Sustained remission of platelet counts following monoclonal anti-CD20 antibody therapy in two cases of idiopathic autoimmune thrombocytopenia and neutropenia.

Idiopathic autoimmune thrombocytopenia and neutropenia (ITN) is a primary haemocytopenic disorder clinically characterised by recurrent mucocutaneous bleeding episodes and infections. Unlike in simple idiopathic thrombocytopenic purpura, the platelet deficiency of ITN tends to be chronic and difficult to treat. We describe two patients with ITN who obtained sustained remission of their platelet counts after therapy with the chimeric monoclonal anti-CD20 antibody Rituximab. In one of two cases, Rituximab also induced prolonged normalisation of the neutrophil count and disappearance of auto-antibodies. Our observations indicate that disturbed B-cell function plays a central role in the pathogenesis of ITN. Anti-CD20 antibody therapy seems to constitute a safe and efficient alternative to corticosteroids for the management of ITN patients with chronic thrombocytopenia.