008). In the British cohort, there were significantly more male patients (P < 0.01). The characteristics of the study cohort are shown in Table 1. An independent confirmation cohort of 377 HCV type 1–infected

patients from Germany was additionally analyzed (for main characteristics, see Supporting Ivacaftor molecular weight Table 2). Chronic HCV infection was diagnosed by positive anti-HCV test and by HCV RNA presence in serum for more than 6 months. All patients were treated with the dual combination therapy of Peg-IFN and RBV. They received the recommended doses and were adherent. Treatment duration ranged from 48 to 72 weeks, depending on the individual treatment response. A standard treatment duration of 48 weeks was applied in 872 patients (93%). An individualized treatment regimen, according to early virologic response pattern with more than 48 weeks, was given to 70 patients (7%) being part of the INDIV-2 study, as described BAY 80-6946 solubility dmso previously.33 Four hundred and ninety-five (54%) patients had sustained virological response (SVR), determined as undetectable HCV RNA levels 6 months after completion of therapy. All other patients were classified as patients with nonsustained virological response (non-SVR). The non-SVR cohort included patients with either nonresponse (N = 336) or relapse (n = 113). Nonresponse was defined as either <2log decline at week

12 or detectable viremia at week 24. Relapse was characterized as HCV RNA undetectable at the end of treatment, but detectable after treatment completion. The study was approved by the local ethic committees, and written informed consent for genetic testing was obtained from all participants. Although data of some cohort parts were already available by GWAS,16 the patients’ DNA samples were analysed anew for the IL28B SNPs, rs12979860, rs8099917, rs12980275, and rs8103142. Genotyping of rs12980275 and rs8103142 was done in only 931 and 605 patients, respectively. For genotyping, Molecular motor we performed real-time polymerase chain reaction (PCR) and melting curve analysis in the Light Cycler 480 System (Roche,

Mannheim, Germany), or we sequenced the specific regions of the IL28B gene. DNA was extracted from whole blood samples with an extraction kit from QIAGEN (Hilden, Germany). Primers and hybridization probes were obtained from TIB MOLBIOL (Berlin, Germany). Primer and probe sequences and PCR conditions are presented Supporting Table 1. Sequencing was performed with the BigDye Terminator and a capillary sequencer from Applied Biosystems (Darmstadt, Germany). Statistical analysis was performed with SPSS 18.0 (SPSS, Inc., Chicago, IL) and R 2.11.0 (www.r-project.org). The significance of differences was assessed in contingency tables by Pearson’s chi-squared test and Fisher’s exact test. All tests were two-sided, and P values less than 0.05 were considered to be statistically significant. The odds ratio (OR) and the 95% confidence interval (CI) were calculated.