Interleukin-17A and-17F Gene Polymorphisms in Chinese Population with Chronic Immune Thrombocytopenia

Background. A case-control study was conducted to evaluate the influence of interleukin (IL)-17A and -17F gene polymorphisms on the risk of primary chronic immune thrombocytopenia (ITP). Methods. The study included 146 Chinese chronic ITP patients and 137 healthy controls. IL-17A G197A and IL-17F A7488G polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results. No significant difference in frequencies of IL-17A G197A genotypes and alleles was found between ITP patients and healthy controls, whereas frequencies of IL-17F A7488G allele A were significantly higher in ITP patients than that in healthy controls (31.85% vs. 18.98%; P<0.01). More specifically, patients with ITP had significantly higher frequencies of the IL-17F A7488G AA and AG genotypes compared with healthy controls (AA: 17.12% vs. 9.49%, P=0.02; AG: 29.46% vs. 18.98%, P=0.02). Logistic regression analysis revealed that AA and AG genotypes of IL-17F A7488G were associated with increased risk of ITP (AA: odds ratio (OR)=2.33, 95% CI 1.11-4.89; AG: OR=2.03, 95% CI 1.14-3.61). Conclusion. Our results suggest that SNPs in IL-17F A7488G but not IL-17A are associated with the development of chronic ITP in China.