Influence of interleukin-6 gene polymorphism on the efficacy of antiviral treatment in patients with chronic hepatitis C

Abstract

Aim. The aim of the work was to determine the influence of interleukin-6 gene polymorphism on the effectiveness of antiviral therapy in patients with chronic hepatitis C. Materials and methods. A total of 83 patients with chronic hepatitis C (CHC). were included in the study. The efficacy of therapy with the peg-IFNα + SOF + RBV was analyzed depending on the polymorphism of interleukin-6 gene (rs1800795). Results. All CHC patients with the CC genotype (14 – 100 %) responded to antiviral therapy with the peg-IFNα + RBV + SOF, but only 85.5 % of the patients with CG/GG genotypes responded (59 of the 69). In CHC patients with CG/GG genotypes, who responded to the therapy by SVR 24 formation, the HCV-RNA negativization was slower, in contrast to patients with the CC genotype, who showed a persistent absence of the virus in the blood from the 4th week of treatment. All patients with the CC genotype of IL-6 gene polymorphism presented complete normalization of ALT activity at this time if SVR 24 had been achieved. In the vast majority of CHC patients with SVR 24 and the CG/GG genotype after the therapy cessation, ALT activity continued to decrease and normalized after 24 weeks of observation in 94.9 % (56 of the 59). However, 20.0 % of patients with the CG/GG genotype who did not respond with the formation of SVR 24, had elevated serum ALT activity at the time of SVR 24 evaluation. Kendall’s rank correlation was performed to determine the factors, which statistically significantly affect the results of peg-IFNα + RBV + SOF therapy. IL-6 gene polymorphism had an effect on the efficacy of therapy, both on the HCV-RNA negativization in the blood at the end of treatment (P = 0.04) and on the achievement of SVR 24 (P = 0.03). The lack of response as well as the lack of SVR 12 and SVR 24 formation at the time of therapy completion were associated with the IL-6 gene CG/GG polymorphism presence and a higher index of ALT activity at the beginning of treatment (τ = -0,18, P < 0.01). Conclusions . In CHC patients, the CC genotype of IL-6 gene (rs1800795) is a favorable prognostic factor for the formation of SVR24 in the treatment of peg-IFNα + RBV + SOF. Patients who did not respond to the treatment by SVR 24 formation had only the IL-6 gene CG/GG polymorphism. Even in HCV patients with CG/GG genotypes who responded to the treatment by SVR 24 formation, the negativization of HCV-RNA in the blood was slower, unlike the patients with CC genotype. The absence of response at the time of therapy completion, as well as the absence of SVR 12 and SVR 24, were associated with the presence of the IL-6 gene CG/GG polymorphism and a higher level of ALT activity at the beginning of therapy (τ = -0,18, P < 0.01).