The research team, led by Saikat Mandal and Guruprasad Aithal of the Nottingham Digestive Diseases Centre at the University of Nottingham, together with colleagues at Hull, Sheffield, Belfast and Imperial College London, mined the US Food and Drug Administration’s Adverse Event Reporting System, known as FAERS, covering the period from the third quarter of 2016 through the first quarter of 2026. Out of 4,700,843 total reports, 19,820 identified a CAR T-cell product as the primary suspect drug, and 734 of those contained at least one hepatic adverse event. To capture liver injury comprehensively, the investigators built a prespecified dictionary of 244 MedDRA-coded terms spanning everything from mild transaminase elevations to frank hepatic failure.

The timing of the reported liver events proved strikingly consistent. The median onset was just five days after infusion, and 73.5 percent of all hepatic reports occurred within the first two weeks. That early window is precisely when cytokine release syndrome, the systemic inflammatory cascade triggered by activated T cells, reaches its peak intensity. When the researchers examined the text of the hepatic reports, they found that CRS was co-mentioned in 77.0 percent of them, whereas terms from the haemophagocytic lymphohistiocytosis spectrum, including the related immune effector cell-associated haemophagocytic syndrome, appeared in only 9.5 percent. This imbalance immediately suggested that the inflammatory storm, rather than a rarer hyperinflammatory syndrome, might be the dominant driver of liver-related signals.

To test that hypothesis formally, the team deployed a battery of classic pharmacovigilance statistics: the reporting odds ratio, the proportional reporting ratio, the information component from a Bayesian confidence propagation neural network, and the empirical Bayes geometric mean. Each metric compares how often a given event is reported with a suspect drug against how often it appears with all other drugs, and requiring agreement across multiple methods helps filter out statistical noise. In the pooled analysis, hepatic events showed a modest but detectable association with CAR T-cell products, with a reporting odds ratio of 1.36. The crucial experiment came next: when the researchers excluded every report that also mentioned cytokine release syndrome, the pooled signal collapsed to 0.54, effectively falling below the threshold expected by chance. Excluding HLH-spectrum reports, by contrast, left the association intact.

That asymmetry is the analytical heart of the study. If liver injury were an independent manifestation of CAR T-cell toxicity, stripping out CRS reports should have left the signal largely undiminished. Instead, the signal vanished, implying that the liver abnormalities captured in spontaneous reporting databases are, in the great majority of cases, a downstream feature of the cytokine storm rather than a separate immune-mediated process. This distinction matters clinically, because the two scenarios demand different responses. CRS is typically managed with the interleukin-6 receptor antibody tocilizumab and supportive care, whereas suspected immune-mediated drug-induced liver injury or HLH may require corticosteroids, etoposide, or other immunosuppressive strategies, and misattributing the cause can delay appropriate treatment.

The product-level analysis added a provocative wrinkle. Among the individual CAR T-cell constructs, idecabtagene vicleucel, the anti-BCMA therapy approved for multiple myeloma, showed the most consistent hepatic reporting pattern across all four statistical methods. More importantly, it retained a supportive signal even after the researchers excluded reports co-mentioning CRS, with a reporting odds ratio of 2.22 and a 95 percent confidence interval of 1.38 to 3.57. In other words, a residue of liver-injury reporting persisted that could not be explained away by the cytokine storm alone. No other product showed comparable persistence, and no product retained four-method positivity beyond the 14-day mark, reinforcing the overall picture of early, CRS-linked injury with one notable exception.

Phenotype analysis deepened the product-specific picture. By clustering the individual MedDRA terms within hepatic reports, the researchers identified mixed hepatocellular and cholestatic reporting patterns that differed across products, a pattern reminiscent of how classical drug-induced liver injury presents in distinct biochemical signatures. Cholestatic patterns, in which bile flow is impaired and alkaline phosphatase rises disproportionately, can point toward different mechanistic pathways than pure hepatocellular injury. The authors suggest these residual, CRS-independent patterns, particularly for idecabtagene vicleucel, warrant prospective clinical evaluation with protocolized liver biochemistry monitoring, rather than reliance on the fragmented and potentially biased data of spontaneous reporting.

