A first case of complete remission of β-interferon sensitive adult T-cell leukemia

A case of complete remission of adult T-cell leukemia (ATL) induced by β-interferon is reported. A 46-year-old male was diagnosed as ATL because of the increased number of ATL cells with deeply indented and lobulated nuclei in the peripheral blood, accompanied by elevated values of the lactic dehydrogenase, the alkaline phosphatase, and the calcium in the serum. The result of the cell surface marker analysis of peripheral blood lymphocytes was compatible with ATL and anti-ATL associated antibody (ATLA) was positive. The integration of proviral deoxyribonucleic acid (DNA) of human T-cell leukemia virus type I(HTLV-I) was proved in the peripheral blood lymphocytes using Southern blot hybridization. Since an ordinal chemotherapy was not so effective for this patient, he was treated with 1.8 times 107 units of recombinant β-interferon (β-IFN) per day for 7 days as one course. After 5 courses of treatment, a markedly favorable response was recognized, and he achieved complete remission. A lower dose of β-IFN (9 times 106 units per day for 3 days as one course, one or two courses per month) has been continued and he has still been in a complete remission state for 10 months. It is concluded that β-IFN should be used to treat ATL.