HCV antigen testing for the diagnosis of hepatitis C infection: a cost-efficient algorithm

Diagnostic performance of hepatitis C core antigen assay to identify active infections: A systematic review and meta-analysis

Hepatitis C virus (HCV) core antigen (HCVcAg) assay is an alternative for diagnosing HCV infection in a single step. This meta-analysis aimed to evaluate the Abbott ARCHITECT HCV Ag assay's diagnostic performance (validity and utility) for diagnosing active hepatitis C. PubMed, EMBASE, Scopus, Web of Science, and Cochrane Library were searched until 10 January 2023. The protocol was registered at the prospective international register of systematic reviews (PROSPERO: CRD42022337191). Abbott ARCHITECT HCV Ag assay was the test for evaluation, and nucleic acid amplification tests with a cut-off ≤50 IU/mL were the gold standard. Statistical analysis was performed using STATA with the MIDAS module and random-effects models. The bivariate analysis was conducted on 46 studies (18,116 samples). The pooled sensitivity was 0.96 (95% CI = 0.94-0.97), specificity 0.99 (95% CI = 0.99-1.00), positive likelihood ratio 141.81 (95% CI = 72.39-277.79), and negative likelihood ratio 0.04 (95% CI = 0.03-0.06). The area under the summary receiver operating characteristic curve was 1.00 (95% CI = 0.34-1.00). For active hepatitis C prevalence values of 0.1%-15%, the probability that a positive test was a true positive was 12%-96%, respectively, indicating that a confirmatory test should be necessary, particularly with a prevalence ≤5%. However, the probability that a negative test was a false negative was close to zero, indicating the absence of HCV infection. The validity (accuracy) of the Abbott ARCHITECT HCV Ag assay for screening active HCV infection in serum/plasma samples was excellent. Although the HCVcAg assay showed limited diagnostic utility in low prevalence settings (≤1%), it might help diagnose hepatitis C in high prevalence scenarios (≥5%).

Current position of viral load versus hepatitis C core antigen testing

Quantification of hepatitis C virus (HCV) RNA (viral load) is the most widely used marker to diagnose and confirm active HCV infection. The HCV core antigen forms part of the internal structure of the virus and, like HCV RNA, its detection also indicates viral replication and presents certain advantages over viral load testing such as its lower cost, the greater stability of the target, the possibility of working with the same primary tube as that used for HCV serology, and the rapidity of obtaining results, since there is no need to work in batches, unlike the situation with most viral load platforms. Although the core antigen has lower analytical sensitivity than HCV RNA for the detection of low viremia levels, several studies and guidelines have already shown their utility in the identification of patients with active HCV infection. This article summarises current platforms for viral load determination, including point-of-care systems, and also reviews the indications attributed to this marker by the main HCV treatment guidelines. The article also reviews the characteristics of HCV core antigen, the available platforms for its determination, its correlation with viral load determination, and the indications for this marker in the distinct guidelines.

HCV core antigen plays an important role in the fight against HCV as an alternative to HCV-RNA detection

Objective

To discuss the clinical significance of HCV‐cAg testing in the diagnosis, activity determination, and monitoring of therapeutic effectiveness of HCV infection and its advantages compared with HCV‐RNA and anti‐HCV antibodies detection.

Methods

By summarizing the published literature, the advantages and significance of HCV core antigen detection were sought.

Results

The expression of HCV‐cAg is highly consistent with that of HCV‐RNA, but compared with HCV‐RNA, detection of HCV‐cAg is easy to operate, time saving, and low cost. HCV‐cAg can be detected within 12~15 days after infection, and the window period can be shortened by5~7 weeks. HCV‐cAg is a serological indicator of virus replication, which can distinguish previous infection of HCV or current infection. HCV‐cAg detection is more suitable for immunocompromised, hemodialysis, organ transplant patients. HCV‐cAg also can be used to monitor antiviral efficacy and predict sustained virological response (SVR).

