Proliferation of T gamma-lymphocytes in two patients: clinical features and functional properties of the proliferating cells.

Two patients suffering form proliferation of T gamma cells exhibited uncommon clinical features, such as activation of intravascular coagulation after low dose irradiation of the enlarged spleen in one patient and isolated neutropenia in the other patients. While the malignant nature of the disease was doubtless in one patient, cell proliferation in the other patient was more likely reactive. In addition to T cell determinants the proliferating cells expressed a monocytic antigen. They did not suppress B-lymphocyte differentiation into plasma cells. In contrast the proliferating cell, especially in one patient, acted as potent effectors in NK and ADCC using melanoma and MOLT 4 target cells. Erythrophagocytosis by T gamma cells was seen in one patient. The data suggest that subsets of T gamma cells are related to the monocytic lineage and that these cells cen mediate both NKA and ADCC and partly can develop phagocytic activity.