Autoimmune-associated hemophagocytic syndrome complicated by anti-MDA5 antibody-positive dermatomyositis successfully treated with immunosuppressive therapy: A case report.

RATIONALE

Anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody-positive dermatomyositis is frequently complicated by rapidly progressive interstitial lung disease and may present with life-threatening hemophagocytic syndrome, a critical but often under-recognized complication. Prompt diagnosis and intervention are essential to improve patient outcomes.

PATIENT CONCERNS

A 38-year-old Japanese woman presented with fever, arthralgia, erythema, and elevated liver enzymes. Physical examination revealed chilblain-like erythema, Gottron and reverse Gottron signs, and tenderness in the thighs.

DIAGNOSES

Blood tests revealed pancytopenia and elevated soluble interleukin-2 receptor and ferritin levels. Bone marrow aspiration showed macrophage activation and hemophagocytosis. Imaging revealed ground-glass opacities in both lower lung lobes and bilateral thigh myositis. The presence of anti-MDA5 antibodies led to the diagnosis of anti-MDA5-positive dermatomyositis complicated by autoimmune-related hemophagocytic syndrome. Liver biopsy suggested cytokine storm-mediated hepatocyte damage and macrophage infiltration.

INTERVENTIONS

The patient received steroid pulse therapy, tacrolimus, and intravenous cyclophosphamide.

OUTCOMES

Pancytopenia and liver dysfunction improved significantly following treatment. The patient was transitioned to outpatient care. After 4 years of follow-up, during which she received 6 courses of cyclophosphamide, steroids, and tacrolimus were successfully tapered off, and she remained in remission without recurrence.

LESSONS

This case underscores the importance of early recognition of hemophagocytic syndrome in patients with anti-MDA5-positive dermatomyositis. Prompt bone marrow evaluation and aggressive immunosuppressive therapy may lead to favorable long-term outcomes. Further studies are warranted to establish standardized treatment strategies for autoimmune-related hemophagocytic syndrome.