Effects of acitretin on expression of Th17/Treg cells and related cytokines in patients with psoriasis vulgaris

Objective To investigate the therapeutic effect of acitretin and its influence on the expression of Th17/Treg cells and related cytokines including interleukin-6(IL-6) and interleukin-10(IL-10) in peripheral blood of patients with psoriasis vulgaris, and to further clarify the therapeutic mechanisms of acitretin. Methods Ninety-two cases of patients with moderate to severe psoriasis vulgaris were treated with acitretin for 8 weeks. The efficacy of treatment was evaluated by Psoriasis Area and Severity Index(PASI)scores. Peripheral blood levels of Th17 and Treg cell percentage were measured by flow cytometry. Enzyme linked immunosorbent assay(ELISA) was used to measure the serum levels of IL-6 and IL-10 in 90 patients with psoriasis before and after treatment. Sixty healthy persons were used as normal controls. Results Compared with normal human controls, patients with psoriasis vulgaris showed higher level of Th17 cells in peripheral blood(P0.01). The ratios of Th17 to Treg cells and serum IL-6 were significantly higher in the patients than those in the normal controls(P0.01), the percentage of Treg cells and serum level of IL-10 were significantly lower between patients and controls(P0.01). After treatment with acitretin, Th17 cells, ratios of Th17 to Treg cells and IL-6 were significantly decreased than before(P0.01).The percentage of Treg cells and IL-10 were significantly higher compared with before treatment(P 0.01).The total effective rate was 80.43%, and the accumulated points of Psoriasis Area and Severity Index(PASI) scores were decreased significantly. The PASI score in patient was positively correlated with the percentage of Th17, Th17/Treg ratios, serum level of IL-6, and negatively correlated with the percentage of Treg cells and IL-10(P0.01). Conclusion Acitretin may affect Th17/Treg and related cytokines to achieve its therapeutic effect on patients with psoriasis. which may be one of the mechanisms of the acitretin treatment in psoriasis.