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.

Diagnostic performance of dried blood spot hepatitis C virus core antigen testing for hepatitis C screening: A systematic review and meta-analysis.

Dried blood spot (DBS) sampling is increasingly used for hepatitis C virus (HCV) screening. HCVcAg testing offers a faster and more streamlined approach to diagnosing HCV infection. We conducted a systematic review and meta-analysis to assess the diagnostic performance of the Abbott ARCHITECT HCV Ag assay for screening active HCV infection using DBS samples. Eight studies (n = 1229) were selected among all published studies available up to October 4, 2024, in different databases with a search strategy registered (PROSPERO: CRD42022363975). The gold standard method was the HCV PCR test. Data were analyzed using the MIDAS module in STATA with a random effects model. Combined diagnostic accuracy measures were as follows: sensitivity 85%, specificity 100%, positive likelihood ratio (PLR) 233.1, negative likelihood ratio (NLR) 0.15, and summary receiver operating characteristic (SROC) 0.99. Likelihood ratios and Fagan's nomogram suggested that the HCVcAg assay with DBS samples can confirm or rule out active HCV infection with over 92% accuracy in high-prevalence settings (≥5%). However, in low-prevalence settings (≤1%), a confirmatory test must be required for positive results. The ability of the test to identify people without HCV infection was high regardless of HCV prevalence, with an error rate of less than 3%. This meta-analysis is subject to limitations, particularly due to the number of included studies and significant heterogeneity among them. HCV screening using the Abbott ARCHITECT HCV Ag assay with DBS samples showed excellent diagnostic performance, but its external validity may be limited when HCV prevalence is low (≤1%).

Seroreactivity of antibodies to hepatitis B core antigen among hepatitis B surface antigen-screened negative blood donors and its implications for blood safety in a resource-constrained country.

BACKGROUND AND OBJECTIVES: Transfusion-related hepatitis B infections have been reduced significantly with the implementation of blood screening using both serology and nucleic acid amplification technology (NAT) in developed countries. However, in resource-constrained countries, where NAT is inaccessible, the risk persists from early acute and occult cases. This study aimed to determine the antibodies to hepatitis B core antigen (anti-HBc) reactive rate among hepatitis B surface antigen (HBsAg)-screened negative blood donors and its impact on blood safety in the Philippines. MATERIALS AND METHODS: A total of 1602 HBsAg-negative samples, randomly collected from nine leading blood service facilities representative of each region in the Philippines, were tested for anti-HBc immunoglobulin M (IgM), Total and antibodies to HBsAg (anti-HBs) using the Architect i2000SR Immunoassay Analyser (Abbott Laboratories, IL). Anti-HBc IgM and/or Total repeat reactive were further tested for hepatitis B virus (HBV) NAT using the Cobas TaqScreen MPX v2.0 (Roche Diagnostics, Basel). RESULTS: Overall, 19.16% HBsAg-negative samples (n = 307/1602) were reactive for either anti-HBc IgM or Total or a combination of both, of which 1.3% (n = 4/307) had detectable HBV-DNA and 80.5% (n = 247/307) were anti-HBs positive. About the anti-HBs titres, 30.27% (n = 485/1602) were positive (≥10 IU/L) with 55.67% (n = 270/485) having titres ≥100 IU/L. Anti-HBs-only-positive samples were 14.85% (n = 238/1602). CONCLUSION: We observed a high anti-HBc reactive rate (19.16%) with 3.7% anti-HBc-only reactive (anti-HBs negative) and 1.3% HBV-DNA positive. This warrants the need to reconsider existing screening practices to improve blood safety in the country.

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%).

Expression and purification of Hepatitis B virus core antigen using Escherichia coli and its utilization for the diagnosis of Hepatitis B virus infections.

Hepatitis B virus (HBV) is responsible for most of the viral hepatitis worldwide. HBV is a partially double stranded DNA virus that is composed of four main open reading frames (ORFs) encoding its important antigens, namely hepatitis B surface antigen (HBsAg), hepatitis B core antigen (HBcAg), HBV polymerase and hepatitis B X antigen (HBxAg). In this study, we report a successful method for the cloning and expression of HBcAg. The ORF of HBcAg was successfully amplified using polymerase chain reaction (PCR), cloned into the expression vector pRSET-B and transformed to Escherichia coli (E. coli) BL-21 (DE3) pLysS strain for protein expression. Successful expression of HBcAg was accomplished, in which an induced protein with a molecular weight of 24 kDa was obtained and confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. The produced HBcAg was successfully used for the diagnosis of HBV infected patient through detection of antibodies against HBcAg (anti-HBcAg) in the serum of the patient utilizing Western blotting. Overall, this study provides a simple, convenient and efficient protocol for the production of HBcAg that can be used as an important candidate to study the diagnosis and prognosis of HBV disease, as well as for understanding the epidemiological prevalence of HBV cases and production of anti-HBcAg.

