Update on the association between interleukin-12 p40 gene polymorphism and risk of psoriasis: A meta-analysis

Abstract

Background: Psoriasis is a common inflammatory skin disease with a strong genetic component. Interleukin (IL)-12 is one of the key cytokines in immune regulation and is overexpressed in psoriasis. The aim of this study was to update the meta-analysis for the association between IL-12 p40 gene (IL-12B) rs3212227 polymorphism and risk of psoriasis. Methods: We performed a literature search from inception to December 2014. Review Manger 5.2 was used for meta-analysis. Odds ratios and their 95% confidence intervals were calculated under five genotype models: C versus A, CC + AC versus AA, CC versus AA + AC, CC versus AA, and CC versus AC. In addition, subgroup analyses were performed by ethnicity. Results: Nine studies involving 6520 psoriasis patients and 11,150 healthy controls were included. Two included studies were newly published studies, which were not analyzed in previous meta-analyses. The overall meta-analysis showed the significant association between psoriasis and IL-12B rs3212227 in all the genotype models, indicating that carriers of genotype CC or allele C had a less risk of psoriasis. Meanwhile, subgroup analyses showed this association existed in not only European, but also Asian populations. Conclusion: This meta-analysis demonstrated that IL-12B rs3212227 was associated with the risk of psoriasis in European and Asian populations.

Keywords

• interleukin-12 p40 gene
• meta-analysis
• polymorphism
• psoriasis
• susceptibility gene