Two fatal cases of anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5) rapidly progressive interstitial lung disease (RP-ILD): Exploring pitfalls and differences.

Introduction: Rapidly progressive interstitial lung disease (RP-ILD) poses a critical challenge in clinical practice, characterized by nonspecific symptoms that rapidly progress to respiratory failure despite intensive management. Anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5), associated with dermatomyositis-related ILD, is a key biomarker in such cases. This report highlights two fatal cases of anti-MDA5-positive RP-ILD, emphasizing diagnostic and management challenges. Case presentation: The first case involved a 56-year-old male without prior autoimmune disease who developed acute respiratory distress syndrome (ARDS) and multiorgan failure. The second case concerned a 49-year-old female with systemic lupus erythematosus (SLE), whose condition similarly culminated in multiorgan failure despite aggressive treatment. Both patients faced delayed diagnoses and suboptimal responses to immunosuppressive therapy, underscoring the complexity of managing RP-ILD. Discussion: Prolonged testing turnaround for MDA5 and reliance on nonspecific clinical indicators remain significant barriers to early diagnosis. Dermatological signs such as Gottron's papules, while indicative of RP-ILD, are associated with poorer prognoses. Current serum biomarkers under investigation lack the sensitivity and specificity of MDA5, complicating early detection efforts. Aggressive immunosuppression in deteriorating patients frequently leads to infectious complications, further compromising outcomes. Conclusion: To address these challenges, early recognition of dermatological indicators, prompt immunosuppressive therapy, and tailored patient management are critical. Additionally, timely referral for extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation may improve survival. Advancing research into serum biomarkers holds promise for enhancing diagnostic precision and therapeutic decision-making in RP-ILD.