Spontaneous reporting databases are powerful but imperfect instruments. FAERS aggregates millions of reports, yet it suffers from underreporting, reporting bias, duplicate submissions, and the well-known Weber effect, in which adverse events are reported more frequently in the period immediately after a drug’s approval. The researchers addressed these vulnerabilities with several safeguards: they deduplicated reports, restricted the analysis to records naming a CAR T-cell product as the primary suspect, and performed sensitivity analyses examining delayed-onset events and specific hepatic phenotypes. They also sought directional confirmation in a second database, Canada Vigilance, where the proportion of hepatic reports co-mentioning CRS was similar at 75.0 percent. However, only four hepatic adverse-event reports existed in the Canadian data, far too few for meaningful product-level comparison, underscoring how sparse real-world evidence remains for some of these newer toxicities.

The study’s framing of the differential diagnosis is one of its most useful contributions to practicing clinicians. Liver dysfunction after CAR T-cell infusion can arise from at least three distinct mechanisms: the inflammatory milieu of cytokine release syndrome, the hyperinflammatory HLH-like syndrome that shares laboratory features with familial hemophagocytic lymphohistiocytosis, and a conventional immune-mediated drug-induced liver injury resembling idiosyncratic hepatotoxicity from small-molecule drugs. Each mechanism has a different temporal signature, a different biomarker profile, and a different treatment algorithm. By quantifying how frequently each appears in real-world reporting, the Nottingham-led team has given clinicians an evidence-based prior for interpreting liver enzyme abnormalities in the days and weeks following infusion.

The authors are careful to emphasize the limits of their findings. Pharmacovigilance signals identify statistical associations, not causation, and the absence of denominator data means incidence rates cannot be calculated from FAERS or Canada Vigilance. The persistent idecabtagene vicleucel signal, while intriguing, is based on a modest number of reports and requires confirmation in prospective cohorts with systematic liver monitoring. Still, the study arrives at a moment when CAR T-cell therapy is expanding rapidly beyond academic centers and into community oncology, meaning more clinicians than ever will confront unexplained liver enzyme elevations in treated patients. For most, the message is reassuring: hepatic events are predominantly early, temporally tied to the cytokine storm, and likely to resolve as the inflammatory phase subsides. For a subset of patients, particularly those receiving BCMA-directed therapy, the possibility of a CRS-independent liver injury remains open, and the authors argue that only carefully designed prospective studies can close it. The work was supported by the NIHR Nottingham Biomedical Research Centre and UK Research and Innovation, and the underlying data are publicly accessible, allowing other groups to interrogate and extend the analysis as the CAR T-cell treated population continues to grow.

Subject of Research: Hepatic adverse-event reporting patterns following CAR T-cell therapy analyzed through pharmacovigilance databases

Article Title: Hepatic adverse-event reporting after CAR T-cell therapy: a pharmacovigilance analysis of FAERS and Canada Vigilance

Article References: Mandal, S., Maji, M., Dhali, A., & Aithal, G. (2026). Hepatic adverse-event reporting after CAR T-cell therapy: a pharmacovigilance analysis of FAERS and Canada Vigilance. Annals of Hematology. https://doi.org/10.1007/s00277-026-07318-0

Image Credits: AI Generated

DOI: 10.1007/s00277-026-07318-0

Keywords: CAR T-cell therapy, hepatic adverse events, cytokine release syndrome, haemophagocytic lymphohistiocytosis, pharmacovigilance, FAERS, Canada Vigilance, drug-induced liver injury, idecabtagene vicleucel, immunotherapy toxicity, liver injury, hematology

The study collected clinical reports of nivolumab-induced cytokine release syndrome published before March 31, 2026, extracting clinical data for retrospective analysis. Thirty-five patients were included, spanning an extraordinarily wide age range from 3 to 86 years, with a median age of 55. That breadth alone carries a message for oncologists: the complication is not confined to any single tumor type, age group or treatment setting. It can emerge in children with refractory Hodgkin lymphoma and in elderly patients with solid tumors alike, wherever nivolumab is deployed to release the brakes on T-cell immunity.

