IL-28B polymorphisms and treatment response in hepatitis C virus patients with persistently normal alanine aminotransferase

Aim: To examine the association between the interleukin 28B (IL-28B) genotype and treatment response in hepatitis C virus (HCV)-infected patients with persistently normal alanine aminotransferase (PNALT).

Methods: We compared the treatment response of HCV-infected patients with PNALT to that of patients with non-PNALT. Between February 2010 and April 2013, 278 patients infected with HCV were enrolled in this study. All of the patients were treated with peginterferon-alpha 2a or 2b plus ribavirin. In addition, 180 μg of peginterferon alpha-2a or 1.5 μg/kg peginterferon alpha-2b per week plus weight-based ribavirin (600-1000 mg/d) were typically administered for 24 wk to HCV genotype 2-infected patients or for 48-72 wk to HCV genotype 1-infected patients. In all of the patients, the IL-28B rs8099917 genotype was determined using a TaqMan single-nucleotide polymorphism assay. HCV RNA was measured using the COBAS TaqMan HCV test.

Results: Female patients were dominant in the PNALT group (P < 0.0001). Among 72 HCV genotype 1-infected patients with PNALT, the early virologic response (EVR) rates (P < 0.01) and the sustained virologic response (SVR) rates (P < 0.01) were higher in patients with the IL-28B TT genotype than in those with the IL-28B TG/GG genotype. In HCV genotype 1-infected patients with PNALT, multivariate logistic-regression analysis showed that SVR was independently predicted by the IL-28B rs8099917 TT type (P < 0.05) and having an EVR (P < 0.01). The IL-28B rs8099917 TT genotype strongly correlated with treatment response in HCV genotype 1-infected Asian patients with PNALT.

Conclusion: The IL-28B genotype may be useful for selecting HCV genotype 1-infected patients with PNALT who should receive interferon-based treatment.