[Rituximab as effective therapy in very severe thrombotic thrombocytopenic purpura (TTP)]

A 26-year-old woman was admitted from another hospital because of an increased serum creatinine (170 micromol/l). She was found to have a thrombocytopenia (14Gpt/l, WHO grade IV) with anaemia and a raised lactate dehydrogenase (25.45 micromol/l). The patient was in a reduced general state when admitted to this hospital. Her mucosal membranes were pale and she had moderate scleral icterus. During the first few hours she became clearly less alert but without motor or sensory deficits.

Laboratory tests showed an increased total bilirubin (73 micromol, decreased haptoglobin (< 0.08 g/l), free hemoglobin was raised (20.7 micromol/l) and the blood smear showed 5.5% fragmentocytes. Direct and indirect Coombs tests were negative.

Thrombotic thrombocytic purpura (TTP) was diagnosed. Daily plasmapheresis with fresh plasma replacement and administration of corticosteroids was initiated. ADAMTS13 activity (reported later) was < 2 % and antibodies against this protease were demonstrated. After initial improvement a motor and sensory aphasia occurred. Because of progressive thrombocytopenia, immunosuppression with a total of four doses of 375 mg/m(2)/bsa rituximab was undertaken (640 mg each), every seven days. Over the next two to three weeks the platelet count very slowly rose. The plasmapheresis was ended after a total of 65 sessions. Nine months after the last plasmapheresis the platelet count and renal functions were normal.

Severe autoantibody TTP can be successfully treated by administering rituximanb, an anti-CD20 antibody, in addition to the standard treatment with plasmapheresis.