A novel test and treat program for hepatitis C virus infection utilizing HCV core antigen testing, among police and general population, Islamabad, Pakistan, 2022

Hepatitis C virus core antigen (HCVcAg) testing can simplify and decrease costs of HCV infection confirmation compared to molecular testing (nucleic acid testing). We piloted HCVcAg testing for the confirmation of active infection. The study was conducted during June through December 2022 among the police and the general population of Islamabad, Pakistan age 18 years and older. Initial screening for HCV antibody was conducted using a rapid diagnostic test (RDT) for all consenting participants. Those who tested positive had venous blood samples tested for HCVcAg, platelets and aspartate aminotransferase (AST). Persons with HCVcAg values ≥3 fmol/L were defined as viremic, and they were offered treatment with direct acting antiviral (DAA) medications, sofosbuvir and daclatasvir. Aspartate aminotransferase to platelet ratio index (APRI) was calculated for each HCV infected person, and those with an APRI score <1.5 received treatment for 12 weeks, while those with APRI ≥ to 1.5 received 24 weeks of treatment. A total of 15,628 persons were screened for anti-HCV using RDT and 643 (4.1%) tested positive. HCVcAg values of ≥3 fmol/L was found in 399/643 (62.1%), and all were offered and accepted treatment. Of those treated, 273/399 (68.4%) returned for a follow-up SVR and HCVcAg was not detected in 261/273, a 95.6% cure rate. The pilot study demonstrated the effectiveness of reaching and treating an urban population using RDT for screening and HCVcAg for confirmation of infection and test of cure.

Performance of HCV core antigen and PCR testing in a predominantly genotype 3 population

Hepatitis C core antigen (HCVcAg) is becoming increasingly recognized as an alternative to molecular testing for the confirmation of chronic hepatitis C. However, there are limited data on the performance of this assay in a genotype 3 (GT3) predominant country like Pakistan. We conducted a study to evaluate the diagnostic performance of HCVcAg against the HCV polymerase chain reaction (PCR) molecular test. HCV antibody-positive patients requiring confirmatory testing were recruited from August to October 2018 at the Pakistan Kidney and Liver Institute and Research Center (PKLI&RC), Lahore, Pakistan. Patients with previously known diagnoses or treatment histories were excluded. The Abbott HCV Ag assay was used for HCVcAg testing. Results ≥3.00 fmol/L were considered positive for HCVcAg. The Abbott RealTime HCV assay was used for PCR testing with a lower detection limit of ≥12 IU/mL. We computed the sensitivity, specificity and correlation of HCVcAg against HCV PCR. A total of 394 patients were recruited. The median age of the patients was 42 years. Most participants were females (51.5%, n = 203), 30.7% (n = 121) had HTN, 10.4% DM (n = 41) and 5% had APRI ≥2. The overall sensitivity was 98.0% and the specificity was 98.6%. The lowest detection limit of cAg was an HCV RNA value of 4657 IU/mL. The levels of cAg were highly correlated with those of HCV RNA by Spearman's rank correlation test (r = 0.935, p < .001). HCVcAg represents a suitable alternative with high sensitivity and specificity compared with HCV PCR in the GT3-predominant population and can be incorporated into algorithms to improve linkage to care.

Hepatitis C community prevalence is over-estimated: a prospective, birth cohort study

BACKGROUND

Hepatitis C virus infection is often asymptomatic, and many patients may be unaware they are infected. Community-based, birth cohort screening has been advocated to identify these patients. It has been estimated that 0.7-1% of individuals born between 1965 and 1985 in Ireland are infected. The cost-effectiveness of screening is critically dependent on the population prevalence.

AIMS

The aim is to determine the community prevalence of hepatitis C virus infection in the birth cohort 1965-1985.

METHODS

Residual serum samples from blood tests ordered by community general practitioners were anonymised and analysed for the presence of hepatitis C antibody ± antigen. Twelve large general hospitals throughout the country participated.

RESULTS

A total of 14,320 samples were tested, 9347 of which were from the birth cohort 1965-1985. Seventy-two samples were positive for hepatitis C antibody of which 12 were positive for hepatitis C antigen (17%). The overall prevalence of hepatitis C antigen in the birth cohort was 0.09%. A higher prevalence (0.39%) was identified in males in two urban areas of Dublin.

