Correlation of peripheral T gamma and K lymphocytes in normal subjects and patients with autoimmune thyroid diseases.

K lymphocytes are thought to be included in the T gamma lymphocyte subpopulation, but the reports on the relation between T gamma and K lymphocyte counts in human peripheral blood are not available. Peripheral T gamma and K lymphocytes were enumerated simultaneously by EA rosette formation and ADCC plaque formation, respectively, in normal subjects and in patients with autoimmune thyroid disease. In thyrotoxic Graves' disease, the percentages of both T gamma and K lymphocytes were lower than in normal subjects. No abnormalities in T gamma and K lymphocytes were observed in euthyroid patients with Graves' disease and with Hashimoto's disease. The percentages of T gamma lymphocytes were higher than those of K lymphocytes and these 2 lymphocyte subpopulations showed significant correlations within groups of patients with Graves' disease and Hashimoto's disease and in normal subjects. The slope of the regression line for the group with Hashimoto's disease was normal but that for the group with Graves' disease was steeper than that for normal subjects. These data indicate that T gamma lymphocytes and K lymphocytes are in overlapping subpopulations of Fc gamma receptor-bearing lymphocytes in human peripheral blood and suggest that there is an abnormal distribution of K lymphocytes in the T gamma lymphocyte subpopulation in Graves' disease.