Assessment of hepatitis c core antigen in epithelial salivary gland neoplasms (ex-vivo study).

BACKGROUND: Salivary gland neoplasms (SGNs) pose a challenge to both pathologists and clinicians. Despite research, the etiology of these neoplasms remains unclear. This study aimed to identify any potential association between the presence of hepatitis C virus (HCV) at the protein or gene level and epithelial salivary gland neoplasms. METHODS: Formalin-fixed paraffin-embedded (FFPE) blocks of epithelial salivary gland neoplasms were retrieved from the archives of the Oral and Maxillofacial Pathology Department, Faculty of Dentistry, Cairo University within the 5-year period from 2016 to 2020. Immunohistochemistry was used to assess HCV core antigen, while reverse transcription polymerase chain reaction was employed for the evaluation of HCV RNA. RESULTS: A total of 44 specimens were collected, 28 of which were benign neoplasms and 16 were malignant neoplasms. There was a statistically significant difference in HCV positivity between the two groups (P-value = 0.036). Benign tumors showed a statistically significant lower percentage of positive cases than malignant tumors. The localization of staining was also evaluated, revealing various patterns of HCV core antigen expression, including diffuse cytoplasmic, patchy cytoplasmic, nuclear, and a combination of nuclear and cytoplasmic expression. There was no statistically significant difference between the expression patterns in benign and malignant tumors (P-value = 0.616). Given that Pleomorphic Adenoma and Mucoepidermoid Carcinoma were the predominant tumor types in this study, four cases were selected for RNA detection. HCV RNA was detected in all cases using RT-PCR. CONCLUSIONS: HCV core antigen is frequently detected in SGNs and is suggested to be a potential risk factor for the development of these neoplasms. Further studies are required to discover other biomarkers, their roles, and the pathways associated with HCV in SGNs.

Opportunities for enhanced prevention and control of hepatitis C through improved screening and testing efforts.

An estimated 2.4 million people in the United States are living with hepatitis C virus (HCV) infection. In 2020, the Centers for Disease Control and Prevention updated hepatitis C screening recommendations to test adults aged ≥ 18 years at least once in a lifetime and pregnant persons during each pregnancy. For those with ongoing exposure to HCV, periodic testing is recommended. The recommended testing sequence is to obtain an HCV antibody test and, when positive, perform an HCV RNA test. Examination of HCV care cascades has found incomplete HCV testing occurs when a separate visit is required to obtain the HCV RNA test. Hepatitis C core antigen (HCVcAg) testing has been shown to be a useful tool for diagnosing current HCV infection is some settings. Hepatitis C testing that is completed, accurate, and efficient is necessary to achieve hepatitis C elimination goals.

Diagnostic Performance of the HCV Core Antigen Test To Identify Hepatitis C in HIV-Infected Patients: a Systematic Review and Meta-Analysis.

The standard algorithm for diagnosing hepatitis C virus (HCV) infection has two steps, an HCV antibody test for screening and a nucleic acid amplification test (NAAT) for confirmation. However, the HCV core antigen (HCVcAg) detection assay is an alternative for one-step diagnosis. We aimed to evaluate the diagnostic performance of the Abbott ARCHITECT HCV Ag assay to detect active hepatitis C in serum/plasma in people living with HIV/AIDS (PLWHA), through a systematic review and meta-analysis. PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library were searched until 20 September 2022 (PROSPERO, CRD42022348351). We included studies evaluating Abbott ARCHITECT HCV Ag assay (index assay) versus NAATs (reference test) in PLWHA coinfected with HCV who did not receive antiviral treatment for HCV. Meta-analysis was performed with the MIDAS module using Stata and random-effects models. The QUADAS-2 tool evaluated the risk of bias. The bivariate analysis was conducted on 11 studies with 2,407 samples. Pooled sensitivity was 0.95 (95% CI = 0.92 to 0.97), specificity 0.97 (95% CI = 0.93 to 0.99), positive likelihood ratio 37.76 (95% CI = 12.84 to 111.02), and negative likelihood ratio 0.06 (95% CI = 0.04 to 0.09). The area under the curve was 0.97 (95% CI = 0.20 to 1.00). For low prevalence (≤5%), the posttest probability that an individual with a positive test was a true positive ranged from 4% to 67%, whereas, at high prevalence (≥10%), the posttest probability was between 81% and 87%, indicating that a confirmatory test should be necessary, particularly with prevalence values of ≤1%. Regardless of prevalence, the probability that an individual with a negative test was a false negative was close to zero, indicating that the individual was not infected with HCV. In conclusion, the accuracy of the Abbott ARCHITECT HCV Ag assay was very good for HCV screening in serum/plasma samples from PLWHA. The clinical utility to confirm HCV infection was acceptable in high-prevalence settings (≥10%) but poor in low-prevalence settings (≤1%). Furthermore, it was excellent in excluding active HCV infection.

