Anti-HCV Core Protein Polyclonal antibody

Background: Hepatitis C virus (HCV) genotype is a predictive marker for treatment response. We sequentially evaluated the performances of two nucleic acid amplification tests (NAATs) and one serology assay for HCV genotype: Abbott RealTime genotype II (RealTime II), GeneMatrix restriction fragment mass polymorphism (RFMP), and Sysmex HISCL HCV Gr (HISCL Gr). Methods: We examined 281 clinical samples with three assays. The accuracy was assessed using the HCV Genotype Performance Panel PHW204 (SeraCare Life Sciences) for two NAATs. Discrepant cases were re-genotyped by the Versant HCV v. 2.0 (line probe 2.0) assay. Results: With the RealTime II assay, clinic samples were analyzed as follows: genotypes 1b (43.1%), 2 (40.2%), 1 subtypes other than 1a and 1b (12.5%), 3 (1.8%), 4 (1.4%), 1a (0.7%), 6 (0.4%), and mixed (1.1%). The RealTime II and RFMP assays showed a type concordance rate of 97.5% (274/281) (. = 0.80) and no significant discordance (p = 0.25). Both assays accurately genotyped all samples in the Performance Panel by the subtype level. The HISCL Gr assay showed concordance rates of about 91% (. < 0.40) and statistically significant discordances with two NAATs (p < 0.05). In confirmation tests, the results of RFMP assay were the most consistent with those of Versant 2.0 assay. Conclusions: The three HCV assays provided genotyping and serotyping results with good concordance rates. The two NAATs (RealTime II and RFMP) showed comparable performance and good agreement. However, the results of the HISCL Gr assay showed statistically significant differences with those of the NAATs.

Background: Simple, affordable diagnostic tools are essential to facilitate global hepatitis C virus (HCV) elimination efforts. Objectives: This study evaluated the clinical performance of core antigen (HCVcAg) assay from plasma samples to monitor HCV treatment efficacy and HCV viral recurrence. Study design: Plasma samples from a study of response-guided pegylated-interferon/ribavirin therapy for people who inject drugs with chronic HCV genotype 2/3 infection were assessed for HCV RNA (AmpliPrep/COBAS Taqman assay, Roche) and HCVcAg (ARCHITECT HCV Ag, Abbott Diagnostics) during and after therapy. The sensitivity and specificity of the HCVcAg assay was compared to the HCV RNA assay (gold standard). Results: A total of 335 samples from 92 enrolled participants were assessed (mean 4 time-points per participant). At baseline, end of treatment response (ETR) and sustained virological response (SVR) visits, the sensitivity of the HCVcAg assay with quantifiable HCV RNA threshold was 94% (95% CI: 88%, 98%), 56% (21%, 86%) and 100%, respectively. The specificity was between 98 to 100% for all time-points assessed. HCVcAg accurately detected all six participants with viral recurrence, demonstrating 100% sensitivity and specificity. One participant with detectable (non-quantifiable) HCV RNA and non-reactive HCVcAg at SVR12 subsequently cleared HCV RNA at SVR24. Conclusions: HCVcAg demonstrated high sensitivity and specificity for detection of pre-treatment and post-treatment viraemia. This study indicates that confirmation of active HCV infection, including recurrent viraemia, by HCVcAg is possible. Reduced on-treatment sensitivity of HCVcAg may be a clinical advantage given the moves toward simplification of monitoring schedules.