-like cells. The team then deployed an unusually broad analytical arsenal: Oil Red O staining to visualize accumulated lipids, confocal microscopy and lipid droplet morphometry to quantify storage architecture, immunoblotting to track signaling proteins, fatty acid profiling by gas chromatography, LC–MS metabolomics to map the cellular lipidome, and transmission electron microscopy to inspect organelle ultrastructure. Each experimental group contained three to five biological replicates.

The first major observation was that all four groups, male and female, wild-type and knockout, successfully induced adipogenic markers and formed lipid-laden adipocyte-like cells. Sirt3 was not required for the basic program of fat cell differentiation. However, the female knockout adipocytes stood out dramatically, displaying the strongest lipid storage phenotype of any group. This female-biased accumulation suggested that Sirt3 exerts a brake on lipid storage specifically in female cells, a brake that disappears when the enzyme is genetically removed.

The mechanistic heart of the study lies in the AMPK–Acc1 signaling axis. AMP-activated protein kinase, or AMPK, is a cellular energy sensor that switches on when energy supplies run low. One of its key downstream targets is acetyl-CoA carboxylase 1, or Acc1, the rate-limiting enzyme of de novo lipogenesis. When AMPK phosphorylates Acc1, Acc1 activity drops, malonyl-CoA synthesis falls, and fat synthesis is throttled back. In wild-type female adipocytes, the researchers found that bortezomib, a clinically used proteasome inhibitor, increased phosphorylation of both AMPK and Acc1, engaging this antilipogenic circuit. But in Sirt3 knockout female cells, basal phosphorylated AMPK relative to total AMPK was already reduced, and the cells failed to mount a comparable AMPK–Acc1 response to bortezomib.

Even more telling was the result with AICAR, a synthetic AMPK activator that bypasses upstream signaling. When the researchers applied AICAR to the knockout female adipocytes, it failed to restore the AMPK–Acc1 signaling axis. This suggests that the defect in Sirt3-deficient cells is not merely a failure of upstream AMPK activation but reflects a deeper breakdown in the coupling between AMPK and its lipogenic target, a breakdown that cannot be rescued simply by pushing AMPK harder pharmacologically.

Fatty acid profiling added a second layer to the story. Sirt3 deficiency increased the abundance of stearoyl-CoA desaturase 1, or Scd1, the enzyme that introduces a double bond into saturated fatty acids, and raised the C16:1 to C16:0 desaturation index, a biochemical readout of Scd1 activity. Elevated desaturation is associated with monounsaturated fatty acid production and has been linked to triglyceride synthesis and metabolic disease in both human and mouse studies. Intriguingly, bortezomib reduced Scd1 abundance in the knockout cells but did not normalize the elevated desaturation ratio, indicating that the desaturation phenotype persists even when Scd1 protein levels are partially brought down.

Metabolomics revealed a predominantly bortezomib-associated remodeling of glycerophospholipids and lysophospholipids, the structural lipid families that form cellular membranes and lipid signaling intermediates. This lipidome shift points to membrane composition changes accompanying the proteasome inhibitor treatment. Qualitative transmission electron microscopy then uncovered bortezomib-associated organelle stress, most pronounced in the Sirt3 knockout adipocytes, consistent with the idea that cells lacking this mitochondrial quality-control enzyme are less equipped to buffer proteotoxic and lipotoxic challenges during adipocyte maturation.

Taken together, the data support a model in which female adipocytes rely on Sirt3-dependent metabolic control during adipogenesis. When Sirt3 is present, it helps maintain AMPK–Acc1 antilipogenic signaling, keeps Scd1-associated desaturation in check, and supports lipid turnover. When Sirt3 is absent, the antilipogenic brake weakens, lipid storage intensifies, desaturation rises, and organelle stress accumulates under proteasome challenge. Male adipocytes, by contrast, did not show the same degree of dependence on Sirt3 for these phenotypes, underscoring the sexual dimorphism that has long been recognized in adipose biology but rarely traced to a single mitochondrial enzyme.

The findings carry implications that extend beyond basic cell biology. Because impaired adipogenesis contributes to adipose tissue dysfunction in obesity and metabolic disease, identifying Sirt3 as a sex-specific regulator of lipid storage signaling opens potential avenues for therapeutic exploration, particularly in conditions where female fat tissue metabolism goes awry. The study also highlights proteasome inhibitors like bortezomib not just as cancer drugs but as experimental tools that expose hidden vulnerabilities in metabolic signaling. As researchers continue to map how mitochondrial sirtuins shape tissue-specific and sex-specific metabolism, this work adds a compelling piece to the puzzle of why fat biology is never one-size-fits-all.

Subject of Research: Sirt3 deficiency and sex-specific adipocyte lipid metabolism

Article Title: Sirt3 deficiency impairs AMPK–Acc1 antilipogenic signaling in female adipocytes

Article References: Šimunić, E., Šešelja, K., Podgorski, I. I., Belužić, R., Hadžija, M. P., Mavar, M. P., Rešetar, M., Halasz, M., Jaganjac, M., Bujak, I. T., Protrka, M., Balog, T., Stojanović, S., Korać, A., & Sobočanec, S. (2026). Sirt3 deficiency impairs AMPK–Acc1 antilipogenic signaling in female adipocytes. Molecular Biology Reports, 53(1), Article 1726. https://doi.org/10.1007/s11033-026-12892-7

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12892-7

Keywords: Sirt3, deficiency, impairs, AMPK, Acc1, antilipogenic, signaling, female, adipocytes, scientific research

The biochemistry of cobalamin explains why deficiency matters so much. Vitamin B12 is a water-soluble vitamin synthesized only by microorganisms, and it is found almost exclusively in animal-derived foods such as red meat, fish, eggs, and milk, with a very small contribution from foods or water exposed to B12-producing bacteria. Within the body, cobalamin serves as a critical cofactor in two reactions: the conversion of homocysteine to methionine via methionine synthase, and the conversion of methylmalonyl-CoA to succinyl-CoA via methylmalonyl-CoA mutase. These reactions make the vitamin essential for DNA synthesis, red cell production, and the maintenance of nerve myelin. Deficiency can therefore manifest as megaloblastic anemia and glossitis, peripheral neuropathy, subacute combined degeneration of the spinal cord, and cognitive impairment. In pregnancy, low maternal B12 has been associated with neural tube defects and other adverse birth outcomes, as well as longer-term metabolic risk in the offspring.