Conclusion

HCV core antigen has similar clinical sensitivity to NAT and can be used as a substitute for HCV‐RNA in the diagnosis of virus infection. Combined detection of HCV‐cAg and antibody serology can help doctors detect HCV infection earlier, accurately diagnose different stages of HCV infection, and evaluate the therapeutic effect of antiviral drugs, which are beneficial in the prevention and treatment of hepatitis C.

Detection of hepatitis C virus core antigen as an alternative method for diagnosis of hepatitis C virus infection in blood donors negative for hepatitis C virus antibody

BACKGROUND

Screening of blood donors in many countries is based on the use of serologic assays to detect specific anti-HCV antibodies (HCV Ab), but it lacks detection sensitivity. So, HCV RNA detection using the current gold standard real-time PCR is a must to rule out HCV infection with the main disadvantage being of high cost. HCV core antigen (HCV-c-Ag) immunoassay is proposed as a more cost efficient alternative to HCV RNA detection with PCR.

AIM

To evaluate the effectiveness of HCV-c-Ag detection as a cheap alternative to HCV RNA (PCR) in diagnosis of HCV infection in blood donors who are HCV Ab negative.

METHODS AND RESULTS

One hundred eighty-six volunteer blood donors who tested negative for HCV Ab were examined for HCV-c-Ag. Seven cases out of these 186 cases were HCV-c-Ag positive (4%). HCV RNA detection (PCR technique) was done to 30 cases (seven cases who test positive for HCV-c-Ag and 23 cases who test negative). Six out of the seven cases who were HCV-c-Ag positive (86%) were HCV RNA positive. Twenty-two cases out of the 23 cases who were HCV-c-Ag negative (96%) were HCV RNA negative.

CONCLUSION

HCV-c-Ag detection is an efficient method for diagnosis of HCV infection during screening of blood donors with high specificity (95.6%) and high negative predictive value (95.6%).

Implications of grey zone results for routine hepatitis C virus screening with the ARCHITECT HCV-Ag assay

AIMS

Hepatitis C virus antigen (HCV-Ag) detection requires retesting for samples with grey zone results (GzR), adding cost and time and decreasing reliability. Our aim in this study was to evaluate the frequency and significance of GzR during the use of the automated Architect HCV-Ag assay in routine clinical practice.

METHODS AND RESULTS

We studied HCV-Ag levels in 952 serum samples using the ARCHITECT HCV-Ag assay. GzR were detected in 33 samples; 25 were reactive on retesting and 19 were anti-HCV positive. Seventeen of these 19 samples were tested for HCV-RNA and were all reactive (viral loads <10⁴  IU ml^-1 ). The remaining six samples were anti-HCV nonreactive and had undetectable HCV-RNA. Eight GzR samples were nonreactive on retesting, seven were anti-HCV nonreactive (three underwent HCV-RNA quantification and were all nonreactive), and one was anti-HCV reactive (HCV-RNA nonreactive). No significant differences were found on comparing HCV-Ag values.

CONCLUSIONS

Grey zone results found to be negative on retesting do not need additional technique testing, except in donor screening scenarios, where the use of molecular methods would be advisable.

SIGNIFICANCE AND IMPACT OF THE STUDY

 The proposed diagnostic algorithm confirms that, eventhough GzR occur, hepatitis C virus antigen is a robust alternative to HCV-RNA detection in the active detection of infections.

HCV core antigen comes of age: a new opportunity for the diagnosis of hepatitis C virus infection

The diagnosis of hepatitis C virus (HCV) infection has been traditionally based on the detection of the host antibody response. Although antibody assays are available in different formats and are fairly accurate, they cannot distinguish between an ongoing infection with HCV replicative activity and a past infection where HCV has been cleared, spontaneously or after a successful therapy. As a chronic infection is mostly asymptomatic until the late clinical stages, there is a compelling need to detect active HCV infection by simple and reproducible methods. On this purpose, the clinical guidelines have suggested to search for the HCV ribonucleic acid (HCV-RNA) after anti-HCV has been detected, but this second step carries several limitations especially for population screening. The availability of fast and automated serological assays for the hepatitis C core antigen (HCVAg) has prompted an update of the guidelines that now encompass the use of HCVAg as a practical alternative to HCV-RNA, both for screening and monitoring purposes. In this paper, we summarize the features, benefits and limitations of HCVAg testing and provide an updated compendium of the evidences on its clinical utility and on the indications for use.

