Then, if the HCV RNA assay with higher sensitivity was used during the follow-up period, the HCV RNA could probably be detected in serum. This may be the cause LDP-341 for the higher reappearance rate detected in that study, compared to previous studies. Among the 8 patients who had reappearance of HCV in that study, only one patient had persistent viremia, 5 patients had transiently positive HCV RNA, and 2 patients were followed-up.21 It is possible that the transiently positive HCV RNA result may be false positive. Therefore, the reappearance rate can be considered as 1.4% (1/73). In a recent study, transient low levels of HCV RNA at single time points were detected in some serum samples during the follow-up, but they were all undetectable on retests.

19 Therefore, the authors reported that these transient positive tests probably represented false positive results.20 In our study, we also experienced one transient postive HCV RNA result which was undetectable on retest. It is not known whether patients who become HCV RNA detectable during follow-up experienced reinfection or reappearance. Another Korean study recently reported that the reappearance rate after SVR was 7.4% (5/68). This higher reappearance rate also may be due to using HCV RNA assay with lower sensitivity in early treatment period.22 In our study, among the 292 patients who achieved the SVR in response to PEG-IFN and ribavirin combination therapy, 224 were followed up for a median period of 18 months (range 6-60 months).

SVR was maintained in all Batimastat patients (n=224, 100%), including patients who were treated with decreased doses of PEG-IFN or ribavirin, therefore the durability of SVR was as high as in previous studies. When patients were treated with decreased doses of PEG-IFN or ribavirin, they had lower SVR.23 After achievement of the SVR, however, we found no relationship between the treatment dose and reappearance. This suggests that, after achievement of the SVR, intensive follow-up is not needed in patients treated with lower doses of PEG-IFN or ribavirin than in patients who received sufficient doses. In patients with CHC, achievement of the SVR has been associated with improvements in liver histology, as well as reduced risk of HCC and liver-related mortality. Similarly, in patients with HCV-related cirrhosis, achievement of the SVR after IFN therapy was associated with reduction of liver-related mortality lowering both the risk of complications and HCC development.13-15,24-26 However, in patients with advanced fibrosis or cirrhosis, achievement of the SVR cannot prevent completely the risk of HCC.23,27,28 In our study, there were two patients who achieved the SVR but developed HCC during the follow-up period.