Association of interleukin-16 polymorphisms with disease progression and susceptibility in endometriosis

Interleukin-16 (IL-16) is a multifunctional pro-inflammatory cytokine that was previously found in association with complex disorders, and it is now cleared that this cytokine plays a critical role in regulation of cellular functions such as homoeostasis. Due to the complexity of endometriosis and its resemblance to cancer, we designed present case-control study to determine the effects of genetic polymorphisms of the human IL-16 gene on Iranian women's susceptibility to endometriosis. A total of 126 patients with endometriosis (stages I-IV) and 144 healthy women as control group were recruited to the study. We genotyped four single nucleotide polymorphisms of IL-16 gene (rs11556218 T>G, rs4778889 T>C, rs4072111 C>T and rs1131445 C>T). Genotyping was performed using PCR and restriction fragment length polymorphism. Our results showed that genotype distribution in two exonic polymorphisms including rs11556218 and rs4072111 was significantly different between Endometriosis patients and healthy individuals (P < 0.05). We have also found an association between rs4072111 and rs1131445 with progression to the severe stages (III-IV) of endometriosis (P < 0.05). Finally, we may conclude that IL-16 gene polymorphisms are highly associated with increased risk of endometriosis and could be considered as a susceptibility factor for endometriosis.