CONCLUSIONS

Hepatitis C virus seroprevalence was much lower than previously estimated. The proportion of antibody positive patients with hepatitis C antigen was also lower than expected suggesting the effects of treatment and/or high spontaneous viral clearance. Universal birth cohort screening is unlikely to be cost-effective. Targeted birth cohort screening in high prevalence areas could be considered.

Performance of HCV Antigen Testing for the Diagnosis and Monitoring of Antiviral Treatment: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Active hepatitis C virus (HCV) infection is based on the detection of HCV RNA that it is effective but presents high cost and the need to hire trained personnel. This systematic review and meta-analysis is aimed at evaluating the diagnostic accuracy of HCV Ag testing to identify HCV cases and to monitor antiviral treatment including DAA treatment.

METHODS

The studies were identified through a search in PubMed, Lilacs, and Scopus from 1990 through March 31, 2020. Cohort, cross-sectional, and randomized controlled trials were included. Two independent reviewers extracted data and assessed quality using an adapted Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Our primary outcome was to determine the accuracy of HCV Ag detection for the diagnosis, which we estimated using random-effects meta-analysis.

RESULTS

Of 3,062 articles identified, 54 met our eligibility criteria. The studies described cohorts from 20 countries, including 14,286 individuals with chronic HCV individuals. Studies for ECLIA technology demonstrated highest quality compared to studies that used ELISA. The pooled sensitivity and specificity (95% CI) for HCV Ag detection of active HCV infection were 98.82% (95%CI = 98.04%; 99.30%) and 98.95% (95%CI = 97.84%; 99.49%), respectively. High concordance was found between HCV Ag testing and HCV RNA detection 89.7% and 95% to evaluate antiviral treatment.

CONCLUSIONS

According to our findings, HCV Ag testing could be useful to identify HCV active cases in low-resource areas. For antiviral treatment, HCV Ag testing will be useful at the end of treatment.

Hepatitis C virus antigen detection is an appropriate test for screening and early diagnosis of hepatitis C virus infection in at-risk populations and immunocompromised hosts

Early diagnosis remains key for effective prevention and treatment. Unfortunately, current screening with anti-hepatitis C virus antibody (anti-HCV Ab) test may have limited utility in the diagnosis of HCV infection and reinfection. This is of special concern to at-risk population, such as immunocompromised hosts and end-stage renal failure patients on hemodialysis. HCV antigen (Ag) could be useful in identifying the ongoing infection in such clinical scenarios. Hence, we aimed to study the utility of HCV Ag testing for the diagnosis of acute and chronic hepatitis C. Of 89 samples studied, 19 were from acute hepatitis C patients who were immunocompromised or were on hemodialysis, 43 were from active chronic hepatitis C patients and 27 were from patients treated for chronic hepatitis C. All samples were tested for HCV Ag using the Abbott ARCHITECT HCV Ag assay. HCV Ag was reactive in 19/19 samples from acute hepatitis C patients and 42/43 samples from active chronic hepatitis C patients. It was nonreactive in all samples from treated patients. The test showed a sensitivity and specificity of 98.4% and 100.0%, respectively. The positive and negative predictive values were 100.0% and 96.4%, respectively. The HCV antigen test has high clinical sensitivity and specificity and is useful for the diagnosis of acute and chronic hepatitis C infection in at-risk and immunocompromised patients. Its short turnaround time and relatively low cost are advantageous for use in patients on hemodialysis and other at-risk patients who require monitoring of HCV infection and reinfection.

Utility of grey zone testing strategy in transfusion transmissible infection testing in blood bank is of limited value!

Several blood banks use grey zone (GZ) phenomenon (defined as samples with optical density within 10% below the cut off in enzyme immuno-assay [EIA]/chemiluminescence immunoassay [CLIA]) to further augment blood safety. There is paucity of data regarding usefulness of GZ sample and its application in Transfusion Transmissible Infection (TTI) screening procedures in blood transfusion services. We looked at our GZ sample results and their confirmatory test results to verify if it adds to blood safety in our set-up? We performed a prospective analytical study on blood donors' samples over two years. All the donors' samples were screened for TTI using CLIA. Samples with signal/cut-off ratio between ≥0.90 and <1.00 were classified under GZ. They were re-tested in duplicate and submitted to confirmatory testing: Neutralization Test for HBsAg, Immunoblot for HCV, and Western blot for HIV. Among the 50,064 blood donors donating the blood during study period, 573 (1.14%) donors were reactive for HBsAg, HCV, and HIV. Forty-seven (0.1%) TTI samples were GZ, but none was "confirmed positive." The utility of GZ testing seems to be limited. However, this may be continued for sake of "erring on the side of caution" and since this only results in negligible wastage (0.1%) of blood units.

