Correlation of natural killer cell function with Leu 7 reactivity in patients with humoral immunodeficiency.

We studied the surface markers Leu 7, Leu 1, Leu 2a and Leu 3a on lymphocytes of 54 healthy blood donors and 19 patients with humoral immunodeficiencies and compared the relative numbers of positive cells with the natural killer cell (NK) activity. In controls, and in 12 out of 19 patients (group A) the percentage of the Leu 7+ cells was positively correlated with NK activity. Seven of 19 patients had increased relative numbers of Leu 7+ cells and low NK activity (group B). In controls and group A patients about 40% of the Leu 7+ cells simultaneously expressed the cell markers Leu 1 and Leu 2a. In group B patients approximately 70% of the Leu 7+ cells carried T cell antigens. Furthermore, a distinct suppressor T cell predominance was noticed and the large granular lymphocytes of these patients showed morphological abnormalities.