HCV Ag quantification as a one‐step procedure in diagnosing chronic hepatitis C infection in Cameroon: the ANRS 12336 study

Abstract

Introduction: The diagnostic procedure for chronic hepatitis C infection (CHC) usually combines anti-HCV antibody (HCV-Ab) and HCV-RNA measurement. Quantifying HCV core antigen (cAg) as a one-step procedure could shorten the diagnostic process. We aimed to assess the performance of cAg quantification in diagnosing CHC and how it is influenced by concomitant HIV or HBV infections.Methods: The cAg was quantified by an automated assay (Abbott Diagnostics) in 465 HCV-Ab negative serum samples and 544 HCV-RNA positive serum samples (n = 1009) collected in patients from the Pasteur Center in Cameroon, some of whom were infected by HBV or HIV. Its performance was evaluated in comparison to the gold standard (ELISA or PCR) by estimating its sensitivity (Se) and specificity (Sp), and by comparing the area under ROC (AUROC) curves in each patient population: HCV mono-infected, HCV-HBV and HIV-HCV co-infected.Results: Among the 465 HCV-Ab negative patients, 51 and 79 were HIV- and HBV-infected, respectively, whereas among the 544 patients with CHC, 27 and 28 were HIV- and HBV-infected, respectively. The Spearman ρ correlation coefficient between cAg and HCV-RNA was 0.75 (p < 0.00001). The assay had a sensitivity of 95.7% (95% CI: 93.2–97.5) and a specificity of 99.7% (95% CI: 98.1–10) in diagnosing CHC, corresponding to an AUROC of 0.99 (95% CI: 0.98–1.0). Being HIV- or HBV-infected did not impact the performance of cAg (Se = 96.4%, Sp = 96.2% and AUROC = 0.98 (95% CI: 0.95–1.0) in the HBV group, Se = 100%, Sp = 88.2% and AUROC = 0.99 (95% CI: 0.97–1.0) in the HIV group, p between AUROC = 0.69).Conclusions: The cAg quantification displayed a high specificity and sensitivity for the diagnosis of CHC in Cameroon, and its performance was not significantly modified by a concomitant HIV or HBV infection. In the context of CHC elimination on a global scale, using cAg quantification as a screening tool to directly identify CHC could be a reliable tool in a “test and treat” strategy.

Hepatitis C virus surveillance and identification of human pegivirus 2 in a large Cameroonian cohort

“…Of these viremic patients, 123 were also HIV positive, including 7 HIV‐HBV‐HCV triple infections (Figure ). The resulting prevalence of HCV RNA within the HIV‐positive group (2.6%, 95% CI: 2.2%‐3.14%) was similar to the overall prevalence, while the rate amongst HBV‐positive participants (0.93%, 95% CI: 0.52%‐1.66%) was lower than that of HBV‐negative participants or the overall prevalence (Figure ), consistent with previous reports . Notably, the prevalence of HCV RNA was nearly twice as high amongst males (3.81%, N = 99/2599) compared to females (2.05%, N = 127/6199, Figure ).…”

Research priorities to achieve universal access to hepatitis C prevention, management and direct-acting antiviral treatment among people who inject drugs

“…In addition to existing high-throughput, laboratory-based platforms, simplified HCV diagnostics using HCV core antigen are also under development and may serve as an alternative to HCV RNA testing, particularly in low- and middle-income settings, and as a one-step diagnostic for high prevalence contexts, such as testing services for PWIDs (Cohn et al, 2015; Duchesne et al, 2017; Freiman et al, 2016; Lamoury et al, 2017; UNITAID, 2015). Obviating the need for serological screening will also benefit HIV-coinfected people, where the accuracy of HCV serology can be significantly compromised.…”

Approaches for simplified HCV diagnostic algorithms

“…The evaluation of these assays compared to HCV RNA was recently presented in a meta‐analysis with Abbott HCV cAg assay and the ORTHO ELISA‐Ag test showing the highest sensitivity (up to 93.4% and 93.2% respectively), with very high specificity (>98%). In the French ANRS 12336 study , the Abbott HCV cAg quantification displayed high performances also in HIV and HBV co‐infected patients from Cameroon. Quantitative data are also available with the Abbott HCV cAg assay showing a close correlation between HCV cAg and HCV RNA at viral loads (VL) above 3000 IU/ml.…”