A hepatitis B virus core antigen-based virus-like particle vaccine expressing SARS-CoV-2 B and T cell epitopes induces epitope-specific humoral and cell-mediated immune responses but confers limited protection against SARS-CoV-2 infection.

The hepatitis B virus core antigen (HBcAg) tolerates insertion of foreign epitopes and maintains its ability to self-assemble into virus-like particles (VLPs). We constructed a ∆HBcAg-based VLP vaccine expressing three predicted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B and T cell epitopes and determined its immunogenicity and protective efficacy. The recombinant ∆HBcAg-SARS-CoV-2 protein was expressed in Escherichia coli, purified, and shown to form VLPs. K18-hACE2 transgenic C57BL/6 mice were immunized intramuscularly with ∆HBcAg VLP control (n = 15) or ∆HBcAg-SARS-CoV-2 VLP vaccine (n = 15). One week after the 2nd booster and before virus challenge, five ∆HBcAg-SARS-CoV-2 vaccinated mice were euthanized to evaluate epitope-specific immune responses. There is a statistically significant increase in epitope-specific Immunoglobulin G (IgG) response, and statistically higher interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) expression levels in ∆HBcAg-SARS-CoV-2 VLP-vaccinated mice compared to ∆HBcAg VLP controls. While not statistically significant, the ∆HBcAg-SARS-CoV-2 VLP mice had numerically more memory CD8+ T-cells, and 3/5 mice also had numerically higher levels of interferon gamma (IFN-γ) and tumor necrosis factor (TNF). After challenge with SARS-CoV-2, ∆HBcAg-SARS-CoV-2 immunized mice had numerically lower viral RNA loads in the lung, and slightly higher survival, but the differences are not statistically significant. These results indicate that the ∆HBcAg-SARS-CoV-2 VLP vaccine elicits epitope-specific humoral and cell-mediated immune responses but they were insufficient against SARS-CoV-2 infection.

Marked reduction in the incidence of transfusion-transmitted hepatitis B virus infection after the introduction of antibody to hepatitis B core antigen and individual donation nucleic acid amplification screening in Japan.

BACKGROUND: In Japan, 41 million blood donations have been screened for hepatitis B virus (HBV) during the past 8.4 years using individual donation nucleic acid amplification testing (ID-NAT) and antibody to hepatitis B core antigen (anti-HBc) screening. STUDY DESIGN AND METHODS: Transfusion-transmitted HBV infection (TT-HBV) incidence was examined. Donated blood implicated in TT-HBV was analyzed for infection stage and DNA levels. Causative HBV strains were phylogenetically analyzed. RESULTS: Among 5162 (0.013%) ID-NAT positives, window period (WP) and occult HBV infection (OBI) accounted for 3.4% (176) and 11.5% (594), respectively. No OBI-related TT-HBV occurred. Seven blood donations caused eight TT-HBV cases, six of which were in the pre-ID-NAT WP, leaving one with an unresolved infection stage. Seven cases were caused by platelet concentrate (180 mL plasma) and one case by fresh-frozen plasma (200 mL plasma), which contained estimated infectious doses varying between 2 and 2300 HBV virions. HBV subgenotypes in five cases were HBV/A2. Complete genome sequences of the transmitting A2 strains were nearly identical (99.6%-100%) and clustered in a group that included HBV/HIV-1 coinfections and a higher proportion of donors in the acute infection phase (69%) than the other group of HBV/A2 sequences (5%). DISCUSSION: The incidence of observed TT-HBV cases has significantly reduced to 0.19 per million in the ID-NAT screening period. OBI-related TT-HBV was eliminated by anti-HBc screening. Established TT-HBV cases were caused by blood products with large plasma volumes containing extremely low HBV concentrations derived from blood donors at a very early infection stage.