Perhaps the most clinically consequential finding concerns timing. The median time from the start of nivolumab to the appearance of cytokine release syndrome was 54.5 days, with cases reported as early as 0.2 days and as late as 391 days after initiation. The median number of infusion cycles before onset was three, but the range stretched from one to seventeen. This late and highly variable onset distinguishes checkpoint inhibitor-associated cytokine release syndrome from the fulminant, early-onset syndrome seen after CAR T-cell infusion, where fever and hypotension typically erupt within days of cell transfer. A patient who develops fever and falling blood pressure months into nivolumab therapy may not immediately suggest a cytokine storm to the treating team, and the authors argue that the possibility of CRS should be explicitly considered throughout the entire course of administration, not just in the first weeks.

The clinical signature the researchers documented is dominated by fever, which affected 85.7 percent of patients. Hypotension followed in 57.1 percent, tachycardia in 42.9 percent, and fatigue, rash and impaired consciousness each appeared in 25.7 percent of cases. This constellation mirrors the physiology of uncontrolled immune activation: activated T cells and macrophages flood the circulation with inflammatory mediators, producing capillary leak, vasodilation and hemodynamic instability. Neurological involvement in the form of impaired consciousness underscores that the brain is not spared when cytokine levels climb, a feature also recognized in severe CAR T-cell-associated toxicity. In practical terms, a patient on nivolumab who presents with unexplained fever plus hypotension or altered mental status should raise immediate suspicion of CRS, even if the last infusion was months earlier.

Laboratory findings reinforce the inflammatory diagnosis. The reviewed cases commonly revealed liver injury, renal injury, elevated C-reactive protein, elevated ferritin and elevated interleukin-6. Each of these markers has a mechanistic rationale. Interleukin-6 is a central driver of the syndrome, amplifying the inflammatory cascade and contributing to vascular permeability. Ferritin, an acute-phase reactant produced abundantly by activated macrophages, has been proposed in prior literature as a diagnostic and prognostic marker for immune-related adverse events. C-reactive protein rises rapidly under interleukin-6 stimulation and serves as a readily available readout of systemic inflammation. Hepatic and renal abnormalities reflect both direct inflammatory organ injury and the hemodynamic consequences of vasodilatory shock, in which reduced perfusion compounds cytokine-mediated tissue damage.

Treatment in the collected cases followed two main pillars: discontinuation of nivolumab and immunosuppressive or immunomodulatory therapy directed at the cytokine cascade itself. Glucocorticoids and tocilizumab, a monoclonal antibody that blocks the interleukin-6 receptor, were widely utilized as the primary therapeutic approaches. After these interventions, 71.4 percent of patients showed improvement in symptoms and clinical markers. The remaining 28.6 percent died. That mortality figure, drawn from published case reports that may overrepresent severe presentations, nevertheless signals that nivolumab-induced cytokine release syndrome can lead to multi-organ functional impairment and can be fatal. The authors emphasize that the syndrome is not a benign infusion reaction but a potentially life-threatening emergency requiring prompt recognition.

The choice of tocilizumab as first-line therapy reflects experience imported from the CAR T-cell field, where interleukin-6 receptor blockade has become standard for severe cytokine release syndrome and is embedded in consensus grading systems such as the ASTCT criteria and in clinical practice guidelines from the Society for Immunotherapy of Cancer and the American Society of Clinical Oncology. Glucocorticoids, which broadly suppress T-cell and macrophage activation, are typically layered on when tocilizumab alone is insufficient or when neurological symptoms are present. For refractory cases, the broader literature on immune effector cell toxicities describes additional salvage options, including plasma exchange, but the evidence base for such measures in checkpoint inhibitor-associated CRS remains thin and largely anecdotal.

Herein lies the central limitation the authors acknowledge: the standardized and optimal treatment strategy for nivolumab-induced cytokine release syndrome remains undefined. Because the analysis is retrospective and built from individually published case reports, it is vulnerable to reporting bias, inconsistent grading and inherent clinical confounders. Patients described in case reports are often the sickest, which may inflate the apparent mortality, and concomitant medications, infections, combination immunotherapy regimens and underlying malignancies can all mimic or exacerbate the syndrome. The researchers also note that the available evidence base is limited, meaning that while glucocorticoids and tocilizumab are the de facto standards in clinical practice, no prospective trial has defined the ideal timing, dosing or sequencing of these agents specifically for nivolumab-triggered CRS.

