Chronic T-cell lymphocytosis with neutropenia: report of a case studied with monoclonal antibody

Abstract

A 55-yr-old man presented with an 8-yr history of lymphocytosis, neutropenia, and infection. There was moderate splenomegaly without lymphadenopathy, and lymphocytosis of the blood (15.000–41,200/cu mm) and bone marrow (30%): the latter also revealed no granulocytes more mature than the myelocyte. A diagnosis of leukemia could not be made from microscopic examination of the liver, spleen, or bone marrow. The circulating lymphocytes were T cells of the cytotoxic-suppressor subset with characteristic surface markers. They formed rosettes with unsensitized sheep erythrocytes (E rosettes), reacted with an antithymocyte heteroantiserum, were positive for the receptor for the Fc portion of IgG, and were devoid of surface immunoglobin. When examined with a panel of monoclonal antibodies, these cells reacted with OKT3, a monoclonal that identifies peripheral T cells, OKT11, which identifies the sheep cell receptor, and OKT5 and OKT8, which identify the cytotoxic suppressor subset of T cells, but not with OKT4, which identifies the inducer/helper subset. These lymphocytes also displayed a high level of antibody-dependent cytotoxicity, but natural killer activity could not be demonstrated. This indolent disorder closely resembles that of 7 patients with lymphocytosis and neutropenia described in the recent medical literature, but sharply contrasts with the more frequently reported cases of T-cell chronic lymphocytic leukemia. Since it is unclear that the present case represents a neoplastic proliferation, the noncommittal term “chronic T-cell lymphocytosis with neutropenia” is proposed for the condition. In view of the neutropenia and the benign course, cytotoxic treatment appropriate for B- and T-cell chronic lymphocytic leukemia should be undertaken only with circumspection. The new condition can be suspected from the clinical picture and can be diagnosed with conventional lymphocyte surface marker techniques and commercially available monoclonal antibodies.