Blood and Marrow Stem Cell Transplant Program, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109, USA. vratanat@umich.edu
BACKGROUND: Autoimmune thrombocytopenia in chronic graft-versus-host disease may represent an instance of B-cell dysregulation leading to clinical disease. OBJECTIVE: To attempt to treat refractory immune-mediated thrombocytopenia in a patient with chronic graft-versus-host disease by using anti-CD20 chimeric monoclonal antibody. DESIGN: Case report. SETTING: Academic medical center. PATIENT: A patient with chronic graft-versus-host disease after allogeneic peripheral blood stem-cell transplantation who had severe refractory immune-mediated thrombocytopenia. INTERVENTION: Weekly infusion of rituximab, 375 mg/m2, for 4 weeks. MEASUREMENTS: Platelet count, CD3+ cell count, and CD19+ cell count. RESULTS: Rituximab therapy resulted in marked depletion of B cells in the peripheral blood and decreased levels of platelet-associated antibody. The increase in platelet count persisted despite tapering and discontinuation of immunosuppressive therapy for chronic graft-versus-host disease. CONCLUSION: The efficacy of rituximab for the treatment of immune-mediated thrombocytopenia suggests that this drug may have activity in other autoimmune diseases or chronic graft-versus-host disease.