Clinical Evaluation of a Newly Developed Chemiluminescent Enzyme Immunoassay for Hepatitis C Virus Core Antigen in Japan

An advanced and fully automated chemiluminescent enzyme immunoassay for the hepatitis C virus core antigen (HCVcAg) was recently developed in Japan. We aimed to evaluate its clinical utility. The new Fujirebio assay (Lumipulse Presto HCVcAg [LP-Presto]) was compared with 2 conventional assays (Lumipulse Ortho HCVcAg [LP-Ortho] and Abbott's Architect HCVcAg). Basic assessments of LP-Presto (reproducibility, stability, range of quantitation, and specificity) were performed on 220 frozen sera (83 positive and 137 negative by LP-Ortho) and 206 fresh sera (all negative by LP-Ortho). Correlation analysis was performed and the rates of concordance for each assay were determined. Additionally, the frozen sera of 42 hyperimmunoglobulinemia patients, including 3 unmeasurable by LP-Ortho, were tested by LP-Presto. All the basic assessments of LP-Presto were consistent with the results of LP-Ortho and Architect. The concordance rate between LP-Presto and LP-Ortho for the 220 frozen sera was 99.5% (219/220), and that between LP-Presto and Architect was 99.1% (218/220). LP-Presto (HCVcAg cut-off value; 20 fmol/L) was fully consistent with LP-Ortho (100%), which found 343 sera negative for HCVcAg. All 42 hyperimmunoglobulinemic sera were measurable using LP-Presto. In conclusion, the performance of LP-Presto was rapid and reliable, and nonspecific test results due to hyperimmunoglobulinemia were reduced when LP-Presto was used. Therefore, LP-Presto is a high-quality HCVcAg assay that shows promising applications.

HCV core antigen is a useful predictor during pegylated-interferon/ribavirin therapy in patients with hepatitis C virus genotype 1b

Enzyme immunoassays for quantifying hepatitis C virus (HCV) core antigen (Ag) have been proposed as an alternative to HCV RNA detection. The present study aimed to investigate the early kinetics of serum HCVcAg and its usefulness in predicting virological responses.The clinical data of 135 patients with chronic hepatitis C treated with pegylated interferon alpha (PEG-IFN-α) and ribavirin was retrospectively collected. The patients were grouped according to their treatment outcomes as follows: sustained virological response (SVR), nonsustained virological response (N-SVR), and relapse.Higher HCVcAg and HCV RNA levels were observed in patients in the N-SVR group than in the other groups at baseline. HCVcAg better predicted rapid virological response (RVR) compared with HCV RNA and had a predictive value similar to that of HCV RNA for SVR and early virological response. In the relapse group, HCV RNA decreased to 0 after 48 weeks, whereas HCVcAg was still detectable, indicating that HCVcAg more sensitively predicted relapse in antiviral therapy than HCV RNA.For patients treated with PEG-INF-α and ribavirin, HCVcAg may more sensitively predict relapse than HCV RNA.

