Evaluation of immunochromatographic assay systems for rapid detection of hepatitis B surface antigen and antibody, Dainascreen HBsAg and Dainascreen Ausab

Point of care and oral fluid hepatitis B testing in remote Indigenous communities of northern Australia

Many Indigenous Australians in northern Australia living with chronic hepatitis B are unaware of their diagnosis due to low screening rates. A venous blood point of care test (POCT) or oral fluid laboratory test could improve testing uptake in this region. The purpose of this study was to assess the field performance of venous blood POCT and laboratory performance of an oral fluid hepatitis B surface antigen (HBsAg) test in Indigenous individuals living in remote northern Australian communities. The study was conducted with four very remote communities in the tropical north of Australia's Northern Territory. Community research workers collected venous blood and oral fluid samples. We performed the venous blood POCT for HBsAg in the field. We assessed the venous blood and oral fluid specimens for the presence of HBsAg using standard laboratory assays. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the POCT and oral fluid test, using serum laboratory detection of HBsAg as the gold standard. From 215 enrolled participants, 155 POCT and 197 oral fluid tests had corresponding serum HBsAg results. The POCT had a sensitivity of 91.7% and specificity of 100%. Based on a population prevalence of 6%, the PPV was 100% and NPV was 99.5%. The oral fluid test had a sensitivity of 56.8%, specificity of 98.1%, PPV of 97.3% and NPV of 65.9%. The venous blood POCT has excellent test characteristics and could be used to identify individuals with chronic HBV infection in high prevalence communities with limited access to health care. Oral fluid performance was suboptimal.

Evaluation of performance testing of different rapid diagnostic kits in comparison with EIAs to validate detection of hepatitis B virus among high risk group in Nigeria

BACKGROUND

Hepatitis B virus (HBV) causes chronic liver-associated diseases and its early detection is of high public health importance. Its diagnosis is mainly based on immunological assays among which Enzyme-Linked Immunosorbent Assay (ELISA) and rapid tests are the most common and widespread methods. However, a major challenge is the discordance of results of any two laboratory assays which cannot be easily resolved. Therefore, this study was designed to evaluate the validity and reliability of commercially available five rapid test kits in comparison with two Enzyme Immunoassays (EIAs) in Nigeria using hepatitis B surface antigen as a reference marker.

METHODS

A total of 100 sera of previously diagnosed consenting HBV-positive patients from private diagnostic laboratories in Ibadan between March and August, 2011 were tested using two EIA and five rapid commercially available HBV test kits in Nigeria. Data were analyzed by SPSS version 15, while bivariate and multivariate analyses were carried out to identify associations at P < 0.05 considered significant.

RESULTS

Overall, the sensitivity rates of the two EIA kits were 100% and 99.9% (95% confidence interval [CI] = 98.9-99.7) with specificity of 100% and 99.9% (95% CI = 98.9-99.7), respectively. The sensitivity of the five rapid test kits ranged from 97.5% (95% CI = 96.4-97.6) to 98.9% (95% CI = 97.9-99.9) with specificity of 80% (95% CI = 79.3-80.9) to 90% (95% CI = 89.2-91.0). Also, the positive predictive value ranged from 88% (95% CI = 88.2-89.9) to 89% (95% CI = 88.2-89.9), while the negative predictive value ranged from 80% (95% CI = 79.3-80.9) to 90% (95% CI = 89.2-91.0) for the five rapid kits. However, that of the two EIAs ranged from 99.9% (98.9-99.7) to 100%. Further analysis showed significant (P = 0.033) variations in the sensitivity and specificity of the EIAs and rapid test kits.

CONCLUSIONS

The results from this study have clearly revealed the challenges of diagnosis of HBV infections in Nigeria. This study has also demonstrated that the sensitivity of most of the rapid test kits may not be adequate when compared with EIA for early detection of HBV infections. The implications of possible misdiagnosis on the various intervention strategies that rely predominantly on correct HBV status of an individual are enormous. Therefore, there is the need to further compliment the use of rapid test kits with EIAs for HBV control in Nigeria.