Comparison of two immunoassays for concurrent detection of HCV antigen and antibodies among HIV/HCV co-infected patients in dried serum/plasma spots

Hepatitis C virus (HCV) antigen/antibody (Ag/Ab) assays offer the benefit of reducing the window period compared to assays that detect only HCV-Ab. In this study the performance of the Murex Ag/Ab (Murex, Abbott) and Monolisa Ag/Ab Ultra (Monolisa, Bio-Rad) ELISAs was compared for the use of filter dried serum/plasma spots (DS/PS) with a focus on the sensitivity and the percentage of correct positive test results. Correct positive ELISA results were assumed for samples that subsequently tested positive for HCV RNA by RT-qPCR, or RNA negative samples that tested positive in a Western blot (confirmed ELISA results). Sensitivity was evaluated from DS/PS eluates using HCV seroconversion panels [plasma samples of subtypes-(St) 1a, 2b)] and longitudinal HCV antibody positive serum panels (St 1b, 2b, 3a, and 4d). The proportion of correct positive test results was evaluated using 1102 newly diagnosed HIV positive clinical dried serum spots (DSS) eluates for screening of potential HCV co-infection. For the plasma HCV seroconversion samples, which were used as a reference for DSS eluates, the Murex became reactive earlier for antigen positive bleeds. However, for the HCV antibody positive eluates and dilutions thereof, the Monolisa demonstrated a superior sensitivity. Of the clinical DSS 22.8 % (28/123) of samples reactive in the Murex were negative in a subsequent RT-qPCR and Western blot, while only 1.9 % (2/105) of the samples reactive in the Monolisa were negative in these confirmatory assays. Our results indicate that the Monolisa provides fewer false positive results for HCV detection in DSS, whereas for undiluted plasma or serum samples, the Murex can serve as an additional diagnostic tool to narrow the window period.

Community screening for hepatitis C virus infection in a low-prevalence population

BACKGROUND

Age cohort screening for hepatitis C virus (HCV) might be an effective strategy if the majority of undiagnosed cases are concentrated in a particular age group. The objective of this study was to determine HCV prevalence in different age cohorts of the general population in the Central European part of Russia and second, to assess feasibility of HCV antigen testing for community screening programs.

METHODS

Sera from 2027 volunteers were tested for anti-HCV (Architect Anti-HCV, Abbott Laboratories). All anti-HCV reactive samples were confirmed in an immunoblot and tested for HCV Ag (ARCHITECT HCV Ag, Abbott Laboratories), HCV RNA and HCV viral load.

RESULTS

Out of 31 individuals with anti-HCV reactive result, 22 (71%) were confirmed by immunoblot, six were false positives and three were indeterminate. Active infection was observed in 73% of anti-HCV confirmed positives. Five out of 16 individuals had low HCV-RNA levels (< 10,000 IU/mL) and one of those had a very low level (594 IU/mL). Agreement between HCV Ag and HCV RNA was 100%. Total anti-HCV and active HCV infection rates were 1.09% (22/2027) and 0.79% (16/2027), respectively. The peak rates were observed in people 60 years or older (anti-HCV: 2.84% [95% CI: 1.66-4.74%], 13/319; HCV RNA/HCV Ag: 2.23% [95% CI: 1.20-4.00%], 10/319).

CONCLUSIONS

Overall HCV prevalence is low, except in people 60 years or older. The latter should be considered as a target group for HCV screening. The high agreement between HCV RNA and HCV Ag suggests the utility of HCV Ag testing to confirm active infection in screening programs.

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.

'HepCheck Dublin': an intensified hepatitis C screening programme in a homeless population demonstrates the need for alternative models of care

BACKGROUND

Hepatitis C virus (HCV) is one of the main causes of chronic liver disease worldwide. Prevalence of HCV in homeless populations ranges from 3.9 to 36.2%. The HepCheck study sought to investigate and establish the characterisation of HCV burden among individuals who attended an intensified screening programme for HCV in homeless services in Dublin, Ireland.

