Interleukin-1 alpha but not interleukin-1 beta gene polymorphism is associated with polycystic ovary syndrome

Interleukin-1 (IL1) is a multifunctional cytokine and IL1-mediated inflammatory processes have been proposed to influence the processes of ovulation, fertilization and implantation. All these parameters are also affected in women with polycystic ovary syndrome (PCOS). This study investigated the association of common polymorphisms of the interleukin-1 genes (IL1A and IL1B) with the occurrence and clinical characteristics of PCOS. We evaluated one polymorphism of the IL1α gene (IL1A C[−889]T) and two of the IL1β gene (IL1B promoter C[−511]T and IL1B exon 5 position +3953) in 105 Caucasian women with PCOS and 102 healthy Caucasian controls by polymerase chain reaction. For the mutated IL1A allele, allele frequencies in women with PCOS and controls were 60% and 46%, respectively, versus 40% and 54%, respectively, for the wild type allele. Allele frequencies in women with PCOS and controls were 59% (54%) and 61% (41%), respectively, for the mutated IL1B promoter (mutated IL1B exon 5) and 41% (46%) and 39% (59%), respectively, for the wild type alleles. Presence of a polymorphism in the interleukin-1α but not the interleukin-1β gene was found to correlate with the occurrence of PCOS (p = 0.04; odds ratio 1.8). The serum level of FSH and subsequent LH/FSH ratio correlated with the polymorphism of IL1A within the PCOS group (p = 0.005 and 0.01, respectively). We have shown that a common polymorphism of the interleukin-1α but not interleukin-1β gene is associated with the presence of PCOS and with clinical parameters of women affected by this condition.