A case of malignant lymphoma producing autoantibody against platelet glycoprotein Ib.

A 61-year-old woman was referred to our hospital for refractory thrombocytopenia (3 x 10(3)/microliter) and massive melena. Bone marrow aspiration revealed normal cellularity and increased megakaryocytes (250/microliter). An abdominal computerized axial tomography scan showed isodensity masses on both adrenal glands. 67 Ga-scintigraphy exhibited strong uptake into the bilateral adrenal tumor and mediastinal region. IgM-type antibody against platelet glycoprotein Ib (GpIb) was detected in the patient's serum. A needle biopsy of the right adrenal tumor was performed, and histology was non-Hodgkin's lymphoma (NHL), diffuse large B-cell type. Following the diagnosis of autoimmune thrombocytopenia associated with lymphoma, administration of corticosteroid (predonisolone 60 mg/day) and high-dose intravenous globulin (15 g/day x 4 days) was carried out, but neither was effective in normalizing the thrombocytopenia. Immunosuppressive therapy (cyclophosphamide 500 mg and 1 mg of vincristine) markedly restored the platelet counts to 7.2 x 10(4)/microliter and ceased the melena; furthermore, the size of adrenal tumors decreased by more than 60% after therapy. We cultured the lymphoma cells drawn by needle biopsy with IL-6 in vitro and found that the lymphoma cells produced IgM-type antiplatelet antibodies against platelet GpIb in the culture supernatant. Thus this is a rare case of NHL in which the production of antiplatelet antibody from lymphoma cells was confirmed in vitro.