The mechanistic puzzle is also unresolved. Nivolumab blocks programmed death-1, a checkpoint receptor that restrains T-cell activity, and cytokine release syndrome after checkpoint blockade is thought to arise when reinvigorated T cells expand and secrete interferon and other mediators that activate macrophages and endothelial cells. Why only a small fraction of the many thousands of patients treated with nivolumab develop this syndrome is unknown, though prior pharmacovigilance analyses of WHO data and case series of checkpoint inhibitor-associated CRS suggest the event is rare and may be more frequent with combination regimens such as ipilimumab plus nivolumab. Host genetic factors influencing interleukin-6 biology, tumor burden, and individual immune repertoire dynamics are plausible contributors that current data cannot disentangle.

For clinicians, the practical takeaways are concrete. Fever developing during nivolumab therapy, particularly when accompanied by hypotension, tachycardia, rash or confusion, should prompt evaluation for cytokine release syndrome rather than automatic attribution to infection or tumor progression. Measurement of C-reactive protein, ferritin and interleukin-6 can support the diagnosis, and early involvement of intensive care may be warranted given the risk of hemodynamic collapse and multi-organ failure. For researchers, the study defines the agenda: prospective registries, standardized grading using consensus CRS criteria, and controlled evaluation of tocilizumab and corticosteroid protocols are needed to move management from case-report empiricism to evidence-based practice. Until then, vigilance remains the most powerful tool, because the window in which glucocorticoids and interleukin-6 blockade can reverse the inflammatory cascade is likely narrow, and the price of missing it, in roughly one of the patients captured in this analysis, was fatal.

Subject of Research: Cytokine release syndrome induced by the immune checkpoint inhibitor nivolumab

Article Title: Clinical characteristics, treatment and prognosis of nivolumab induced cytokine release syndrome

Article References: Zhao, S., Sun, W., Peng, L., & Wang, C. (2026). Clinical characteristics, treatment and prognosis of nivolumab induced cytokine release syndrome. Supportive Care in Cancer, 34(10), Article 1039. https://doi.org/10.1007/s00520-026-11303-8

Image Credits: AI Generated

DOI: 10.1007/s00520-026-11303-8

Keywords: nivolumab, cytokine release syndrome, immune checkpoint inhibitors, tocilizumab, glucocorticoids, interleukin-6, immune-related adverse events, ferritin, hypotension, immunotherapy toxicity, PD-1 inhibitor, retrospective analysis

The biology of CRS begins the moment engineered T cells recognize their target. CAR T cells are autologous lymphocytes genetically modified to express synthetic receptors that bind tumor-associated antigens such as CD19 or BCMA. Upon antigen engagement, the cells unleash perforin and granzyme to kill malignant cells while simultaneously secreting a cocktail of pro-inflammatory signaling proteins, including interferon-gamma, tumor necrosis factor alpha, GM-CSF, and interleukin-2. These signals then recruit and activate innate immune players, chiefly monocytes and macrophages, which respond by pouring out interleukin-6 and interleukin-1 beta. This amplification loop between adaptive and innate immunity is what transforms a targeted attack into a systemic cytokine storm. Vascular endothelial cells become activated, blood vessels leak, and patients develop the classic clinical picture: fever, fatigue, hypotension, hypoxia, and in the worst cases multi-organ dysfunction. In severe instances, the syndrome can escalate into an immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome and contribute to disruption of the blood-brain barrier, setting the stage for neurological complications.

How sick a patient becomes is not a matter of chance. Tumor burden at baseline, the specific CAR construct used, and the magnitude of T-cell expansion all shape the intensity of the inflammatory response. The intracellular costimulatory domain built into the receptor plays a particularly important role: constructs carrying the CD28 domain drive rapid T-cell expansion and are associated with a higher incidence of acute, severe adverse events, whereas 4-1BB-based constructs expand more slowly and persistently, producing a more gradual and generally less toxic immune response. Higher CAR T-cell doses enhance antitumor efficacy but also raise the risk of massive simultaneous T-cell activation. Patient factors matter as well. Elevated pre-infusion inflammatory markers such as interleukin-6 and C-reactive protein, advanced age, cardiovascular or renal comorbidities, certain lymphoma subtypes including primary mediastinal B-cell lymphoma, and pediatric or young adult patients treated for acute lymphoblastic leukemia all signal elevated risk. Bridging therapy to shrink the tumor before infusion is one practical strategy to lower the odds of explosive cytokine release.

