The study, published in BMC Pediatrics by Martin Jouza, Petr Jabandziev, and colleagues at University Hospital Brno and Masaryk University, focused on microRNAs, or miRNAs. These are short, non-coding RNA fragments, typically around 19 to 24 nucleotides long, that do not carry instructions for building proteins. Instead, they act as fine-tuners of gene expression, binding to messenger RNA transcripts and dampening their translation. Crucially for diagnostic medicine, miRNAs are remarkably stable in body fluids, protected from degradation by their small size and by packaging inside membrane-bound vesicles or association with carrier proteins. That stability makes them attractive candidates for liquid biopsy-style biomarkers, molecules measurable from a simple blood draw rather than invasive tissue sampling.

The rationale for looking at miRNAs in sepsis is rooted in immunology. Sepsis is fundamentally a dysregulated inflammatory response to infection, and miRNAs are deeply embedded in the control of that response. Individual miRNAs regulate networks of cytokine signaling, neutrophil function, and macrophage polarization. When infection tips the immune system into overdrive, the circulating profile of these molecules shifts measurably. Previous smaller studies had hinted that specific miRNAs change in septic newborns, but independent confirmation has been scarce, and the field has repeatedly seen promising biomarker candidates fail when tested in new cohorts. The Brno team set out to provide exactly that independent test.

The researchers assembled a cohort of 64 newborns with sepsis and 21 control infants without signs of systemic infection. Within the sepsis group, 20 patients were classified as having early-onset sepsis, typically acquired around the time of birth, and 41 had late-onset sepsis, acquired later during hospitalization. Blood cultures were positive in 45 percent of cases, with Staphylococcus epidermidis, Escherichia coli, and Staphylococcus aureus standing out as the most common pathogens. From each patient, peripheral blood was collected and plasma was separated, from which total RNA enriched for small RNA species was extracted.

On the technical side, the team selected eight candidate miRNAs based on a systematic search of the existing literature: hsa-miR-29a-3p, hsa-miR-96-5p, hsa-miR-185-5p, hsa-miR-16-5p, hsa-miR-15a-5p, hsa-miR-132-3p, hsa-miR-223-3p, and hsa-miR-26a-5p. Levels of each molecule were quantified using quantitative polymerase chain reaction, the workhorse technique of nucleic acid measurement, which amplifies specific RNA sequences and allows their relative abundance to be calculated. To control for technical variation between samples, the researchers normalized the results to the average expression of all measured miRNAs, a common strategy when no single endogenous reference is reliable across inflammatory states. Statistical analysis was performed in GraphPad Prism 8.

The results were clear-cut. Of the eight miRNAs examined, three were significantly dysregulated in septic newborns compared with controls: miR-15a, miR-132, and miR-223. MiR-15a showed the most pronounced effect, with a p-value of 0.0009, indicating a difference between groups that would arise by chance less than one time in a thousand. To translate these molecular findings into something clinically usable, the team built a combined diagnostic model using logistic regression, a statistical method that weighs multiple inputs to estimate the probability that a patient belongs to one group or another. Incorporating the three most significantly dysregulated miRNAs, the model achieved an area under the curve, or AUC, of 0.78. In diagnostic terms, an AUC of 1.0 represents perfect discrimination and 0.5 represents a coin flip, so 0.78 indicates meaningful, though not definitive, diagnostic power.

Several secondary findings add depth to the picture. No significant differences in miRNA expression emerged between early-onset and late-onset sepsis, suggesting that the molecular signature reflects the septic process itself rather than the timing of infection. More intriguingly, the researchers tracked miRNA levels longitudinally. MiR-15a showed significant dysregulation during the acute phase of the disease and returned to baseline levels by day seven, behaving like a dynamic readout of the inflammatory storm rather than a static marker. When the team stratified patients by nSOFA score, a neonatal adaptation of the Sequential Organ Failure Assessment used to gauge sepsis severity, they found divergent miRNA normalization trajectories between severity subgroups. MiR-15a and miR-223 were significantly dysregulated in patients with higher nSOFA scores, hinting that these molecules could flag which infants are heading toward severe disease before the clinical picture fully declares itself.

The researchers also examined how the miRNA signals relate to C-reactive protein, or CRP, the standard inflammatory marker measured in virtually every suspected sepsis workup. CRP was systematically assessed in all patients, and correlations between CRP and miR-15a, miR-132, and miR-223 were analyzed. CRP has well-known limitations in newborns: it rises slowly after the onset of infection, can be elevated for benign reasons related to birth trauma, and lacks specificity. A biomarker panel that captures complementary information, or that responds faster than CRP, would fill a genuine clinical gap. The study’s design, pairing molecular measurements with routine CRP data, positions the miRNAs as potential partners rather than immediate replacements for existing tests.

The authors conclude that miRNAs could serve as semi-invasive biomarkers for neonatal sepsis, and they emphasize the prognostic dimension of their findings. Because miR-15a and miR-223 tracked with nSOFA-based severity, they may function as predictive biomarkers for severe disease progression, not merely diagnostic ones. In practical terms, a neonatologist armed with such a test could, in principle, stratify patients at the bedside, intensify monitoring or escalate antibiotics for infants whose molecular profile signals high risk, and personalize treatment intensity in a condition where both undertreatment and overtreatment carry serious costs. The study is also notable as the first independent evaluation of these particular miRNA findings in neonatal sepsis, addressing a reproducibility problem that has long dogged the biomarker literature.

