Clinical bottom line
Patients with autoimmune myocarditis receiving immunosuppressive therapy represent a complex clinical population at heightened risk for infectious complications due to both disease-related immune dysregulation and treatment-induced immunosuppression. Current evidence underscores the need for vigilant infection surveillance, tailored antimicrobial prophylaxis, and careful balancing of immunosuppressive regimens to mitigate infection risk without compromising myocarditis control. Although data remain limited, emerging clinical experience and expert consensus highlight the importance of multidisciplinary management and individualized risk assessment to optimize outcomes.
What the evidence shows
Autoimmune myocarditis, characterized by immune-mediated myocardial inflammation, often requires immunosuppressive therapy including corticosteroids, azathioprine, or other agents to control cardiac inflammation and prevent progression to heart failure (Marcolongo et al., 2020). Immunosuppressive therapy, however, predisposes patients to opportunistic and conventional infections, necessitating careful clinical vigilance.
Marcolongo et al. (2020) provide a comprehensive overview of myocarditis management, emphasizing infection risk monitoring during immunosuppression. They recommend baseline infectious disease screening and ongoing surveillance, particularly for latent infections such as tuberculosis or viral reactivations. Although specific antimicrobial prophylaxis protocols are not standardized, clinical judgment guided by local epidemiology is advised.
Case reports illustrate the potential for severe infectious complications in this population. Chauhan et al. (2026) describe a patient with systemic lupus erythematosus and antiphospholipid syndrome who developed concurrent catastrophic antiphospholipid syndrome, hemophagocytic lymphohistiocytosis, and myocarditis leading to multi-organ failure, highlighting the complex interplay of autoimmunity, immunosuppression, and infection. This underscores the need for heightened infection awareness in autoimmune myocarditis patients receiving immunosuppressants.
Infectious complications in immunosuppressed patients with autoimmune disorders extend beyond myocarditis. Ranches et al. (2018) report on nontuberculous mycobacterial infections in patients receiving immunosuppressive agents, emphasizing that atypical pathogens may cause significant morbidity in this setting. This suggests that clinicians should maintain a broad differential when evaluating infections in autoimmune myocarditis patients.
The EULAR points to consider for immune-related adverse events due to cancer immunotherapy (Kostine et al., 2021) provide relevant insights into managing infections in patients receiving immunomodulatory therapies, including myocarditis induced by checkpoint inhibitors. These guidelines stress early recognition and management of infections alongside immunosuppression adjustments, principles applicable to autoimmune myocarditis management.
Caveats and uncertainty
Robust clinical trial data specifically addressing infection management in autoimmune myocarditis patients on immunosuppressive therapy are lacking. Most evidence derives from case series, expert opinion, and extrapolation from related autoimmune conditions or immunosuppressed populations. The heterogeneity of immunosuppressive regimens and underlying autoimmune diseases complicates generalization.
The optimal antimicrobial prophylaxis strategy remains undefined, with no consensus on indications, agents, or duration. Risk stratification tools specific to this population are not established, limiting individualized infection risk prediction.
Furthermore, distinguishing infectious myocarditis from autoimmune myocarditis is challenging, and misdiagnosis can lead to inappropriate immunosuppression or delayed antimicrobial therapy (Shangguan et al., 2025). This diagnostic uncertainty adds complexity to clinical decision-making.
How this may change practice
Clinicians managing autoimmune myocarditis patients on immunosuppressive therapy should adopt a proactive infection risk mitigation approach. This includes:
- Baseline screening for latent infections (e.g., tuberculosis, hepatitis viruses) prior to immunosuppression initiation.
- Regular clinical and laboratory monitoring for early infection signs.
- Consideration of antimicrobial prophylaxis tailored to individual risk factors and local epidemiology.
- Multidisciplinary collaboration involving cardiology, infectious diseases, and rheumatology specialists.
- Prompt evaluation and management of febrile episodes with a low threshold for microbiological investigations.
- Careful immunosuppressive regimen adjustments balancing myocarditis control and infection risk.
Heightened awareness of atypical and opportunistic infections is warranted, with diagnostic vigilance to avoid misclassification of myocarditis etiology.