Evaluation of the highly sensitive chemiluminescent enzyme immunoassay "Lumipulse HBsAg-HQ" for hepatitis B virus screening.
ABSTRACT: BACKGROUND:Ongoing efforts in the development of HBsAg detection kits are focused on improving sensitivity and specificity. The purpose of this study was to evaluate an improved, highly sensitive quantitative assay, "Lumipulse HBsAg-HQ", a chemiluminescent enzyme immunoassay designed for a fully automated instrument, the "Lumipulse G1200". METHODS:Serum samples for reproducibility, dilution, correlation, sensitivity, and specificity studies were obtained from patients at the Osaka University Hospital. Seroconversion and sensitivity panels were purchased from a commercial vender. Subtype, sensitivity panels, and HBsAg recombinant proteins with one or two amino acid substitutions were prepared in-house. RESULTS:The coefficients of variation for the low, medium, and high concentration samples ranged from 1.93 to 2.55%. The HBsAg-HQ reagent for dilution testing showed good linearity in the 0.005-150 HBsAg IU/mL range and no prozone phenomenon. All 102 HBV carrier samples were positive by HBsAg-HQ, while other commercial reagents showed one or more to be negative. In the seroconversion panel, the 14-day blood sample was positive. The sensitivity against HBsAg-HQ "ad" and "ay" subtypes was 0.025 ng/mL. Comparisons among the HBsAg-HQ, HISCL, and Architect HBsAg reagents were performed using the Bland-Altman plot. Specificity for 1000 seronegative individuals was 99.7%. HBsAg-HQ detected 29 positive serum among 12 231 routinely obtained serum samples, which showed concentrations of 0.005-0.05 HBsAg IU/mL. CONCLUSIONS:According to these results, the Lumipulse HBsAg-HQ assay, with a highly sensitive limit of detection of 0.005 IU/mL, may facilitate the development of a better management strategy for a considerable proportion of infected patients.
Project description:Detection of hepatitis B Virus surface antigen (HBsAg) is an established method for diagnosing both acute and chronic hepatitis B virus (HBV) infection. In addition to enzyme immunoassays (EIAs), rapid diagnostic tests (RDTs) are available for the detection of HBsAg in resource-poor settings. However, the available RDTs have inadequate sensitivity and therefore are not suitable for diagnosis of patients with low levels of HBsAg and for blood screening. To provide a high-sensitivity RDT, we developed a lateral flow immunoassay (LFIA) for HBsAg utilizing upconverting nanoparticle (UCNP) reporter. The UCNP-LFIA can use whole blood, serum, or plasma and the results can be read in 30 min using a reader device. When compared with a commercial conventional visually read LFIA, the developed UCNP-LFIA had a Limit of Detection (LoD) of 0.1 IU HBsAg/ml in spiked serum, whereas the LoD of the conventional LFIA was 3.2 IU HBsAg/ml. The developed UCNP-LFIA fulfills the WHO criterion for blood screening (LoD ??0.13 IU HBsAg/ml) in terms of LoD. The UCNP-LFIA and conventional LFIA were evaluated with well-characterized sample panels. The UCNP-LFIA detected 20/24 HBsAg-positive samples within the HBsAg Performance Panel and 8/10 samples within the Mixed Titer Performance Panel, whereas the conventional LFIA detected 8/24 and 4/10 samples in these panels, respectively. The performance of the assays was further evaluated with HBsAg-positive (n?=?108) and HBsAg-negative (n?=?315) patient samples. In comparison with a central laboratory test, UCNP-LFIA showed 95.4% (95% CI: 89.5-98.5%) sensitivity whereas sensitivity of the conventional LFIA was 87.7% (95%CI: 79.9-93.3%).
Project description:BACKGROUND: Rapid point-of-care tests provide plausible diagnostic strategy for hepatitis B surface antigen (HBsAg) in low resource areas. However, their utility depends upon their overall performance. Our objective was to meta-analyze the diagnostic accuracy of rapid point-of-care tests for HBsAg. METHODS: Literature search was done with the help of a metasearch engine Mett?, a query interface for retrieving articles from five leading medical databases. Studies that employed rapid point-of-care tests for detection of HBsAg and compared the results with reference test were included. Two reviewers performed quality assessment of the studies and extracted data for estimating test accuracy. Twenty-seven studies were meta-analyzed and stratified by multiple parameters. RESULTS: Twenty-seven studies had evaluated 49 test brands and generated 76 data points. Sensitivity of individual tests varied widely and were heterogeneous (range 43.5%-99.8%); while specificity estimates were more robust and close to 100% (range 90%-100%). Overall pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR and diagnostic odds ratio for all tests were 97.1% (95% CI, 96.1%-97.9%), 99.9% (CI, 99.8%-100%), 118.4 (CI, 84.7-165.5), 0.032 (CI, 0.023-0.045) and 4094.7 (CI, 2504.1-6600.8) respectively. This suggested high pooled accuracy for all studies. We found substantial heterogeneity between studies. Three factors (study location, reference standard and study score) appeared most strongly associated with test estimates and observed heterogeneity. The Determine test showed consistency in performance in studies done across developed and developing countries and the Determine and the BinaxNOW tests had significantly higher estimates than pooled estimates of remaining tests. Tests revealed analytical sensitivity of 4 IU/ml against manufacturer's claim of 0.5 IU/ml; reduced sensitivity with HBsAg mutants and poor performance in seroconversion panels. CONCLUSIONS: Tests with better analytical sensitivity need to be developed and their feasibility and outcomes in various clinical settings need to be addressed.