The life-course pattern reported in India is striking. According to the CNNS, the first nationally representative estimate of pediatric B12 status, deficiency affects 13.8 percent of pre-school children aged 1 to 4 years and 17.3 percent of school-age children aged 5 to 9 years, with little difference between boys and girls at these ages. The rate roughly doubles in adolescence: 31.0 percent of adolescents aged 10 to 19 years were deficient in the CNNS, and a pooled meta-analytic estimate for the 0 to 17-year age band was higher still, at 57 percent, though based on fewer studies and a wider confidence interval. Among adults, the pooled prevalence across the largest meta-analysis was 48 percent, with a 95 percent confidence interval of 35 to 62 percent, and one Indian study reported deficiency as high as 78.5 percent in healthy adults depending on the serum cut-off used. Among the elderly, a review of Indian adults reported 61.7 percent deficiency using varied cut-offs, and hospital series show diagnosed cases increasing with age and peaking around 50 to 65 years.

Pregnant women represent a particularly vulnerable group. A synthesis of 46 studies on B12 status among pregnant and lactating women in India found deficiency prevalence ranging from 40 to 70 percent, and a meta-analysis estimated that approximately 67 percent of pregnant women are affected. International meta-analyses have similarly found insufficient B12 during pregnancy to be common globally and associated with lower birth weight. In Indian cohorts, low maternal B12 alongside adequate-to-high folate has been associated with neural tube defects, recurrent pregnancy loss, gestational diabetes, pre-eclampsia, intrauterine growth restriction, and adverse metabolic and cognitive outcomes in the child, although the review emphasizes that these data derive from observational cohorts and should be interpreted as associations rather than demonstrated causal pathways. The risk persists into lactation, since low maternal stores lower breast-milk B12 and place exclusively breastfed infants at risk, yet current Indian antenatal policy supplements only iron and folate, not vitamin B12.

Diet is the single most important determinant of B12 status in India. Individuals consuming a lacto-vegetarian diet, a substantial share of the Indian population, have significantly lower cobalamin levels than those consuming a mixed diet, and reviews consistently show several-fold higher deficiency among lacto-vegetarians than non-vegetarians. In one study of healthy young vegetarian adults, approximately 50 percent had serum B12 below the deficiency threshold, 70 percent of men and 50 percent of women had low holotranscobalamin, and 92 percent of men and 50 percent of women had hyperhomocysteinaemia. Dietary insufficiency, not pernicious anemia, is the dominant cause of B12 deficiency in India, reflecting the combined effects of a largely cereal-based lacto-vegetarian diet, low consumption of animal-based foods, and high rates of poverty. Beyond diet, the most consistently reported associated factors are low socioeconomic status, advancing age, and female sex, with age-related malabsorption from atrophic gastritis, reduced gastric acid secretion, and Helicobacter pylori infection adding to the burden among older adults.

Regional heterogeneity within India is substantial. In the CNNS, B12 deficiency prevalence was highest in the central region of India across every pediatric age band assessed: 21.0 percent in pre-schoolers, 29.1 percent in school-age children, and 42.7 percent in adolescents, each substantially above the corresponding national estimates. Despite this marked regional gradient, the same survey found no consistent difference in B12 deficiency between rural and urban locations at the national level, a pattern that sits alongside inconsistent rural/urban findings from individual state-level studies. Studies from Pune comparing middle-aged men in rural, slum, and middle-class urban settings found a high frequency of low B12 across all three settings, with rural and slum residents faring worse than urban middle-class residents, suggesting that dietary intake and socioeconomic status appear to be stronger determinants of B12 status than geographic setting per se.

Outside India, B12 deficiency follows clear geographic and economic lines. High-income populations with adequate access to animal-source foods have lower deficiency prevalence, while low- and middle-income populations are more affected owing to both scarcity of animal-source foods and a higher burden of malabsorptive conditions. A widely cited compilation of national and regional datasets found serum B12 deficiency in 11 to 15 percent of women in Germany and the United Kingdom, 31 percent of elderly individuals in the UK, 49 percent of adults in India, 40 percent of children in Kenya, 28 percent of pregnant women in Nepal, and 20 percent of the same demographic group in New Zealand. In Latin America and the Caribbean, an analysis of 41 studies suggested up to 61 percent of individuals in Mexico and Central/South America had inadequate B12 stores. In sub-Saharan Africa, available national micronutrient surveys indicate 54 percent, 35 percent, and 15 percent B12 deficiency among reproductive-age women in Malawi, Kenya, and Ethiopia respectively, with a lower prevalence of 7 percent in Ghana. The Indian subcontinent and neighboring South Asian countries report the highest deficiency prevalence worldwide, 70 to 80 percent in some series, primarily reflecting a predominantly vegetarian, carbohydrate-based diet.

