Associations of genetic polymorphisms in CTLA-4 and IL-18 with chronic liver diseases: Evidence from a meta-analysis

Background The aim of this meta-analysis was to explore associations between polymorphisms in CTLA-4/IL-18 and chronic liver diseases by combing the results of all relevant studies. Methods Eligible studies were searched from Pubmed, Embase, Web of Science and Cochrane library. We used Review Manager to combine the results of eligible studies. Results Sixty-seven studies were included in this meta-analysis. Combined results revealed that CTLA-4 rs231775 (dominant, recessive and allele comparisons), IL-18 rs1946518 (dominant, recessive and allele comparisons) and IL-18 rs187238 (dominant, over-dominant and allele comparisons) polymorphisms were all significantly associated with chronic liver diseases in the overall population. We also obtained similar positive results for rs231775, rs5742909, rs3087243, rs1946518 and rs187238 polymorphisms in subgroup analyses by ethnicity and type of disease. Conclusions This meta-analysis demonstrated that CTLA-4 rs231775, CTLA-4 rs5742909, CTLA-4 rs3087243, IL-18 rs1946518 and IL-18 rs187238 polymorphisms may confer susceptibility to certain types of chronic liver diseases.