Hepatitis C virus Core Antigen as a predictor of non-response in genotype 1 chronic hepatitis C patients treated with peginterferon alpha-2b plus ribavirin.

Background/aims: Chronic hepatitis C patients infected by genotype 1 are the least responsive to combination therapy and therefore monitoring response is important in identifying non-responders quickly, permitting therapy discontinuation and avoiding side effects and costs. We examined the usefulness of measuring total HCV Core Ag in early treatment with peginterferon alpha-2b and ribavirin in genotype 1 patients in the prediction of response and compared the results with those from HCV RNA quantification.
Methods: Two hundred and sixty-eight serum samples from 46 genotype 1 patients receiving combination therapy were examined for HCV Core Ag and quantitative HCV RNA.
Results: At baseline, mean HCV RNA and HCV Core Ag concentrations were significantly lower in sustained virologic responders than in non-responders. The negative predictive value of HCV Core Ag testing in predicting non-response at week 12 is 100%, and for a 2 log drop in HCV RNA, using two quantitative tests, it is 88%.
Conclusions: HCV Core Ag determination allows the identification of non-responders with only one test at week 12 and permits stopping therapy in these patients. HCV Core Antigen testing is cheaper and easier to perform than HCV RNA quantification.