High predictability of a sustained virological response (87%) in chronic hepatitis C virus genotype 1 infection treatment by combined IL28B genotype analysis and γ-glutamyltransferase/alanine aminotransferase ratio: a retrospective single-center study.

BACKGROUND: Chronic hepatitis C virus genotype 1 (HCV-G1) infection is treated with pegylated interferon-α and ribavirin. Predictive factors for treatment success are even more important now as direct-acting antiviral agents are available.
METHODS: Clinical and laboratory parameters were analyzed by uni- and multivariate statistical means in 264 patients with HCV-G1 infections with regard to treatment outcome.
RESULTS: The overall sustained virological response (SVR) rate was 44%. Univariate analyses revealed SVRs to be associated with age, high alanine aminotransferase (ALT) and low γ-glutamyltransferase (γ-GT) serum activities, a low pretreatment γ-GT/ALT ratio, rapid virological response (RVR), and absence of steatosis. Multivariate analyses unveiled IL28B rs12979860 genotype (CC vs. CT: OR = 2.8, CI: 1.5-4.9, p = 0.001; CC vs. TT: OR = 7.1, CI: 3.1-16.7, p < 0.001), low pretreatment γ-GT/ALT ratio (OR = 2.5, CI: 1.7-3.3, p < 0.001), age (OR = 0.96, CI: 0.94-0.98, p = 0.001) and RVR (OR = 4.18, CI: 2.85-8.65, p < 0.001) to be significantly related to treatment outcome. Patients with the IL28B rs12979860 CC genotype and a low pretreatment γ-GT/ALT ratio achieved the highest rate of a SVR with the highest predictive values (OR = 26.7, 95% CI: 10-71.1, p < 0.0001).
CONCLUSION: The pretreatment γ-GT/ALT ratio significantly enhances the predictability of the IL28B genotype. Employing this combination will help to identify patients who will most likely benefit from an interferon-α-based combination therapy in a nontriaged ordinary setting.