Detection of HBsAg mutants in the blood donor population of Pakistan

BACKGROUND

Infection with the Hepatitis B virus (HBV) continues to be one of the leading healthcare issues in Pakistan, affecting over 6 million people. The existence of HBsAg mutants is well documented in many countries. In Pakistan, HBV screening in the majority of the blood banks is performed by Rapid Detection Devices or ELISA tests. These tests are designed to detect HBsAg, but may not detect the mutant HBsAg. Failure to detect the HBsAg mutant may result in the transmission of HBV infection from donor to recipient. Hence, there is a need to identify a HBsAg assay which can detect mutants in a country where simple and conventional HBsAg assays with varying sensitivity and specificity are used to detect HBV infections.

MATERIAL AND METHODS

Three routinely used diagnostic tests (Rapid Detection Devices, ELISA and CLIA) for HBsAg were compared with the LIAISON® XL Murex HBsAg Quant Assay to determine the prevalence of HBV mutants in the Pakistani blood donor population. The samples of blood donors from different cities of Pakistan were collected. The testing was performed using SD Bioline rapid assay (n = 1500), ELISA (n = 1500), and Abbott ARCHITECT®CLIA system (n = 1500) at the centers where the donations were collected. All samples (n = 4500) were re-tested for comparative analysis on the LIAISON® XL Murex HBsAg Quant assay (DiaSorin S.p.A.). PCR testing was performed as a gold standard on all discordant samples.

RESULTS

119/4500 (2.64%) of the samples were positive for antibodies against HBsAg. The sensitivity of SD Bioline Rapid, GB HBsAg ELISA, Abbott ARCHITECT® and LIAISON® XL Murex HBsAg Quant assay was 17.24%, 43.75%, 90.91%and 100% respectively. The specificity of SD Bioline Rapid, GB HBsAg ELISA, Abbott ARCHITECT® and LIAISON® XL Murex HBsAg Quant Assay was 98.82%, 99.59%, 100% and 100%, respectively.

CONCLUSION

LIAISON® XL Murex HBsAg Quant assay is a highly sensitive, specific and accurate screening assay for detecting wild type as well as mutant HBsAg.

Diagnostic accuracy of tests to detect hepatitis B surface antigen: a systematic review of the literature and meta-analysis

BACKGROUND

Chronic Hepatitis B Virus (HBV) infection is characterised by the persistence of hepatitis B surface antigen (HBsAg). Expanding HBV diagnosis and treatment programmes into low resource settings will require high quality but inexpensive rapid diagnostic tests (RDTs) in addition to laboratory-based enzyme immunoassays (EIAs) to detect HBsAg. The purpose of this review is to assess the clinical accuracy of available diagnostic tests to detect HBsAg to inform recommendations on testing strategies in 2017 WHO hepatitis testing guidelines.

METHODS

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using 9 databases. Two reviewers independently extracted data according to a pre-specified plan and evaluated study quality. Meta-analysis was performed. HBsAg diagnostic accuracy of rapid diagnostic tests (RDTs) was compared to enzyme immunoassay (EIA) and nucleic-acid test (NAT) reference standards. Subanalyses were performed to determine accuracy among brands, HIV-status and specimen type.

RESULTS

Of the 40 studies that met the inclusion criteria, 33 compared RDTs and/or EIAs against EIAs and 7 against NATs as reference standards. Thirty studies assessed diagnostic accuracy of 33 brands of RDTs in 23,716 individuals from 23 countries using EIA as the reference standard. The pooled sensitivity and specificity were 90.0% (95% CI: 89.1, 90.8) and 99.5% (95% CI: 99.4, 99.5) respectively, but accuracy varied widely among brands. Accuracy did not differ significantly whether serum, plasma, venous or capillary whole blood was used. Pooled sensitivity of RDTs in 5 studies of HIV-positive persons was lower at 72.3% (95% CI: 67.9, 76.4) compared to that in HIV-negative persons, but specificity remained high. Five studies evaluated 8 EIAs against a chemiluminescence immunoassay reference standard with a pooled sensitivity and specificity of 88.9% (95% CI: 87.0, 90.6) and 98.4% (95% CI: 97.8, 98.8), respectively. Accuracy of both RDTs and EIAs using a NAT reference were generally lower, especially amongst HIV-positive cohorts.

CONCLUSIONS

HBsAg RDTs have good sensitivity and excellent specificity compared to laboratory immunoassays as a reference standard. Sensitivity of HBsAg RDTs may be lower in HIV infected individuals.

Accuracy of Rapid Point-of-Care Diagnostic Tests for Hepatitis B Surface Antigen-A Systematic Review and Meta-analysis

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 Mettā, 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.