Accurate grading is the backbone of treatment decisions. The consensus system from the American Society for Transplantation and Cellular Therapy classifies CRS into four grades based on fever, hypotension, hypoxia, and organ toxicity, deliberately moving beyond fever alone to incorporate the need for vasopressors and supplemental oxygen. Grade 1 disease, essentially fever by itself, is usually managed conservatively with antipyretics and observation. Grade 2, marked by hypotension or mild hypoxia, requires hospital monitoring and often pharmacologic intervention. Grade 3 and 4 cases, involving refractory low blood pressure, multisystem injury, shock, or respiratory failure, demand escalation to corticosteroids, vasopressors, and intensive care, with mechanical ventilation reserved for the critically ill. Because the boundary between CRS and sepsis can be blurred, clinicians must constantly weigh early immunosuppression against the danger of masking an underlying infection, a balancing act that defines much of the day-to-day management of these patients.

At the center of the pharmacologic arsenal sits tocilizumab, a monoclonal antibody that blocks the interleukin-6 receptor and remains the only drug approved by the FDA specifically for CRS. By interrupting the interleukin-6 signaling axis, it rapidly reverses fever, hypotension, and capillary leak without impairing the antitumor activity of the CAR T cells, and in most patients one or two doses suffice to control grade 2 or higher disease. Its speed has made it the emergency drug of choice, stocked in treatment centers with STAT ordering protocols. But tocilizumab is not without caveats. Blocking the receptor can cause circulating interleukin-6 levels to rebound, and there is concern that unbound cytokine may then cross the blood-brain barrier, potentially triggering or worsening immune effector cell-associated neurotoxicity syndrome, known as ICANS. This interplay between the two syndromes complicates therapy, since ICANS typically emerges days after CRS onset and, unlike CRS, does not respond to tocilizumab because the antibody penetrates the central nervous system poorly.

For patients who fail interleukin-6 blockade or who develop neurological symptoms, corticosteroids such as dexamethasone and methylprednisolone serve as the crucial second line. Historical worries that steroids might blunt CAR T-cell proliferation have been tempered by more recent evidence showing that early administration at moderate doses and limited duration does not significantly compromise antitumor efficacy. Typical regimens involve intravenous dexamethasone at 10 milligrams every six hours or methylprednisolone at 1 to 2 milligrams per kilogram per day, tapered over three to five days according to clinical response. Beyond steroids, a growing set of targeted agents is expanding the toolkit. Anakinra, an interleukin-1 receptor antagonist, crosses the blood-brain barrier readily and is increasingly valued for tocilizumab-refractory CRS and concurrent neurotoxicity. Lenzilumab, targeting GM-CSF, and emapalumab, targeting interferon-gamma, are under clinical evaluation for severe or steroid-refractory disease. In a striking example of drug repurposing, the beta-blocker metoprolol has been shown in laboratory and clinical studies to directly inhibit interleukin-6 translation in human monocytes, reducing CRS severity without harming CAR T-cell function and opening a novel therapeutic target: the protein synthesis machinery of inflammatory cells.

Monitoring is where modern CRS care increasingly meets data science. Routine protocols call for daily ferritin, C-reactive protein, and cytokine panels during the first ten days after infusion, or longer in high-risk patients, because rising interleukin-6, ferritin, and CRP levels precede clinical symptoms and correlate with severity. Soluble interleukin-2 receptor and coagulation markers flag the hemophagocytic syndrome variant and coagulopathy. Artificial intelligence is now pushing surveillance further. A model called PrCRS, built on U-Net and Transformer architectures with transfer learning, can predict severe CRS one to three days before symptom onset. Other multimodal machine learning systems analyze vital signs, laboratory results, and early cytokine profiles to identify high-risk patients within hours of infusion, and an explainable algorithm proposed by Bogatu and colleagues incorporates domain literature to detect CRS from cytokine peak levels despite limited training data. Real-time dashboards linked to electronic health records are already being piloted at academic centers, alerting care teams and enabling preemptive tocilizumab or steroid administration based on algorithmic triggers.

