Abstract: The NK cell activity and cyclic nucleotides levels (CAMP, cGMP) in lymphocytes of peri-pheral blood mononuclear cells (PBMC) of 20 controls and 26 patients were studied. The diagnosis of all the patients were consistent with ARA criteria. The cAMP levels between the controls and patients showed no significant difference before dexamethasone and amino phylline treatment. The lymphocytes from the patients elicited a ditninished response to dex-amethasone and aminophylline, but the lymp-hocytes from the controls showed a significant increase of CAMP level by this two agents. cGMP level of lymphocytes from the patients was signifieantly higher than that from the controls. Dexamethasone and aminophylline induced significant inhibition of NK cell activity in the controls, while this phenomenon was not observed in the patients. Though our study is preliminary, it may seggest that cynic nucleotides play a conspicuous role in the pathogenesis of SLE. There txray be an intMnsic impairment of the CAMP dependent regulatory mechanism in PSMC from the patients, which may result in abnormal NK cell activity.

Key words: Lupus erythematosus, systemic, Adenosine cyclic monophosphate, Guanosine cyclic mvnophosphate, Killer cells, natural