Impaired Monocyte Cyclic AMP Responses and Monocyte Cytotoxicity in Atopic Dermatitis

Purified monocytes from 21 patients with mild and severe atopic dermatitis (AD) were compared with 22 healthy controls with respect to antibody-dependent cell-mediated cytotoxicity (ADCC) and cyclic adenosine 3',5'-monophosphate (cAMP) responses to stimulatory agents. ADCC was depressed in both severe and mild atopic dermatitis. The patients showed decreased cAMP responses to isoproterenol and histamine, the decrement being more distinct in severe atopic dermatitis. Formation of cAMP was diminished with PGE, only in patients with severe AD. ADCC is inhibited by the agents that increase cAMP. In the severe dermatitis group reduced inhibition induced by isoproterenol, histamine, but not PGE₁, was obtained. It is suggested that a general suppression of membrane activation may explain the reduced cAMP responses to various stimulatory agents and the impaired monocyte cytotoxicity.