METHODS

The HepCheck study was conducted as part of a larger European wide initiative called HepCare Europe. The study consisted of three phases; 1) all subjects completed a short survey and were offered a rapid oral HCV test; 2) a convenience sample of HCV positive participants from phase 1 were selected to complete a survey on health and social risk factors and 3) subjects were tracked along the referral pathway to identify whether they were referred to a specialist clinic, attended the specialist clinic, were assessed for cirrhosis by transient elastography (Fibroscan) and were treated for HCV.

RESULTS

Five hundred ninety-seven individuals were offered HCV screening, 73% were male and 63% reported having had a previous HCV screening. We screened 538 (90%) of those offered screening, with 37% testing positive. Among those who tested positive, 112 (56%) were 'new positives' and 44% were 'known positives'. Undiagnosed HCV was prevalent in 19% of the study sample. Active past 30-day drug use was common, along with attendance for drug treatment. Unstable accommodation was the most common barrier to attending specialist appointments and accessing treatment. Depression and anxiety, dental problems and respiratory conditions were common reported health problems. Forty-six subjects were referred to specialised services and two subjects completed HCV treatment.

CONCLUSIONS

This study demonstrates that the current hospital-based model of care is inadequate in addressing the specific needs of a homeless population and emphasises the need for a community-based treatment approach. Findings are intended to inform HepCare Europe in their development of a community-based model of care in order to engage with homeless individuals with multiple co-morbidities including substance abuse, who are affected by or infected with HCV.

HCV NS3Ag: a reliable and clinically useful predictor of antiviral outcomes in genotype 1b hepatitis C virus-infected patients

Since hepatitis C virus (HCV) non-structural 3 (NS3) protease inhibitor (PI) combined with pegylated interferon/ribavirin (PR) has been approved for chronic HCV genotype (GT) 1b infection, a reliable and clinically useful predictor combining with serum HCV RNA to predict early virologic response, breakthrough, and relapse is important during HCV antiviral treatment. We evaluated the role of HCV NS3 antigen (HCV NS3Ag) on the prediction of virologic response in patients with HCV GT1b during PR or PR/simeprevir (triple) therapy. Three hundred patients were recruited, and HCV RNA and HCV NS3Ag were tested at baseline and weeks 2, 4, 12, 24, 48, and 72. NS3Ag and HCV RNA were significantly related (r(2) = 0.67) in the whole patient selection. The kinetic pattern of HCV RNA and HCV NS3Ag during triple treatment was similar. HCV NS3Ag levels in the triple group closely followed those of HCV RNA; the r(2) values were 0.756 (baseline), 0.837 (2 weeks), 0.989 (4 weeks), and 0.993 (12 weeks), respectively. For patients treated with PR, the positive and negative predictive values (PPVs and NPVs) for viral response were 96.31 % and 67.19 %, respectively, at week 4 by using the decrease of NS3Ag (dHCV NS3Ag) combined with HCV RNA. At week 12, the PPV was similar at 94.16 %, while the NPV reached 87.26 %. The PPV and NPV for the prediction of relapse and breakthrough were 90.6 % and 76.7 %, respectively. HCV NS3Ag is a valuable marker and could be a supplementary predictor of HCV RNA for the prediction of antiviral response, breakthrough, or relapse during HCV antiviral treatment.

HEPATITIS C VIRUS (HCV) SEROPREVALENCE, ANTIGENAEMIA AND ASSOCIATED RISK FACTORS AMONG PREGNANT WOMEN IN NIGERIA

BACKGROUND & AIMS

Hepatitis C viral infection is a significant public health challenge with potential risk of progressing to liver cirrhosis and hepatocellular carcinoma (HCC). Actively infected mothers can transmit the virus to their babies who may develop liver cirrhosis and HCC as young adults. We determined the seroprevalence of HCV, its antigenaemia and associated risk factors among pregnant women.

METHODS

We recruited 400 pregnant women and tested their serum for HCV antibodies using immune-chromatographic test and determined the HCV core antigenaemia among HCV sero-positives by enzyme-immunoassay (EIA). The bio-socio-demographic variables of the participants were statistically correlated to the test results.

RESULTS

Seroprevalence of HCV was 5.8% (23/400) and the prevalence of HCV core antigenaemia was 73.9% (17/23). None of the bio-socio-demographic variables of the participants and other known risk factors evaluated had. significant influence on either seroprevalence of HCV or its antigenaemia. Only the employment status of the participants' husbands (p = 0.01) significantly affected seropositivity of HCV.

