Rituximab in recurrent idiopathic giant cell myocarditis after heart transplantation: a potential therapeutic approach

Summary Giant cell myocarditis ( GCM ) is a very aggressive form of myocardial inflammation. While immunosuppressive therapy is usually able to keep under control the disease and prolong the average transplant‐free survival in many patients, effective therapeutic strategies to prevent or treat the recurrence of GCM in transplanted organs are still to be defined. We report the case of a young woman with idiopathic GCM who, despite immediate aggressive immunosuppressive therapy, rapidly progressed to irreversible heart failure and required urgent heart transplantation. Yet, 2 months later, the disease recurred in the transplanted heart, despite an intensive four‐drug antirejection regimen. The introduction of rituximab, an anti‐ CD 20 monoclonal antibody, 375 mg/m 2 /week i.v. for four consecutive weeks and then every 4 months as maintenance therapy, determined a complete and steady clinical remission of the disease. After nineteen months since rituximab administration, the patient is doing well and repeated follow‐up endo‐myocardial biopsies confirmed the complete resolution of myocardial inflammation. Our experience seems to suggest that rituximab can be a reasonably effective and safe therapeutic option in GCM recurring in transplanted organs.