Cytokine gene polymorphisms in northern Indian women with recurrent miscarriages

Objective: To determine association of cytokine gene polymorphism with risk for recurrent miscarriages (RM). Design: Retrospective case-control study on northern Indian RM cases versus control subjects. Setting: Medical facility. Patient(s): A total of 200 women with at least three unexplained spontaneous abortions before 20 weeks of gestation. Intervention(s): Subjects were genotyped by polymerase chain reaction amplification followed by restriction digestion and allele-specific oligonucleotides. Main Outcome Measure(s): Detection of pro- and antiinflammatory gene polymorphism genotypes and allele frequencies. Result(s): We applied dominant and recessive models of inheritance, showing no association among T_H2 [interleukin (IL) 10 (592 C/A) and transforming growth factor β] gene polymorphisms, while significant association was observed between T_H2 [IL-4 (C590T), IL-6 (G174C), IL-10 (1082A/G and 819C/T)], and T_H1 [interferon-γ (+874A/T)] with RM compared with control subjects. However, when classification and regression tree analysis was applied, this effect disappeared and demonstrated that IL-10 plays an important role in maintenance of pregnancy. Conclusion(s): Interleukin-10 acts as an immunosuppressive by keeping a balance of pro- and antiinflammatory signals that coordinate the satisfactory development of pregnancy, placental growth, and remodeling for favorable pregnancy outcome.