IL1A and IL1B gene polymorphisms and keratoconus susceptibility: evidence from an updated meta-analysis.

Background

Several single-nucleotide polymorphisms (SNPs) in IL1B genes have been associated with KTCN. However, the results of these studies were not conclusive. This meta-analysis association study is aimed to quantitatively estimate the association of IL1B rs16944 (g.4490T>C) and rs1143627 (g.4970C>T), and IL1A rs2071376 (c.615 + 169C>A) polymorphisms with KTCN susceptibility.Materials and

Methods

Systematic literature search was performed in Web of Science, MEDLINE, PubMed, Scopus, and Google Scholar databases. The odds ratios (ORs) and 95% confidence intervals (CI) were calculated assuming different contrasted genetic models.

Results

The reference T allele of IL1B (g.4490T>C) polymorphism was significantly associated with decreased KTCN risk under all assessed genetic models. Regarding the reference C allele of IL1B (g.4970C>T) polymorphism, decreased risk of KTCN was found. The reference C allele of IL1A (c.615 + 169C>A) polymorphism conferred a decreased risk of KTCN under heterozygous codominant (AC vs. AA), homozygous codominant (CC vs. AA), and dominant (AC+CC vs. AA) genetic models. The pooling estimates showed that the T C haplotype was associated with a significant increase in KTCN risk. In contrast, the T T haplotype was correlated with a decreased risk of KTCN. With the assumption of a prior probability of 0.25, the false-positive report probability (FPRP) values were less than 0.2, indicating the observed significant associations were notable.

Conclusion

These findings propose that the studied IL1B polymorphisms and the IL1A variation have opposite effects on KTCN susceptibility. More large-scale replication studies are warranted to illuminate the precise role of these SNPs on the etiology of eye disorders.