CONCLUSION

HCV core antigenaemia is high among pregnant women who have antibodies to HCV in our environment and this signifies an active hepatitis C virus infection.

Perinatal transmission of hepatitis C antigens: envelope 1, envelope 2 and non-structural 4

BACKGROUND

Perinatal exposure to hepatitis C virus (HCV) antigens during pregnancy may affect the developing immune system in the fetus. We aimed to study the perinatal transmission of HCV structural and non-structural antigens.

METHODS

Sera from 402 pregnant mothers were tested for anti-HCV antibody and HCV RNA. HCV antigens were determined in sera from 101 HCV-infected mothers and their cord blood.

RESULTS

In both serum and cord blood samples, HCV NS4 (non-structural 4) at 27 kDa, E1 (envelope 1) at 38 kDa and E2 (envelope 2) at 40 kDa were identified, purified and quantified using western blotting, electroelution and ELISA. Maternal sera and neonate cord blood samples had similar detection rates for NS4 (94.1%), E1 (90.1%) and E2 (90.1%). The mean maternal serum levels (optical density, OD) of HCV NS4 (0.87 ± 0.01), E1 (0.86 ± 0.01) and E2 (0.85 ± 0.01) did not differ significantly (p > 0.05) from those of neonatal cord blood (0.83 ± 0.01, 0.87 ± 0.01 and 0.85 ± 0.01, respectively). Also, strong correlations (p < 0.0001) were shown between sera and cord blood sample levels of HCV NS4, r = 0.77; E1, r = 0.76 and E2, r = 0.80. The vertical transmission of these antigens in vaginal delivery did not differ significantly (p > 0.05) from those in caesarean section.

CONCLUSIONS

These findings indicate that vertical transmission of HCV NS4, E1 and E2 antigens was very high. Thus, exposure to these antigens may influence the developing immune responses to natural infection or future vaccination.

Significance of the hepatitis C virus core antigen testing as an alternative marker for hepatitis diagnosis in Egyptian patients

OBJECTIVE

Hepatitis C virus (HCV) core antigen (Ag) quantification by enzyme-immunoassays has been proposed as an economic and simpler alternative to HCV RNA detection. The current study was undertaken to assess the significance of HCV core antigen assay for the diagnosis of chronic HCV infection and monitoring response to antiviral therapy in Egyptian patients.

PATIENTS AND METHODS

Sixty three HCV antibody positive patients and ten interferon-treated patients were included in the current study. The included patients were divided according to their viral load into four groups as follows; group I (n=10): HCV RNA loads ≤ 10000 IU/ml, group II (n=20): HCV RNA loads > 10000 ≤ 100000 IU/ml, group III (n=33): HCV RNA loads >100000 IU/ml and group IV (n=10): interferon-treated HCV patients with a negative HCV RNA.  Serum HCV core Ag and RNA loads were assayed and their correlations, including linear regression lines, were calculated.

RESULTS

HCV core Ag exhibited a non-significant (p > 0.05) difference between all the studied groups. Concerning, group I patients, HCV core Ag levels and HCV RNA loads were positively correlated, with a correlation coefficient of 0.73 (p < 0.05). Group II and III showed stronger correlations; the recorded values were 0.81 (p < 0.0001) and 0.94 (p < 0.0001) for group II and III, respectively.

CONCLUSIONS

HCV core Ag test can be used as an alternative to HCV RNA tests to evaluate chronic infection when the HCV RNA test is unavailable, but is not reliable enough for treatment monitoring.

Hepatitis C virus core antigen testing: Role in diagnosis, disease monitoring and treatment

While hepatitis B virus (HBV) screening relies on hepatitis B surface antigen to confirm HBV infection since the early days of hepatitis B disease management, hepatitis C virus (HCV) infection screening is based on anti-HCV testing which does not discriminate active from past infection. Thus to confirm infection HCV RNA testing has been required; recently a HCV core antigen assay became widely commercially available which could serve to confirm infection. That assay is less sensitive than current HCV RNA assays, but as more than 50% of anti-HCV positive persons will be HCV core antigen positive, HCV core antigen testing can be a cost effective and reflex test to confirm HCV infection in anti-HCV positive individuals and will be easier as it can be applied on the same platform. For treatment monitoring, more data need to be generated, but the early data available at present suggest that HCV core antigen may be an alternative to HCV RNA monitoring. With direct antivirals, HCV core antigen could even be superior to HCV RNA testing, as direct antivirals might already prevent virus formation when HCV core antigen is still produced and thereby correlates better with eventual viral clearance.