Caution is still warranted before such a test reaches the nursery. The cohort, while well characterized, is modest in size, and the AUC of 0.78, though respectable, falls short of the near-perfect discrimination clinicians would want for a stand-alone diagnostic. Normalization strategies for circulating miRNAs remain debated, and standardization across laboratories will be essential before any clinical deployment. Still, the convergence of diagnostic signal, longitudinal dynamics, and severity correlation in a single validated panel marks real progress. If larger multicenter trials confirm these results, the humble microRNA, a molecule once dismissed as genetic noise, could become a routine part of the arsenal against one of newborn medicine’s deadliest adversaries.

Subject of Research: Circulating microRNA biomarkers for diagnosing and predicting severity of neonatal sepsis

Article Title: Dysregulated microRNA expression in neonatal sepsis: validation study of potential novel biomarkers

Article References: Jouza, M., Bohosova, J., Sonawane, S., Naar, O., Slaba, K., Stanikova, A., Slaby, O., & Jabandziev, P. (2026). Dysregulated microRNA expression in neonatal sepsis: validation study of potential novel biomarkers. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07703-8

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07703-8

Keywords: microRNA, neonatal sepsis, biomarkers, miR-15a, miR-223, nSOFA, logistic regression, quantitative PCR, C-reactive protein, neonatology, non-coding RNA, liquid biopsy

The research team, led by investigators at Children’s Hospital, Zhejiang University School of Medicine, together with collaborators spanning thirteen pediatric intensive care units across China, assembled a retrospective cohort of 2,374 children under eighteen years of age who were admitted to intensive care with suspected infections between 2023 and 2025. Rather than treating this population as a single undifferentiated group, the investigators prespecified two clinically distinct sub-cohorts for focused analysis: a neonatal group of 576 infants aged twenty-eight days or younger, and a hematology group of 494 children, a population in which underlying malignancies, immunosuppression, and hematologic abnormalities complicate both the diagnosis of sepsis and the interpretation of laboratory-based severity scores. This design choice reflects a growing recognition in the field that a scoring system validated in a general pediatric intensive care population may not transfer cleanly to the extremes of age or to immunocompromised patients.

Methodologically, the study followed a disciplined approach to score calculation. For each child, both the Phoenix sepsis score and the pSOFA score were computed using the worst available physiological and laboratory values recorded within the first twenty-four hours of intensive care unit admission. This window matters: early severity assessment is precisely what clinicians need when deciding how aggressively to resuscitate, monitor, and escalate care. The primary outcome was in-hospital mortality, and the principal metric of prognostic accuracy was the adjusted area under the receiver operating characteristic curve, or AUROC, a statistic that captures how well a score discriminates between children who died and those who survived, with 0.5 representing chance-level performance and 1.0 representing perfect discrimination. By adjusting the AUROC, the researchers accounted for confounding structure in the data, strengthening the comparability of the two scores.

The headline finding is statistically clear. Across the full cohort of 2,374 critically ill children, the Phoenix sepsis score achieved an adjusted AUROC of 0.840, significantly outperforming the pSOFA score’s 0.817, with a P value below 0.001. In absolute terms the difference may appear modest, but in the world of mortality prediction models, where incremental gains in discrimination can translate into earlier recognition and redirected resources for the sickest patients, such a difference across a cohort of this size carries weight. The result provides external validation, on a scale and in a healthcare context distinct from the original derivation studies, that the Phoenix framework’s emphasis on four organ systems, respiratory, cardiovascular, coagulation, and neurologic, captures lethal trajectories in infected children at least as well as, and slightly better than, the older pSOFA construct.

The picture grows more complicated in the predefined sub-cohorts. In the hematology group, the Phoenix score again outperformed pSOFA, with adjusted AUROCs of 0.718 versus 0.682, a difference that reached statistical significance at P equal to 0.006. Yet the investigators were careful to characterize discriminative ability in this subgroup as limited for both tools. Children with hematologic disease present a notoriously difficult prediction problem: baseline cytopenias, chemotherapy-related organ toxicity, and altered inflammatory responses can all inflate or deflate organ dysfunction scores independent of sepsis severity. A score of 0.718, while better than chance, leaves substantial room for misclassification, and the authors’ framing suggests that neither score should be treated as a reliable standalone prognostic instrument in this vulnerable population.

In neonates, the story changes again. Among the 576 infants aged twenty-eight days or younger, the Phoenix score posted a strikingly high adjusted AUROC of 0.915 compared with 0.850 for pSOFA, but the difference did not reach statistical significance, with P equal to 0.222. The absence of a significant gap does not mean either score performed poorly; indeed, both achieved excellent discrimination in this low-event-rate setting. Rather, the finding suggests that in newborns the two instruments are statistically interchangeable for mortality prediction, an important practical conclusion given that the Phoenix criteria were designed to span pediatric and neonatal populations and that neonatal sepsis has long posed unique challenges, from nonspecific clinical presentation to the scarcity of neonate-specific validation data for adult-derived scoring frameworks.