A key constraint on reconstructing a 50-year trend is that no single longitudinal, nationally representative cobalamin survey exists in India, or indeed anywhere else, spanning this period. Most available estimates are cross-sectional snapshots using different biomarkers, cut-offs, and populations. Evidence from the 1970s and 1980s was largely clinical and descriptive, with early recognition that asymptomatic Indian lacto-vegetarians had lower B12 than non-vegetarian counterparts and observations of anemia among Asian immigrants in London raising the possibility of a population-level problem. Systematic biochemical assessment began at the turn of the millennium with the Pune studies, which documented a high prevalence of low cobalamin with concomitantly elevated homocysteine across sampled Indian populations. Since 2000, the evidence base has grown substantially, with clinic and community studies through the 2010s consistently showing an adult prevalence of approximately 47 percent, the CNNS providing the first national pediatric and adolescent estimates, and two independent meta-analyses synthesizing studies to 2020 and 2023 reporting pooled adult prevalence of 51 to 53 percent. A large 2024 health-check dataset of over 15,000 asymptomatic adults across seven northern Indian states reported a considerably lower figure of 24.2 percent, which most plausibly reflects a higher serum cut-off and a more affluent, urban, self-selected sample rather than a genuine decline in burden.

A limitation running through every prevalence estimate cited in the review is the absence of biomarker and cut-off harmonization. Total serum/plasma B12 thresholds used across the cited studies range from below 150 pmol/L to below 211 pg/mL, and most studies rely on total B12 rather than on functional markers such as holotranscobalamin or methylmalonic acid, which more directly reflect tissue cobalamin status. Total serum B12 is itself an indirect marker that can be influenced by recent dietary intake, by pregnancy-related haemodilution, and by inter-laboratory assay variability. A concrete illustration of the resulting inconsistency comes from a single cohort of healthy young Indian vegetarians, in which roughly 50 percent were deficient by total serum B12, but 70 percent of men and 50 percent of women had low holotranscobalamin, and 92 percent of men and 50 percent of women had hyperhomocysteinaemia, meaning a 20-percentage-point-or-greater spread in deficiency depending solely on which biomarker was used. Consequently, differences between surveys, such as the 24.2 percent from the 2024 health-check sample versus 51 to 53 percent from pooled meta-analyses, are driven substantially by differences in cut-points, biomarkers, and sampling frames in addition to any true temporal change.

The review concludes that vitamin B12 deficiency is a largely preventable, straightforward-to-treat disorder whose continued neglect in India’s public health programming is difficult to attribute to anything other than insufficient prioritization relative to its documented scale. From a public health perspective, the authors call for harmonized diagnostic criteria for B12 deficiency, ideally combining total circulating B12 with a functional marker such as holotranscobalamin or methylmalonic acid, and routine screening particularly for pregnant and lactating women, adolescents, the elderly, and strict vegans and vegetarians. Evidence-based strategies to reduce the burden include dietary diversification, food fortification, and the addition of B12 to existing antenatal and adolescent supplementation programmes, which currently contain only iron and folic acid. On fortification specifically, the evidence is directionally supportive but implementation-dependent: India’s current 2018 FSSAI fortification standards for folic acid and vitamin B12 are set at roughly 90 percent below WHO-recommended levels for Indian consumption patterns, having been lowered from stronger 2016 standards, and a recent review identifies concrete barriers to more effective scale-up, including uneven regulatory enforcement, continued reliance on voluntary fortification of open-market atta, variable miller-level capacity and quality assurance, and insufficient long-term monitoring of nutritional outcomes among beneficiaries. Large-scale staple fortification has also drawn published concerns from Indian public-health researchers regarding the strength of the underlying evidence base and potential safety considerations at higher fortification levels, so any revision of national standards should be accompanied by the monitoring and evaluation infrastructure needed to track both benefit and safety at population scale. Regional data gaps, particularly the absence of CNNS-scale state-level surveillance in adults, should also be prioritized in future national nutrition surveys.

Subject of Research: Vitamin B12 deficiency epidemiology in India and worldwide

Article Title: Vitamin B12 deficiency: epidemiological trends and risk factors

Article References: Toteja, G. S., & Toteja, N. (2026). Vitamin B12 deficiency: epidemiological trends and risk factors. Frontiers in Nutrition, 13, Article 1930037. https://doi.org/10.3389/fnut.2026.1930037

Image Credits: AI Generated

DOI: 10.3389/fnut.2026.1930037

Keywords: vitamin B12, cobalamin, micronutrient deficiency, India, epidemiology, vegetarian diet, pregnancy, food fortification, Vitamin, deficiency, epidemiological, trends

The researchers, led by Mami Amaki and Yasutomo Imai, hypothesized that caspase-1 might control IL-33 release from keratinocytes in vivo. Their reasoning drew on a parallel case: IL-1α, like IL-33, is a nuclear cytokine stored under steady-state conditions, and its extracellular release requires caspase-1. Previous studies, however, had suggested that IL-33 release is independent of caspase-1, but those conclusions came largely from non-cutaneous tissues or in vitro systems. In the airway epithelium, for example, allergen protease-activated stress granule assembly and gasdermin D fragmentation have been shown to control IL-33 secretion without caspase-1. The Japanese team suspected that the skin might operate by different rules, and their new findings support that idea.

The first technical step was to establish where caspase-1 actually resides in skin. Using immunofluorescence staining of mouse skin sections with a Cy3-conjugated anti-caspase-1 P10 polyclonal antibody, the researchers detected caspase-1 immunoreactivity in the nuclei of epidermal keratinocytes. No specific staining appeared in caspase-1/11-deficient mice, which served as negative controls. This was a significant observation because earlier studies had concluded that caspase-1 expression was restricted to hematopoietic cells, conclusions based largely on the absence of detectable interleukin-1 beta-processing activity and the limited sensitivity of the detection methods available at the time. Subsequent work with improved methodologies has revealed low-level but functional caspase-1 expression in epithelial cells, including keratinocytes. For caspase-1 to be involved in the release of a nuclear alarmin like IL-33, the protease would need to be present in keratinocyte nuclei, and the new staining data confirm exactly that.