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

BACKGROUND

In North America, diagnosis of active hepatitis C virus (HCV) infection is currently performed using RNA testing which is highly sensitive and specific but is associated with three major limitations: lability of RNA molecules, higher costs, and longer turn-around time as compared with commercially-available HCV core antigen testing. In the current study, a new HCV core antigen assay product was evaluated for the diagnosis of HCV infection and its cost reducing potential.

METHODS

Ninety plasma specimens positive for HCV RNA along with 25 negative HCV specimens were used for HCV antigen assay. Twenty-four specimens positive for a panel of agents were used for possible cross-reactivity. Sixty-four HCV antibody-positive specimens with negative HCV RNA and indeterminate HCV immunoblot results were also employed.

RESULTS

In the first group, 78/90 (86.6%) tested positive for HCV antigen with regression analysis showing no significant deviation from linearity. None of the prenatal specimens tested positive for HCV antigen. Non-specific reactions were not observed. In the HCV antibody-indeterminate group, only 2/64 (3.1%) were antigen positive. In the last group, none of the HCV antibody very-low-positive specimens tested positive for HCV antigen. Both inter- and intra-run reproducibility of 100% were noted. The cost analysis showed a minimum of 52.13% reduction in costs associated with qualitative RNA testing.

CONCLUSIONS

Considering the complexity of HCV infection diagnosis and the significant cost and turn-around time burden it imposes on clinical laboratories, HCV antigen testing seems an attractive adjunct to the current battery of laboratory diagnosis that demands more attention.

Prevalence and estimation of hepatitis B and C infections in the WHO European Region: a review of data focusing on the countries outside the European Union and the European Free Trade Association

Knowledge of hepatitis B and C prevalence, and numbers infected, are important for planning responses. Published HBsAg and anti-HCV prevalences for the 20 WHO European Region countries outside the EU/EFTA were extracted, to complement published data for the EU/EFTA. The general population prevalence of HBsAg (median 3·8%, mean 5·0%, seven countries) ranged from 1·3% (Ukraine) to 13% (Uzbekistan), and anti-HCV (median 2·3%, mean 3·8%, 10 countries) from 0·5% (Serbia, Tajikistan) to 13% (Uzbekistan). People who inject drugs had the highest prevalence of both infections (HBsAg: median 6·8%, mean 8·2%, 13 countries; anti-HCV: median 46%, mean 46%, 17 countries), and prevalence was also elevated in men who have sex with men and sex workers. Simple estimates indicated 13·3 million (1·8%) adults have HBsAg and 15·0 million (2·0%) HCV RNA in the WHO European Region; prevalences were higher outside the EU/EFTA countries. Efforts to prevent, diagnose, and treat these infections need to be maintained and improved. This article may not be reprinted or reused in any way in order to promote any commercial products or services.

Screening for hepatitis C virus infection in a high prevalence country by an antigen/antibody combination assay versus a rapid test

In low-income-countries, screening for hepatitis C virus (HCV) infection is often based on rapid tests (RT). Their lower sensitivity compared to enzyme immunoassay (EIA) suggests that newer HCV Antigen/Antibody (Ag/Ab) combination assays might have a role in such countries. To test this idea, 1998 blood donors were tested at the University Teaching Hospital blood bank in Yaoundé, Cameroon simultaneously with a RT (HCV rapid test, Human Diagnostics, Berlin, Germany) according to standard practice (S1) and with an Ag/Ab assay (Monolisa HCV Ag/Ab Ultra, Biorad, France) (S2). All discordant, borderline and reactive samples were submitted to confirmatory testing by immunoblot and/or HCV-RNA. Of the 86 (4.3%) samples positive with one or both strategies, 29 were confirmed negative, 37 positive and 20 were false positive or resolved infection. There was a significant difference in test sensitivity (p=0.01) between S1 (70.3%) and S2 (91.9%) but not in test specificity (99.4% and 98.6%, respectively). The benefit of the Ag/Ab assay in the detection of recent HCV seronegative infections could not be evaluated since no Antigen-only donations were identified. However, better Ag/Ab test sensitivity compared to RT supports the implementation of these newer immunoassays for HCV screening in the African blood bank setting.