Beyond discrimination, the study examined how the scores behave at their operational threshold, the cutoff clinicians actually use to flag sepsis. At the standard threshold of two or more points, both the Phoenix score and pSOFA maintained high sensitivity, exceeding 80 percent across all cohorts, meaning they rarely missed a child who went on to die. The trade-off came in specificity: positive predictive values were low, at or below 50 percent everywhere, and in the neonatal sub-cohort they fell below 8 percent. This asymmetry is not a flaw unique to these scores but a mathematical consequence of applying screening thresholds in settings where deaths are, thankfully, uncommon. A highly sensitive tool catches nearly everyone at risk, but in a population where most children survive, most flagged children will nonetheless survive, producing many false alarms.

The trade-off between sensitivity and positive predictive value took on a different character in the hematology sub-cohort, where the event rate was high enough to make predictive values more meaningful. There, the Phoenix score traded approximately five percentage points of sensitivity for a meaningfully higher positive predictive value than pSOFA. In practical terms, the Phoenix score was somewhat more likely to miss a child who died, but when it flagged a child, that flag was more often correct. Which trade-off a clinician or unit should prefer depends on context: in settings where missing a death is the dominant concern, sensitivity may reign; where flagged patients trigger resource-intensive interventions, a higher positive predictive value reduces unnecessary escalations. The study does not prescribe a choice but equips decision-makers with the quantitative texture needed to make one.

The findings land amid an active international debate about the Phoenix criteria, which were developed and validated by a global consensus effort published in JAMA in 2024 and have since undergone external validation in cohorts from the United States, Bolivia, Australia, and beyond, with mixed results in low-resource settings and emergency departments. The new Chinese multicenter analysis adds a critical piece: evidence from a large, geographically diverse, non-Western cohort, with dedicated attention to neonates and hematology patients, two groups underrepresented in earlier validation work. It also complements the research group’s own prior multicenter study of the Phoenix score, pSOFA, and SIRS criteria in non-intensive care settings, extending the comparison to the sickest children in intensive care.

For the field, the message is one of calibrated confidence. The Phoenix sepsis score can now claim superior discrimination for in-hospital mortality in the general population of critically ill children with suspected infection, supporting its adoption in pediatric intensive care contexts. But the study simultaneously cautions against universal enthusiasm: in neonates, the older pSOFA remains an equally defensible choice, and in children with hematologic disease, both scores fall short of what clinicians would want from a decision-support tool, underscoring the need for population-specific approaches, whether through recalibration, integration of novel biomarkers, or entirely new models tailored to immunocompromised hosts. As sepsis mortality prediction moves from one-size-fits-all scores toward precision risk stratification, this study provides both a benchmark and a reminder that the sickest children often defy the averages on which general scores are built.

Subject of Research: External validation comparing the Phoenix sepsis score and pSOFA for predicting in-hospital mortality in critically ill children with suspected infection.

Article Title: Discrimination performance of the Phoenix sepsis score versus pediatric sequential organ failure assessment for predicting in-hospital mortality in critically ill children: a multicenter external validation study

Article References: Ru, X.-W., Liu, R.-Y., Yang, Z.-H., Huang, C.-Z., Zhang, C., Li, T.-W., Yang, J.-M., Liu, Y., Cui, X.-Y., Chen, H.-B., Zhou, X., Tang, F., Gong, X.-Y., Ling, P., Lv, X., Zeng, Q., Ma, Z., Yuan, B.-Y., Zhu, H., … Ye, Q. (2026). Discrimination performance of the Phoenix sepsis score versus pediatric sequential organ failure assessment for predicting in-hospital mortality in critically ill children: a multicenter external validation study. World Journal of Pediatrics. https://doi.org/10.1007/s12519-026-01073-y

Image Credits: AI Generated

DOI: 10.1007/s12519-026-01073-y

Keywords: Phoenix sepsis score, pSOFA, pediatric sepsis, in-hospital mortality, critical care, neonatal sepsis, hematology, AUROC, external validation, organ dysfunction, predictive scoring, intensive care unit

The review, published in the Journal of Perinatology by a large international team led from Trinity College Dublin, set out to answer a focused question: how do randomised controlled trials, the most rigorous experiments in medicine, actually diagnose and stage NEC? The question matters because a trial is only as good as its outcome measures. If two trials use different definitions of the same disease, their results cannot be cleanly compared or combined in meta-analyses, and regulators and clinicians are left guessing about whether a treatment that appears to work in one setting will work in another.

NEC is a significant cause of morbidity and mortality for preterm neonates, and its stakes have only risen as survival at earlier gestational ages improves. Whole-population surveillance in England has documented the scale of severe disease across neonatal networks, and reviews of contemporary outcomes continue to report substantial mortality among infants who require surgery. The disease is understood to involve a destructive interplay between an immature intestinal barrier, an unstable and often dysbiotic gut microbiome, inflammation mediated in part by innate immune receptors such as toll-like receptor 4, and haemodynamic fragility of the preterm mesentery. Risk factors described in the literature include enteral feeding practices, the protective association of early human milk, maternal smoking, and even in-utero exposures such as indomethacin tocolysis.

Against this complicated biological backdrop sits a diagnostic framework born in 1978. In that year, Bell and colleagues published a staging system for neonatal necrotizing enterocolitis in the Annals of Surgery, designed to guide therapeutic decisions based on clinical staging. The scheme stratified suspected disease from stage one, or suspected NEC with nonspecific systemic signs, through stage two, in which radiographic findings such as pneumatosis intestinalis, gas trapped within the bowel wall, confirm the diagnosis, to stage three, advanced disease with perforation or profound systemic collapse. Walsh and Kliegman refined the criteria in 1986, producing the modified Bell’s staging that generations of neonatologists have since memorised.

