A case of CD4+/CD8- adult T-cell leukemia with good response to interferon-beta terminating as a CD4+/CD8+ adult T-cell lymphoma.

The leukemic cells of adult T-cell leukemia (ATL) usually express the helper/inducer associated antigen reactive with anti-CD4 antibodies but not with anti-CD8. We present a 63-yr-old woman with ATL characterized by circulating leukemic cells with CD4+/CD8- phenotype, hepatosplenomegaly with no lymphadenopathy, and the presence of proviral DNA of human T-cell leukemia virus I in the leukemic cells. She was successfully treated with interferon beta and the remission lasted for 12 months. She then relapsed in the lymph nodes with minimal peripheral blood involvement. The neoplastic cells of the lymph node now co-expressed CD4 and CD8 antigens indicating that the change in clinical manifestation was accompanied by a phenotypic change of the leukemic cells.