Hepatitis C core antigen highly correlated to HCV RNA

Hepatitis C virus core antigen (HCV-Ag) immunoassay has been proposed as a more cost and time efficient one-step alternative to the current two-step screening and diagnostic process. This study investigates the correlation between the HCV-Ag immunoassay and the current gold standard of Hepatitis C Virus (HCV) ribonucleic acid (RNA) molecular assay. Stored sera of 221 consecutive treatment-naive patients tested anti-HCV positive were selected to undergo both HCV-Ag immunoassay and HCV RNA molecular assay. Active infection status and HCV genotype were determined using both assays, and correlation was calculated using a logarithmic scale. Among 221 anti-HCV-positive sera, 197 were positive for both HCV Ag (≥3 fmol/L) and HCV RNA (>15 IU/mL), 22 were negative for both tests, while 2 were positive to HCV RNA only. The sensitivity and specificity for HCV Ag in predicting HCV RNA were 99% and 100%, respectively. Out of 199 patients (90%) tested positive for HCV viremia, 107 (56%) were of genotype 1, 77 (38.7%) of genotype 2 and 15 of other genotypes. Analysis of 221 anti-HCV-positive patient sera found a strong positive correlation between HCV RNA and HCV-Ag (r = 0.960, p < 0.001). Genotype 1 (log [HCV RNA] = 0.988 x log [HCV-Ag] + 2.768), with correlation coefficient 0.945, exhibited a stronger correlation than genotype 2 (log [HCV RNA] = 0.859 x log [HCV-Ag] + 2.859; r = 0.862). Given the strong positive correlation between HCV-Ag immunoassay and HCV RNA molecular assay in genotyping affected individuals, we propose that HCV-Ag immunoassay is a more cost and time efficient alternative to the current two-step diagnostic process.

Identifying cost-effective screening algorithms for active hepatitis C virus infections in a high prevalence setting

OBJECTIVE

To evaluate the cost-effectiveness of different screening patterns for active chronic hepatitis C virus (HCV) infections utilizing the hepatitis C core antigen test compared to standard care in the context of a general screening program in a high-prevalence country.

METHODS

This study developed a decision analytic model to estimate the cost-effectiveness of four screening algorithms for the detection of active HCV infections among asymptomatic individuals with an unknown HCV status in a context of high (>5%) HCV prevalence. Three algorithms started with a serological test for antibodies (AB) followed by a nucleic acid test for HCV-RNA (RNA), the HCVAg (AG) assay, or both. An additional single marker screening strategy with AG was added to the analysis. By the example of the Republic of Georgia, strategies were compared in terms of total costs for screening and diagnosis of an active infection from a health system perspective.

RESULTS

Replacing RNA with AG for confirmation of positive AB identified fewer active infections (-110 per 100,000 screened subjects) at significantly reduced total costs (-$2.74 per screened) and costs per diagnosed infection (-$44). Adding a subsequent RNA confirmatory test on AG negative results captured at least the same rate compared to the standard (AB followed by RNA) at still reduced costs (-$1.16 per subject screened, -$22 per case detected). Utilizing AG as the frontline test revealed the highest detection rate (97.9%) at the highest costs (+$3.80 per subject, +$323 per case detected vs standard).

CONCLUSION

A combined pattern of HCV AB screening followed by sequential confirmation with AG and RNA on AG negatives would provide equal or better diagnostic performance at lower cost over a broad range of scenarios. Potential long-term consequences of screening strategies to patients and society have to be considered, since the latency period for HCV to develop into severe liver disease is long.

HCV core antigen as an alternate test to HCV RNA for assessment of virologic responses to all-oral, interferon-free treatment in HCV genotype 1 infected patients

