[Association between the influential factors and the effectiveness of pegylated interferon alpha-2a plus ribavirin as a combination treatment for chronic hepatitis C patients].

To evaluate the efficacy and to investigate the association between the length of the treatment period and the cumulative dose of pegylated interferon alpha-2a (PegIFN alpha-2a) plus ribavirin (RBV) and the effectiveness of antiviral therapy. We analyzed data from 117 patients treated for 48 weeks with PEG-IFN alpha-2a (135mug or 180mug/week) plus weight-based RBV (800 mg/d for patients is less than or equal to 65 kg, 1000 mg/d for patients 65-75 kg and 1200 mg/d for patients is more than or equal to 75 kg) under care at West China Hospital. HCV RNA was assessed at baseline, Week 4, 12 and 24, the end of treatment (EOT) and after 24 weeks follow-up (sustained virological response; SVR) with a test range of 1.010(3) to 5.010(7) IU/ml. Patients were stratified by age, gender, weight, route of transmission, duration of infection, baseline HCV RNA level and PegIFN alpha-2a or RBV dosage. HCV genotype was assessed in 29 patients (genotype 1b, 21; genotype 2a, 7; genotype 1b/2a, 1). Rapid virological response (RVR; HCV RNA negative at week 4), complete early virological response (cEVR; HCV RNA negative at week 12), EOT response, and SVR were achieved in 88 (75.2%), 110 (94%), 114 (97.4%) and 96 (82.1%) patients, respectively. Younger age, lower weight and shorter speculated infection years were associated with higher SVR rates (91.4% vs 72.9%, x2=6.796, P value is less than 0.05; 85% vs 50%, x2=5.433, P value is less than 0.05; 96.7% vs 77%, x2=5.852, P value is less than 0.05). SVR significantly increased with treatment length (38.5%, 66.7%, and 88.8% for is less than or equal to 29 weeks, 29-38 weeks, and is more than or equal to 38 weeks, respectively). SVR significantly increased with total cumulative treatment doses (38.5%, 66.7% and 88.8% for is less than or equal to 60%, 60%-80% and is more than or equal to 80% of PegIFN dose respectively; 33.3%, 85.3% and 96.8% for is less than or equal to 60%, 60%-80% and is more than or equal to 80% in RBV dose respectively) in all patients. Less than 80% of standard dose of RBV was not sufficient even if given enough PegIFN (is more than or equal to 80% cumulative treatment dose) in patients who achieved RVR. Chinese patients treated with peginterferon alpha-2a plus ribavirin have high rates of SVR. It is important to complete the target length of treatment and to continue the target dosage to achieve SVR.