Anti-HBc: a significant host predictor of spontaneous HBsAg seroclearance in chronic hepatitis B patients - a retrospective longitudinal study.

BACKGROUND AND AIM: In chronic hepatitis B infection (CHB), seroclearance of hepatitis B surface antigen (HBsAg) is associated with favourable clinical outcomes compared to those with persistent HBsAg seropositivity, and thus considered as a desired treatment endpoint. This current study explores the possibility of serum antibody to hepatitis B core antigen (anti-HBc) as a potential predictive factor of HBsAg seroclearance. METHODS: This is a retrospective study that analyzed the plasma samples of CHB patients using the LUMIPULSE® G1200 analyzer. The longitudinal anti-HBc level between patients who subsequently achieved HBsAg seroclearance (S-losers) and those with persistent HBsAg-positivity (controls) were compared at multiple time points before the event. RESULTS: A total of 240 subjects (120 S-losers and 120 controls; age- and gender-matched) were included (mean age 56.42 ± 10.81, 65% male). Compared to controls, S-losers had significantly lower plasma anti-HBc levels prior to HBsAg seroclearance, with a significant trend of declining plasma anti-HBc 8-5 years prior to HBsAg seroclearance (p < 0.01), while such trend was not observed in controls. ROC curve analysis revealed that plasma anti-HBc at multiple time points before HBsAg seroclearance return AUC greater than 0.7. Plasma anti-HBc level at the cut-off value of 82.50 COI was 68.3% sensitive and 90% specific for HBsAg seroclearance within 1 year. Combining with quantitative HBsAg < 100 IU/mL, anti-HBc < 82.5 COI identified 88.2% patients who would develop HBsAg seroclearance within 1 year. CONCLUSION: Plasma anti-HBc level began to decline 10 years prior to HBsAg seroclearance and can serve as a potential predictor for subsequent HBsAg seroclearance.

Immune response induced by recombinant pres2/S-protein and a pres2-S-protein fused with a core 18-27 antigen fragment of hepatitis B virus compared to conventional HBV vaccine.

Although comprehensive vaccination is the cornerstone of public health programs to control hepatitis B virus (HBV) infections, 5% of people who receive the existing vaccine do not develop proper immunity against HBV. To overcome this challenge, researchers have tried using various protein fragments encoded by the virus genome to achieve better immunization rates. An important antigenic component of HBsAg called the preS2/S or M protein has also received much attention in this area. The gene sequences of preS2/S and Core18-27 peptide were extracted from the GenBank (NCBI). Final gene synthesis was conducted with pET28. Groups of BALB/c mice were immunized with 10 µg/ml of recombinant proteins and 1 µg/ml CPG7909 adjuvant. Serum levels of IF-γ, TNF-α, IL-2, IL-4, and IL-10 were measured by ELISA assay method on spleen cell cultures on day 45, and IgG1, IgG2a, and total IgG titers obtained from mice serum were quantified on days 14 and 45. Statistical analysis did not show any significant difference between the groups regarding IF-γ level. There were, however, significant differences in terms of IL-2 and IL-4 levels between the groups receiving preS2/S-C18-27 with and without adjuvant and the groups receiving both preS2/S and preS2/S-C18-27 (Plus Recomb-Plus Recomb: the group of mice that received both preS2/S and preS2/S-C18-27 simultaneously). The strongest total antibody production was induced by immunization with both recombinant proteins without CPG adjuvant. The groups that received both preS2/S and preS2/S-C18-27, whether with or without adjuvant, were significantly different from those that received the conventional vaccine considering most abundant interleukins. This difference suggested that higher levels of efficacy can be achieved by the use of multiple virus antigen fragments rather than using a single fragment.

Hepatitis B virus core-related antigen (HBcrAg) as a prognostic marker for the development of hepatocellular carcinoma: A mini systematic review of the literature.

