[Recent advances in clinical research on T-cell lymphoma]

Immunophenotypic analysis on 34 cases of T-cell malignancies using monoclonal antibodies against T-cell receptors (TCR) revealed 25 cases of alpha beta-type and two of gamma delta-type. The two patients with gamma delta-type showed cutaneous involvement of tumor cells. Immunoblastic lymphadenopathy (IBL)-like T-cell lymphoma is divided into three histologic categories; inconspicuous type, patchy type and diffuse type. DNA hybridization analysis revealed that 11 of 16 cases showed clonal rearrangement of TCR beta-chain gene without rearrangement of immunoglobulin heavy chain gene, providing strong evidence for clonal proliferation of T-cells. Among 185 patients with adult T-cell leukemia (ATL), 18 cases (9.7%) were found not to be associated with human T-cell leukemia virus type I (HTLV-I). They consisted of 10 of acute type, five of chronic type, two of lymphoma type and one of smoldering type, indicating a diversity in clinical features. Two Japanese patients with ATL developed secondary monoclonal B-cell lymphomas of diffuse, large cell, non-Burkitt type. They were seropositive for HTLV-I but negative for human immunodeficiency virus (HIV). They also suffered from pulmonary tuberculosis, and one from adenovirus type 11-induced hemorrhagic cystitis, indicating an immunodeficient state. Epstein-Barr virus genome was found in lymphoma cells from one patient. It is suggested that opportunistic B-cell lymphomas may occur in the immunodeficient stage of ATL.