Performance of two real-time PCR assays for hepatitis B virus DNA detection and quantitation

Dried Blood Matrix as a New Material for the Detection of DNA Viruses

The gold standard for diagnosing viruses such as the Hepatitis B Virus has remained largely unchanged, relying on conventional methods involving extraction, purification, and polymerase chain reaction (PCR). This approach is hindered by limited availability, as it is time-consuming and requires highly trained personnel. Moreover, it suffers from low recovery rates of the nucleic acid molecules for samples with low copy numbers. To address the challenges of complex instrumentation and low recovery rate of DNA, a drying process coupled with thermal treatment of whole blood is employed, resulting in the creation of a dried blood matrix characterized by a porous structure with a high surface-to-volume ratio where it also inactivates the amplification inhibitors present in whole blood. Drawing on insights from Brunauer-Emmett-Teller (BET)- Barrett-Joyner-Halenda (BJH) analysis, scanning electron microscopy (SEM), and fluorescence recovery after photobleaching (FRAP), detection assay is devised for HBV, as a demonstration, from whole blood with high recovery of DNA and simplified instrumentation achieving a limit of detection (LOD) of 10 IU mL-1. This assay can be completed in <1.5 h using a simple heater, can be applied to other DNA viruses, and is expected to be suitable for point-of-care, especially in low-resource settings.

Development and field evaluation in African and Asian countries of an hepatitis B virus PCR on open polyvalent platforms to determine treatment eligibility: results from the "Agence Nationale de Recherche sur le Sida et les hépatites" 12327 study

OBJECTIVES

Widespread testing and treatment are essential to eliminate hepatitis B virus (HBV) infection as a public health concern. However, in resource-limited countries, access to HBV PCR is limited. In this study, we developed a quantitative HBV PCR assay on open molecular platforms and evaluate its performance in diagnosing clinically significant HBV DNA thresholds as defined by the WHO (2000 IU/mL, 20 000 IU/mL, and 200 000 IU/mL).

METHODS

We implemented our HBV PCR test in seven African and Asian countries and France, using either an in-house laboratory method or a European conformity for in vitro diagnostic (CE-IVD) marked version of the PCR (Generic HBV Charge Virale, Biocentric). Results were compared with reference tests (Roche Cobas AmpliPrep/Cobas TaqMan and Abbott RealTime on Abbott m2000).

RESULTS

There was a good agreement between the HBV DNA results of 1015 samples tested by the PCR on open polyvalent platforms and the results from reference tests (mean difference (bias ± standard deviation [SD]): -0.3 ± 0.7 log10 IU/mL and -0.2 ± 0.9 log10 IU/mL when compared with Roche and Abbott tests, respectively). Kappa-Cohen agreements between the HBV PCR on open polyvalent platforms and the Roche/Abbott assays appeared almost perfect for HBV DNA levels ranged from >20 000 to 200 000 IU/mL and >200 000 IU/mL, substantial and moderate for HBV DNA levels ranged from 2000 to 20 000 IU/mL when compared with Abbott and Roche, respectively. The assay's performance was consistent across genotypes A, B, C, D, and E.

DISCUSSION

This field evaluation showed that our HBV PCR test is a valuable alternative to proprietary PCR systems. PCR assays on open platforms contribute to expanding clinical laboratory solutions for diagnosing individuals who meet the viral load criteria for antiviral therapy (>20 000 IU/mL) and mother-to-child prophylaxis (>200 000 IU/mL).

Simple and Feasible Detection of Hepatitis B Virus via Combination of Multienzyme Isothermal Rapid Amplification and Lateral Flow Dipstick Strip

Hepatitis B virus infection is not only a huge burden in the field of social health but also a major public health problem that affects the lives and health of the people. Simple, rapid, feasible detection of HBV is critical for its prevention and spread, especially in the developing countries with low-resource laboratories. To this end, we combined multienzyme isothermal rapid amplification (MIRA) and lateral flow dipstick (LFD) strip to detect HBV. A pair of primers targeting the conserved region of HBV genome was designed and used in MIRA-LFD assay. Our results found that the entire amplification of MIRA-LFD only takes 10 min at 37°C and the dilution of the amplification products was added in the LFD strip and observed by the naked eye after 10 min. The detection sensitivity of this method can reach 10 pg. The 45 clinical samples were detected by MIRA-LFD and real-time PCR. The accuracy rate of MIRA-LFD was 100%. Therefore, these characteristics of our newly developed MIRA-LFD assay make it particularly useful and suitable for detecting HBV in the resource-limited condition.