Next, the team examined what happens to nuclear IL-33 when the skin is stimulated. They applied 20 microliters of 0.5 percent 2,4-dinitrofluorobenzene (DNFB), a contact-sensitizing hapten dissolved in acetone and olive oil, to the left ear of mice while the right ear received vehicle alone. Six hours later, they processed the ear skin for immunofluorescence staining for IL-33, using an affinity-purified rabbit anti-mouse IL-33 polyclonal antibody detected with a biotinylated goat anti-rabbit IgG secondary antibody and streptavidin-conjugated Alexa Fluor 594, with nuclei counterstained using DAPI. The disappearance of nuclear IL-33 staining in keratinocytes was interpreted as evidence that IL-33 had been released into the extracellular space, an established surrogate readout that parallels findings in experimental allergic rhinitis, where allergen challenge induces a rapid loss of IL-33 staining in nasal epithelial cells alongside increased IL-33 levels in nasal lavage fluids.

The result was striking. In wild-type mice, IL-33 fluorescence in the epidermis was substantially reduced six hours after DNFB treatment, consistent with the team’s previous report that cutaneous stimulation triggers extracellular IL-33 release in vivo. In caspase-1/11-deficient mice, however, IL-33 immunoreactivity remained clearly detectable in the nuclei of epidermal keratinocytes at the same time point. In other words, deleting caspase-1/11 prevented the DNFB-induced loss of keratinocyte IL-33. Notably, quantitative real-time PCR showed that DNFB application increased Il33 mRNA expression in both wild-type and caspase-1/11-deficient mice, even though nuclear IL-33 staining persisted in the knockout animals. This indicates that Il33 transcription is induced by DNFB independently of IL-33 release, meaning the protease is specifically required for the release step rather than for the transcriptional response.

To test whether this release mechanism matters for actual disease, the researchers crossed their caspase-1/11-deficient mice with the hK14mIL33tg transgenic line, which overexpresses murine IL-33 in keratinocytes under the control of the human keratin-14 promoter. These IL33tg mice spontaneously develop atopic dermatitis-like skin inflammation. When caspase-1/11 was deleted in this background, the resulting IL33tg Casp1/11KO mice exhibited markedly attenuated skin inflammation compared with IL33tg mice. Histological examination of hematoxylin and eosin-stained skin sections showed pronounced leukocyte and eosinophil infiltration accompanied by epidermal hyperplasia in IL33tg mice, while these pathological features were minimal in the double-deficient animals, indicating a substantially reduced inflammatory response in the absence of caspase-1/11.

The molecular signature of the type 2 immune response told the same story. Quantitative PCR analysis of skin tissue, performed with a TaqMan RNA-to-Ct Kit and an ABI7900HT sequence detection system, revealed significant reductions in the expression of type 2 cytokines including Il4, Il5, and Il13, as well as Prg2, which encodes eosinophil peroxidase and serves as a specific marker of murine eosinophils. The reduction in Prg2 expression was consistent with the histological findings showing markedly reduced eosinophil infiltration in IL33tg Casp1/11KO mice. Together, these data indicate that caspase-1/11 deficiency suppresses IL-33-driven type 2 immune responses in the skin, dampening the entire downstream allergic cascade that IL-33 normally sets in motion through ILC2 activation.

The findings carry important caveats that the authors address candidly. The knockout mice used in the study have historically been described as caspase-1-deficient, but they are now recognized to carry a combined deficiency of both caspase-1 and caspase-11, because the Casp1 and Casp11 genes lie in close genomic proximity within the same gene cluster, resulting in simultaneous disruption of both loci in this strain. The potential contribution of caspase-11 therefore cannot be formally excluded. However, previous studies indicate that epithelial inflammasome-related responses, including IL-33 regulation, are mainly mediated by caspase-1 rather than caspase-11. Caspase-11 is primarily implicated in noncanonical inflammasome signaling in myeloid cells and localizes predominantly in the cytoplasm, making its direct involvement in the nuclear export of IL-33 from keratinocytes less likely. The authors also note that loss of nuclear staining does not directly quantify extracellular IL-33 levels, so future studies using biochemical measurements will be needed to confirm the release mechanism.

There is another puzzle worth noting. Several studies have suggested a role for caspase-1 in IL-33 inactivation rather than release, since IL-33 can be inactivated after maturation by caspase-1. If caspase-1-mediated inactivation were essential in vivo, IL-33-transgenic mice lacking caspase-1/11 would be expected to show exacerbated skin inflammation, yet the opposite was observed. The authors also point out that pharmacological inhibition of caspase-1 may not fully reflect its role in alarmin release, because for IL-1α the presence of caspase-1 protein, rather than its enzymatic activity, can be required for secretion. Because caspase-1/11 was deleted in all cells in the mice used, the possibility that caspase-1 deficiency in immune cells influences IL-33-induced skin inflammation cannot be excluded, though the marked reduction in inflammation suggests that caspase-1/11 deficiency affects an early step in IL-33-driven skin inflammation, most likely IL-33 release from keratinocytes.

The broader implication is that alarmin biology may be tissue-specific in ways the field has not fully appreciated. IL-33 can be released independently of caspase-1 in other tissues, notably the airway epithelium, where gasdermin D-mediated pathways dominate. But in the skin, the new evidence suggests that caspase-1 is involved in the pathogenic release of IL-33 from keratinocytes in vivo, and that this release step is a critical control point for atopic dermatitis-like inflammation. If the findings hold up in biochemical assays and in human tissue, they could reshape how researchers think about targeting IL-33 in atopic dermatitis, pointing to the release machinery within keratinocytes as a potential therapeutic frontier alongside the IL-33-blocking antibodies already in clinical development.