Chronic hepatitis B (CHB) infection is a risk factor for hepatocellular carcinoma (HCC). Previous studies showed that elevated levels of Hepatitis B Virus (HBV) DNA and HBsAg are associated with increased HCC risk in patients with chronic HBV infection. Multiple studies showed that high levels of HBV DNA and Hepatitis B Surface Antigen (HBsAg) are associated with higher HCC risk in CHB patients. Patients treated with antiviral therapy may have undetectable or low levels of HBV DNA and HBsAg loss. However, HCC may develop in some patients with low-level HBV DNA and HBsAg seroconversion. In this study, we evaluated the role of HBcrAg in predicting HBV related HCC development. We searched PubMed, Scopus, and Web of Science databases using keywords (hepatitis B core-related antigen, hepatocellular carcinoma, liver neoplasm, hepatocellular and hepatic cancer, to identify studies assessing serum level of HBcrAg in patients with CHB and HCC. The search resulted in 184 studies. Seven studies were included: Four of which were retrospective cohort studies, and the rest were prospective cohort, case controls. Six of them reported a higher HBcrAg positivity rate in the HCC group when compared with the HBV DNA assay, yet with similar hazard ratio (HR) in predicting the incidence of HCC. However, four studies found that HBcrAg positivity was an independent risk factor for HCC development with a HR ranging from 3.27 to 7.05. HBV-related HCC has many proposed biomarkers in its prediction, yet our findings revealed HBcrAg to may have superiority over other biomarkers. High quality studies with bigger sample size research is needed to understand the potential role of HBcrAg in CHB induced HCC.

Prevalence and genotype distribution of hepatitis C virus within hemodialysis units in Thailand: role of HCV core antigen in the assessment of viremia.

BACKGROUND: Individuals with end-stage renal disease have a higher risk of hepatitis C virus (HCV) acquisition during long-term hemodialysis (HD). Our report was designed to investigate HCV prevalence and genotype, in addition to the clinical use of HCV core antigen (HCVcAg), within multiple HD facilities in Thailand. METHODS: This cross-sectional report was investigated between January and June 2019. HCV infection was assessed by anti-HCV and confirmed active infection by measuring HCV RNA and HCVcAg. HCV genotype was determined by phylogenetic analysis using nucleotide sequences of NS5B region. RESULTS: Overall, 140 of 3,305 (4.2%) patients in 15 dialysis centers had anti-HCV positive. Among them, HCV RNA was further assessed in 93 patients and was detectable in 59 (63.4%) persons. Considering HCV viremia, HCVcAg measurement exhibited high accuracy (96.8%), sensitivity (94.9%) and specificity (100%) in comparison with HCV RNA testing. Moreover, individuals infected with HCV received a longer duration of dialysis vintage when compared to anti-HCV negative controls. The major sub-genotypes were 1a, 1b, 3a, 3b, 6f and 6n. Regarding phylogenetic analysis, there were 7 clusters of isolates with high sequence homology affecting 17 individuals, indicating possible HCV transmission within the same HD centers. CONCLUSIONS: HCV frequency and common sub-genotypes in HD centers were different from those found in the Thai general population. HCVcAg might be an alternate testing for viremia within resource-limited countries. Enhanced preventive practices, dialyzer reuse policy and better access to antiviral therapy are crucial for HCV micro-elimination within HD facilities.

Anti-HBc IgG Levels: A Predictor of HBsAg Seroclearance in Chronic Hepatitis B Patients with Nucleos(t)ide Analogue-Induced HBeAg Seroclearance.

BACKGROUND/AIMS: We investigated the efficiency of the indirect ratio of anti-HBc IgG at predicting HBsAg seroclearance in patients with nucleos(t)ide analogue (NA)-induced HBeAg seroclearance. METHODS: We performed a retrospective study that included 366 chronic hepatitis B patients (March 2007 to December 2016) at a single tertiary hospital. These patients were HBsAg seropositive, and experienced NA-induced HBeAg seroclearance. The indirect ratio of light absorbance of anti-HBc IgG levels were measured with chemiluminescent microparticle immunoassay using the Architect Anti-HBc assay (Abbott Laboratories, IL, USA) as a qualitative method prior to antiviral therapy. We calculated the cumulative incidences of HBsAg seroclearance based on the anti-HBc IgG levels. RESULTS: After a 10-year follow-up, 48 patients experienced HBsAg seroclearance (13.1%). Thirty-three of 179 patients who had an indirect ratio of light absorbance of anti-HBc IgG < 11 RLU (relative light unit) showed HBsAg seroclearance (18.4%); 15 of 187 patients who had an indirect ratio of light absorbance of anti-HBc IgG ≥ 11 RLU showed HBsAg seroclerance (8.0%) (p = 0.003). In multivariate analysis, age, and ALT at the time of HBeAg seroclearance were predictors of HBsAg seroclearance. Especially, the relative risk of HBsAg seroclearance in patients with baseline anti-HBc IgG levels < 11 RLU was 2.213 (95% CI, 1.220-4.014), compared to that in patients with higher levels of anti-HBc IgG at baseline (p = 0.009). CONCLUSION: Using an indirect method for anti-HBc IgG levels, baseline anti-HBc IgG levels (< 11RLU), age (≥ 50 years), and ALT (≥ 40 IU/L) might be associated with HBsAg seroclearance in patients with NA-induced HBeAg seroclearance.

