Antibody-dependent cell-mediated cytotoxicity by peripheral blood mononuclear cells from patients with Sjögren's syndrome, with special reference to differentiation from phagocytic activity.

Antibody-dependent cell-mediated cytotoxicity (ADCC) by peripheral blood mononuclear cells in patients with Sjögren's syndrome (SjS) was estimated with special reference to differentiation from phagocytic activity caused by phagocytes. There was no significant difference in ADCC activity of peripheral blood lymphocytes (phagocyte-depleted lymphocyte fraction) between patients with SjS and normal persons. Higher ADCC activity of the crude lymphocyte fraction (CLF), however, was demonstrated in patients with SjS than in normal persons. It was proved that increased ADCC activity of CLF in patients with SjS resulted from reduced erythro-phagocytic activity of contaminating monocytes in this fraction.