Profile of cytokine mRNA expression in spontaneous and UV-induced skin lesions from actinic prurigo patients.

BACKGROUND: Actinic prurigo (AP) appears to be an immune-mediated disease triggered by exposure to ultraviolet light (UV).

OBJECTIVE: To assess the profile of cytokine production in skin lesions from AP patients.

METHODS: The cytokine production (IL-1 beta, IL-2, IL-4, IL-6, IL-10, IL-13, TNF-alpha, IFN-tau, and TGF-beta) in skin biopsies from 12 AP lesions was determined by a semiquantitative coupled reverse transcription-polymerase chain reaction.

RESULTS: We found expression of TGF-beta and IL-13 genes in most AP skin lesions; IL-1 beta, IL-6, TNF-alpha, IFN-tau, and IL-10 were detected in some of these specimens. However, the levels of expression of all cytokines studied were not significantly different in AP skin lesions compared to nonlesional skin.

CONCLUSIONS: TGF-beta and IL-13 might have a key role in both the inflammatory phenomenon and absence of significant expression of most cytokines in AP skin. The cytokine production in AP skin resembles that observed in rheumatoid synovium, a paucity in cytokine expression despite the presence of infiltrating activated mononuclear cells.