The significance of IL-6 gene polymorphisms in preterm delivery

Objective: Assessment of relevance of IL-6 (-174G>C, -596G>A) genes polymorphisms in the etiology of preterm delivery (PTD). Material and methods: Study group: 150 women with PTD (22+0 36 + 6 gw.); controls: 150 women who delivered > 37 gw. Genetical analysis was performed by PCR/RLFP method. Results: In PTD group -596GA genotype (48.6 vs. 42.7%) and -596AA genotype (24.7 vs. 21.3%) occurred more frequently. PTD group was divided into subgroups: a) delivery between 22-28 gw. b) 28-32 gw. and c) 32-36+6 gw. Higher frequency of -596A allele (57.89 vs. 42.67%, p = 0.05), -174CC genotype (47.4 vs. 24.0%, p = 0.03), and -174A allele (65.8 vs. 50.0%. p = 0.04) in the subgroup 28-32gw. was observed. Interesting noted fact was overrepresentation of coexistence of -174GC genotype with -596GG genotype (-174GC/-596GG) in the control group in comparison to the study group (10.7 vs. 2.0%, p = 0.00166). Furthermore, only in the PTD group coexistence of -174GC/-596AA genotypes has been observed (1.3 vs. 0.0% in controls). Conclusion: Significant correlation between -596G>A, -174G>C IL-6 gene polymorphisms and PTD risk has been shown. Analysis of the prevalence of genotypes and alleles of investigated polymorphisms suggests the most significant role of polymorphic variants of IL-6 gene in the etiology of PTD in women delivering between 28 and 32 gw.