Subject of Research: Immunology

Article Title: Deficiency of inflammatory caspases attenuates IL-33–mediated dermatitis

Article References: Amaki, M., Murata, T., Kanazawa, N., & Imai, Y. (2026). Deficiency of inflammatory caspases attenuates IL-33–mediated dermatitis. Journal of Cutaneous Immunology and Allergy, 9, Article 16358. https://doi.org/10.3389/jcia.2026.16358

Image Credits: AI Generated

DOI: 10.3389/jcia.2026.16358

Keywords: atopic dermatitis, IL-33, caspase-1, keratinocytes, alarmin, skin inflammation, type 2 cytokines, innate lymphoid cells, Deficiency, inflammatory, caspases, attenuates

The study, published in Frontiers in Clinical Diabetes and Healthcare, was conducted at two hospitals in Thai Binh province by a team from Thai Binh University of Medicine and Pharmacy and Hai Phong University of Medicine and Pharmacy. Between January 2024 and September 2025, the researchers recruited 400 adults with type 2 diabetes who had been taking metformin for at least six months. They deliberately excluded anyone whose vitamin B12 status could be compromised by other factors: patients with gastrectomy, ileal resection, Crohn disease, or celiac disease; those taking proton pump inhibitors, H2 receptor antagonists, or colchicine for more than a year; people with pernicious anemia or malignancies; strict vegetarians; and anyone already taking vitamin B12 supplements. The exclusions were designed to isolate the relationship between metformin itself and the vitamin’s availability in the bloodstream.

The numbers tell a layered story. Of the 400 participants, 103, or 25.75 percent, fell below the study-defined threshold of 300 picograms per milliliter. But only 29 of them, 7.25 percent, had absolute deficiency, defined as concentrations under 200 picograms per milliliter. The remaining 74, or 18.50 percent, occupied the marginal band between 200 and 300 picograms per milliliter, a zone whose clinical meaning is far less certain. The authors are careful to note that this serum-based definition includes marginal values and does not, by itself, establish functional deficiency, which would normally require additional biomarkers such as methylmalonic acid or homocysteine that were not measured in this study.

When the researchers examined which clinical characteristics tracked with low vitamin B12, two factors stood out in their exploratory adjusted analysis. Patients who had been taking metformin for more than five years had nearly twice the odds of falling below the threshold compared with those on shorter courses, with an adjusted odds ratio of 1.84 and a 95 percent confidence interval spanning 1.07 to 3.18. Anemia, defined by conventional World Health Organization hemoglobin cutoffs of under 130 grams per liter in men and under 120 grams per liter in women, carried even greater weight, with an adjusted odds ratio of 3.43 and a confidence interval of 1.62 to 7.23. Male sex and self-reported alcohol consumption showed higher proportions of low vitamin B12 in unadjusted comparisons, but neither retained statistical significance in the reported multivariable model.

The duration signal is consistent with what randomized and longitudinal evidence has long suggested. In a placebo-controlled trial published in BMJ in 2010, de Jager and colleagues observed a greater occurrence of biochemical vitamin B12 deficiency among insulin-treated patients with type 2 diabetes during long-term metformin treatment. The Diabetes Prevention Program Outcomes Study, a longitudinal analysis published in 2016, associated longer cumulative metformin exposure with low vitamin B12 status, though that population was originally recruited for diabetes prevention rather than treatment of established disease. The proposed mechanism centers on the gut: metformin appears to impair the calcium-dependent absorption of the vitamin B12-intrinsic factor complex in the ileum. In a small physiological study published in Diabetes Care in 2000, Bauman and colleagues demonstrated that calcium supplementation could reverse metformin-associated malabsorption, providing mechanistic support for the calcium-dependent hypothesis, though the authors of the new study emphasize that this does not constitute evidence for routine calcium supplementation in clinical practice.

The Vietnamese findings sit within a wider international landscape of prevalence estimates that vary with thresholds, supplementation, and sampling. Kim and colleagues reported vitamin B12 deficiency in 22.2 percent of 1,111 metformin-treated patients in Korea using the same threshold of under 300 picograms per milliliter. A multicenter Chinese study by Gao and colleagues evaluated definite and borderline categories separately and found associations with higher daily metformin doses but not with their selected duration categories. Within Vietnam itself, previous studies have reported prevalences of 18.6 percent in 156 patients by Huynh and colleagues and 22.1 percent among 145 patients at a southern tertiary hospital by Phan and colleagues, with the latter identifying adjusted associations with treatment duration, dose, and HbA1c. A study of elderly patients at Friendship Hospital by Vu and colleagues found that nearly 80 percent of participants reported vitamin B12 supplementation, making that population fundamentally incomparable with the supplement-free sample in the new study.

One of the most clinically consequential aspects of the study concerns the relationship between biochemical deficiency and symptoms that patients actually experience. Vitamin B12 deficiency can cause anemia and macrocytosis, an enlargement of red blood cells defined here as a mean corpuscular volume above 100 femtoliters. But macrocytosis was not statistically significant in either the univariable analysis or the reported multivariable model, and its adjusted confidence interval, spanning 0.79 to 79.37, is so wide that the point estimate cannot be reliably interpreted. More troubling is the neurological dimension: vitamin B12 deficiency can produce neuropathic symptoms that overlap with diabetic peripheral neuropathy, making it easy to attribute one condition’s damage to the other. Observational evidence on this overlap is inconsistent. Ahmed and colleagues did not identify a significant association between biochemical deficiency and peripheral neuropathy in their cross-sectional study, whereas Didangelos and colleagues reported improvement in several neurological measures after vitamin B12 supplementation in a randomized trial of selected metformin-treated patients with neuropathy. The authors caution that a low serum result and clinically manifest deficiency should not be treated as interchangeable outcomes.

