Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by pruritic chronic eczema. The immunopathogenesis of this condition is still not well understood. We assessed the transcription and production of IFN-gamma, the Th1 cytokine, and the Th2 cytokine IL-5 in peripheral blood mononuclear cells (PBMCs) from patients with severe AD.
Methods: The subjects included 17 severe (serum IgE: 5,000-92,000 U/ml, median: 20,000 U/ml), 4 mild AD (IgE: 2-520 U/ml) and 8 nonatopic controls (IgE: <100 U/ml). The severe AD patients were classified into two groups according to the response to standard treatment with topical glucocorticoids. Individuals were classified as poorly responsive (AD-P) if the clinical score decreased less than one third after 2 weeks of hospital treatment and as responsive (AD-R) if the score decreased more than one third. PBMCs isolated from the subjects were stimulated with PHA and PMA.
Results: The expression of IFN-gamma in PBMCs in the AD-P group was much lower than that observed in the other groups at both mRNA and protein levels. There were no significant differences in the levels of IL-5 both in mRNA and protein levels between the groups. There were no significant differences in STAT4 DNA-binding activity following PHA/IL-2/IL-12 stimulation between AD-P and controls.
Conclusions: These results suggest that the decreased INF-gamma production may account for the abnormal immunopathogenesis of severe, intractable AD.
Copyright 2004 S. Karger AG, Basel