In light of the advances in HCV therapy, simplification of diagnosis confirmation, pre- treatment diagnostic workup and treatment monitoring is required to ensure broad access to interferon-free therapies. HCV core antigen (HCV cAg) testing is rapid, giving results in approximately 60min, and less expensive than HCV RNA methods. While extensive data on the analytical performance of HCV cAg relative to RNA or comparisons in longitudinal studies of patients on interferon based (response guided) therapy there is very limited data on the relative performance of HCV cAg in diagnosis and monitoring patients receiving all-oral interferon free regimens. Furthermore, there is no data in the literature that describes the specificity of HCV cAg in patients with resolved HCV infection i.e. anti-HCV positive/HCV RNA negative. In this study a total of 1201 plasma samples from the 411 HCV genotype 1 subjects with a HCV RNA viral load >50,000IU/ml who enrolled in a clinical trial with ombitasvir, ritonavir-boosted paritaprevir and dasabuvir, with or without ribavirin were retrospectively tested in a blinded fashion with HCV cAg test and results were compared to HCV RNA levels. The specificity of the HCV cAg test was also evaluated in anti-HCV positive but HCV RNA negative samples. Overall concordance between HCV cAg and HCV RNA was 98.6% while concordance in pre-treatment samples was 99.5% (409/411; n=2 HCV RNA pos. with viral loads>3 Mill IU/ml but HCV cAg neg.) and 99.24% in post treatment week 12 samples (391/394; n=2 HCV RNA pos.<25IU/ml and n=1 HCV RNA pos. 2180IU/ml). Specificity in anti-HCV positive HCV RNA negative samples tested was 100%.

Hepatitis C virus core antigen assay: an alternative method for hepatitis C diagnosis

Background The study aimed to evaluate a fully automated chemiluminescent immunoassay and compared it with a quantitative RNA assay and anti-HCV assay to verify the utility of this automated Ag assay as an alternative method for hepatitis C diagnosis. Methods A total of 229 serum samples previously tested for anti-HCV concentrations by the Architect Anti-HCV assay, were selected for HCV RNA testing by real time RT-PCR kit (Shanghai ZJ Bio-Tec Co., Ltd) and 125 specimens were tested for HCV Ag by the Architect HCV core Antigen kit. Results The log₁₀ HCVAg and HCV RNA concentrations were highly correlated [ r = 0.834); with HCV RNA as the comparator test, HCVAg had 100% specificity, 100% positive predictive value (PPV) and 94.8% sensitivity. We found 1 pg/mL of total HCV core Ag is equivalent to approximately 6607HCV RNA international units (IU)/mL. Receiver operator characteristic curve analysis showed that the area under the curve of HCV core Ag (0.989) was greater than HCV Ab (0.871). HCV Ag concentrations and RNA-to-Ag ratio of the groups for HCV RNA concentrations ≤10⁵ and >10⁵IU/mL were both significantly different from each other ( P < 0.05). Conclusion The Architect HCV core Ag assay may be an alternative method for hepatitis C diagnosis, performed on the same analytical platform and sample as the anti-HCV assay, shortening the diagnostic window period, demonstrating good correlation with HCV RNA assay with high specificity and positive predictive value.

The Role of Hepatitis C Virus Core Antigen Testing in the Era of Direct Acting Antiviral Therapies: What We Can Learn from the Protease Inhibitors

Direct-acting antiviral (DAA) therapies have revolutionised the treatment of hepatitis C virus (HCV). The financial cost of DAAs however is significant, and first generation protease inhibitors (PIs) also require frequent monitoring of viral RNA levels to guide treatment. In this context, we examined the relevance of HCV antigen testing to evaluate the potential role in monitoring virological response to HCV antiviral treatment with the PI-based triple therapies, telaprevir (TVR) and boceprevir (BOC). Chronic HCV-infected individuals (n = 152) enrolled in the Irish Hepatitis C Outcomes Research Network (ICORN) study were prospectively analysed for baseline markers and the early viral kinetics associated with SVR. The sustained virological response (SVR) rates in the cohort receiving TVR and BOC were 87.3% and 73.8%, respectively. Baseline factors associated with successful outcome in TVR therapy were age (P = 0.0098), IFNL3 genotype (P = 0.0330) and viral load (P = 0.0456). RNA level at week 4 (P = 0.0068) and viral antigen negativity at week 2 (P = 0.0359) were predictive of SVR for TVR-based therapy. In BOC therapy, prior interferon treatment (P = 0.0209) and IFNL3 genotype (P = 0.0410) were baseline predictors of SVR. Evidence of viraemia based either on viral RNA or antigen at week 4 predicted SVR in these patients. Our data showed that rapid decline of HCV antigen to negative level at week 2 in TVR treatment and <0.96 log fmol/l in BOC treatment after commencement of PI triple therapy were associated with SVR. HCV antigen measurement should be considered as a potential alternative for monitoring treatment response during DAA-based regimens.