Isolated anti-HBc is an independent risk factor for tumor recurrence in intrahepatic cholangiocarcinoma after curative resection.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is a poorly understood and aggressive malignancy with increasing incidence and mortality. Hepatitis B virus (HBV) infection is recognized as one of the important risk factors of ICC. There are few reports focusing on whether isolated antibody to hepatitis B core antigen (isolated anti-HBc, IAHBc) have prognostic role in ICC, while positive hepatitis B surface antigen (HBsAg) has been reported to be associated with the prognosis of ICC. The aim of this study was to investigate the prognostic value of IAHBc in ICC patients after curative resection, in order to identify those who have the high risk of ICC recurrence in the early stage. METHODS: We divided 209 ICC patients who underwent curative resection into 4 groups: group I (n = 40), HBsAg (-)/antibody to hepatitis B surface antigen (anti-HBs) (-)/anti-HBc (+); group II (n = 70), HBsAg (+)/anti-HBc (-); group III (n = 55), HBsAg (-)/anti-HBs (+)/anti-HBc (+); and group IV (n = 44), HBsAg (-)/anti-HBc (-). We compared the recurrence-free survival (RFS) and overall survival (OS) among these four groups. RESULTS: The median follow-up time was 16.93 months (range 1-34.6 months). The 1- and 2-year RFS and OS rates were 60% and 42%, and 78% and 63% respectively in all patients. Compared to the whole non-IAHBc patients (group II + group III + group IV), IAHBc patients (group I) showed significantly lower RFS at 1 year (39.8% vs. 64.4%, P = 0.001) and 2 years (20.7% vs. 46.7%, P = 0.001). When compared to other three individual groups, IAHBc patients (group I) also had the lowest RFS. We did not find significant difference in OS among the four groups. Further multivariate analysis revealed that IAHBc was an independent risk factor of RFS. CONCLUSIONS: IAHBc is an independent poor prognostic factor for tumor recurrence in ICC patients after curative resection.

Electrochemical immunoassay for detection of hepatitis C virus core antigen using electrode modified with Pt-decorated single-walled carbon nanotubes.

Pt nanoparticles deposited on single-walled carbon nanotubes (PtSWCNTs), synthesized via the deposition precipitation (DP) method, were introduced as a substrate for immobilizing antibodies on an electrode surface and then enhancing the electrochemical sensitivity. A PtSWCNT-modified paper-based screen-printed graphene electrode was successfully developed to diagnose hepatitis C virus (HCV) infection. The hepatitis C virus core antigen (HCV-cAg) level was determined by differential pulse voltammetry (DPV) using [Fe(CN)6]3-/4- as a redox solution. In the presence of HCV-cAg, the DPV current response decreased with increasing HCV-cAg concentration. Under the optimal conditions, the change in current response provides a good linear correlation with the logarithm of HCV-cAg concentration in the range 0.05 to 1000 pg mL-1 (RSD < 5%), and the limit of detection was 0.015 pg mL-1 (or 0.71 fmol L-1). Furthermore, the proposed immunosensor has been utilized to quantify HCV-cAg in human serum samples with reliable results compared with standard immunoassays (% relative error < 10%). This sensor offers a simple, sensitive, selective, disposable, and inexpensive means for determination of HCV-cAg in human serum samples. The paper-based label-free immunosensor is versatile and feasible for clinical diagnosis.

High-level production of recombinant HBcAg virus-like particles in a mathematically modelled P. pastoris GS115 Mut+ bioreactor process under controlled residual methanol concentration.