The alcohol finding adds another layer of biological complexity. In unadjusted comparisons, participants reporting alcohol consumption had a low vitamin B12 proportion of 37.3 percent versus 22.7 percent among those not reporting consumption, with a crude odds ratio of 2.03. But the association attenuated in the adjusted model, and the binary self-reported measure did not characterize quantity, duration, or drinking pattern. Evidence from other populations suggests the relationship between alcohol and measured vitamin B12 status is more complex than a uniform decrease in serum concentration. Gibson and colleagues found that a controlled alcohol intervention reduced serum vitamin B12 in healthy male volunteers, while Fragasso and colleagues described alcohol-dependent patients with megaloblastic anemia who responded to vitamin B12 treatment despite normal or borderline serum concentrations. The authors cannot determine whether alcohol explains the higher unadjusted proportion in male participants or whether sex modifies an alcohol-related association, and no mediation or interaction analyses were presented.

The study’s limitations are substantial and the authors are unusually transparent about them. The cross-sectional design precludes temporal or causal conclusions, and hospital-based convenience sampling limits generalizability. All participants received metformin, so excess risk relative to nonuse could not be estimated. Baseline vitamin B12 values, dietary intake, methylmalonic acid, and homocysteine were unavailable. The reported adjusted model omitted diabetes duration and daily metformin dose, leaving potential residual confounding by treatment history. The macrocytosis estimate was highly imprecise, and no sensitivity analyses were performed to establish the stability of the adjusted estimates under alternative model specifications. The authors explicitly state that the adjusted findings remain exploratory and do not establish causality or model robustness, and that significance for one exposure and nonsignificance for another are not a test of the difference between their effects.

What practical guidance emerges from this evidence? The American Diabetes Association and the UK Medicines and Healthcare products Regulatory Agency already advise consideration of periodic vitamin B12 assessment during long-term metformin treatment, particularly in patients with risk factors or suggestive hematological or neurological findings. The new study’s five-year duration category can serve as a pragmatic prompt to prioritize review of vitamin B12 status, but the authors stress it is not a validated testing threshold and should not be a reason to defer testing earlier when deficiency is suspected. Patients with unexplained anemia or new neuropathic symptoms should be assessed regardless of treatment duration. Importantly, a low vitamin B12 result does not itself require discontinuation of metformin when the drug remains tolerated and otherwise appropriate. The study cannot specify an optimal testing interval or demonstrate a benefit of routine supplementation, and longitudinal research with detailed exposure measurement, functional biomarkers, and documented analytical plans is needed to clarify how metformin’s benefits and its biochemical side effects can be balanced over decades of treatment.

Subject of Research: Vitamin B12 deficiency prevalence and clinical factors among Vietnamese patients with type 2 diabetes receiving metformin therapy

Article Title: Prevalence and associated factors of vitamin B12 deficiency among Vietnamese patients with type 2 diabetes receiving metformin therapy: a cross-sectional study

Article References: Nguyen, T. K. D., Ke, T. L. A., Pham, V. L., Tran, X. T., & Vu, T. B. (2026). Prevalence and associated factors of vitamin B12 deficiency among Vietnamese patients with type 2 diabetes receiving metformin therapy: a cross-sectional study. Frontiers in Clinical Diabetes and Healthcare, 7, Article 1924740. https://doi.org/10.3389/fcdhc.2026.1924740

Image Credits: AI Generated

DOI: 10.3389/fcdhc.2026.1924740

Keywords: metformin, vitamin B12, type 2 diabetes, anemia, Vietnam, cross-sectional study, diabetic neuropathy, Prevalence, associated, factors, vitamin, deficiency

Glucose-6-phosphate dehydrogenase, commonly abbreviated G6PD, is an enzyme that protects red blood cells from oxidative damage. When the enzyme is deficient, the cells become vulnerable to destruction under oxidative stress, predisposing affected individuals to hemolytic crises. The condition is the most common enzymatic disorder of red blood cells worldwide, affecting more than 400 million people, with particularly high prevalence in the Mediterranean basin, the Middle East, sub-Saharan Africa, and parts of Asia. In newborns, G6PD deficiency is consistently recognized as one of the leading causes of severe hyperbilirubinemia and kernicterus, a devastating form of bilirubin-induced brain injury that can cause sensorineural hearing loss and long-term neurodevelopmental impairment.

What makes neonatal jaundice in G6PD-deficient infants particularly insidious is that it does not always arise from acute hemolysis. Although oxidative triggers can abruptly increase bilirubin production, many affected newborns develop jaundice through a more gradual imbalance between bilirubin production and conjugation, with low-grade hemolysis compounded by impaired bilirubin clearance. This means that clinicians cannot rely on classic laboratory signs of hemolysis to identify at-risk babies, and the jaundice may not appear until bilirubin levels have already climbed to dangerous territory.

Current clinical guidelines reflect a selective approach to testing. The 2022 American Academy of Pediatrics guideline recommends G6PD testing in cases of unexplained jaundice or hemolysis, particularly in high-risk populations. The World Health Organization similarly recommends screening only in at-risk populations where more than 3 to 5 percent of males are affected. But these targeted strategies, based on reported ethnicity, family history, or clinical suspicion, may have limited sensitivity. Prior studies from diverse populations have indicated that a substantial proportion of G6PD-deficient neonates are missed by targeted screening protocols, and there is particular concern that female heterozygotes with intermediate enzyme activity may be overlooked despite being at risk for hemolysis and severe jaundice.

Israel presents a uniquely challenging context for ethnicity-based screening. The population includes Ashkenazi and Sephardic Jews, Arab and Druze communities, and increasing rates of interethnic marriage. Earlier studies demonstrated a highly variable prevalence of G6PD deficiency across specific populations, ranging from less than 1 percent in Ashkenazi Jews up to 58 percent in Sephardic Jews of Kurdish descent. As ethnic admixture has increased, ancestry-based screening strategies have become progressively less reliable. Recognizing this, the Israeli Ministry of Health recommended in 2021 that universal G6PD deficiency screening be added to the newborn screening program, though this recommendation has not yet been fully implemented across all Israeli hospitals.

