Association between plasma interleukin-17 levels and risk of psoriasis: a meta-analysis.

BACKGROUND: Emerging evidence indicates that plasma interleukin (IL)-17 levels may be associated with increased risk of psoriasis, but the individual published results are inconclusive.

AIM: To evaluate IL-17 levels in patients with psoriasis using a meta-analysis of studies comparing IL-17 levels in controls and in patients with psoriasis.

METHODS: All relevant studies were identified by searching PubMed, Web of Science and MEDLINE databases before 1 November 2015. Pooled risk estimates were calculated by random-effects models. Crude OR and standardized mean difference (SMD) with corresponding 95% CI were also calculated.

RESULTS: In total, eight cross-sectional study studies were included in the final analysis. The mean plasma levels of IL-17 were higher in patients with psoriasis than in healthy controls (SMD = 0.47, 95% CI = 0.07-0.86, P < 0.001).

CONCLUSIONS: Based on this literature review, there appears to be a positive association between IL-17 plasma levels and psoriasis.