Influence of IL10 gene polymorphisms on the severity of liver fibrosis and susceptibility to liver cirrhosis in HBV/HCV-infected patients

Background Previous studies about the association of the interleukin-10 (IL-10) polymorphisms with the progression of liver fibrosis or cirrhosis susceptibility in chronic hepatitis B/C (CHB/C) disease were inconsistent. The aim of this meta-analysis was to derive a more precise estimation of the association. Methods We searched Medline, PubMed, EMBASE and Web of Science electronic databases using the following key words: liver fibrosis/cirrhosis, IL10, and polymorphism. Statistical analyses were performed by STATA11.0 software, with odds ratios (ORs) and their 95% confidence intervals (CIs). Results 12 independent studies in relation to IL10-1082A/G, -819C/T and -592C/A polymorphisms were included in our study, which consisted of 197 moderate/severe liver fibrosis cases and 426 mild fibrosis controls as well as 536 liver cirrhosis cases and 881 non-cirrhosis controls. The results indicated that a significantly decreased risk of moderate/severe fibrosis was associated with the GCC haplotype (IL10-1082G, -819C and -592C) in the overall CHB/C patients (OR: 0.547, 95% CI: 0.317–0.946, P=0.031). We did not detect any significant association between these polymorphisms and liver cirrhosis susceptibility in the total population or a subgroup of Asians. However, subgroup analyses by different aetiologies showed that the -819T heterozygotes (TC) were associated with a significantly increased risk of HCV-related liver cirrhosis in the Japanese population (OR: 1.254, 95% CI: 1.033–1.522, P=0.022). Conclusions The putative high IL-10 production haplotype GCC is more likely to be associated with less severe liver fibrosis in CHB/C patients. Additionally, the IL10-819T allele may be a susceptible factor for HCV-related liver cirrhosis in the Japanese population.