Herein lies the conceptual tension that the Dublin-led review interrogates. As the authors point out, Bell’s criteria were never intended as a case definition of NEC. They were a staging tool, created for an era when the sickest infants were often older and more mature than the micro-preemies cared for today. With the survival of neonates at earlier gestations, the clinical phenotype of intestinal injury has shifted, and researchers have repeatedly questioned whether a single framework can capture what is now a heterogeneous spectrum of disease. Some have argued that spontaneous intestinal perforation, a condition with different pathology and outcomes, has been inappropriately lumped together with classic NEC in older trials, muddying the interpretation of surgical studies comparing laparotomy with peritoneal drainage.

To map how trials actually define the disease, the team performed a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, the PRISMA guidelines that standardise how such evidence syntheses are conducted and reported. They searched PubMed to identify randomised controlled trials published in the last twenty years that used NEC in the study title and included NEC either as a primary outcome or as an inclusion criterion. This dual requirement ensured that every trial analysed genuinely placed NEC at the centre of its scientific question rather than treating it as a passing safety mention.

The screening funnel distilled a large body of literature into a focused evidence base. The initial search identified fifty-six randomised controlled trials, of which thirty-six proceeded to full-text analysis. The headline finding was striking in its consistency: thirty-three of the thirty-six trials used Bell’s criteria or the modified Bell’s criteria to define NEC, while only three trials deployed unique, author-created definitions. In other words, when researchers design the most rigorous experiments on NEC prevention and treatment, the overwhelming majority still anchor their case ascertainment to a staging framework conceived before the advent of modern neonatal intensive care as it exists today.

What does that anchoring mean in practice? Bell’s staging relies on a combination of nonspecific systemic signs, abdominal findings, radiographic evidence such as pneumatosis intestinalis or portal venous gas, and, at the severe end, surgical or autopsy confirmation. Its strengths are real: it is universally recognised, cheap to apply, and requires no specialised laboratory infrastructure. But its weaknesses are equally well documented. Interobserver agreement on stage one disease is notoriously poor, the criteria were never gestational-age adjusted, and they predate the biomarker and imaging revolution now reshaping neonatal diagnostics. Recent work has evaluated neutrophil CD64 as a surveillance marker, explored data-driven diagnostic algorithms integrating clinical and laboratory features, and compared abdominal ultrasonography with plain radiography for detecting disease and predicting severity.

The review’s authors situate their findings within a broader reform movement. A gestational age-specific case definition developed by the UK Neonatal Collaborative has been proposed to capture disease more accurately across the preterm spectrum, and the Vermont Oxford Network maintains its own surveillance definitions, as do the CDC’s NHSN surveillance criteria. Critical evaluations of current definitions have concluded that the field’s diagnostic heterogeneity impedes both research and drug development, with regulatory scientists arguing that a consensus case definition is a prerequisite for any licensed therapy for NEC. The authors of the new review conclude that while the consistent use of Bell’s and modified Bell’s criteria in trials is itself informative, international consensus on further modification of the definition would greatly contribute to both research and clinical practice, allowing greater consistency in staging and therefore optimal management.

The trials catalogued in the review span the full range of neonatal intervention research: prophylactic and therapeutic probiotics including Bifidobacterium breve and Lactobacillus strains, bovine lactoferrin, synbiotics, oral glutamine, enteral L-arginine, docosahexaenoic acid supplementation, bovine colostrum and oropharyngeal colostrum administration, donor human milk fortification, early versus delayed minimal enteral feeding, maternal dietary manipulation, early caffeine treatment and erythropoietin. Each of these trials judged success or failure largely through the lens of a 1978 staging system. If the field can converge on a modern, gestational-age-aware, biologically informed definition, one that perhaps integrates imaging advances, biomarkers and patient-centred research priorities championed by families through organisations such as the NEC Society, the resulting consistency could sharpen future trials, accelerate regulatory approval of preventives and treatments, and ultimately help clinicians identify, stage and treat this devastating disease more reliably.

Subject of Research: How necrotizing enterocolitis is defined and staged in randomised controlled trials involving preterm neonates

Article Title: Definitions of neonatal Necrotizing Enterocolitis (NEC) in randomised controlled trials: a systematic review

Article References: Ballantine, R. S., Campbell, E., Croitoru, O., Jackson, E., Lyne, E. J., McGoldrick, C., Murphy, S. M., Oganezova, K., Shukla, T., Yogesan, S. S., Trayer, J., Stewart, P., Carroll, S., Branagan, A., Roche, E., Tabassum, S., Abrahamsson, T., Embleton, N., Berrington, J., … Molloy, E. J. (2026). Definitions of neonatal Necrotizing Enterocolitis (NEC) in randomised controlled trials: a systematic review. Journal of Perinatology. https://doi.org/10.1038/s41372-026-02905-5

Image Credits: AI Generated

DOI: 10.1038/s41372-026-02905-5

Keywords: necrotizing enterocolitis, Bell's criteria, preterm infants, randomised controlled trials, systematic review, neonatology, clinical staging, PRISMA, gut microbiome, neonatal mortality, case definition, Journal of Perinatology