[Evaluation of indigenously manufactured immunochromatographic assay systems for rapid detection of hepatitis B surface antigen and antibody.]

BACKGROUND

We evaluated three indigenously produced immunochromatography (ICA) kits for the rapid detection of hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti-HBs) by comparing them with a microparticle enzyme immunoassay (MEIA).

METHODS

HBsAg and anti-HBs were tested by the ICA kits manufactured by three domestic companies, SD HBsAg and Anti-HBs (Standard Diagnostics, Inc., Yongin, Korea); Asan Easy Test(R) HBsAg and Anti-HBs (Asan Pharm Co., Ltd., Whasung, Korea); and GENEDIA(R) HBsAg Rapid Device and Anti-HBs Rapid Device (Green Cross MS, Inc., Yongin, Korea).

RESULTS

Results by ICA agreed completely with those of MEIA in all the 20 HBsAg-negative sera and in all the anti-HBs-negative sera except one sample. Among the 20 HBsAg-positive sera by MEIA, 17 were positive by ICA using Green Cross MS, 16 using Asan Pharm Co., and 13 using SD and reverse passive hemagglutination. Among the 20 anti-HBs-positive sera by MEIA, 19 were positive by ICA using Green Cross MS and Asan Pharm Co., 17 using SD, and 18 by passive hemagglutination. Elapsed time for the control and test line to be visualized in ICA might be longer and the color of the lines lighter when using SD than Green Cross MS or Asan Pharm Co.

CONCLUSIONS

Three indigenously produced ICA kits are as sensitive as MEIA for the detection of anti-HBs, but are less sensitive than MEIA for HBsAg. The ICA kits for the rapid detection of HBsAg might be recommended for a limited use in the clinical laboratory.

Validity of the rapid strip assay test for detecting HBsAg in patients admitted to hospital in Uganda

Commercially available rapid strip assays (RSAs) for hepatitis B surface antigen (HBsAg) are used for most routine clinical testing in sub-Saharan Africa. This study evaluated the validity of RSA and a more sophisticated enzyme immunoassay (EIA) with confirmation by nucleic acid testing (NAT) in hospitalized patients in Uganda. Sera from 380 consecutive patients collected and tested for HBsAg and anti-HIV in Kampala, Uganda by RSA were sent frozen to Dallas for EIA including HBsAg, total anti-hepatitis B core, hepatitis B e antigen, and anti-HIV. NAT was performed on all HBsAg-positives and on a random sample of 102 patients that were HBsAg-negative by both assays. Overall, 31 (8%) were HBsAg positive by RSA while 50 (13%) were HBsAg-positive by EIA; 26 were concordant between the two assays. Of 55 HBsAg-positive patients, nearly all showed detectable serum hepatitis B virus (HBV) DNA by bDNA (46) or PCR (4) assay. The 26 patients who were HBsAg positive by both EIA and RSA had significantly higher median serum HBV DNA levels than the 24 patients who were HBsAg positive by EIA alone. An additional 12/102 (12%) HBsAg negative patients had very low serum HBV DNA levels by NAT. Several differences in expected results of serologic testing were observed in this large series of African patients. RSA HBsAg testing is less sensitive than EIA; even EIA failed to detect all HBV DNA positive sera. A more complex testing protocol than RSA alone will be needed in Africa to improve patient care.

[Comparison of nine different qualitative HBsAg assay kits]

BACKGROUND

Qualitative hepatitis B surface antigen (HBsAg) assay kits are still commonly used in Korea where hepatitis B virus (HBV) infection is endemic. The accurate determination of HBsAg plays a crucial role in the diagnosis and prevention of HBV infection, especially in endemic areas. The aim of this study was to compare the detection sensitivities of 9 qualitative HBsAg assay kits.

METHODS

Seven pooled sera with HBsAg concentration ranging from 0.14 IU/mL to 29.96 IU/mL were prepared. The HBsAg concentration of each pooled serum was determined by a quantitative HBsAg assay, Architect HBsAg (Abbott Laboratories, Ireland). The fully automated immunoassay kits included Elecsys HBsAg (Roche Diagnostics, Germany) and Immulite 2000 HBsAg (DPC, USA) and the rapid tests included 5 immunochromatographic assay (ICA) kits and 2 reverse passive hemagglutination assay (RPHA) kits.

