Rituximab‐induced acute severe thrombocytopenia

A 73-year-old woman with a past medical history of hypertension was evaluated haematologically because of lymphocytosis found on a routine blood count. Her only complaint was of progressive fatigue for a few months. Physical examination showed pallor, right posterior cervical lymphadenopathy and moderate splenomegaly. A full blood count showed a white cell count of 18AE2 · 10/l with 82% lymphocytes and a normocytic normochromic anaemia with haemoglobin concentration of 100 g/l. A computed tomography scan of the abdomen showed an enlarged spleen (25 cm). Bone marrow biopsy showed mantle cell lymphoma. The patient was treated with a modified Hyper-CVAD-R (cyclophosphamide, vincristine, doxorubicin, dexamethasone, rituximab) regimen. She developed chills without fever or hypotension during the rituximab infusion on day 1 of cycle 1. Her platelet count dropped from a preinfusion level of 85 · 10/l to 14 · 10/l the next day but there were no signs of bleeding. Three days later, her platelet count had increased to 118 · 10/l. She did not require platelet transfusion and was discharged home in good condition. She developed acute severe thrombocytopenia following each dose of rituximab during subsequent cycles of chemotherapy (Figure). The thrombocytopenia improved spontaneously over 2–3 d on each occasion.