The biological characteristics of newborns further complicate management. The neonatal immune system is not yet fully developed, so once sepsis occurs, infants are prone to rapid progression toward septic shock and multiple organ dysfunction syndrome. At the same time, the metabolic and enzyme systems of the liver and kidneys remain immature, limiting the ability to clear drugs. Antibiotics routinely used in adults, such as fluoroquinolones and sulfonamides, cannot be directly administered to neonates. Against this backdrop, researchers have increasingly focused on adjunctive therapies built upon standard antibiotic treatment, and plasma transfusion has emerged as one of the most debated candidates. Yet the timing and precise indications for plasma transfusion in neonates remain deeply controversial, prompting a new editorial in the World Journal of Pediatrics by Fang-Rui Ding and Xiao-Yan Li that systematically examines the theoretical foundation, risks, and current clinical application of this approach.

The rationale for using plasma transfusion in sepsis originated in trauma care. Trauma and sepsis share a striking degree of pathophysiological similarity. Both conditions trigger acute intravascular volume depletion and tissue hypoperfusion, as systemic vasodilation and elevated vascular permeability drive massive fluid extravasation, destabilizing the circulation and rapidly progressing to shock. Both disorders also induce severe coagulopathy, marked by excessive consumption of coagulation factors, disrupted anticoagulant pathways, and dysregulated fibrinolysis. Given these overlapping mechanisms, and given that multiple studies have demonstrated that early and active plasma transfusion in trauma patients significantly improves survival and clinical outcomes, it is biologically plausible to infer that plasma might confer comparable benefits in sepsis. This reasoning has shaped clinical intuition for decades, even in the absence of direct evidence in septic patients.

Neonates, especially preterm infants, have inherently low levels of coagulation factors, insufficient immunoglobulins and complement, and a fragile vascular endothelial barrier. When sepsis strikes, the systemic inflammatory response further consumes immune and coagulation-related mediators, worsening disease progression. In theory, plasma transfusion could rapidly replenish these deficient bioactive substances. Immunoglobulin supplementation could strengthen specific immune defenses against pathogens, neutralize toxins, and facilitate infection control. Coagulation factors and fibronectin could optimize hemostasis, preventing and treating sepsis-associated coagulopathy. Complement components could boost bacteriolytic and opsonizing capacity, promoting pathogen clearance. Colloid supplementation might also help maintain blood volume and plasma osmotic pressure, improving tissue perfusion and correcting septic shock. These mechanisms form a coherent and appealing therapeutic hypothesis.

Animal studies have lent support to these theoretical inferences. In a septic rat model, Chang and colleagues found that plasma transfusion raised the 48-hour survival rate from 14 percent to 57 percent compared with normal saline resuscitation. In foals, McTaggart and colleagues demonstrated that plasma transfusion elevated serum immunoglobulin G levels in both healthy and septic animals, and although it exerted no benefit on neutrophil function in healthy foals, it significantly improved neutrophil activity in septic ones. More strikingly, Pereira and colleagues studied neonatal puppies with sepsis and found that combined treatment with plasma and antibiotics improved immune and metabolic parameters, including blood glucose, white blood cell counts, and IgM levels, within 24 hours, shortened recovery of leukocyte indices, reduced lactate levels, and resulted in zero mortality, compared with a 22 percent mortality rate in the antibiotic-only group. Despite these encouraging results, the editorial’s authors caution that no high-grade human evidence has confirmed clinical efficacy, and findings from animal models may not be directly applicable to human neonates because of inherent species and environmental differences.

In humans, the picture grows considerably murkier. Clinical studies of plasma transfusion in sepsis have produced conflicting results, and some have associated transfusion with increased incidence of complications and poorer prognosis. Qin and colleagues, analyzing data from the Medical Information Mart for Intensive Care III database, found that both 28-day and 90-day mortality were significantly higher in the plasma transfusion group than in the non-transfusion group, and plasma transfusion did not improve prognosis even among sepsis patients with coagulopathy, regardless of coagulation state. In a pediatric study by Duan and colleagues involving 262 children with sepsis, 28-day mortality, in-hospital mortality, and multiple organ dysfunction syndrome morbidity were all significantly higher in the plasma transfusion group. Plasma transfusion demonstrated no benefit and was instead significantly associated with an increased risk of adverse outcomes, findings that directly challenge the intuitive appeal of the therapy.

Beyond questions of efficacy, plasma transfusion carries substantial safety risks. Allergic reactions occur at an approximate incidence of 1 to 3 percent. Transfusion-related acute lung injury, or TRALI, has an estimated incidence of 0.08 to 15.1 percent in critically ill patients and accounts for 34 percent of transfusion-related fatalities, although improved mechanistic understanding and donor selection have reduced risks in recent years. Transfusion-associated circulatory overload, or TACO, occurs in roughly 1 percent of transfusions overall but reaches 3.6 to 5.8 percent in critically ill patients, with widespread underdiagnosis and underreporting. While donor screening and pathogen inactivation have substantially reduced infection transmission, residual risks persist, with HIV and hepatitis C transmission rates of approximately 0.02 per 10,000 transfusions, and newly emerging pathogens remain a potential threat. Plasma transfusion may also increase nosocomial infection risk through transfusion-related immunomodulation, a phenomenon linked to postoperative infection in critically ill patients.

