Successful Treatment With Rituximab for Severe Immune Thrombocytopenic Purpura During Hemodialysis

Immune thrombocytopenic purpura (ITP), an autoimmune disorder characterized by peripheral platelet destruction, is uncommon in patients undergoing hemodialysis, who have an inherently elevated bleeding risk. We report a case of severe ITP in a 68-year-old woman on maintenance hemodialysis for 10 years due to myeloperoxidase-anti-neutrophil cytoplasmic antibody (MPO-ANCA)-associated glomerulonephritis, treated with rituximab. Three years before admission, she was diagnosed with rheumatoid arthritis (RA) and had unexplained thrombocytopenia that improved with prednisolone, resolving her arthritis. The disease activity of both MPO-ANCA-associated vasculitis and RA was later controlled without prednisolone. Four months prior, her platelet count suddenly dropped to 54,000/μL. Laboratory tests showed elevated platelet-associated IgG (PA-IgG), increased bone marrow megakaryocytes, negative antinuclear antibody, MPO-ANCA, anti-Helicobacter pylori antibody, and no splenomegaly, leading to a diagnosis of ITP. The absence of a temporal relationship with heparin exposure, the extremely low platelet count (