Significance of IL-1Ra and IL-6 gene variants in Turkish patients with Crimean-Congo hemorrhagic fever

Objective: To investigate the association between IL-1Ra variable number of tandem repeat (rs2234663), IL-6 -597GA (rs1800797), IL-6 -572GC (rs1800796) and the risk of Crimean-Congo hemorrhagic fever (CCHF) in the Turkish patients. Methods: This study included 50 patients infected with CCHF and 50 healthy controls. These variants were genotyped using polymerase chain reaction and/or restriction fragment length polymorphism method. Results: The distribution of the IL-6 -572GC genotypes and alleles varied significantly between the patients and the controls. The subjects carrying IL-6 -572GC GG genotype and G allele had increased risk of developing CCHF compared to the control group ( P =0.006, P =0.014, respectively). IL-6 -572GC GC genotype was higher in the controls than the patients ( P =0.006). For the triple genotype combinations, the 1/2-GC-GG genotype combination was detected more frequently in the control group than CCHF patients ( P =0.016). IL-6 (-572/-597) GG-GG genotype was significantly higher in the patient group ( P =0.015), while the GC-GG genotype was significantly lower in the patient group ( P =0.005). Additionally, the G-G haplotype was significantly higher in the patient group ( P =0.042), whereas C-G was found to be significantly lower in the patients than the control group ( P =0.037). Conclusions: The results of this study suggest the IL-6 -572GC variant might be genetic markers of sensitivity to CCHF in the Turkish population and may facilitate greater protection against the disease.