Current practice reveals a striking gap between guidelines and reality. Plasma transfusion is relatively common in neonatal intensive care units, with use varying dramatically across centers from 0.17 percent to 8.2 percent, and rates are generally higher for surgical cases and extremely preterm neonates. International guidelines are consistent in their core recommendation: plasma should be given only for active bleeding accompanied by coagulation disorders, and prophylactic transfusion is not recommended. No current sepsis guideline recommends plasma for sepsis itself. Yet observational surveys consistently reveal widespread non-adherence. In European countries, only 29.4 percent of plasma transfusions were given for bleeding, while in South Africa 75 percent of transfusions complied with national guidelines. The authors attribute this deviation to two interrelated factors: the lack of effective targeted interventions for neonatal septic shock, which drives clinicians to adopt plasma as a salvage therapy out of clinical urgency, and the extrapolation of trauma resuscitation experience combined with assumptions about neonatal immune and coagulation immaturity.

The limited human studies specific to neonatal sepsis offer mixed signals. A 1994 study by Acunas and colleagues involving 67 infected neonates found that while intravenous immunoglobulin exerted prominent immune-enhancing effects, plasma transfusion failed to elevate key anti-infective IgG or alter inflammatory markers such as C-reactive protein and fibronectin, indicating no clinical benefit. Conversely, a Nigerian retrospective study by Ogunlesi and colleagues in neonatal tetanus with suspected sepsis observed lower mortality in plasma-transfused neonates, though the difference was statistically insignificant due to small sample size, and all blood culture-positive patients in the transfusion group survived. Eisenfeld and colleagues further demonstrated that plasma transfusion significantly improved neutrophil chemotactic function in critically ill neonates with suspected severe sepsis. Data from other neonatal contexts add further complexity, with studies linking plasma transfusion to retinopathy of prematurity, bronchopulmonary dysplasia, hemodynamically significant patent ductus arteriosus, and necrotizing enterocolitis, though results remain contradictory and appear to depend heavily on transfusion timing, indication, and patient characteristics.

The editorial concludes that there are no definitive evidence-based data confirming that plasma transfusion benefits neonatal sepsis, but this does not mean benefits are absent. The authors call for large-sample, multicenter retrospective and prospective randomized controlled trials with carefully defined inclusion criteria, appropriate coagulation and infection outcomes, and stratified analysis by gestational age and weight to enable individualized treatment. They also urge deeper mechanistic research into the roles of immunoglobulins, coagulation factors, complements, and fibronectin in plasma, alongside safety studies addressing both short-term risks such as TACO, viral transmission, and allergic reactions, and long-term neonatal complications. Until such evidence arrives, plasma transfusion in neonatal sepsis remains a therapy caught between biological plausibility and clinical uncertainty, a gap that only rigorous research can close.

Subject of Research: The use of plasma transfusion as an adjunctive therapy for neonatal sepsis, including its theoretical benefits, clinical evidence, safety risks, and guideline recommendations.

Article Title: Plasma transfusion in neonatal sepsis

Article References: Ding, F.-R., & Li, X.-Y. (2026). Plasma transfusion in neonatal sepsis. World Journal of Pediatrics. https://doi.org/10.1007/s12519-026-01095-6

Image Credits: AI Generated

DOI: 10.1007/s12519-026-01095-6

Keywords: neonatal sepsis, plasma transfusion, fresh frozen plasma, neonatal intensive care, coagulopathy, septic shock, transfusion-related acute lung injury, immunoglobulins, randomized controlled trials, preterm infants, transfusion safety, clinical guidelines

A rare form of newborn sepsis caused by Streptococcus pneumoniae can develop with startling speed and produce severe respiratory failure, blood-cell abnormalities and systemic collapse, according to a case report and 25-year review published in BMC Pediatrics. The study focuses on pneumococcal serotype 3, a strain distinguished by an unusually thick polysaccharide capsule and a reputation for causing invasive disease. In the reported case, a full-term girl became critically ill on her first day of life, yet recovered after clinicians identified the bacterium and treated it with intravenous ampicillin. The case highlights a troubling clinical paradox: serotype 3 may cause especially aggressive neonatal disease even when the organism remains fully susceptible to penicillin-class antibiotics. The findings suggest that the danger may lie less in drug resistance than in the interaction between the bacterium’s surface architecture and the extreme vulnerability of a newborn immune system.

Early-onset sepsis, or EOS, is generally defined as a bloodstream infection appearing during the first days of life, often through transmission from the mother around the time of birth. In newborns, the immune system is still developing, the physical barriers protecting the lungs and bloodstream are fragile, and physiological reserves are limited. A bacterial infection can therefore progress before obvious symptoms become apparent. Pneumococcal EOS is exceptionally uncommon compared with infections caused by group B Streptococcus or Escherichia coli, the organisms more typically associated with neonatal sepsis. Its rarity can make recognition difficult, especially because the initial signs—rapid breathing, poor oxygenation, temperature instability or lethargy—can resemble complications of birth or prematurity. The researchers’ review found that the illness was frequently hyper-acute: 26 of 41 confirmed cases, or 63.4 percent, became symptomatic within the first 24 hours of life.

