Moving ahead in HCV diagnostics: Need for the introduction of HCV core antigen assay in low and middle-income countries

Hepatitis C virus (HCV) infections are associated with significant morbidity and mortality globally. The diagnosis of HCV is primarily based on indirect serological assays such as enzyme-linked immunosorbent assay (ELISA), chemiluminescence immunoassay (CIA), and rapid diagnostic tests to detect HCV antibodies. Direct tests detect/quantify components of HCV virions, such as HCV ribonucleic acid (RNA) (nucleic acid test or nucleic acid amplification test [NAT]) and HCV core antigen (HCVcAg). The HCVcAg assay (CIA, Abbott ARCHITECT) is an immune assay used for the quantitative determination of the HCVcAg. This test is simple and fast with the potential to be incorporated into diagnostic guidelines and be used in combination with anti-HCV (CIA) as an effective screening test. HCVcAg can also be used as a potential biomarker for treatment initiation and monitoring patients to assess the treatment response. Apart from this, the scope for implementation of the HCVcAg assay in resource limited setting lies in screening of immune compromised patients where anti-HCV serology is not dependable. However, concerns related to lower sensitivity compared to HCV RNA do exist. Nevertheless, the HCVcAg assay can make a significant difference in the measures taken for the control and eradication of hepatitis C and its complications in India.

HCV Core Antigen as an alternative test to Quantitative HCV RNA for assessment of SVR in Chronic HCV infected patients treated with Direct Acting Antiviral agents

Background and aims Widespread use of direct-acting antiviral (DAA) agents to treat patients with hepatitis C virus (HCV) infection has reduced the need for monitoring of HCV-RNA levels, because viral kinetics do not predict sustained virologic response (SVR) to these drugs. However, the performance of cheaper tests, such as the assay to quantify HCV core antigen (HCV Ag), has not been determined. This study was aimed at investigating the accuracy of the HCV Ag test in predicting which patients receiving DAAs will achieve SVR at week 12 (SVR12). Methods We performed a prospective study on 90 patients, chronically infected with HCV, receiving DAAs therapy from different NCCVH centers in Cairo during the period from August 2017 to June 2018. We collected blood samples and measured the levels of HCV core Ag and HCV-RNA at baseline and 12 weeks after end of treatment. We compared the ability of these assays to predict which patients would have SVR12. Results The median baseline level of HCV-RNA was 1688529.6 ± 994697.3 IU/ml (range, 312700 IU/ml to 3491100 IU/ml) and HCV Ag was 179.2 ± 83.5 pg/ml (range, 33.5 pg/ml to 315.6 pg/ml). HCV Ag became undetectable in 92.2% 12 weeks after the end of treatment. HCV-RNA became undetectable in 87.8% at the end of treatment (P<.0001). 79 out of 90 patients (87.8%) achieved an SVR12; the test for HCV Ag identified 63.6% of these patients. Conclusions Tests that measure HCV Ag monitor efficacy of DAA therapy for HCV infection as well as assays that measure HCV-RNA, and hence could be recommended for clinical practice.

Quantification of Core Antigen Monitors Efficacy of Combination Therapy of Sofosbuvir, Daclatasvir and Ribavirin in Egyptian Cirrhotic Patients with HCV Infection as an Alternative to PCR

Background Hepatitis C virus (HCV) is a major public health problem throughout the world. Acute HCV infection is asymptomatic in most cases, and only 15% of cases are symptomatic,but Chronic hepatitis C (CHC) shows a variable clinical course, ranging from mild histopathological changes to active hepatitis and the development of hepatic fibrosis, cirrhosis and HCC. The aim of this work is to detect accuracy of core antigen in Egyptian cirrhotic patients with HCV Infection treated with combination therapy of Sofosbuvir, Daclatasvir and Ribavirin as an alternative to PCR. Patients and methods: The study included20 Egyptian treatment-naïve chronic hepatitis C patients with cirrhosis (Cirrhosis was diagnosed on ultrasound basis) on Sofosbuvir, Daclatasvir and Ribavirin. Results Treatment with sofosbuvir plus Daclatasvir and Ribavirin for 12 weeks resulted in undetectable HCV RNA by PCR in 95% (19/20) of the patients at the end of treatment and only 5% (1/20) of the patients achieved SVR after 6 months not 3(both HCV RNA AND HCV Core Antigen tests were negative for all patients). Conclusion: In our study there was a correlation between HCV RNA and HCV core antigen results, so HCV core antigen can be used as an alternative marker to HCV RNA in treatment of HCV infected cirrhotic patients receiving Sofosbuvir, Daclatasvir and Ribavirin.during treatment and for monitoring its efficacy.

PREVALENCE AND GENOTYPING OF HEPATITIS C VIRUS IN HEMODIALYSIS PATIENTS AND EVALUATION OF HCV-CORE ANTIGEN TEST IN SCREENING PATIENTS FOR DIALYSIS IN SANA'A CITY, YEMEN

Hepatitis C virus infection is a constant worldwide public health concern. The prevalence of HCV infection is higher in patients on chronic haemodialysis (HD) than in the general population. Despite the control of blood products, hepatitis C virus transmission is still being observed among patients undergoing dialysis. Detection systems for serum HCV antibodies are insensitive in the acute phase because of the long serological window. Direct detection of HCV depends on PCR test but this test is not suitable for routine screening. The objective of this study was to determine prevalence of HCV, genotyping and if HCV core antigen test could be a better alternative to NAT techniques for the diagnosis of HCV infection during the window period and whether the sensitivity for antibody detection is preserved. We screened 159 patients on long-term dialysis by HVC antibodies test, PCR HCV-RNA and HCV core antigen test by commercial tests. The prevalence of HCV was 10.7% (17 patients) and genotype 4 was the most common one (64.7%). The sensitivity of HCV core antigen test was 94.1%, the specificity 100%, the positive predictive power 100%, and the negative predictive power 97.9%. In conclusions; patients on maintenance HD in Yemen have a high prevalence of HCV infection comparing with general population; and genotype 4 is predominant. The performance of serological detection of HCV core antigen was better than that of HCV antibodies test and may be an alternative to nucleic acid amplification technology (NAT) for routine monitoring of patients on chronic dialysis.