None of these tools work in isolation, and the review emphasizes that the hallmark of contemporary CRS management is multidisciplinary coordination. Optimal outcomes emerge when hematologists, oncologists, intensivists, neurologists, infectious disease specialists, pharmacists, and specialized nurses operate under unified protocols with rapid triage pathways and seamless escalation from ward to intensive care. Many centers have established cellular therapy toxicity boards, early warning systems, and dedicated CAR T-cell response teams equipped with predesigned protocols, immediate drug access, and intensive care beds on standby. Standardized operating procedures embed CRS and ICANS flowcharts directly into electronic medical records, while simulation training for nurses and residents sharpens recognition of early warning signs. Age also shapes strategy: pediatric patients generally tolerate higher cytokine loads, so clinicians lean on supportive care and reserve steroids for refractory cases, whereas elderly patients, vulnerable to cardiovascular and renal decompensation, warrant a lower threshold for early intervention, cardiac monitoring, and bridging therapy to reduce disease burden before infusion.

Looking ahead, the field is moving from reactive treatment to engineered prevention. Ruxolitinib, a Janus kinase 1/2 inhibitor, dampens downstream signaling from multiple cytokines and may help when interleukin-6 blockade alone is insufficient. Siltuximab, which binds interleukin-6 directly rather than its receptor, offers an alternative where receptor blockade falls short. More radically, next-generation CAR constructs are being designed with safety built in: bispecific and split-signaling receptors that require dual-antigen recognition to activate, ON/OFF-switch systems controlled by administered small molecules, suicide genes such as inducible caspase 9, and so-called armored CARs that co-express anti-cytokine payloads like interleukin-1 receptor antagonists to neutralize inflammation at its source. Researchers are also probing the upstream triggers of CRS, implicating inflammasome activation, pyroptotic cell death, and tissue-resident macrophages, and pursuing multi-omics biomarker discovery to shift management from reactive to proactive. Together, these advances promise to widen the therapeutic window of CAR T-cell therapy, allowing its remarkable curative potential to reach broader and more fragile patient populations safely.

Subject of Research: Management of cytokine release syndrome following CAR T-cell therapy

Article Title: Management of Cytokine Release Syndrome (CRS) following CAR T-cell therapy: a comprehensive review

Article References: Zhang, Y., & Han, W. (2025). Management of Cytokine Release Syndrome (CRS) following CAR T-cell therapy: a comprehensive review. Clinical Cancer Bulletin, 4(1), Article 15. https://doi.org/10.1007/s44272-025-00044-0

Image Credits: AI Generated

DOI: 10.1007/s44272-025-00044-0

Keywords: CAR T-cell therapy, cytokine release syndrome, tocilizumab, ICANS, immunotherapy toxicity, interleukin-6, corticosteroids, anakinra, biomarkers, artificial intelligence prediction, risk stratification, hematological malignancies

The numbers behind the warning are sobering. The overall incidence of checkpoint inhibitor-associated myocarditis ranges from 0.3 percent to 2.2 percent, with severe disease, graded 3 or higher on the Common Terminology Criteria for Adverse Events version 5.0, accounting for 0.15 percent to 0.69 percent of treated patients. Mortality remains stubbornly high at 37 to 50 percent, and combination immunotherapy is more dangerous than monotherapy, with reported death rates of 66 percent versus 44 percent. A Chinese cohort of 55,219 patients with advanced non-small cell lung cancer found an annual incidence of 0.51 percent for PD-1 inhibitor-associated myocarditis, or 5.1 cases per 1,000 person-years, underscoring that the threat scales with the enormous and growing global use of these drugs.

Combination regimens are a central theme of the new guidance. A French nationwide database analysis showed that the six-month cumulative incidence of myocarditis reached 1.6 percent for PD-1 plus CTLA-4 inhibitor combinations, compared with 0.2 to 0.4 percent for monotherapy. In a large retrospective cohort of 53,018 patients, combination therapy carried a hazard ratio of 2.92 for myocarditis relative to monotherapy. Pharmacovigilance data drawn from 171,132 case reports in the United States Food and Drug Administration safety database identified 1,326 myocarditis cases across nine checkpoint inhibitors, with a reporting odds ratio of 30.1 overall, and the signal for PD-L1 plus CTLA-4 combination therapy was more than double that of PD-L1 monotherapy. The 2026 recommendations also extend their scope to newer agents, including the PD-1/CTLA-4 bispecific antibodies cadonilimab and iparomlimab/tuvonralimab, the PD-1/VEGF bispecific antibody ivonescimab, and other novel constructs now approved in China, reflecting emerging evidence on cardiac injury linked to bispecific antibodies.

