Gastroenterology Section, University of Chile Clinical Hospital , Santiago, Chile .
Lambda interferon IL-28A/B and IL-29 serum levels have been associated with the course of hepatitis C virus (HCV) infection. However, there is not information about these cytokine in patients with antiviral therapy. We investigated IL-28A/B and IL-29 serum levels in 45 samples from patients chronically infected with HCV genotype 1, and undergoing therapy with PEG-IFN/RBV, at baseline and after 12 weeks of therapy, comparing those that developed a sustained virologic response (SVR) with null responders (NR). IL-28B polymorphisms (rs12979860, rs12980275, and rs8099917) were also considered. We found that, IL-28A/B and IL-29 levels were not significantly different between SVR and NR patients at baseline or after 12 weeks of therapy. TT rs8099917 genotype carriers had significantly higher IL29 levels at baseline (60.5 vs 19.5 pg/mL; p=0.045) and after 12 weeks of therapy (35 vs 16.5 pg/mL; p=0.023) than non-TT carriers. In conclusion, there were no differences in IL-28A/B or IL-29 levels according to response to therapy, suggesting that these cytokines do not play an important role in viral elimination during treatment, at least not during the first 12 weeks of therapy. Genotypes associated with high IL-28B levels may be related to a mechanism of protection against infection but are not involved in the response to antiviral therapy.