Clinical utility of the ARCHITECT HCV Ag assay for early treatment monitoring in patients with chronic hepatitis C genotype 1 infection

BACKGROUND

Virologic response-monitoring is essential for determining therapy duration in patients with chronic hepatitis C virus (HCV) infection. This is usually performed using highly sensitive HCV-RNA assays. However, HCV-RNA assays are time-consuming, expensive and require highly trained personnel. Quantitative determination of HCV core-antigen (HCVAg) levels may be used to supplement treatment monitoring.

OBJECTIVES

The clinical utility of the ARCHITECT HCV Ag assay (Abbott Diagnostics) for response-guided therapy was investigated.

STUDY DESIGN

We analyzed serum from 160 patients with HCV genotype 1 infection who had been treated with peg-interferon alfa-2b/ribavirin. HCVAg levels were determined at baseline, weeks 1, 2, 4 and 12. HCVAg levels were compared to those obtained with HCV-RNA assays: VERSANT HCV Quantitative 3.0 (bDNA) and Qualitative (TMA, both Siemens Healthcare) assay and the Abbott RealTime HCV assay (ART; Abbott Diagnostics).

RESULTS

Baseline HCVAg levels correlated well with HCV-RNA as assessed by bDNA (r=0.91; p<0.0001) and ART (r=0.92; p<0.0001), respectively. Patients with undetectable HCVAg levels at week 1 had a 90.9% probability (positive predictive value) to achieve a rapid virologic response (HCV-RNA undetectable at week 4) based on TMA and 86.4% based on ART, respectively. Patients with less than 1 log(10) reduction in HCVAg between baseline and week 12 had a 90% probability (negative predictive value) to achieve a nonresponse (<2 log(10) decline in HCV-RNA between baseline and week 12) based on bDNA and 100% based on ART, respectively.

CONCLUSIONS

Determination of HCVAg may be useful for antiviral response-monitoring in patients with HCV genotype 1 infection.

Hepatitis C virus-multispecific T-cell responses without viremia or seroconversion among Egyptian health care workers at high risk of infection

Hepatitis C virus (HCV)-specific cell-mediated immunity (CMI) has been reported among exposed individuals without viremia or seroconversion. Limited data are available regarding CMI among at-risk, seronegative, aviremic Egyptian health care workers (HCW), where HCV genotype 4 predominates. We investigated CMI responses among HCW at the National Liver Institute, where over 85% of the patients are HCV infected. We quantified HCV-specific CMI in 52 seronegative aviremic Egyptian HCW using a gamma interferon (IFN-γ) enzyme-linked immunospot assay in response to 7 HCV genotype 4a overlapping 15-mer peptide pools covering most of the viral genome. A positive HCV-specific IFN-γ response was detected in 29 of 52 HCW (55.8%), where 21 (40.4%) had a positive response for two to seven HCV pools and 8 (15.4%) responded to only one pool. The average numbers of IFN-γ total spot-forming cells (SFC) per million peripheral blood mononuclear cells (PBMC) (± standard error of the mean [SEM]) in the 29 responding and 23 nonresponding HCW were 842 ± 141 and 64 ± 15, respectively (P < 0.001). Flow cytometry indicated that both CD4(+) and CD4(-) T cells produced IFN-γ. In summary, more than half of Egyptian HCW demonstrated strong HCV multispecific CMI without viremia or seroconversion, suggesting possible clearance of low HCV exposure(s). These data suggest that detecting anti-HCV and viremia to determine past exposure to HCV can lead to an underestimation of the true disease exposure and that CMI response may contribute to the low degree of chronic HCV infection in these HCW. These findings could have strong implications for planning vaccine studies among populations with a high HCV exposure rate. Further studies are needed to determine whether these responses are protective.

Characterization and application of monoclonal antibody against hepatitis C virus nonstructual protein three

Developing assays for detecting HCV antigens could be beneficial because viral proteins appear earlier than antibodies and are more stable than RNA in the serum. Monoclonal antibody was prepared by immunization and cell fusion. Subclass, specificity, and efficiency of monoclonal antibodies were determined by ELISA. Epitope specificity of monoclonal antibodies was analyzed by ELISA additivity test. HCV antigen in serum of hepatitis patients was examined by double monoclonal antibody sandwich ELISA. Five hybridoma cell lines were screened and named HCV(1), HCV(2), HCV(3), HCV(4), and HCV(5). These five monoclonal antibodies had high specificity and efficiency. The additivity test showed that HCV(2), HCV(4), and HCV(5) recognized different epitopes, which can be matched in ELISA. Of 173 anti-HCV positive patients, 37 (21.4%) were positive for HCV antigen. Of 1498 anti-HCV negative patients, 10 (0.67%) were positive for HCV antigen. Fifty normal controls were negative for HCV antigen. HCV antigen detection had moderate agreement and correlation with HCV RNA detection (kappa=0.577, p<0.01; r=0.59, p<0.01). This result indicates that the monoclonal antibody against HCV NS(3) may be a potential diagnostic reagent, which would provide a foundation for developing a sandwich ELISA of HCV antigen detection.