Among the most striking updates is the formal incorporation of thymic imaging into risk stratification. Patients with thymic epithelial tumors, particularly thymoma, face dramatically elevated risk: one analysis found an odds ratio of 32 for myocarditis in thymoma patients, while a meta-analysis showed myocarditis rates of 29 percent in thymoma versus 2 percent in thymic carcinoma. These patients also develop myocarditis earlier, with a median time to onset of 21 days compared with 41 days for other cancers, and suffer more life-threatening arrhythmias, more concomitant myositis and myasthenia gravis-like syndromes, and higher 30-day mortality. A multicenter study established a thymic grading system based on chest computed tomography, finding that a pretreatment thymic grade of 3 or higher, indicating a solid component above 50 percent, was far more common in patients who went on to develop myocarditis, with an odds ratio of 25. Acetylcholine receptor antibody positivity, a marker of thymus-associated autoimmunity, was also significantly more frequent in affected patients and predicted early cardiotoxic events.

The recommendations therefore advise that before starting checkpoint inhibitors, all patients undergo baseline evaluation including family and personal history, biomarkers of myocardial injury, electrocardiography and echocardiography. For patients with a history of thymic tumors or suspected thymic abnormalities, chest CT is recommended to assess thymic size, morphology and density, along with acetylcholine receptor antibody testing when autoimmune thymic disease is suspected. Those with residual thymic tissue, abnormal ovoid thymic morphology or abnormal mediastinal fat attenuation should be evaluated by a multidisciplinary cardio-oncology team to weigh the benefit-risk ratio and design individualized monitoring. Coexisting autoimmune disease is not an absolute contraindication to immunotherapy, but the panel recommends assessing disease activity first, coordinating with rheumatology, and keeping baseline immunosuppression at the lowest effective dose, ideally no more than 10 milligrams per day of prednisone equivalent. Routine prophylactic glucocorticoids to prevent immune-related adverse events are explicitly not recommended, because baseline immunosuppression has been associated with shorter survival and higher relapse of underlying autoimmune disease.

Once therapy begins, the guidance prescribes an intensive early monitoring schedule built around the observation that most myocarditis cases strike within the first three months, with median time to onset of 28 to 65 days across studies. For patients treated every two weeks, symptom assessment, electrocardiography and cardiac troponin testing are recommended before cycles 2 through 9; for three-week schedules, before cycles 2 through 6. Biomarker data show why vigilance matters: in hospitalized patients, cardiac troponin T was elevated in 98 percent, troponin I in 88 percent and creatine kinase in 75 percent, and troponin T proved the most sensitive early marker, remaining elevated for months while other markers normalized faster. Baseline troponin T at twice the upper reference limit carried a hazard ratio of 31.71 for subsequent myocarditis in one prospective cohort. Electrocardiographic changes also carry prognostic weight, with new QRS widening beyond 110 milliseconds associated with a more than threefold increase in major adverse cardiac events.

Diagnosis follows a hierarchical framework anchored either by histopathology or by clinical criteria. Endomyocardial biopsy remains the gold standard, revealing multifocal inflammatory infiltration dominated by CD8-positive T lymphocytes with significant cardiomyocyte loss, but the panel individualizes its use given sampling error and procedural risk. Without biopsy, diagnosis requires elevated troponin, preferably troponin T, plus either one major criterion, cardiac magnetic resonance findings meeting the modified Lake Louise criteria with evidence of myocardial edema on T2 mapping and non-ischemic injury on T1 mapping, or at least two minor criteria such as a compatible clinical syndrome, ventricular arrhythmias or conduction abnormalities, reduced left ventricular function, concurrent immune-related adverse events like myositis or myasthenia gravis, or partially concordant cardiac magnetic resonance findings. The panel cautions that conventional cardiac magnetic resonance has limited early sensitivity: late gadolinium enhancement was detected in only 48 percent of cases overall and just 21.6 percent within four days of admission, so quantitative T1 and T2 mapping and, in selected cases, positron emission tomography with tracers such as 18F-FDG, 68Ga-DOTATOC or 68Ga-FAPI can provide complementary information. Differential diagnosis must exclude infectious myocarditis, acute coronary syndrome, Takotsubo cardiomyopathy, pulmonary embolism and tumor progression, with coronary angiography reserved for ST-elevation patterns.

