Hepatitis C minimal residual viremia (MRV) detected by TMA at the end of Peg-IFN plus ribavirin therapy predicts post-treatment relapse

BACKGROUND/AIMS: Around 15-25% of chronic hepatitis C patients treated with Peg-IFN plus ribavirin become HCV-RNA negative by PCR during therapy but relapse after its withdrawal. We investigated whether minimal residual viremia (MRV) might be detected in these cases by Transcription-Mediated Amplification (TMA). METHODS: Two hundred and ninety-two consecutive patients (143 HCV-1, 82 HCV-2, 56 HCV-3 and 11 HCV-4) were prospectively treated with a standard schedule of Peg-IFNalpha 2b plus ribavirin combination and end-of-therapy response was assessed by conventional PCR using 2 protocol serum samples obtained 6-8h before the last two scheduled weekly injections of Peg-IFN. PCR negative samples were re-tested by TMA and the results were then correlated with the virological outcome after therapy withdrawal. RESULTS: Among 208 patients who were repeatedly HCV-RNA negative by PCR at the end-of-therapy, 26 (12.5%) were found HCV-RNA positive by TMA. Twenty-two of them, (96%) were PCR-relapsers after therapy withdrawal, compared to only 14% of the 182 TMA negative patients (P<0.0001). This virological profile was more frequent in HCV-1 and HCV-3 infected patients and correlated with a slower virological response during therapy. CONCLUSIONS: At the end of Peg-IFN plus ribavirin therapy, TMA is superior to PCR in identifying patients with sustained HCV-RNA clearance.