Chronic refractory idiopathic thrombocytopenic purpura (ITP) and anti-CD20 monoclonal antibody: a case report.

Idiopathic thrombocytopenic purpura (ITP) is an immune-mediated disorder characterized by accelerated and premature destruction of platelets by reticuloendothelial system. CD20, a trans-membrane B-cell-specific antigen, is a potential target for treatment of certain malignant and nonmalignant plasma cell disorders including refractory ITP. Rituximab is a genetically engineered human anti-CD20 monoclonal antibody, which is approved for the treatment of low-grade non-Hodgkin's lymphoma. Recent clinical reports suggest that rituximab may be useful in treating certain patients with chronic refractory ITP. A 59-year-old woman with refractory ITP was placed on rituximab (four weekly doses of 375 mg/m(2)) and her condition and platelet count were observed for 18 months. There was a gradual increase in platelet count and she was symptom free in this period and no side effects of the drug were reported. Anti-CD20 antibodies are likely to be used in the treatment of refractory ITP cases, but further studies about treatment schedule and criteria for patient selection should be done.