Abstract: Objective: To determine the association of Th17 cells levels in peripheral blood among the patients with psoriasis vulgaris at active and quiescent stages. Methods: The articles of randomized, controlled?clinical?trials on Th17 cells level in peripheral blood and lesions of the patients with psoriasis vulgaris at active and quiescent stage were searched in Wanfang Med Online, China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals and CBM, PubMed and Embase. The quality of the articles was assessed by two reviewers and meta-analysis was performed using the RevMan 5.3 software. Results: A total of 12 articles met the criteria. The results of meta-analysis showed that the levels of Th17 cells in the peripheral blood and lesions in the active group were higher than those in the quiescent group [SMD=2.15, 95% CI (1.28, 3.02)]. Conclusion: The progression of psoriasis may be associated with the Th17 cells level.

Key words: psoriasis, Progress period, Quiescent period, Meta analysis