Recombinant hepatitis B core antigen (HBcAg) molecules, produced in heterologous expression systems, self-assemble into highly homogenous and non-infectious virus-like particles (VLPs) that are under extensive research for biomedical applications. HBcAg production in the methylotrophic yeast P. pastoris has been well documented; however, productivity screening under various residual methanol levels has not been reported for bioreactor processes. HBcAg production under various excess methanol levels of 0.1, 1.0 and 2.0 g L-1 was investigated in this research. Results indicate that, under these particular conditions, the total process and specific protein yields of 876-1308 mg L-1 and 7.9-11.2 mg gDCW-1, respectively, were achieved after 67-75 h of cultivation. Produced HBcAg molecules were efficiently purified and the presence of highly immunogenic, correctly formed and homogenous HBcAg-VLPs with an estimated purity of 90% was confirmed by electron microscopy. The highest reported HBcAg yield of 1308 mg L-1 and 11.2 mg gDCW-1 was achieved under limiting residual methanol concentration, which is about 2.5 times higher than the next highest reported result. A PI-algorithm-based residual methanol concentration feed rate controller was employed to maintain a set residual methanol concentration. Finally, mathematical process models to characterise the vegetative, dead and total cell biomass (Xv, Xd and X), substrate (Glycerol and Methanol) concentration, reactor volume (V), and product (HBcAg) dynamics during cultivation, were identified. A rare attempt to model the residual methanol concentration during induction is also presented.

A simple method to purify recombinant HCV core protein expressed in Pichia pastoris for obtaining virus-like particles and producing monoclonal antibodies.

In this study, we describe an optimized method of obtaining virus-like particles (VLPs) of the recombinant hepatitis C virus (HCV) core protein (HCcAg) expressed in yeast cells (Pichia pastoris), which can be used for the construction of diagnostic test systems and vaccine engineering. The described simplified procedure was developed to enable in vitro self-assembly of HCcAg molecules into VLPs during protein purification. In brief, the HCcAg protein was precipitated from yeast cell lysates with ammonium sulfate and renatured by gel filtration on Sephadex G-25 under reducing conditions. VLPs were self-assembled after the removal of the reducing agent by gel filtration on Sephadex G-25. Protein purity and specificity were evaluated by SDS-PAGE and immunoblotting analysis. The molecular mass of VLPs and their relative quantity were measured by HPLC, followed by confirmation of VLPs production and estimation of their shape and size by transmission electron microscopy. As a result, we obtained recombinant HCcAg preparation (with ~90% purity) in the form of VLPs and monomers, which has been used to produce hybridomas secreting monoclonal antibodies (mAbs) against HCcAg.

Hepatitis C virus core antigen as alternative diagnostic algorithm for active hepatitis C virus infection among haemodialysis population: Cost implications.

AIMS: In Malaysia, majority anti-HCV positive haemodialysis patients do not undergo hepatitis C confirmation due to the high cost of HCV RNA. HCV Core Antigen might be a cost-effective diagnostic test to identify HD patients who have active HCV infection eligible for Direct Acting Anti-viral therapy. METHODS: A cross-sectional study was conducted to assess the correlation between HCV Ag and HCV RNA and the cost implications of different diagnostic algorithms to diagnose active HCV infection using Anti-HCV, HCV Ag, and HCV RNA. Pre-dialysis blood was tested for both HCV Ag and HCV RNA. HCV Ag was tested with Abbott ARCHITECT HCV Ag test. RESULTS: Two-hundred twenty-seven haemodialysis patients were recruited from 20 centres with mean age of 57.68 ± 12.48 years, and male constitutes 56.8% (129) of the study population. HCV Ag correlated well with HCV RNA (Spearman test coefficient 0.943, p < .001) with sensitivity of 93.9%, specificity 99.3%, and the accuracy was 97.36%. Cost analysis indicated that a sequential test involving Anti-HCV antibody as initial screening, followed by HCV Ag on Anti-HCV positive and HCV RNA on HCV Ag negative cases translated to a modest cost-saving algorithm compared to standard diagnostic algorithm. CONCLUSION: HCV Ag correlated well with HCV RNA and can potentially be fused in an alternative diagnostic algorithm to generate cost savings methods to diagnose active HCV infection among haemodialysis patients. This alternative algorithm is especially relevant in low to middle-income countries such as Malaysia to optimize the use of the healthcare resource and gains in clinical outcomes.