Natural killer-cell immunodeficiency in patients with chronic myelogenous leukemia. I. Analysis of the defect using the monoclonal antibodies HNK-1 (LEU-7) and B73.1

Abstract

Quantitative evaluation of natural killer (NK) cells using the HNK-1 (Leu-7) and B73.1 monoclonal antibodies (MAbs) was correlated with NK activity in 13 patients with chronic myelogenous leukemia (CML) and compared to normal donor controls. A consistent observation was the presence of normal absolute numbers of B73.1+ lymphocytes as well as normal to increased absolute numbers of HNK-1+ lymphoid cells in the peripheral blood of chronic-phase CML patients. Despite normal to increased numbers of B73.1+ and HNK-1+ lymphoid cells, these patients consistently demonstrated a significant impairment of lymphocyte-mediated NK activity in their peripheral blood. Further experiments demonstrated that chronic-phase CML patients, in contrast to normal controls, had significantly increased percentages of HNK-1+, E+ and B73.1+, E+ lymphoid cells and significantly decreased percentages of HNK-1+, E- and B73.1, E- lymphoid cells, which resulted in significant reversals of the HNK-1+, E+ to HNK-1+, E- and B73.1+, E+ to B73.1+, E- lymphoid cell ratios. (HNK-1+ [E+/E-] greater than B73.1+ [E+/E-]). Furthermore, as compared to normals, both FACS-sorted HNK-1+ and B73.1+ lymphoid cells from the E+ fraction of CML patients were consistently defective in NK activity, and could not be substantially augmented with alpha-interferon preparations. Although markedly defective in their ability to lyse K-562, HNK-1+ lymphoid cells from the E+ fraction of CML patients were not defective in their ability to bind to the NK-sensitive target, K-562. In contrast, NK-defective B73.1+ lymphoid cells were partially defective in their ability to bind to K-562.