Differential cytokine profiles in peripheral blood lymphocyte supernatants and skin biopsies from patients with different forms of atopic dermatitis, psoriasis and normal individuals.

There is increasing evidence that the activation of a selected T helper cell population producing a Th2-related cytokine pattern with IL-4 and IL-5 but not IL-2 and interferon-gamma (IFN-gamma) may be involved in the pathogenesis of IgE-mediated atopic diseases and in particular of atopic dermatitis (AD). However, the existence of a 'nonatopic' (intrinsic) form of AD (NAD) with normal serum IgE levels, negative RAST tests, negative immediate type skin reactions towards environmental allergens and a negative patients and family history for IgE-mediated allergies raised the question whether this form may be explained by a different T cell activation and cytokine pattern. In the present study we compared the distribution of peripheral blood leukocyte and lymphocyte subpopulations, their activation state and cytokine production in peripheral blood lymphocyte supernatants and skin biopsies of patients with AD (n = 19), NAD (n = 14), psoriasis (n = 6) and normal individuals (n = 13). A characteristic eosinophilia was present in AD and NAD but not in psoriasis and normal controls. The three patient groups showed significantly increased numbers of activated CD4+ and CD8+ cells as measured by IL-2R and HLA-DR expression. Determination of spontaneously released IL-2, IL-4, IL-5 and IFN-gamma from peripheral blood lymphocytes demonstrated a Th2-related cytokine pattern with elevated levels for IL-4 and IL-5 in AD patients only. Increasingly enough, patients with NAD displayed high IL-5 but low IL-4 levels.(ABSTRACT TRUNCATED AT 250 WORDS)