Project description:The performance of hepatitis B surface antigen (HBsAg) screening assays is continuously improved to reduce the risk of transfusion-associated hepatitis B. In this study, a semiautomated immune complex transfer chemiluminescence enzyme immunoassay (ICT-CLEIA) for the detection of HBsAg, which is as sensitive as hepatitis B virus (HBV) DNA PCR, was developed; the ICT-CLEIA assay performance was compared with the performance of the Architect HBsAg QT assay and HBV DNA PCR. The specificities in the initial assay and after retesting were 99.50% (1,988/1,998 samples) and 99.95% (1,997/1,998 samples), respectively. The analytical detection limit was determined to be 0.2 mIU/ml using the 2nd International WHO HBsAg standard, and the cutoff value (0.5 mIU/ml) of the ICT-CLEIA assay was 8.0 standard deviations (SD) above the mean of the HBsAg-negative specimens. The ICT-CLEIA assay could detect HBsAg even in the presence of anti-HBs antibodies and demonstrated a 23.6-day-shorter window period using commercially available HBsAg seroconversion panels than the Architect HBsAg QT assay. Furthermore, the monitoring of the viral kinetics by the ICT-CLEIA assay and the HBV DNA PCR produced very similarly shaped curves during both the HBsAg seroconversion and reverse seroconversion periods. Therefore, the ICT-CLEIA assay may be useful not only for an earlier detection of HBV reactivation but also for the monitoring of hepatitis B patients.
Project description:Information on the efficacy of pegylated interferon (PEG-IFN) treatment of chronic hepatitis B (CHB) patients and predictors of the response based on real-world data is limited. Consecutive 201 patients who underwent PEG-IFN treatment for CHB were reviewed. A virological response (VR) was defined as a serum HBV DNA of <2000?IU/mL, and a combined response (CR) was defined a VR accompanied by serological response for hepatitis B e antigen (HBeAg)-positive CHB. For HBeAg-positive CHB patients, the HBeAg seroconversion rate and CR rate were 30.5% and 21.2% at 48 weeks after end of treatment (EOT), respectively. Baseline alanine aminotransferase (ALT) level was associated with HBeAg seroconversion, while baseline hepatitis B s antigen (HBsAg) levels of <250?IU/mL and HBV DNA <2.5?×?10(7)?IU/mL were strongly associated with sustained off-treatment CR. For HBeAg-negative CHB, the VR rates were 85.5%, and 27.7% at EOT, and 48 weeks after EOT, respectively; a baseline HBsAg <1,250?IU/mL was associated with sustained off-treatment VR. PEG-IFN treatment has durable HBeAg seroconversion in HBeAg-positive CHB, but results in a high risk of relapse among HBeAg-negative CHB patients. Pre-treatment HBsAg level is an important predictor of VR in CHB patients undergoing PEG-IFN treatment.
Project description:Patients with low hepatitis B surface antigen (HBsAg) levels and hepatitis B virus (HBV) DNA suppression by nucleos(t)ide analogues (NAs) achieve high rate of HBsAg loss through switching to PegIFNα in pre-registration study. The aim of this study was to achieve higher rate of HBsAg loss through extended PegIFN treatment. 98 patients with HBsAg < 2,000 IU/ml and HBV DNA < 20 IU/ml were randomized to receive PegIFNα-2b or continuing NA therapy for 60 weeks. At the end of treatment (EOT) and end of follow-up (EOF), only patients who switched to PegIFNα-2b achieved HBsAg loss (32.6%) and HBsAg seroconversion (27.9% and 25.6%). Patients who switched to PegIFNα-2b also achieved higher HBeAg seroconversion rates (65.1%) and HBeAg loss (81.4% and 90.7%) than those who continued NAs treatment. On-treatment HBsAg declines predicted the responses at EOT, and HBsAg declines at post-baseline times predicted the responses at EOF. The rates of responses were not increased through extended PegIFNα treatment. For patients with low HBsAg and HBV suppression with NAs, switching to PegIFNα-2b significantly increased the rates of HBsAg loss and HBsAg seroconversion. HBsAg decline can predict the response of switching to PegIFNα-2b following from NAs.
