Simultaneous Detection of Hepatitis C Virus (HCV) Core Antigen and Anti-HCV Antibodies Improves the Early Detection of HCV Infection

Abstract

Since the development of the first assay in 1989 (20), assays for detection of hepatitis C virus (HCV) antibodies (Ab) have allowed progress in the early detection of HCV infection (46). This increased sensitivity of the last-generation assays has dramatically reduced the risk of HCV transmission by blood components by reducing the window period from 82 days (5) to 66 days (3, 12). To further reduce the residual risk (2,5,16,18,36,37,41,48), nucleic acid testing (NAT) for HCV RNA was introduced in several high-income countries (2,14,15,21,30,39). In some countries, an assay for the detection of HCV core antigen (Ag) by use of the enzyme immunoassay (EIA) technology has been chosen as an alternative to NAT for the early diagnosis of infection (1,8,25,38). In addition, some authors emphasized the clinical advantage of HCV core Ag quantification as a direct marker of viral replication in the chronic phase of infection (4) and as a relevant marker for predicting and monitoring the response to therapy (7,29,31). Indeed, the HCV core Ag assays have sensitivities close to that of NAT, with mean detection differences of 1 to 2 days in the window period with the specific assay developed for blood screening (11,32,35,45) and 0.29 day with the immunoassay capable of detecting and quantifying HCV core Ag (23). A recent study reported that a prototype assay based on the simultaneous detection of HCV core Ag and anti-HCV Ab significantly closed the time gap between HCV RNA detection and the first appearance of detectable anti-HCV Ab (42). However, this assay is not yet available for routine use. More recently, a new combination assay has been developed and licensed in Europe (Monolisa HCV Ag/Ab ULTRA; Bio-Rad, Marnes la Coquette, France). To assess its sensitivity for the detection of HCV infection during the window period or at the early phase after seroconversion, we tested two panels and compared the results with those obtained using the two available assays for HCV Ag (HCV core Ag EIA blood screening assay and trak-C assay) and HCV RNA. The overall objective was to determine if this new test could constitute an alternative to NAT for the diagnosis of HCV infection during the window period and whether the sensitivity for antibody detection is preserved. (Table 1) consisted of 12 blood donor samples which were negative for anti-HCV Ab (Ortho HCV 3.0 EIA test system Enhanced SAVe; Ortho Clinical Diagnostics, Raritan, NJ) but positive for HCV RNA. The plasma from each of these blood donations was immediately aliquoted and stored at Ϫ30°C until it was MATERIALS AND METHODS Panels

Evaluation of Hepatitis C Virus Infection in Antibody Positive Orphan Newborns

“…The importance of HCVcoreAg in the early diagnosis of HCV infection has been established in many studies (25)(26)(27). Also, the monitoring of HCVcoreAg during the treatment course can help to predict responses to anti-viral therapy (28,29).…”

Infectious Agents Transmitted by Blood and Blood Component and Impacts of Nükleik Asit Amplifikasyon Test (NAT)

“…HCV araştırmasın-da kullanılan kitlerin paraproteinemi, üremi, RF pozitifliği gibi durumlarda yalancı pozitifliği de söz konusudur (35) . HCV antijen testi ve NAT kullanımı ile kan güvenliğinin arttırılması sağlanabilir (20,(22)(23)(24)(25)(26)(27)(28)(29)(30)36) . Amerika Birleşik Devletlerinde NAT kullanımı sonrası kan ve bileşenleri ile HCV bulaş riski 1:1,935,000 ünite olarak hesaplanmaktadır (21) .…”

Hepatitis C: Viral Features and Clinical Aspects

“…Genotypes 1, 2 and 3 and their subtypes are widely distributed, while others are restricted to certain areas [21,38,41]. Genotype 4 is prevalent in North Africa, the Middle East and Europe, whereas genotypes 5and 6 prevail in South Africa and in Southeast Asia [42].…”