Natural cytotoxicity and antibody-dependent cytotoxicity in solid tumor cancer patients: Regulation by adherent cells

Abstract

Natural cytotoxicity (NK) and antibody-dependent cellular cytotoxicity (ADCC) were measured in peripheral blood mononuclear cells (PBMC) from 30 normal subjects and from 60 untreated patients with solid tumors at various stages of disease. NK, but not ADCC, activity of PBMC from patients with disseminated disease was significantly lower than NK activity of either normal donors or patients with localized disease. This decreased NK activity was not related to decreased numbers of T cells or target-binding cells or to immune complex levels in patient sera. Glass-adherent cell depletion augmented decreased NK levels significantly to normal levels of function. Addition of indomethacin did not alter NK activity in any of the patients studied. We conclude that decreased NK activity in PBMC from cancer patients with disseminated disease is due to a suppression which may be mediated by glass-adherent cells. This is not dependent on a prostaglandin-mediated mechanism of suppression. © 1982.