Evaluation of the dried blood spot (DBS) collection method as a tool for detection of HIV Ag/Ab, HBsAg, anti-HBs and anti-HCV in a Malaysian tertiary referral hospital

INTRODUCTION

Dried blood spot (DBS) collection is an appealing alternative to whole blood or plasma sampling, as it has technical and economic advantages over the latter.

MATERIALS AND METHODS

A prospective cross-sectional study was conducted at a Malaysian tertiary referral hospital from November 2009 to March 2010. One hundred and fifty paired specimens of DBS and plasma were analysed by the standard assays for HIV Ag/Ab, HBsAg, anti-HBS and anti-HCV, separately (total 600 paired specimens). DBS sample titres were then compared to the results of plasma testing, which was used as the gold standard.

RESULTS

For the HIV Ag/Ab assay with a cut-off point of 0.35 Relative Light Units (RLUs), the sensitivity and specificity were both 100%. For the HBsAg assay, the sensitivity was 96.5% and the specificity was 97.8%, with a cut-off point of 1.72 RLUs. Sensitivity for the anti-HBs test was 74.2% and the specificity was 86.9%, using a cut-off point of 0.635 RLUs. For the anti-HCV assay, the sensitivity was 97.3% and the specificity was 100%, with a cut-off point of 0.10 RLUs.

CONCLUSION

DBS is an ideal choice to be used as a screening tool for the detection of HIV, Hepatitis B and Hepatitis C virus infections. However, different cut-off values need to be used for the validation of test positivity in DBS samples because the small amount of blood in the DBS specimens leads to lower assay titres.

[Detection of hepatitis C core antigen in intravenous drug addictions]

OBJECTIVE

To study the status of detection of hepatitis C core antigen in intravenous drug addictions, and discuss the foreground of the hepatitis C core antigen ELISA test system.

METHODS

HCV core antigen, HCV RNA quantity, anti HCV-IgG, HBsAg were analysis in all the plasma samples taken from 93 cases of intravenous drug users.

RESULTS

The specialty and sensitivity of HCV core antigen in intravenous drug addictions 100% -54% separately. When HBsAg were positive, the sensitivity of HCV core antigen was 38%, while HBsAg negative, the sensitivity of HCV core antigen was 69% (P < 0.01).

CONCLUSION

The detections of HCV core antigen showed high specialty but low sensitivity in intravenous drug addictions. The positive rate has positive relation with HCV RNA virus logarithm quantity. Coinfection with HBV are the interfere factor of HCV core antigen detection. In screening experimentations, the detection of HCV core antigen in plasma may be applied as supplement method for anti-HCV-IgG. It can also be used to monitor viremia in HCV infection.

[Serum alpha-fetoprotein levels in pregnant women with indeterminate result of anti hepatitis C virus antibodies analysis]

AIM

Comparison of alpha-fetoprotein (AFP) levels in blood sera samples of women in the early stages of pregnancy with positive or indeterminate results of anti-HCV.

MATERIALS AND METHODS

Blood sera samples of women in the first trimester of pregnancy were analyzed by using microplate test systems for enzyme immunoassay (EIA) with complex and separate detection of antibodies against hepatitis C virus (HCV) antigens.

RESULTS

AFP levels were higher in women in the first trimester of pregnancy with anti-HCV than in women without anti-HCV. AFP levels in blood sera samples of pregnant women with indeterminate results of anti-HCV analysis were higher than in blood sera samples of pregnant women without anti-HCV. No differences in serum AFP levels were observed between anti-HCV positive samples and samples with indeterminate results of analysis.

CONCLUSION

Increased AFP level in the first trimester of pregnancy was observed not only in women with HCV infection, but also in women with indeterminate results of anti-HCV analysis. The data suggest that these groups may have epidemiological similarity.