The new case involved a term female neonate who developed severe respiratory distress and metabolic acidosis during her first day. Respiratory distress indicates that the lungs are failing to exchange oxygen and carbon dioxide adequately, while metabolic acidosis reflects an accumulation of acid or loss of bicarbonate commonly associated with inadequate tissue oxygenation, shock or serious infection. Chest radiography showed a reticulonodular pattern consistent with neonatal pneumonia, suggesting that the infection was not confined to the bloodstream but had already affected the lungs. Laboratory testing also revealed multilineage cytopenias, meaning that more than one major blood-cell population—including red cells, white cells or platelets—was abnormally reduced. Such widespread changes can signal severe systemic inflammation, consumption of blood components or bone-marrow suppression during overwhelming infection. Blood cultures rapidly grew S. pneumoniae, and further testing identified the organism as serotype 3.

Serotyping classifies pneumococci according to the chemical structure of the polysaccharide capsule surrounding each bacterial cell. This capsule is not a passive coating. It can interfere with recognition and engulfment by immune cells, allowing bacteria to persist in the bloodstream and evade parts of the complement system, a network of proteins that marks microbes for destruction. Serotype 3 is notable because it produces a particularly abundant, gel-like capsule. In principle, a thicker capsule can make it more difficult for neutrophils and macrophages to bind to and ingest the bacterium, potentially increasing the amount of time the organism has to multiply or spread. The study does not prove that capsule thickness directly caused the newborn’s severe illness, but the biological mechanism offers a plausible explanation for why a susceptible strain could still behave aggressively. In a neonate, whose antibody-mediated and cellular immune responses are not yet mature, the consequences of that additional barrier may be magnified.

The literature review identified 41 confirmed cases of pneumococcal early-onset sepsis reported over the preceding quarter-century. Of the 34 cases in which the infecting strain was successfully serotyped, serotype 3 accounted for nine, or 26.5 percent, making it the most frequently identified serotype in the available data. The researchers compared cases involving serotype 3 with those caused by other pneumococcal serotypes. Mortality was higher in the serotype 3 group—33.3 percent compared with 16 percent among non-serotype 3 infections. However, the difference did not meet conventional statistical significance, with a reported P value of 0.33. That result is important: the pattern is concerning, but the small number of cases means the review cannot establish that serotype 3 independently increases the risk of death. Rare-disease case series are especially vulnerable to chance findings, differences in clinical care and incomplete reporting, so the mortality signal should be treated as a warning for further investigation rather than a definitive risk estimate.

Antibiotic susceptibility added another layer to the findings. Eight of the nine serotype 3 isolates, including the isolate from the new case, remained fully susceptible to penicillin. The patient was successfully treated with targeted intravenous ampicillin, a beta-lactam antibiotic that interferes with bacterial cell-wall construction. Beta-lactams work by binding proteins involved in assembling the peptidoglycan network that gives bacterial cells mechanical strength. When those proteins are blocked, growing pneumococci become unable to maintain their cell walls and rupture. The successful response shows that prompt microbiological diagnosis and appropriate treatment can overcome even a rapidly progressive infection. At the same time, the result challenges the assumption that a severe bacterial presentation necessarily reflects antimicrobial resistance. A pathogen can be easy to kill in laboratory testing but still cause life-threatening disease before treatment takes effect, particularly when it carries virulence traits that promote rapid invasion or immune evasion.

The persistence of serotype 3 is also relevant to vaccination. Pneumococcal conjugate vaccines, or PCVs, link bacterial polysaccharides to a carrier protein so that infants can develop a stronger, more durable immune response than they would against the polysaccharide alone. Serotype 3 is included in commonly used PCV formulations, and widespread vaccination has changed the epidemiology of invasive pneumococcal disease in older children and adults. Yet vaccine inclusion does not mean that every infection has disappeared, especially in newborns who have not completed their own infant immunization series. Protection during the earliest period of life may depend partly on maternal antibodies transferred across the placenta, and the amount and effectiveness of that protection can vary. The researchers therefore argue for continued surveillance, including laboratory serotyping of neonatal isolates, to determine whether serotype 3 is persisting in particular populations or clinical settings despite vaccine-driven changes elsewhere.

The report has practical implications for neonatal medicine without suggesting that every newborn with breathing difficulty has pneumococcal disease. Because pneumococcal EOS is rare, clinicians must continue to use established sepsis protocols and empiric antibiotics while cultures and susceptibility tests are pending. What the case emphasizes is the need to recognize how quickly the infection can evolve and to avoid equating antibiotic susceptibility with low clinical risk. Blood cultures, bacterial identification and serotyping can help distinguish pneumococcal disease from other causes of neonatal respiratory failure and may clarify whether unusual clusters or changing serotypes are emerging. The authors acknowledge that their evidence comes from a single case combined with a small retrospective literature review, not from a controlled clinical trial. Nevertheless, the combination of abrupt onset, severe pulmonary and systemic involvement, frequent serotype 3 identification and largely preserved penicillin susceptibility points to a phenotype that deserves closer study. Understanding how the pneumococcal capsule interacts with neonatal immunity could ultimately improve risk assessment, vaccine strategies and treatment decisions for one of the rarest—and most dangerous—forms of newborn infection.

Group B Streptococcus, commonly abbreviated GBS or Streptococcus agalactiae, is a bacterium that can colonize the gastrointestinal and genital tracts without causing symptoms in adults. During pregnancy, however, a colonized mother can transmit the organism to her infant before, during or shortly after delivery. Most exposed babies remain healthy, but some develop invasive disease, in which bacteria enter normally sterile sites such as the bloodstream, lungs or central nervous system. In newborns, the consequences can be severe, including sepsis, pneumonia and meningitis. Clinicians generally divide GBS disease into early-onset disease, occurring during the first days of life, and late-onset disease, emerging later in infancy.

