Re-treatment of chronic idiopathic thrombocytopenic purpura with rituximab: literature review.

The aim of this literature review was to identify from published reports, the characteristics and response to rituximab of nine patients with chronic idiopathic thrombocytopenic purpura who had been re-treated after responding to an initial course of therapy. The female/male ratio of re-treated patients was eight, suggesting selection or their suitability for treatment because the female/male ratio of 95 initially treated patients in all published reports between December 1998 and June 2003 was 2. Almost three times as many females responded to the first course of rituximab. All second responses, where recorded, were complete despite two previous partial responses and one minor response. The duration of the second response was at least as durable and more so than the first. Of the nine re-treated patients, the two failures had not undergone splenectomy, yet had achieved a complete response to the first course. All four patients who had previously responded to intravenous immunoglobulin responded to both the initial and subsequent course of rituximab. The influence of prior splenectomy, response to intravenous immunoglobulin, and distinctive patterns of time course until platelet response suggest that there might be different mechanisms of response to rituximab.