IMMUNE STATUS IN CROHNS-DISEASE .5. DECREASED INVITRO NATURAL-KILLER CELL-ACTIVITY IN PERIPHERAL-BLOOD

Abstract

To identify and measure the spontaneous cell-mediated cytotoxicity of natural killer cells, the lysis of an established [human B] lymphoblastoid cell line [LIK cells] as target in a 4 h 51Cr-release assay was used. Mononuclear cell suspensions of the peripheral blood of 34 patients with Crohn''s disease (group CD), 11 patients with inflammatory bowel disease other than CD or ulcerative colitis (group D) and 45 healthy subjects matched for age and sex with the patients were studied. Depletion of phagocytic, plastic-adherent cells (purified suspensions) led to a significant increase of the natural killer cell activity as compared with unseparated suspensions. This was seen to occur in all groups. In CD patients the natural killer cell activity was significantly below normal levels in unseparated and purified suspensions. This was independent of disease duration. In purified suspensions the natural killer cell activity was inversely related to the disease activity. In group D the natural cytotoxicity was significantly lower in unseparated suspensions than that in healthy controls. In purified suspensions it was still slightly lower than in healthy controls.