RESULTS

Elecsys HBsAg (Roche Diagnostics) showed positive result in pooled serum with HBsAg concentration of 0.14 IU/mL, but Immulite 2000 HBsAg (DPC) showed negative result in the same concentration. Although ICA kits showed variable results among different assay kits, all of them showed negative results in pooled sera with HBsAg concentration of < or = 1.89 IU/mL. Two RPHA kits showed negative results in pooled sera with HBsAg concentration of < or = 7.98 IU/mL.

CONCLUSIONS

Although ICAs were more sensitive than RPHAs, they had variable sensitivities for HBsAg and were less sensitive than the automated immunoassay kits. Therefore, ICAs and RPHAs should be used with caution in the screening tests for HBsAg and their sensitivities need to be improved.

Serologic and molecular characteristics of hepatitis B virus among school children in East Java, Indonesia

Universal childhood hepatitis B vaccination was introduced in Indonesia in 1997; by 2008, coverage was estimated to be 78%. This study aimed to investigate the serologic status and virologic characteristics of hepatitis B virus (HBV) among the children in East Java. A total of 229 healthy children born during 1994-1999 were enrolled in this study. Overall, 3.1% were positive for hepatitis B surface antigen (HBsAg) and 23.6% were positive for antibody to HBsAg (anti-HBs). HBV DNA was detected in 5 of 222 HBsAg-negative carriers, which were suggested to be cases of occult HBV infection. A single amino substitution (T126I) in the S region was frequently found. HBV infection remains endemic, and the prevalence of anti-HBs remains insufficient among children in East Java, Indonesia.

[Meta-analysis for the pooled sensitivity and specificity of hepatitis B surface antigen rapid tests]

BACKGROUND

Although hepatitis B surface antigen (HBsAg) rapid test based on immunochromatographic assay (ICA) is now widely used, the test has not been evaluated sufficiently enough to validate its performance. Thus, it is important to summarize the clinical performance of the test kits. In this study, we performed meta-analysis for the performance of the HBsAg rapid tests.

METHODS

PubMed database was searched using keywords about the accuracy of diagnostic tests for hepatitis B virus (HBV) infection. Two investigators assessed methodological quality utilizing standards for reporting of diagnostic accuracy studies (STARD) checklist. After performing a heterogeneity test, we obtained pooled sensitivity and specificity. Positive and negative predictive values (PPV and NPV) were simulated according to HBV prevalence.

RESULTS

A total of 38 studies was selected from 10 papers. The quality scores ranged from 3 to 13 (median, 8). Kappa value was good (0.85). The performance of the 38 studies was heterogeneous. When 33 studies with better quality from 7 papers were re-selected, the pooled sensitivity and specificity were 98.07% (95% confidence interval, CI: 97.67-98.47%) and 99.56% (95% CI: 99.21-99.91%), respectively. With an HBV prevalence of 5%, PPV and NPV were predicted to be 92.14% and 99.90%, respectively.

CONCLUSIONS

In view of high HBV prevalence in Korea, it is thought that the HBsAg rapid test can be used for HBV screening in small-sized laboratories or for epidemiologic studies. This study should be helpful in establishing a guideline for the proper performance evaluation of the HBsAg rapid tests.

Immunochromatographic assay for simple and rapid detection of Satsuma dwarf virus and related viruses using monoclonal antibodies

A simple and rapid immunochromatographic assay (ICA) to detect Satsuma dwarf virus (SDV) was developed using colloidal gold conjugates of anti-SDV monoclonal antibodies. Of six homogenization buffers tested, 0.1 M citrate buffer (pH 7.0) gave the best results for the ICA. In the ICA, addition of 0.1% thioglycolic acid in the homogenization buffers that have been widely used in enzyme-linked immunosorbent assays (ELISA) was deleterious to the reaction because of undesirable coagulation of the colloidal gold. ICA using the anti-SDV monoclonal antibodies was 8 times and 16 times more sensitive than double antibody sandwich-ELISA and ICA using the anti-SDV polyclonal antibody, respectively. The analysis is complete in only 15 min. Furthermore, ICA using the anti-SDV monoclonal antibodies could also detect SDV-related viruses.

