[Effective pentostatin-based treatment of adult T cell leukemia in a patient with severe arthritis]

We report a 48-year-old woman with adult T-cell leukemia who had refractory arthralgia, intense headaches, and fever. Leukemic cell infiltration of the cerebrospinal fluid was detected but no other acute signs were observed. Abnormal lymphocytes with lobulated nuclei were found in the synovial fluid, and a histologic examination revealed proliferation into the synovium. Because combination chemotherapy did not elicit a favorable response, the patient was treated with a pentostatin bolus injection. The articular symptoms disappeared and complete remission was obtained. Six months later, she experienced arthralgia again together with a gradual increase of abnormal lymphocytes in peripheral blood. Sixteen months later, the patient was given pentostatin and achieved a complete remission again. She is still free from relapse without further therapy after 36 months, and her articular symptoms have not returned either. There were no adverse effects due to pentostatin. The patient's serum IL-6 level was elevated, suggesting that IL-6 may play a role in arthropathy.