Background: The phenotypic heterogeneity of psoriasis is suspected to reflect differences in its pathogenesis, but not yet completely elucidated. Studies of the Th1 and Th17 cytokines associated with different phenotypes of psoriasis have yielded inconsistent results.
Objective: To investigate the tissue expression levels of Th1 and Th17 cytokines among patients with chronic plaque psoriasis, acute guttate psoriasis, and healthy control.
Methods: A total of 20 patients with psoriasis (10 with chronic plaque type and 10 with acute guttate type) and 5 healthy controls were enrolled. The tissue mRNA and protein levels of following cytokines were measured: interleukin (IL)-12, IL-2, interferon (IFN)-γ, IL-23, IL-17A, and IL-22.
Results: The tissue mRNA levels of IL-12, IFN-γ, IL-23, IL-17A, IL-22 and the protein levels of IL-12, IL-2, IFN-γ, IL-17A, IL-22 were significantly increased in the psoriasis patients compared with the healthy controls. In comparisons of the subtypes, the tissue mRNA level of IFN-γ was increased in acute guttate psoriasis, whereas the protein levels of IL-12 and IL-17A were significantly increased in chronic plaque psoriasis. The cytokine ratios of IL-17A/IL-2 and IL-22/IL-2 were significantly higher in chronic plaque psoriasis than in acute guttate psoriasis.
Conclusion: We confirmed that the tissue levels of Th1 and Th17 cytokines were increased in psoriasis patients compared with healthy controls. The increased IFN-γ mRNA level in acute guttate psoriasis and increased IL-12 and IL-17A protein levels in chronic plaque psoriasis suggest that an imbalance between Th1 and Th17 cytokines may play a role in the phenotypic transition of psoriasis.
Keywords: Cytokine; Immunity; Interleukins; Phenotype; Psoriasis.
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