Immunological Functions and T-Cell Receptor Gene Rearrangement of Proliferating Lymphocytes in a Case of T Gamma Lymphocytosis with Neutropenia

OKABE, M., TANAKA, M., UEHARA, Y., MATSUSHIMA, S., KAKINUMA, M., ABE, F., KOBAYASHI, M., TACHIBANA, N., SAKURADA, K., SAITO, H. and MIYAZAKI, T. Immunological Functions and T-Cell Receptor Gene Rearrangement of Proliferating Lymphocytes in a Case of T Gamma Lymphocytosis with Neutropenia. Tohoku J. exp. Med., 1987, 151(1), 105-115-A case of Tγ lymphocytosis with neutropenia is presented. The patient showed mild lymphocytosis, splenomegaly, anemia, neutropenia and recurrent infections without progression for 15 years. The expanded lymphoid cells were morphologically large granular lymphocytes (LGL), had receptors for both sheep red blood cells and IgG-Fc portion and were positive for OKT3 and 8 antigens. They displayed ADCC activity, whereas they showed low responses to T-cell mitogens and deficient NK activity. They showed neither suppressor activity on antibody production by B-cells nor suppressor activity on CFU-C formation. The DNA isolated from the expanded cells of the patient showed T-cell β-chain (Tβ) gene rearrangement, indicating monoclonality of the proliferation. This finding supports that the proliferation of T8 lymphocytes in the present case is neoplastic rather than reactive, regardless of the benign clinical course.