At Hadassah Medical Center, universal G6PD screening has been part of routine care for more than five years, but its clinical impact had never been formally evaluated. The research team, led by Aviad Schnapp and Ohad Neufeld, conducted a retrospective cohort study with a nested case-control analysis, reviewing the medical records of all neonates born between January 1 and June 30, 2024. The cohort included 5,413 newborns with gestational ages ranging from 32 to 42 weeks. Of these, 4,867 infants, or 89.9 percent, had a valid enzyme activity result. Screening was routinely performed on umbilical cord blood collected at birth, using a quantitative Motulsky enzymatic assay. Results were reported as international units per gram of hemoglobin within 24 hours of laboratory analysis.

The findings revealed that 81 neonates had severe G6PD deficiency, defined as enzyme activity below 2 IU/g Hb, representing 1.66 percent of all screened newborns and 2.9 percent of screened males. An additional 108 neonates had intermediate G6PD activity, between 2 and 10 IU/g Hb, corresponding to 2.2 percent of all screened newborns and 4.4 percent of screened females. Because the number of normal-screen infants substantially exceeded those with deficient or intermediate activity, the researchers used a nested case-control sampling strategy, randomly selecting 567 controls with normal enzyme activity in a 3:1 ratio to form a detailed comparison group of 756 newborns.

The clinical outcomes were striking. Phototherapy was required in 29.6 percent of neonates with severe deficiency, compared with 13.0 percent of those with intermediate activity and 10.1 percent with normal activity. After adjusting for known risk factors including prematurity, mode of delivery, presence of hematoma, ABO or Rh alloimmunization, and family history of conditions that increase hyperbilirubinemia risk, severe G6PD deficiency remained an independent predictor of phototherapy, with an adjusted odds ratio of 4.78. Notably, the time to reach the phototherapy threshold during the birth hospitalization did not differ between infants with and without G6PD deficiency, challenging the common clinical assumption that jaundice in G6PD deficiency evolves later than jaundice due to blood group alloimmunization.

Perhaps the most consequential finding relates to what targeted screening would have missed. Among neonates with G6PD deficiency, a substantial proportion of parents reported no family history of the condition, with 43.2 percent of those with complete deficiency and 53.7 percent of those with partial deficiency reporting no known family history. These infants would not have undergone enzyme testing under a targeted approach. Furthermore, many were not prescribed enhanced bilirubin surveillance during the first 24 hours of life. Six of 94 neonates who required phototherapy, or 6.4 percent, were identified through universal screening as having G6PD deficiency despite the absence of any reported family history. Identification enabled enhanced monitoring and earlier initiation of phototherapy in accordance with the lower treatment thresholds applied to G6PD-deficient neonates.

The biological basis of jaundice in G6PD-deficient newborns is complex. Prior work has shown that clinically important hyperbilirubinemia may occur with limited classic laboratory evidence of hemolysis, while reduced bilirubin conjugation, particularly when G6PD deficiency coexists with UGT1A1 variants associated with Gilbert syndrome, may increase risk. The findings are consistent with the current view that neonatal G6PD-associated jaundice reflects an imbalance between bilirubin production and conjugation rather than a single mechanism. The intermediate-activity group warrants careful interpretation: partial G6PD deficiency was not associated with the excess phototherapy use seen in infants with severe deficiency, though the study was not powered to establish equivalence between the intermediate and normal groups. Because genotyping was not performed, the phenotype-based activity bands cannot be directly aligned with the revised WHO classification, which combines former class II and III variants into a single category and recognizes that heterozygous females may still confer risk. The researchers emphasize that their findings should not be interpreted as excluding risk among infants with intermediate activity or heterozygosity, and that future genotype-informed studies are needed to refine risk stratification. Nationwide neonatal screening for G6PD deficiency is currently implemented in only a limited number of countries worldwide, and this study provides additional evidence from a distinct population and healthcare setting that universal screening identifies infants who would otherwise be missed by targeted approaches, potentially enabling earlier risk-informed management, follow-up planning, and parental education about avoiding oxidative triggers later in life.

Subject of Research: Universal newborn screening for G6PD deficiency and severe hyperbilirubinemia at a tertiary center in Jerusalem

Article Title: Universal newborn screening for G6PD deficiency and severe hyperbilirubinemia at a tertiary center in Jerusalem

Article References: Schnapp, A., Neufeld, O., Abu-Leil, S., Abu Omar, R., Azzam, H., Ofek Shlomai, N., & Eventov Friedman, S. (2026). Universal newborn screening for G6PD deficiency and severe hyperbilirubinemia at a tertiary center in Jerusalem. Journal of Perinatology. https://doi.org/10.1038/s41372-026-02901-9

Image Credits: AI Generated

DOI: 10.1038/s41372-026-02901-9

Keywords: Universal, newborn, screening, G6PD, deficiency, severe, hyperbilirubinemia, tertiary, center, Jerusalem, scientific research

The study, titled ‘Deficiency of protein kinase Cδ reprograms macrophage immunometabolism to suppress pyroptosis and stabilize atherosclerotic plaques,’ examines how removing this single kinase alters the metabolic machinery inside macrophages and, as a consequence, changes the inflammatory character of atherosclerotic lesions. The finding is notable because it links three areas that have usually been studied in isolation: kinase signaling, immunometabolism, and the inflammatory form of cell death known as pyroptosis. By connecting them, the work suggests that a pathway long associated with immune activation may instead be a liability in chronic vascular disease.