Rapid Detection of Hepatitis B Virus in Blood Samples Using a Combination of Polymerase Spiral Reaction With Nanoparticles Lateral-Flow Biosensor

A rapid, highly sensitive, and robust diagnostic technique for point-of-care (PoC) testing can be developed using the combination of the nanoparticle-based lateral flow biosensors (LFB) and isothermal nucleic acid amplification technology. Here, we developed a polymerase spiral reaction (PSR) containing FITC-labeled DNA probes coupled with the nanoparticle-based LFB assay (PSR-LFB) to detect the amplified products to detect HBV visually. Under the optimized conditions, the PSR assay involved incubation of the reaction mixture for 20 min at 63°C, followed by visual detection of positive amplicons using LFB, which would generate a red test line based on the biotin/streptavidin interaction and immunoreactions, within 5 min. A cross-reactivity test revealed that the developed PSR-LFB assay showed good specificity for HBV and could distinguish HBV from other pathogenic microorganisms. For the analytical sensitivity, the limit of detection (LoD) of PSR-LFB assay was recorded as 5.4 copies/mL of HBV genomic DNA, which was ten-times more sensitive than qPCR and loop-mediated isothermal amplification (LAMP). Additionally, all the HBV-positive (29/82) samples, identified using ELISA, were also successfully detected by the PSR-LFB assay. We found that the true positive rate of the PSR-LFB assay was higher than that of qPCR (100 vs. 89.66%, respectively), as well as the LAMP assay (100 vs. 96.55%, respectively). Furthermore, the integrated procedure could be completed in 60 min, including the processing of the blood samples (30 min), an isothermal reaction (20 min), and result visualization (5 min). Thus, this PSR-LFB assay could be a potentially useful technique for PoC diagnosis of HBV in resource-limited countries.

Field applicable detection of hepatitis B virus using internal controlled duplex recombinase-aided amplification assay and lateral flow dipstick assay

Hepatitis B virus (HBV) is a widespread blood-borne pathogen associated with the complication of liver cirrhosis and hepatocellular carcinoma, particularly in south-east Asian and African countries where HBV is highly endemic and the budget and resources are limited. Therefore, simple, rapid, and portable field detection methods are crucial to efficiently control HBV infection. In this study, using heat-treated DNA, we developed two-field applicable detection assays for HBV based on recombinase-aided amplification (RAA). One was an internal controlled duplex RAA assay using a portable real-time fluorescence detection device, another was an instrument-free visual observation assay using lateral flow dipsticks. The entire experimental time was greatly shortened to less than 40 minutes at 39.0°C. The sensitivities, specificities, and clinical performance of both assays were evaluated. Compared with quantitative polymerase chain reaction assay as a reference, our results demonstrated that the two RAA-based assay obtained 97.18% and 95.77% of sensitivity, respectively, and the specificity was 100%, by testing a total of 157 serum samples with HBsAg positive. We conclude that the advantages of rapidity, simplicity, portability, and visualization of proposed two assays make them great potentials in point-of-care testing of HBV infection by untrained people in resource-limited situations.

Usefulness of a serial algorithm of HBsAg and HBeAg rapid diagnosis tests to detect pregnant women at risk of HBV mother-to-child transmission in Cambodia, the ANRS 12328 pilot study

BACKGROUND

In Cambodia, access to hepatitis B surface antigen (HBsAg) screening is low for pregnant women and Hepatitis B Virus (HBV) DNA quantification is poorly accessible.

OBJECTIVES

To evaluate the performance of a serial algorithm using two HBV rapid diagnostic tests (RDTs), in which samples positive for HBsAg were further tested for HBeAg as a surrogate marker for HBV DNA quantification.

STUDY DESIGN

In 2015, we prospectively collected plasma samples from 250 pregnant women consulting for antenatal care in one hospital in Phnom Penh including 128 with a known positive HBsAg status. All specimens were tested with the SD BIOLINE HBsAg RDT and HBsAg ELISA assay. In ELISA-positive samples, HBeAg status was determined using the SD BIOLINE HBeAg RDT and HBV DNA quantification was assessed.

