BACKGROUND: Viral kinetics and host interleukin 28B (IL-28B) genotype determine treatment outcome in hepatitis C virus genotype 1 (HCV-1) infection. OBJECTIVES: We aimed to explore the interplay between interferon responsiveness at treatment week 4 and IL28B genotype in the achievement of a sustained virological response (SVR; undetectable HCV RNA 24-weeks after end-of-treatment). STUDY DESIGNS: Rs8099917 genotypes were determined in 528 HCV-1 patients with peginterferon/ribavirin. Interferon responsiveness were evaluated by the degree of week 4 viral reduction: <1 log(10) IU/mL, 1-2 logs(10) IU/mL, 2-3 logs(10) IU/mL, 3-4 logs(10) IU/mL and ≥4 logs(10) IU/mL reduction and/or undetectable HCV RNA, respectively. RESULTS: The SVR rate was significantly higher in patients with great interferon responsiveness at week 4. A great interferon responsiveness was associated with younger age (P < 0.0001), lower body mass index (P = 0.0056), lower aspartate aminotransferase levels (P = 0.0009), higher hemogloblin concentration (P = 0.0033), higher platelet counts (P < 0.0001), male gender (P < 0.0001) and rs809997 TT-genotype (P < 0.0001). Comparing to non-TT genotype patients, TT genotype patients had a significantly higher SVR rate with moderate viral reduction (1-3 logs(10) IU/mL) at week 4 (58.9% vs. 18.2%, P < 0.001), and the SVR rate did not differ between TT/non-TT patients on the extreme ends (<1 or >3 log(10) IU/mL reduction) of week 4 interferon responsiveness. For non-TT genotype carriers who were with <3 logs(10) reduction, none (0/15) could have a complete early virological response and only 10.9% (7/64) of the patients had an SVR. CONCLUSIONS: More profound interferon responsiveness is mandatory for HCV-1 patients with unfavorable IL-28B genotype.
BACKGROUND: Viral kinetics and host interleukin 28B (IL-28B) genotype determine treatment outcome in hepatitis C virus genotype 1 (HCV-1) infection. OBJECTIVES: We aimed to explore the interplay between interferon responsiveness at treatment week 4 and IL28B genotype in the achievement of a sustained virological response (SVR; undetectable HCV RNA 24-weeks after end-of-treatment). STUDY DESIGNS: Rs8099917 genotypes were determined in 528 HCV-1patients with peginterferon/ribavirin. Interferon responsiveness were evaluated by the degree of week 4 viral reduction: <1 log(10) IU/mL, 1-2 logs(10) IU/mL, 2-3 logs(10) IU/mL, 3-4 logs(10) IU/mL and ≥4 logs(10) IU/mL reduction and/or undetectable HCV RNA, respectively. RESULTS: The SVR rate was significantly higher in patients with great interferon responsiveness at week 4. A great interferon responsiveness was associated with younger age (P < 0.0001), lower body mass index (P = 0.0056), lower aspartate aminotransferase levels (P = 0.0009), higher hemogloblin concentration (P = 0.0033), higher platelet counts (P < 0.0001), male gender (P < 0.0001) and rs809997 TT-genotype (P < 0.0001). Comparing to non-TT genotype patients, TT genotype patients had a significantly higher SVR rate with moderate viral reduction (1-3 logs(10) IU/mL) at week 4 (58.9% vs. 18.2%, P < 0.001), and the SVR rate did not differ between TT/non-TT patients on the extreme ends (<1 or >3 log(10) IU/mL reduction) of week 4 interferon responsiveness. For non-TT genotype carriers who were with <3 logs(10) reduction, none (0/15) could have a complete early virological response and only 10.9% (7/64) of the patients had an SVR. CONCLUSIONS: More profound interferon responsiveness is mandatory for HCV-1patients with unfavorable IL-28B genotype.