Induction of thyroid remission using rituximab in a patient with type 3 autoimmune polyglandular syndrome including Graves’ disease and type 1 diabetes mellitus: A case report

Rituximab (RTX) is a monoclonal antibody that targets the B-cell-specific CD20 antigen. Recent reports indicate that RTX is effective against type 1 diabetes mellitus (T1DM) and hematologic as well as autoimmune diseases. Other studies have indicated that RTX therapy leads to the remission of recurrent or active Graves’ disease (GD). However, the efficacy of RTX in Japanese patients with autoimmune polyglandular syndrome (APS) has not been reported to date. Herein, we report the case of a patient with GD and T1DM with sustained endogenous insulin secretion capacity. To protect pancreatic β cells, we administered RTX at a dose of 500 mg (approximately 300 mg/m2) on 2 occasions 1 week apart. After treatment, no adverse effects were observed, and thyroid stimulating hormone receptor antibody (TRAb) was no longer detectable 4 months after RTX administration. In addition, the reduction in TRAb level improved thyroid function. Notably, the treatment induced remission over a period of 1 year after the diagnosis of GD.