Interleukin-1 gene cluster variants and recurrent pregnancy loss among North Indian women: retrospective study and meta-analysis.

The aim of this study was to determine whether or not interleukin-1 alpha (IL-1a), interleukin-1 beta (IL-1b) and IL-1 receptor antagonist (IL-1RA) polymorphisms are associated with risk of unexplained recurrent pregnancy loss (RPL) among North Indian women. This retrospective case–control study examine 200 well-characterized RPL cases for IL-1 gene cluster variants, determined by restriction fragment length polymorphism-PCR. The observed allele, genotype and haplotype distributions were compared with those obtained from 300 ethnically matched negative controls. Invariant distribution of IL-1 gene cluster single-nucleotide polymorphisms was observed among RPL cases and controls. Meta-analysis of IL-1b _511, +3953 and IL-1RN 86-bp variable number tandem repeat from the reported literature and this study did not reveal any significant association with the risk of RPL. In conclusion, no significant difference between RPL and control groups was observed at the allele, genotype or haplotype levels when tested for association using the dominant, recessive and additive models of inheritance for IL-1 gene cluster variants. As far as is known, this is the first report from India pertaining to IL-1 gene cluster variants’ association with the risk of RPL from North India.