To understand why this matters, it helps to recall what macrophages do inside an artery wall. These cells are recruited to sites where low-density lipoprotein particles have accumulated beneath the endothelial lining. Once there, they engulf lipids, and in doing so they can become the foam cells that give early plaques their fatty appearance. But macrophages are not passive containers. They are metabolically active, decision-making cells whose internal fuel choices, whether to burn glucose rapidly through glycolysis, whether to rely on mitochondrial oxidative phosphorylation, whether to draw on fatty acid oxidation, shape the inflammatory signals they emit. A plaque dominated by pro-inflammatory macrophages tends to be rich in degradative enzymes and death signals, thinning its protective fibrous cap and raising the risk of rupture.

Pyroptosis is one of the most incendiary of those death signals. Unlike ordinary apoptosis, which quietly packages cellular debris for removal, pyroptosis is a lytic, inflammatory death driven by the activation of inflammasomes, multiprotein complexes that trigger caspase enzymes to cleave gasdermin proteins. Cleaved gasdermins form pores in the cell membrane, causing the cell to swell, burst, and spill its contents, including potent inflammatory messengers such as interleukin-1 family cytokines, into the surrounding tissue. Within a plaque, waves of pyroptotic macrophage death enlarge the necrotic core, weaken the fibrous cap, and promote the thrombus formation that turns a stable lesion into a clinical emergency.

Protein kinase C delta has long been recognized as a versatile signaling molecule in immune cells, participating in pathways that regulate activation, migration, and death decisions. The new research asked a direct question: what happens to macrophage behavior, and to atherosclerotic disease, when this kinase is missing? The answer, according to the study, is that deficiency of the kinase reprograms macrophage immunometabolism, shifting the internal metabolic set points of the cells in a direction that suppresses pyroptosis. In other words, without protein kinase C delta, macrophages appear to become less prone to the explosive inflammatory death that destabilizes plaques.

The concept of immunometabolic reprogramming is central to interpreting this result. Macrophages adopt broadly distinguishable metabolic profiles depending on their activation state, and these profiles are not merely byproducts of inflammation; they actively reinforce it. A glycolytic shift, for example, supports the rapid production of inflammatory mediators, while a more oxidative, mitochondrial-oriented metabolism tends to accompany reparative, tissue-tolerant behavior. By showing that removing protein kinase C delta rewrites these metabolic choices, the study positions the kinase as a kind of metabolic gatekeeper whose activity licenses the inflammatory, pyroptosis-prone phenotype in the plaque environment.

The downstream consequence reported in the work is plaque stabilization. In atherosclerosis research, stability is assessed through structural features: the thickness of the fibrous cap that separates the thrombogenic necrotic core from the bloodstream, the size of that necrotic core, the collagen content of the cap, and the burden of dead and dying cells within the lesion. A plaque that retains a thick cap, a modest necrotic core, and abundant collagen is far less likely to rupture than one riddled with pyroptotic debris. The finding that PKC delta deficiency suppresses pyroptosis and stabilizes plaques implies that the kinase contributes to precisely the features that make lesions dangerous, and that its removal tilts lesions toward a safer architecture.

These results arrive amid a broader reassessment of inflammation as a therapeutic target in cardiovascular medicine. Landmark clinical trials have already demonstrated that blunting inflammatory signaling, for instance through interleukin-1 beta blockade or colchicine treatment, reduces cardiovascular events in selected patients, validating the idea that the immune component of atherosclerosis is druggable. Against that backdrop, a kinase that governs whether plaque macrophages die inflammatory deaths is an attractive candidate for intervention, because it acts upstream of the terminal events, inflammasome activation, gasdermin pore formation, cytokine release, and necrotic core expansion, that directly damage plaque integrity.

At the same time, the study invites caution. Protein kinase C delta participates in many physiological processes beyond the plaque, including immune defense against infection, platelet function, and the regulation of cell survival in multiple tissues. Any therapeutic strategy aimed at inhibiting the kinase, or at exploiting the metabolic programs it controls, would need to weigh the benefit of calmer plaque macrophages against the risk of impairing the host responses that depend on this enzyme. Translating a reprogramming effect observed in experimental models into a safe clinical approach will require a detailed map of which downstream metabolic and inflammasome pathways mediate the protection, and whether those pathways can be targeted selectively.

Even so, the conceptual contribution is substantial. The work reframes atherosclerotic plaque stability not simply as a matter of lipid lowering, which remains the foundation of therapy, but as a matter of immune cell fate, decided by intracellular metabolic wiring that can be shifted by manipulating a single signaling node. If the findings hold up across models and, eventually, in human tissue, they suggest that future treatment could combine lipid management with agents that nudge plaque macrophages away from pyroptosis and toward a stable, reparative state. In a disease that kills millions each year largely through plaque rupture, teaching immune cells to keep their composure may prove to be one of the more consequential ideas in modern cardiovascular research.

Subject of Research: The role of protein kinase C delta deficiency in reprogramming macrophage immunometabolism to suppress pyroptosis and stabilize atherosclerotic plaques

Article Title: Deficiency of protein kinase Cδ reprograms macrophage immunometabolism to suppress pyroptosis and stabilize atherosclerotic plaques

Article References: Lien, C.-F., Chang, H.-Y., Yu, S.-H., Cho, R.-L., Chen, S.-J., Kuo, T.-T., Chong, P. C.-T., Ye, C.-H., Lin, F.-Y., Wu, W.-L., Lin, S.-H., Tsai, C.-S., & Lin, C.-S. (2026). Deficiency of protein kinase Cδ reprograms macrophage immunometabolism to suppress pyroptosis and stabilize atherosclerotic plaques. Experimental & Molecular Medicine. https://doi.org/10.1038/s12276-026-01842-9

Image Credits: AI Generated

DOI: 10.1038/s12276-026-01842-9

Keywords: protein kinase C delta, macrophages, immunometabolism, pyroptosis, atherosclerosis, plaque stability, inflammasome, foam cells, cardiovascular disease, inflammation, Deficiency, protein