Successful bridge to recovery in a patient with fulminant giant cell myocarditis that developed from multiple autoimmune disorders including myasthenia gravis: a case report

BACKGROUND: A recently indicated immunotherapy strategy, combined with mechanical circulatory support (MCS), seems to improve outcomes in patients with fulminant giant cell myocarditis (GCM). However, characterizing a definitive clinical outcome of this strategy remains challenging, and the autoimmunity associated with the onset of GCM remains controversial. CASE SUMMARY: A 26-year-old man with poor control of atopic dermatitis and ulcerative colitis presented with cardiogenic shock requiring MCS. He was diagnosed with fulminant GCM; hence, immunotherapy (including steroids and intravenous immunoglobulin) was administered and an extracorporeal left ventricular assist device (LVAD) was needed. As the patient complained of prominent fatigue and double vision before myocarditis onset, and acetylcholine receptor-binding antibody titres were elevated, he was diagnosed with myasthenia gravis (MG). No anti-striational antibodies known to be associated with GCM in patients with MG were found in the patient’s serum. Cyclosporin-based immunosuppression under LVAD therapy led to an almost complete resolution of his muscle weakness, intermittent ptosis, and cardiac dysfunction along with the histopathological remission of GCM resulting in LVAD removal. He remained at home without recurrence of GCM and worsening symptoms of MG over the 6-month period following discharge. DISCUSSION: We describe a case of GCM with multiple autoimmune disorders, which recovered by treatment with early cyclosporin-based immunosuppressive therapy under LVAD therapy. The present case suggests the involvement of unknown anti-striational antibodies in the development of GCM in patients with MG and may provide information to guide a novel therapeutic regimen for patients with fulminant GCM requiring mechanical circulatory support.