Inflammatory cytokine gene polymorphisms and spontaneous preterm birth.

The objective was to search for an association between spontaneous preterm birth (sPTB) and single and/or combined polymorphisms in genes TNFA -308 G>A, IL10 -1082 G>A, IL10 -819 C>T, IL10 -592 C>A, IL6 -174 G>C, and IFNG +874 A>T. Genotyping was performed on 410 Brazilian ethnically matched women managed at two hospitals (two independent case-control sets). One set consisted of 122 cases and 101 controls, and the other set comprised 82 cases and 105 controls. We compared genotype and genotype-combination frequencies between cases and controls using Fisher's exact or the chi(2) tests and confirmed results using logistic regression. Among the six SNPs studied, we found no independent association between any single SNP and sPTB risk. The multi-locus analysis revealed a significant association between sPTB and the TNFA(GG)/IL6(GG)/IFNG(AA) genotype combination (p=0.002), confirmed by logistic regression. Our data suggest that the combination of TNF-alpha, IFN-gamma, and IL-6 maternal gene polymorphisms might contribute to susceptibility to sPTB. This finding could be investigated as a possible genetic marker for the risk of spontaneous preterm birth.