Project description:Patients with chronic hepatitis B virus (HBV) infection who are hepatitis B virus e antigen (HBeAg) positive are increasingly being treated with nucleos(t)ide analogs (NUCs). However, the predictive value of serum hepatitis B virus core antibody (HBcAb) levels for HBeAg seroconversion among patients with high viral load remains unclear.This study consisted of 74 patients with high viral load (HBV DNA >1 × 107 copies/mL) enrolled in a multicenter, randomized, controlled trial, treated with lamivudine and adefovir (N = 32) or entecavir (N = 42) for up to 96 weeks. Serum HBV DNA, quantitative hepatitis B virus surface antigen (HBsAg), HBeAg, and HBeAb was tested at each visit. Quantitative HBcAb evaluation was conducted for all the available samples in the trial, by using a newly developed double-sandwich anti-HBc immunoassay.Serum HBcAb levels were significantly higher in patients with a serum alanine aminotransferase (ALT) level more than five times the upper limit of normal (ULN) compared with patients with ALT levels within 5 × ULN (4.25 ± 0.61 vs. 3.94 ± 0.47 log10 IU/mL, P = 0.0345). Patients with HBeAg seroconversion were associated with a higher level of HBcAb at baseline, compared with those without HBeAg seroconversion (4.38 ± 0.54 vs. 4.02 ± 0.58 log10 IU/mL, P = 0.029). The area under receiver operating characteristic curve of baseline HBcAb for HBeAg seroconversion was 0.71 (95% CI: 0.55-0.86, P = 0.013). When the baseline HBcAb level was >4.375 log10 IU/mL, the sensitivity and specificity to predict HBeAg seroconversion at week 96 were 62.5% and 74.2%, and the positive likelihood ratio (LR) and negative LR were 2.42 and 0.51, respectively. The multivariate analysis result indicated that baseline serum HBcAb level was the only independent predictor for HBeAg seroconversion at week 96, with an odds ratio of 4.78.Baseline serum HBcAb level >4.375 log10 IU/mL could satisfactorily predict HBeAg seroconversion among patients with high viral load treated with NUC.
Project description:BACKGROUND AND OBJECTIVES: This study was conducted by the International Consortium for Blood Safety (ICBS) to identify high-quality test kits for detection of hepatitis B virus (HBV) surface antigen (HBsAg) for the benefit of developing countries. MATERIALS AND METHODS: The 70 HBsAg test kits from around the world were evaluated comparatively for their clinical sensitivity, analytical sensitivity, sensitivity to HBV genotypes and HBsAg subtypes, and specificity using 394 (146 clinical, 48 analytical and 200 negative) ICBS Master Panel members of diverse geographical origin comprising the major HBV genotypes A-F and the HBsAg subtypes adw2,4, adr and ayw1-4. RESULTS: Seventeen HBsAg enzyme immunoassay (EIA) kits had high analytical sensitivity <0.13 IU/ml, showed 100% diagnostic sensitivity, and were even sensitive for the various HBV variants tested. An additional six test kits had high sensitivity (<0.13 IU/ml) but missed HBsAg mutants and/or showed reduced sensitivity to certain HBV genotypes. Twenty HBsAg EIA kits were in the sensitivity range of 0.13-1 IU/ml. The other eight EIAs and the 19 rapid assays had analytical sensitivities of 1 to >4 IU/ml. These assays were falsely negative for 1-4 clinical samples and 17 of these test kits showed genotype dependent sensitivity reduction. Analytical sensitivities for HBsAg of >1 IU/ml significantly reduce the length of the HBsAg positive period which renders them less reliable for detecting HBsAg in asymptomatic HBV infections. Reduced sensitivity for HBsAg with genetic diversity of HBV occurred with genotypes/subtypes D/ayw3, E/ayw4, F/adw4 and by S gene mutants. Specificity of the HBsAg assays was >or=99.5% in 57 test kits and 96.4-99.0% in the remaining test kits. CONCLUSION: Diagnostic efficacy of the evaluated HBsAg test kits differed substantially. Laboratories should therefore be aware of the analytical sensitivity for HBsAg and check for the relevant HBV variants circulating in the relevant population.