Treatment hinges on speed and severity stratification. Once myocarditis is confirmed, checkpoint inhibitor therapy is stopped immediately and glucocorticoids started, ideally within 24 hours of symptom onset; a multicenter study of 126 patients showed that steroids begun within 24 hours significantly reduced peak troponin compared with later initiation, and high-dose regimens of 501 to 1,000 milligrams per day of methylprednisolone were associated with a major adverse cardiac event rate of 22 percent versus 54.6 to 61.9 percent with lower doses. Occult subclinical injury warrants observation or modest prednisone dosing, mild disease calls for 1 to 2 milligrams per kilogram per day of methylprednisolone, severe disease requires 500-milligram pulse therapy plus intravenous immunoglobulin at 0.4 grams per kilogram daily, and critical disease demands intensive care, 500 to 1,000 milligram daily pulses, immunoglobulin, immediate second-line immunosuppression and life support including temporary pacing, plasma exchange and mechanical circulatory support. Steroid resistance, defined by failure of troponin to fall by at least half or persistence of conduction block, arrhythmias or ventricular dysfunction after three days, triggers escalation to agents such as abatacept, antithymocyte globulin, mycophenolate mofetil, tacrolimus, the JAK inhibitors tofacitinib and ruxolitinib, or biologics including tocilizumab and alemtuzumab, with infliximab used cautiously given signals of increased cardiovascular death. Notably, a prospective strategy combining high-dose abatacept with ruxolitinib and glucocorticoids cut mortality to 3 percent versus 60 percent with high-dose steroids alone, and randomized trials including ATRIUM and ACHLYS are now testing abatacept as initial therapy.

Recovery does not end the story. The panel recommends weekly monitoring of symptoms, electrocardiography and troponin during steroid tapering over roughly four to six weeks, followed by visits every two to three weeks for three months after discontinuation, since troponin T can remain elevated for months and late cardiac events still occur. Resumption of immunotherapy is reserved for fully resolved, biologically recovered disease, defined as normalized troponin T and complete steroid withdrawal, and is generally limited to patients with occult or mild initial episodes; severe or critical myocarditis mandates permanent discontinuation. When rechallenge is unavoidable and no alternatives exist, the decision should be made jointly by cardiology and oncology, with de-escalation from combination therapy to PD-1 or PD-L1 monotherapy and intensified biomarker surveillance, acknowledging that roughly a third to half of rechallenged patients experience recurrent immune-related adverse events. Looking ahead, the guidelines highlight artificial intelligence-assisted early screening, machine learning risk scores integrating baseline characteristics and treatment regimens, and multimodal imaging analytics as promising tools to catch this elusive, fast-moving complication before it becomes fatal, while emphasizing that multidisciplinary cardio-oncology collaboration remains the backbone of safe immunotherapy.

Subject of Research: Clinical diagnosis and treatment of immune checkpoint inhibitor-associated myocarditis

Article Title: Clinical diagnosis and treatment recommendations for immune checkpoint inhibitor-associated myocarditis (2026 edition)

Article References: Yan, W., Qingqing, C., Yuan, L., Jiahui, C., Hao, L., Jinyi, L., Zhiming, W., Yinman, W., Zhifeng, Y., Shilong, Z., Lingying, M., Ji, Z., Shufu, C., Chi, Z., Rongle, L., Xin, Z., Cong, W., Xianling, Q., Zheng, L., … Junbo, G. (2026). Clinical diagnosis and treatment recommendations for immune checkpoint inhibitor-associated myocarditis (2026 edition). Clinical Cancer Bulletin, 5(1), Article 13. https://doi.org/10.1007/s44272-026-00065-3

Image Credits: AI Generated

DOI: 10.1007/s44272-026-00065-3

Keywords: immune checkpoint inhibitors, myocarditis, cardio-oncology, immunotherapy toxicity, glucocorticoids, abatacept, cardiac troponin, thymoma, cardiac magnetic resonance, bispecific antibodies, immunosuppression, clinical guidelines