[HTLV-I negative adult T cell leukemia; a case report of acute type].

We described a case of adult T cell leukemia (ATL) not associated with human T-cell leukemia virus type I (HTLV-I), a clinical entity that was first reported by Shimoyama et al. A 79-year-old male was admitted with anorexia and fever in October, 1989. Physical examination revealed marked hepatosplenomegaly and superficial lymphadenopathies. Hematological examination revealed marked leukocytosis (136,300/microliters) with abnormal lymphoid cells showing highly lobulated nuclei. Hypercalcemia (11.2 mg/dl) and elevation of lactic dehydrogenase were also recognized. Surface marker analysis showed that the abnormal lymphoid cells in the peripheral blood were positive for CD2 and CD4 but negative for CD8. Southern blot analysis of the DNA from peripheral blood leukemic cells revealed monoclonal rearrangement of T-cell receptor beta-chain gene. The clinical and hematological findings of the patient were compatible with those of acute type ATL, however, serum anti-HTLV-I antibody was negative and HTLV-I proviral DNA was not detected in the leukemic cells by Southern blot analysis. Furthermore, the polymerase chain reaction showed no integration of the HTLV-I proviral DNA in the leukemic cells.