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 (<10,000/µL), and the preceding clinical course suggested that heparin-induced thrombocytopenia was unlikely. One month prior, the platelet count declined further to 3,000/μL; prednisolone (25 mg/day) was started without improvement. On admission, she had subcutaneous bleeding and an elevated immature platelet fraction. Eltrombopag was added but was ineffective. Rituximab (520 mg/body) was administered weekly for four weeks from day 9 after admission. By day 35, platelets improved to 175,000/μL with decreased immature platelet fraction and PA-IgG. Her condition stabilized, and prednisolone was tapered to 6 mg/day within four months post-discharge. Rituximab is a safe and effective treatment for severe ITP, even in hemodialysis patients, and is helpful for steadily tapering steroid therapy. According to a literature review of four ITP cases on dialysis, including our case, rituximab-based therapy is a reason.