The clinical significance of HCV core antigen detection during Telaprevir/Peg-Interferon/Ribavir in therapy in patients with HCV 1 genotype infection

Background: Direct-acting antiviral drugs (DAA) regimen improve the SVR rate. However, adverse effects often lead to therapy interruption. This underlines the importance to find some predictive parameters of response in order to consider the possibility of a shorter time of antiviral treatment in the appearance of adverse effects without affecting the success of the therapy. Objectives: We aimed to examine the HCVAg kinetics in the early phase of treatment and its predictive value of SVR in patients undergoing TPV/Peg-IFN/RBV treatment. Study design: Twenty-three patients infected by HCV genotype 1 (1a n = 11; 1b n = 12) were included in this prospective study. Results: At baseline the median Log of HCVAg concentration in RVR and EVR patients were 3.15 fmol/L and 3.45 fmol/L, respectively with no significant differences. The baseline median HCV-RNA to HCVAg ratio was 233.77, this ratio was significantly lower when measured on day 1 (27.52) and on day 6 (24.84) (p < 0.001). The two-tailed Fisher's exact test indicated that the SVR response is statistically significantly different in patients with detected HCVAg at week1 compared to patients with no detectable HCVAg (p = 0.05). The sensitivity, specificity, and negative and positive predictive values (NPV, PPV) were 53.8, 87.5, 53.8 and 87.5%, respectively. The area under the ROC curve was 0.71 at day T6, the best cut-off of 3 fmol/L when evaluated with the HCVAg plasma concentration at dayT6. Conclusion: Undetectable HCVAg in the early phase of TPV/Peg-IFN/RBV treatment could represent an important parameter for predicting SVR.