Project description:BACKGROUND:Accurate, rapid, and cost-effective screening tests for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection may be useful in laboratories that cannot afford automated chemiluminescent immunoassays (CLIAs). We evaluated the diagnostic performance of a novel rapid automated fluorescent lateral flow immunoassay (LFIA). METHODS:A fluorescent LFIA using a small bench-top fluorescence reader, Automated Fluorescent Immunoassay System (AFIAS; Boditech Med Inc., Chuncheon, Korea), was developed for qualitative detection of hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs), and antibody to HCV (anti-HCV) within 20 minutes. We compared the diagnostic performance of AFIAS with that of automated CLIAs-Elecsys (Roche Diagnostics GmbH, Penzberg, Germany) and ARCHITECT (Abbott Laboratories, Abbott Park, IL, USA)-using 20 seroconversion panels and 3,500 clinical serum samples. RESULTS:Evaluation with the seroconversion panels demonstrated that AFIAS had adequate sensitivity for HBsAg and anti-HCV detection. From the clinical samples, AFIAS sensitivity and specificity were 99.8% and 99.3% for the HBsAg test, 100.0% and 100.0% for the anti-HBs test, and 98.8% and 99.1% for the anti-HCV test, respectively. Its agreement rates with the Elecsys HBsAg, anti-HBs, and anti-HCV detection assays were 99.4%, 100.0%, and 99.0%, respectively. AFIAS detected all samples with HBsAg genotypes A-F and H and anti-HCV genotypes 1, 1a, 1b, 2a, 2b, 4, and 6. Cross-reactivity with other infections was not observed. CONCLUSIONS:The AFIAS HBsAg, anti-HBs, and anti-HCV tests demonstrated diagnostic performance equivalent to current automated CLIAs. AFIAS could be used for a large-scale HBV or HCV screening in low-resource laboratories or low-to middle-income areas.
Project description:Nucleos(t)ide analogues rarely result in a durable off-treatment response in chronic hepatitis B infection, whereas pegylated interferon (Peg-IFN) induces a long-lasting response only in a subset of patients. We assessed the effect of sequential combination therapy with Peg-IFN-?2a and entecavir in hepatitis B e antigen (HBeAg)-positive patients with prior long-term entecavir therapy and investigated the predictors of response to treatment. HBeAg-positive individuals who did not achieve HBeAg seroconversion during previous long-term entecavir therapy, receiving Peg-IFN-?2a added to ongoing entecavir therapy (sequential combination [S-C] therapy; n = 81) for 48 weeks or remaining on entecavir monotherapy (n = 116), were retrospectively included. A matched pair was created at a 1:1 ratio from each treatment group. The primary endpoint was HBeAg seroconversion at week 48. Subgroup analysis of response prediction was conducted for 81 patients with S-C therapy. More patients in the S-C therapy group achieved HBeAg seroconversion than those in the entecavir group (44% versus 6%; P < 0.0001). An HBeAg level of <200 signal-to-cutoff ratio (S/CO) at baseline was a strong predictor for higher HBeAg seroconversion than that achieved when HBeAg was ?200 S/CO (64.2% versus 17.9%; P < 0.0001). Hepatitis B surface antigen (HBsAg) levels at baseline and the decrease in HBsAg levels predicted HBsAg loss in the S-C therapy group. The combination of baseline HBeAg of <200 S/CO and HBsAg of <1,000 IU/ml and an HBsAg decline at week 12 of ?0.5 log10 IU/ml provided the highest rate of HBeAg seroconversion (92.31%) and HBsAg loss (83.3%) at week 48. Patients receiving sequential combination therapy have a higher rate of HBeAg seroconversion and are more likely to experience HBsAg clearance than do those continuing entecavir monotherapy. Sequential combination therapy can be guided by baseline HBsAg/HBeAg levels and on-treatment HBsAg dynamics.
Project description:Background:None of the current guidelines recommend antiviral therapy for inactive hepatitis B virus (HBV) carriers (IHCs). Methods:In this real-world, multicenter, nonrandomized study, 32 participants meeting the inclusion criteria were enrolled 1:1 for treatment with peginterferon ?-2b or monitoring without treatment based on participant preference. The expected treatment duration was 48 weeks. The primary end point was hepatitis B surface antigen (HBsAg) loss. The HBV vaccine could be injected after HBsAg loss. Results:All patients had HBsAg levels of <20 IU/mL. The mean baseline HBsAg levels were 6.6 IU/mL and 5.8 IU/mL in the treated and untreated groups, respectively. Fifteen (93.8%) participants achieved HBsAg loss, 5 obtained HBsAg seroconversion after undergoing a mean of 19.7 weeks of therapy in the treated group, and no one in the follow-up group achieved HBsAg loss during a mean follow-up time of 12.6 months (P < .0001). Generally, the therapy was well tolerated. Nine of 11 individuals who exhibited HBsAg loss benefited from receiving the HBV vaccine. Conclusions:This study provides justification for further studies of short-course peginterferon ?-2b for the functional cure of IHCs with low HBsAg levels. Additionally, HBV vaccine injection is beneficial after interferon-induced HBsAg loss.