Defective natural-killer- and killer-cell activity associated with increased polymorphonuclear leukocyte adherence in psoriasis.

Patients (n = 45) with psoriasis vulgaris were studied for natural killer (NK) cell activity and antibody-dependent cell cytotoxicity (ADCC) of their peripheral blood mononuclear cells against K-562 and L1210 target cells, respectively. Simultaneously, the studies were performed on the adherence to human endothelium of polymorphonuclear leukocytes (PMN) from various forms of the disease. Mean values of NK-cell activity in psoriasis vulgaris, as a whole, and mean values of ADCC in male patients were significantly lower than in a group of healthy controls. This decrease was most pronounced in patients with the active form of the disease, in whom in vitro PMN adherence to human endothelium was found to be increased. Neutrophils from both patients with active psoriasis and healthy individuals were capable of reducing NK-cell activity of normal human mononuclear cells.