Who to test and how to test for chronic hepatitis C infection - 2016 WHO testing guidance for low- and middle-income countries

Testing and diagnosis of hepatitis C virus (HCV) infection is the gateway for access to both treatment and prevention services, and crucial for an effective hepatitis epidemic response. In contrast to HIV, a systematic approach to hepatitis C testing has been fragmented and limited to a few countries, and there remains a large burden of undiagnosed cases globally. Key challenges in the current hepatitis testing response, include lack of simple, reliable, and low cost diagnostic tests, laboratory capacity, and testing facilities; inadequate data to guide country-specific hepatitis testing approaches and who to test; stigmatization and social marginalization of some groups with or at risk of viral hepatitis; and lack of international or national guidelines on hepatitis testing for resource-limited settings. New tools to support the hepatitis global response include the 2016 Global Hepatitis Health Sector Strategy which include targets for testing and diagnosis, and World Health Organization (WHO) 2016 hepatitis testing guidelines for adults, adolescents, and children in low- and middle-income countries. The testing guidance complements recent published WHO guidance on the prevention, care and treatment of chronic hepatitis C and hepatitis B infection. These testing guidelines outline the public health approach to strengthening and expanding current testing practices for HCV and HBV and address what serological and virological assays to use, and who to test, as well as interventions to promote linkage to prevention and care after testing. They are intended for use across all age groups and populations. See boxes for key recommendations. Future directions and innovations in viral hepatitis testing include use of point-of-care assays for nucleic acid testing (NAT) and core antigen; validation of dried blood spots specimens with different commercial serological and NAT assays; multiplex and polyvalent platforms for integrated testing of HIV, HBV and HCV; and potential for self-testing.

Hepatitis C Core Antigen Testing for Diagnosis of Hepatitis C Virus Infection: A Systematic Review and Meta-analysis

BACKGROUND

Diagnosis of chronic hepatitis C virus (HCV) infection requires both a positive HCV antibody screen and confirmatory nucleic acid testing (NAT). Testing for hepatitis C virus core antigen (HCVcAg) is a potential alternative to NAT.

PURPOSE

To evaluate the accuracy of diagnosis of active HCV infection among adults and children for 5 HCVcAg tests compared with NAT.

DATA SOURCES

EMBASE, PubMed, Web of Science, Scopus, and Cochrane Database of Systematic Reviews from 1990 through 31 March 2016.

STUDY SELECTION

Case-control, cross-sectional, cohort, or randomized trials that compared any of 5 HCVcAg tests with an NAT reference standard.

DATA EXTRACTION

2 independent reviewers extracted data and assessed quality using an adapted QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) tool.

DATA SYNTHESIS

44 studies evaluated 5 index tests. Studies for the Abbott ARCHITECT HCV Ag assay had the highest quality, whereas those for the Ortho HCV Ag enzyme-linked immunosorbent assay (ELISA) had the lowest quality. From bivariate analyses, the sensitivity and specificity of the assays were as follows: Abbott ARCHITECT, 93.4% (95% CI, 90.1% to 96.4%) and 98.8% (CI, 97.4% to 99.5%); Ortho ELISA, 93.2% (CI, 81.6% to 97.7%) and 99.2% (CI, 87.9% to 100%); and Hunan Jynda Bioengineering Group HCV Ag ELISA, 59.5% (CI, 46.0% to 71.7%) and 82.9% (CI, 58.6% to 94.3%). Insufficient data were available for a meta-analysis about the Fujirebio Lumipulse Ortho HCV Ag and Eiken Lumispot HCV Ag assays. In 3 quantitative studies using Abbott ARCHITECT, HCVcAg correlated closely with HCV RNA levels greater than 3000 IU/mL.

