Interleukin-17F gene polymorphism in patients with chronic immune thrombocytopenia

Abstract

Introduction: IL‐17F is a novel inflammatory cytokine and plays an important role in some autoimmune diseases. We investigated the association between chronic ITP and the frequency of the single‐nucleotide polymorphism rs763780 (7488T/C), which causes a His‐to‐Arg substitution at amino acid 161. Patients and methods: We examined 102 patients (men/women, 40/62; median age, 42) diagnosed with chronic ITP and 188 healthy controls (men/women, 78/110; median age, 38). Genotyping was determined by the polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) technique. Results: Compared with the control group, patients with chronic ITP had a significantly lower frequency of the IL‐17F 7488CC genotype (0% vs. 4.8%, P < 0.05). The number of IL‐17F 7488C alleles among the patients with chronic ITP was also significantly lower than in the control group (8.7% vs. 15.2% OR = 0.48, 95%CI = 0.27–0.84, P = 0.016). Furthermore, patients with the IL‐17F 7488TT genotype showed a severe thrombocytopenic state (platelet count < 10×10⁹/L) at diagnosis than those with the IL‐17F 7488TC genotype (20.9% vs. 0%, P = 0.04). Conclusion: These findings suggest that the IL‐17F 7488 T allele is significantly associated with the development of chronic ITP, suggesting a role for IL‐17F in the pathogenesis of chronic ITP.