RESULTS

Sensitivity and specificity of HBsAg RDT were 99.2% (97.7-99.9) and 100% (97.0-100), respectively. Among the 128 ELISA-positive samples, 29 (23%) tested HBeAg positive and 34 (26.5%) had HBV DNA > 5.3 Log₁₀ IU/mL. Sensitivity and specificity of HBeAg RDT in identifying viremic samples were 76.5% (62.2.0-90.7) and 96.8% (93.3-100) for HBV DNA > 5.3 Log₁₀ IU/mL and 89.3% (77.8-100) and 96.0% (92.2-99.8) for HBV DNA > 7.3 Log₁₀IU/mL. Among the 99 negative HBeAg RDT women, 8 had HBV DNA > 5.3 Log10 IU/mL and 7 of them harbored BCP/PC HBV mutants.

CONCLUSIONS

A combination of HBsAg and HBeAg RDTs could be a low-cost strategy to identify HBV-infected pregnant women at risk of perinatal transmission in a country were HBV DNA quantification is not routinely available.

Usefulness of in-house real time PCR for HBV DNA quantification in serum and oral fluid samples

For quantification of hepatitis B virus DNA (HBV DNA), commercial assays are used with serum or plasma samples, but oral fluid samples could be an alternative for HBV diagnosis due to ease of collection. This study aims to develop in-house real time PCR using synthetic curve for HBV DNA quantification for serum and oral fluid samples. Samples were collected from 103 individuals (55 HBsAg reactive and HBV DNA reactive by commercial assay and 48 without HBV markers) and submitted to two in-house real time PCR assays for HBV pre-S/S region with different standard curves: qPCR plasmidial and qPCR synthetic. A total of 27 serum samples were HBV DNA positive by qPCR plasmidial and 40 with qPCR synthetic (72% and 85% of concordance, respectively). Quantitative PCR synthetic presented efficiency of 99% and sensitivity of 2log10 copies/mL. Among oral fluid samples, five and ten were detected using qPCR plasmidial and synthetic, respectively. This study demonstrated that qPCR synthetic using serum samples could be used as alternative for HBV DNA quantification due to its sensitivity. In addition, it was possible to quantify HBV DNA in oral fluid samples suggesting the potential of this specimen for molecular diagnosis of HBV.

Real time PCR to evaluate HSV-2 shedding from anal and genital samples among men who have sex with men, living with HIV

This study shows the relative quantification of HSV-2 by qPCR, using the MIQE Guidelines. The reaction efficiency was evaluated, and the relative quantification used the R = 2^-ΔCq method. The relative quantification of HSV-2 was conducted with anal and genital samples from men who have sex with men (MSM), living with HIV. The presence of a single amplification product was validated with a dissociation curves profile and the determination of the melting temperature. The limit of detection for β-globin was determined as 3.3 × 10^-5  ng/μL, and for HSV-2 at 6.0 × 10^-6  ng/μL. The efficiency for β-globin was 100.2% and for HSV-2 was 106.8%. From 336 MSM, 2.1% and 3.9% individuals presented anal or genital HSV-2 shedding, respectively. The HSV-2 viral load was 9.2 RU, individuals with fewer CD4⁺ presented higher HSV-2 viral load. The qPCR method is reproducible and has optimal reaction efficiency.

Investigation of a Medieval Pilgrim Burial Excavated from the Leprosarium of St Mary Magdalen Winchester, UK

We have examined the remains of a Pilgrim burial from St Mary Magdalen, Winchester. The individual was a young adult male, aged around 18–25 years at the time of death. Radiocarbon dating showed the remains dated to the late 11^th–early 12^th centuries, a time when pilgrimages were at their height in Europe. Several lines of evidence in connection with the burial suggested this was an individual of some means and prestige. Although buried within the leprosarium cemetery, the skeleton showed only minimal skeletal evidence for leprosy, which was confined to the bones of the feet and legs. Nonetheless, molecular testing of several skeletal elements, including uninvolved bones all showed robust evidence of DNA from Mycobacterium leprae, consistent with the lepromatous or multibacillary form of the disease. We infer that in life, this individual almost certainly suffered with multiple soft tissue lesions. Genotyping of the M.leprae strain showed this belonged to the 2F lineage, today associated with cases from South-Central and Western Asia. During osteological examination it was noted that the cranium and facial features displayed atypical morphology for northern European populations. Subsequently, geochemical isotopic analyses carried out on tooth enamel indicated that this individual was indeed not local to the Winchester region, although it was not possible to be more specific about their geographic origin.

