| Abstract: | We have studied NK cell activity in 32 patients with sarcoidosis and in 29 control subjects. Cytotoxicity was increased in both active and inactive sarcoids, the lytic activity of sarcoid peripheral blood mononuclear cells (PBMC) being approximately 50% higher than that of control subjects. The number of lymphocytes bearing Fc receptors for IgG (FcR-IgG) was correlated with NK cell activity, both parameters being increased in the sarcoid group. Sarcoid NK cell activity was reduced to control levels after depletion of plastic adherent cells, whilst inhibition of cytotoxicity by PGE2 was increased using non-adherent sarcoid PBMC. Plastic depletion had no effect on NK cell activity or its inhibition by PGE2 using PBMC from control subjects. The results demonstrate the presence of a weakly adherent, PGE2 insensitive NK cell in sarcoid PBMC preparations. |