LIMITATIONS

Insufficient data were available on covariates, such as HIV or hepatitis B virus status, for subgroup analyses. Few studies reported genotypes of isolates, and data for genotypes 4, 5, and 6 were scant. Most studies were conducted in high-resource settings and reference laboratories.

CONCLUSION

The HCVcAg assays with signal amplification have high sensitivity, high specificity, and good correlation with HCV RNA levels greater than 3000 IU/mL and have the potential to replace NAT in settings with high HCV prevalence.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Evolving strategy for HCV testing in an Italian tertiary care hospital

BACKGROUND

Diagnostic tests for hepatitis C virus (HCV) infection should be adapted according to the clinical status of the patient.

OBJECTIVES

We exploited the application of different HCV diagnostic algorithms in a tertiary care hospital practice.

STUDY DESIGN

The laboratory clinical reports to the medical orders for HCV testing during three years were clustered by different combinations of assays for anti-HCV antibodies (HCV Ab) (screening and confirmatory), HCV nucleic acid (HCV-RNA), HCV core antigen (HCV Ag). The latter was the first-line assay in acute HCV infections requiring a rapid assessment of the infectious state.

RESULTS

The majority (91.9%) of the 2726 subjects whose samples were analyzed were inpatients. Most of the patients/subjects were tested for clinical suspicion of viral hepatitis (49.2%), or occupational accident to health care professionals (20.0%). On 66% of samples HCV Ag test alone was performed and resulted positive in 116 cases (6%), while it was detected in 50.3% of anti-HCV positive samples. The agreement between HCV Ag and HCV-RNA was very high (k=0.97); HCV Ag positivity rates increased according to the signal of the HCV Ab screening test.

CONCLUSIONS

The use of different testing strategies according to the patients' history and clinical status allowed a significant reduction of the number of tests performed and the time needed to provide a diagnostic response useful for patients' management without compromising the overall diagnostic accuracy for HCV infection.

The accuracy and cost-effectiveness of hepatitis C core antigen assay in the monitoring of anti-viral therapy in patients with chronic hepatitis C genotype 4

BACKGROUND

Quantitative hepatitis C (HCV) polymerase chain reaction (qtHCV-PCR), the gold standard for monitoring HCV therapy, is an expensive, time-consuming procedure that requires equipped laboratories and trained personnel.

AIMS

To assess the accuracy and cost-effectiveness of the automated Abbott ARCHITECT HCV Ag assay (Wiesbaden, Germany) in monitoring response to pagylated interferon (PEG-IFN) and ribavirin therapy for chronic HCV genotype 4 (G4).

METHODS

This longitudinal, non-inferiority study compared the efficacy and cost benefit of an All-HCV core antigen assay protocol and a hybrid qtHCV RNA PCR and HCV core Ag assay protocol to the standard All-qtHCV-PCR protocol in chronic HCV G4 patients treated with pegylated interferon (PEG IFN) and ribavirin.

RESULTS

Four hundred and ten patients with chronic hepatitis C genotype 4 met inclusion criteria and were enrolled in the study. The sustained virological response rate (SVR) was 66.34%. The All-HCV core antigen and hybrid monitoring assays resulted in the significant cost savings without compromising performance. A good correlation existed between HCV viral load and HCV core antigen levels (r = 0.944; P < 0.0001). Baseline HCV RNA values <600 IU/mL, baseline HCV core Ag levels <2000 fmol/L, rapid virological response, rapid decline in HCV core antigen were strong predictors of SVR.

CONCLUSION

Hepatitis C core Ag assay is a point-of-care, reproducible, reliable, cost-effective monitoring tool with rapid turnaround time that, which can effectively replace or adjunct to qRT-PCR in monitoring interferon based or interferon-free anti-viral therapy in chronic hepatitis genotype 4 patients in resource-limited countries with a high burden of hepatitis C.