Genetic polymorphisms of interleukin-6 modulate fibrosis progression in mild chronic hepatitis C

Abstract

Genetic polymorphisms of interleukin-6 (IL-6) (-1363G>T, -597G>A, -572G>C, -174G>C, +2954G>C) may affect the outcomes of several diseases. This study was aimed to verify the role of these polymorphisms on the disease progression of patients with hepatitis C virus (HCV) infection and persistently normal transaminases (PNALT). A total of 121 PNALT patients did not receive any antiviral treatment but underwent periodic clinical monitoring, including repeat biopsies, for a median of 120 months. IL6-1363G>T, -597G>A, -572G>C, -174G>C, +2954G>C polymorphisms were related to histologic fibrosis progression. Among patients whose grading and staging scores increased at the end of the follow-up ≥2 Ishak points (N = 60 and N = 26, respectively), IL-6 -174G>C genotype frequencies were GG 37/66, GC 21/45, CC 2/10 (p = 0.041) and GG 18/66, GC 8/45, CC 0/10 (p = 0.040), respectively. The following frequencies were observed for the 572G>C polymorphism: GG 50/105, GC 10/16, CC 0/0, and GG 19/105, GC 7/16, CC 0/0, respectively. Grading progression was independently associated with carriage of the G allele in -174G>C polymorphism (oddd ratio = 5.07%, 95% confidence interval = 0.959-26.8, p = 0.023). Staging progression was independently associated with carriage of the C allele in -572G>C polymorphism (odd ratio = 4.60%, 95% confidence interval 1.42-14.8, p = 0.012). IL-6 polymorphisms influence histologic progression of HCV in patients with PNALT.