Er 24 weeks of standard-of-care, these patients remained at a great risk of liver disease progression.[2,29] However, standard strategies toward treatment-experienced HCV-2 patients has not been clearly setup. Discordant results regarding HCV-1 retreatment by interferon-based therapy have been observed across studies.[30] Similarly, an SVR rate of ranging from 31 to 79 has been reported in small-scale studies of HCV-2 retreatment (table 6). [22?8] The divergent reports might be attributed to the limited sample size and the diverse patient characteristics. A variety of previous and current treatment regimens might also 47931-85-1 biological activity account for the inconclusive results. Basso et al.[23] has reported an SVR rate of 78.6 in previous relapsers, in which study patients who failed to eradicate HCV infection by conventional interferon (3 MU 117793 thrice weekly)/ribavirin were retreated with suboptimal pegylated interferon alpha-2b (1 mg/kg/week) plus ribavirin (800?200 mg/day) for 24 weeks. In the current study, 25331948 we demonstrated a similar SVR rate for previous relapsers retreated with 24 weeks of peginterferon/weight-based ribavirin. The treatment efficacy remained consistent irrespective of the previous treatment regimen. The finding might provide more insight for clinicians 15900046 in daily practice because pegylated interferon/ribavirin has been the standard of care for a decade, and most of the HCV-2 treatment experienced patients nowadays might have received an optimal regimen previously. It raised the issue that extending therapy to 48 weeks might be beneficial for certain ?treatment naive patients with unfavorable early viral kinetics and researches that identify the potential candidates for 
prolonged treatment remain elusive.[19] A common finding in studies regarding HCV-1 retreatment was that compared with previous relapsers, non-responders had significantly worse retreatment outcomes.[30] However, this was not always the case in HCV-2 studies. Jacobson et al. [25] reported an SVR of 5 for non-responders who received 48 weeks of pegylated interferon alpha-2b (1.0?.5 mg/kg/week) plus ribavirin (800?200 mg/day) combination therapy. On the contrary, an SVR rate of 57?5 for non-responders has been reported by other studies.[26,28] None of the non-responders inTable 4. Univariate analysis of factors associated with sustained virological response in previous relapsers.SVR (+) (n = 33) Rs8099917 TT genotype, n ( ) Male sex, n ( ) Age (yrs, mean(SD)) Body weight, kg, mean (SD) Baseline HCV RNA (log IU/ml, mean(SD)) Baseline HCV RNA . 400,000 IU/mL, n ( ) APRI, mean (SD) AST (IU/l, mean (SD)) ALT (IU/l, mean (SD)) Previous optimal treatment regimen*, n ( ) RVR (+), n ( ) EVR (+), n ( ) 29 (87.9) 18 (54.5) 57.7 (10.4) 63.9 (8.6) 5.29 (0.82) 15 (45.5) 2.04 (1.49) 111.4 (78.6) 169.1(141.3) 20 (60.6) 28 (84.8) 33 (100)SVR(-) (n = 9) 7 (77.8) 5 (55.6) 62.1 (7.8) 62.9 (10.4) 5.78 (0.73) 5 (55.6) 1.81 (1.29) 99.3 (68.4) 146.8 (117.6) 8 (88.9) 5 (55.6) 7 (77.8)P value0.59 1 0.24 0.78 0.11 0.71 0.67 0.68 0.67 0.23 0.08 0.Note: SD: standard deviation; SVR: sustained virological response; RVR: rapid virological response; EVR, early virological response. AST: aspartate aminotransferase; ALT: alanine aminotransferase; APRI: aspartate aminotransferase-to-platelet ratio index.* defined as patients who had received 24 weeks of peginterferon/ribavirin. doi:10.1371/journal.pone.0058882.tHCV-2 RetreatmentTable 5. Accuracy of the achievement of a RVR and an EVR in predicting an SVR.On t.Er 24 weeks of standard-of-care, these patients remained at a great risk of liver disease progression.[2,29] However, standard strategies toward treatment-experienced HCV-2 patients has not been clearly setup. Discordant results regarding HCV-1 retreatment by interferon-based therapy have been observed across studies.[30] Similarly, an SVR rate of ranging from 31 to 79 has been reported in small-scale studies of HCV-2 retreatment (table 6). [22?8] The divergent reports might be attributed to the limited sample size and the diverse patient characteristics. A variety of previous and current treatment regimens might also account for the inconclusive results. Basso et al.[23] has reported an SVR rate of 78.6 in previous relapsers, in which study patients who failed to eradicate HCV 
infection by conventional interferon (3 MU thrice weekly)/ribavirin were retreated with suboptimal pegylated interferon alpha-2b (1 mg/kg/week) plus ribavirin (800?200 mg/day) for 24 weeks. In the current study, 25331948 we demonstrated a similar SVR rate for previous relapsers retreated with 24 weeks of peginterferon/weight-based ribavirin. The treatment efficacy remained consistent irrespective of the previous treatment regimen. The finding might provide more insight for clinicians 15900046 in daily practice because pegylated interferon/ribavirin has been the standard of care for a decade, and most of the HCV-2 treatment experienced patients nowadays might have received an optimal regimen previously. It raised the issue that extending therapy to 48 weeks might be beneficial for certain ?treatment naive patients with unfavorable early viral kinetics and researches that identify the potential candidates for prolonged treatment remain elusive.[19] A common finding in studies regarding HCV-1 retreatment was that compared with previous relapsers, non-responders had significantly worse retreatment outcomes.[30] However, this was not always the case in HCV-2 studies. Jacobson et al. [25] reported an SVR of 5 for non-responders who received 48 weeks of pegylated interferon alpha-2b (1.0?.5 mg/kg/week) plus ribavirin (800?200 mg/day) combination therapy. On the contrary, an SVR rate of 57?5 for non-responders has been reported by other studies.[26,28] None of the non-responders inTable 4. Univariate analysis of factors associated with sustained virological response in previous relapsers.SVR (+) (n = 33) Rs8099917 TT genotype, n ( ) Male sex, n ( ) Age (yrs, mean(SD)) Body weight, kg, mean (SD) Baseline HCV RNA (log IU/ml, mean(SD)) Baseline HCV RNA . 400,000 IU/mL, n ( ) APRI, mean (SD) AST (IU/l, mean (SD)) ALT (IU/l, mean (SD)) Previous optimal treatment regimen*, n ( ) RVR (+), n ( ) EVR (+), n ( ) 29 (87.9) 18 (54.5) 57.7 (10.4) 63.9 (8.6) 5.29 (0.82) 15 (45.5) 2.04 (1.49) 111.4 (78.6) 169.1(141.3) 20 (60.6) 28 (84.8) 33 (100)SVR(-) (n = 9) 7 (77.8) 5 (55.6) 62.1 (7.8) 62.9 (10.4) 5.78 (0.73) 5 (55.6) 1.81 (1.29) 99.3 (68.4) 146.8 (117.6) 8 (88.9) 5 (55.6) 7 (77.8)P value0.59 1 0.24 0.78 0.11 0.71 0.67 0.68 0.67 0.23 0.08 0.Note: SD: standard deviation; SVR: sustained virological response; RVR: rapid virological response; EVR, early virological response. AST: aspartate aminotransferase; ALT: alanine aminotransferase; APRI: aspartate aminotransferase-to-platelet ratio index.* defined as patients who had received 24 weeks of peginterferon/ribavirin. doi:10.1371/journal.pone.0058882.tHCV-2 RetreatmentTable 5. Accuracy of the achievement of a RVR and an EVR in predicting an SVR.On t.