That classification is clinically useful, but it can also conceal important biological variation. A baby born prematurely does not enter the world with the same immune maturity, lung development, skin barrier function or microbial environment as a full-term infant. Prematurity may also change the duration and route of exposure to GBS, including whether transmission occurs before birth, during labor or after delivery. The new research focuses on this interaction, asking whether the association between a GBS strain’s genome and the age at which disease appears changes according to gestational age—the number of weeks of pregnancy completed before birth.

The investigators’ approach reflects a broader transformation in infectious-disease research. Instead of treating GBS as a single, uniform pathogen, genomic epidemiology views it as a population of related but genetically diverse bacterial lineages. Whole-genome sequencing can identify differences across bacterial strains, including their capsular types, sequence lineages and genes associated with colonization, immune evasion, toxin production, surface attachment or antimicrobial resistance. These features do not operate in isolation, and the presence of a gene does not automatically prove that it causes more severe disease. Nevertheless, genome-wide data can reveal patterns that are invisible when infections are classified only by symptoms or by the broad label of “GBS.”

The central finding signaled by the study is that gestational age modifies the relationship between genomic characteristics and postnatal age at disease onset. In statistical terms, gestational age functions as an effect modifier: the strength or direction of an association between bacterial genetic features and disease timing is not necessarily the same for preterm and full-term infants. This distinction is important. An effect modifier is not simply another risk factor added to a list; it changes how researchers must interpret the relationship between two variables. A strain characteristic associated with earlier disease in one gestational-age group may show a weaker association, or a different pattern, in another.

This finding offers a possible explanation for why efforts to identify universally “high-risk” GBS strains have often produced an incomplete picture. A bacterial lineage may be particularly successful at causing disease shortly after birth in infants whose immune systems and physiological barriers are still immature, while the same lineage may behave differently in more mature newborns. Conversely, genetic traits that matter during later infant disease could have less influence during the earliest hours of life, when exposure route, delivery circumstances and maternal-to-infant transmission may dominate. The bacterium’s genome remains important, but its effects are filtered through the developmental state of the host.

The study also highlights why gestational age must be integrated into genomic surveillance and clinical research rather than treated as a background demographic detail. Premature infants are already known to face elevated risks of infection because their immune responses are developing and because they often require invasive medical support. If particular GBS genomic profiles are linked to distinct onset patterns within specific gestational-age groups, future surveillance systems may be able to detect more precise warning signals. Such systems could combine maternal colonization data, neonatal symptoms, delivery history and bacterial sequencing to estimate which infants require especially close observation after birth.

The implications extend to prevention, although the research does not by itself create a new diagnostic test or treatment. Current prevention strategies include screening pregnant women for GBS colonization and administering antibiotics during labor when indicated. These measures have helped reduce many cases of early-onset disease, but they do not eliminate all infections, and they offer limited protection against disease that develops later. A clearer understanding of how bacterial genomes interact with fetal maturity could inform the design of vaccines, refine risk models and help researchers determine whether prevention should be tailored to particular bacterial lineages or clinical settings. It could also encourage more careful interpretation of studies that combine preterm and term infants into a single analysis.

For families and clinicians, the work reinforces a practical message: the timing of symptoms is biologically meaningful, but it should never be used to dismiss a newborn’s sudden deterioration. GBS sepsis can progress quickly, and signs such as poor feeding, breathing difficulty, unusual sleepiness, temperature instability or changes in muscle tone require urgent medical assessment. The study does not suggest that parents can identify dangerous strains themselves, nor does it imply that genomic information can replace clinical care. Instead, it shows why the same bacterial species can produce different disease trajectories in different newborns, and why a more personalized understanding of neonatal infection is becoming possible.

The broader lesson is that infectious disease is shaped by a three-way conversation between pathogen, host and time. GBS carries a genome that influences how it survives and spreads, but the newborn provides a changing biological environment, one that differs dramatically between a very premature infant and a baby born at term. By demonstrating that gestational age modifies associations between bacterial genomic characteristics and the postnatal timing of disease, Murra, Henriksen, Andersen and colleagues move the field beyond one-size-fits-all descriptions of neonatal GBS infection. Their work points toward a future in which genomic epidemiology is combined with developmental biology to explain not only who becomes infected, but also why disease emerges when it does.

Subject of Research: The interaction between Group B Streptococcus genomic characteristics, gestational age and the timing of neonatal disease onset.

Article Title: Gestational age modifies associations between Group B Streptococcus genomic characteristics and postnatal age at disease onset.

Article References: Murra, M., Henriksen, T.B., Andersen, M. et al. “Gestational age modifies associations between Group B Streptococcus genomic characteristics and postnatal age at disease onset.” Nature Communications (2026). https://doi.org/10.1038/s41467-026-76999-y

Image Credits: AI Generated

DOI: 10.1038/s41467-026-76999-y

Keywords: Group B Streptococcus, neonatal sepsis, genomic epidemiology, gestational age, preterm infants, early-onset disease, late-onset disease, neonatal infection, whole-genome sequencing, bacterial genomics