An Enzyme Immunoanalytical System Based on Sequential Cross-Flow Chromatography

A new enzyme immunoanalytical concept that can be used for point-of-care testing has been investigated. Enzyme as a tracer requires a separate reaction step for signal generation, which follows the completion of immune complex formation with analyte (e.g., Hepatitis B surface antigen) in a sample. This has been a major factor limiting its utilization within the laboratory. We carried out such sequential processes employing chromatographic analysis, using two crosswise-arranged membrane pads in vertical and horizontal directions. The vertically arranged pads were the same as those in the usual format for pregnancy testing, for instance, with the exception of the use of horseradish peroxidase (HRP) as tracer. By placing the horizontally arranged pads on each lateral side of the signal generation pad in the vertical arrangement, they were employed to supply substrate to the enzyme present in the immune complexes. The substrate flow was initiated after the antigen-antibody bindings to produce a signal, which was typically a color change in proportion to the analyte concentration. Under optimal conditions, the use of HRP labeling increased the detection capability of the assay approximately 30 times compared to that of gold colloids. Potential advantages of using the concept investigated are (1) provision of a rapid and simple immunoassay, (2) satisfaction of a clinical need for highly sensitive determination of analyte, and (3) utilization of relatively inexpensive, portable quantitation means.

A rapid immunochromatographic assay for hepatitis B virus screening

Simple, rapid and accurate assays for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) are helpful for clinical diagnosis and field epidemiological surveys. A commercially developed, rapid immunochromatographic test for simultaneous detection of HBsAg and HBeAg was evaluated using a total of 2463 selected samples (827 frozen sera, 1011 fresh sera, and 625 whole blood samples). Results of the rapid test were compared with standard enzyme immunoassay (EIA) methods for HBsAg and HBeAg detection. The accuracy of the rapid test was excellent and was similar for frozen sera, fresh sera and whole blood. The overall sensitivity and specificity for the detection of HBsAg were 95 and 100%, and the corresponding positive and negative predictive values were 100 and 99.7%, respectively. The sensitivity and specificity for the detection of HBeAg were slightly less than that for HBsAg, and were 80 and 98%, with positive and negative predictive values of 91 and 94%, respectively. Thus, compared with the EIA method, the rapid test was highly sensitive and accurate for the detection of HBsAg although somewhat less sensitive and specific for detection of HBeAg. Because of its speed, simplicity and flexibility, the rapid test is ideally suited for HBsAg and HBeAg screening in population-based epidemiological studies and in low risk populations, particularly in regions of the world where hepatitis B is endemic.

Semiquantitative, bar code version of immunochromatographic assay system for human serum albumin as model analyte

An immunochromatographic assay system was devised that can express the concentration ranges of analyte (e.g., urinary human serum albumin) as distinct numbers of the ladder bar (bar coding) for semiquantitation. We constructed a model system consisting of five membrane pad strips partially superimposed in a length. Upon wicking of sample from the bottom, the medium dissolved two different biotinylated species, antibody to the analyte and conjugates of the antibody with colloidal gold, and antigen-antibody reactions took place in the hollow space of the glass fiber membrane. After eliminating unreacted biotinylated molecules at the next strip with an immobilized albumin, the immune complexes were transferred to the pad with streptavidin immobilized in a ladder bar pattern. Analytical conditions here were set for competition between the two biotinylated species for the streptavidin binding sites. The degree of such competition was proportional to the analyte concentration and, consequently, the bar signal number was elevated as the concentration increased. Under optimal conditions for sensitivity, the analytical system responded to the analyte doses at between 30 and 120 mg/dL by producing different bar codes within 5 min.

Pretreatment of whole blood for use in immunochromatographic assays for hepatitis B virus surface antigen

Immunochromatographic assays (ICAs) are also referred to as rapid tests, since they are simple and the results can be obtained within minutes after manually loading a few drops of a sample into each sample well of the test device. However, whole blood cannot be tested with ICA kits due to the visual hindrance caused by the color of red blood cells (RBCs), unless a cell-removing device such as a filter is mounted on the kits. Thus, when testing with blood, the advantage of the ICA kit is lost because of the additional time and machines required to coagulate and separate whole blood before preparing the serum. To overcome this limitation, whole-blood samples were added to a pretreatment solution to decolor the RBCs; the resulting mixtures were then loaded into the sample wells of the test device. The pretreating solution was composed of hydrogen peroxide (H(2)O(2)) to decolor the RBCs, Sag 471 (Osi Specialties) to restrain the mixture from vigorous foaming, sodium azide (NaN(3)) to inhibit the enzyme, which generates excessive foam at the beginning of decolorization, and EDTA as a chelating agent. As a result of this pretreatment, whole blood could be used with the ICA kit without reducing its simplicity and rapidity.