This multidisciplinary research article, involving biomolecular analysis, osteology, strontium and oxygen isotopic analyses and archaeology, examines the remains of a Pilgrim burial excavated from the medieval leprosy hospital of St Mary Magdalen, Winchester, UK. Radiocarbon dating showed the remains dated to the late 11^th–early 12^th centuries, a time when pilgrimages were at their height in Europe. The leprosarium at Winchester is one of the earliest excavated examples from Western Europe and has been the subject of a series of recent academic papers. The site is remarkable for the high number of burials displaying skeletal lesions characteristic of leprosy (86%) and the state of preservation of biomolecular markers of the disease, including mycolipids and DNA. Genotyping of the M.leprae strain showed this belonged to the 2F lineage, today associated with cases from South-Central and Western Asia. Several aspects of the burial and dietary isotope analysis indicated this was an individual of some prestige and means; an unusual cranial morphology pointed to possible origin outside of the British Isles. Strontium and oxygen isotopic analyses confirmed he was not local to the Winchester area but were not able to pinpoint his precise origins. Overall these findings confirm the benefits of a multidisciplinary approach which allows investigation of the wider relationship between leprosy, medieval pilgrimage and M.leprae transmission.

Implementation of an in-house quantitative real-time polymerase chain reaction method for Hepatitis B virus quantification in West African countries

Hepatitis B virus (HBV) is a major cause of chronic liver disease worldwide. HBV infection is diagnosed by serological tests, while real-time polymerase chain reaction (qRT-PCR) assays are used to quantify viral load, which is a crucial parameter to determine viral replication and to monitor antiviral treatments. However, measuring viral load in resource-limited countries remains nonsystematic, due to the high cost of commercial kits. Here, we describe the development, validation and implementation of a low-cost, in-house qRT-PCR assay to monitor HBV viral load in chronic carriers enrolled in the PROLIFICA programme in the Gambia and Senegal. Over 1500 HBsAg-positive patients, including 210 chronically infected HBV patients, who were given antiviral treatment (tenofovir), were monitored by qRT-PCR using the SYBR Green- and HBV-specific primers. Twenty-four tenofovir-treated patients were followed up and their viral load was tested every 3 months over the 12-month experimental time course. Compared to commercial assays, our in-house assay was shown to be (i) highly reliable, with good intra- and interassay reproducibility over a wide range (45-4.5 × 108 copies mL-1 ), (ii) very similar in the viral loads detected (R2  = .90), (iii) highly sensitive, as it detected loads as low as 30 copies mL-1 (~5 IU mL-1 ), (iv) cheaper (2- to 3-fold), (v) easier to implement and (vi) more rapid. Based on our experience, we recommend this assay as a reliable alternative to commercial assays, for monitoring HBV viraemia in resource-limited, highly endemic countries to reduce the cost and technical obstacles associated with commercial kits.

Update on hepatitis B and C virus diagnosis

Viral hepatitis B and C virus (HBV and HCV) are responsible for the most of chronic liver disease worldwide and are transmitted by parenteral route, sexual and vertical transmission. One important measure to reduce the burden of these infections is the diagnosis of acute and chronic cases of HBV and HCV. In order to provide an effective diagnosis and monitoring of antiviral treatment, it is important to choose sensitive, rapid, inexpensive, and robust analytical methods. Primary diagnosis of HBV and HCV infection is made by using serological tests for detecting antigens and antibodies against these viruses. In order to confirm primary diagnosis, to quantify viral load, to determine genotypes and resistance mutants for antiviral treatment, qualitative and quantitative molecular tests are used. In this manuscript, we review the current serological and molecular methods for the diagnosis of hepatitis B and C.

Detection of hepatitis B virus infection: A systematic review

AIM: To review published methods for detection of hepatitis B virus (HBV) infection.

METHODS: A thorough search on Medline database was conducted to find original articles describing different methods or techniques of detection of HBV, which are published in English in last 10 years. Articles outlining methods of detection of mutants or drug resistance were excluded. Full texts and abstracts (if full text not available) were reviewed thoroughly. Manual search of references of retrieved articles were also done. We extracted data on different samples and techniques of detection of HBV, their sensitivity (Sn), specificity (Sp) and applicability.

RESULTS: A total of 72 studies were reviewed. HBV was detected from dried blood/plasma spots, hepatocytes, ovarian tissue, cerumen, saliva, parotid tissue, renal tissue, oocytes and embryos, cholangiocarcinoma tissue, etc. Sensitivity of dried blood spot for detecting HBV was > 90% in all the studies. In case of seronegative patients, HBV DNA or serological markers have been detected from hepatocytes or renal tissue in many instances. Enzyme linked immunosorbent assay and Chemiluminescent immunoassay (CLIA) are most commonly used serological tests for detection. CLIA systems are also used for quantitation. Molecular techniques are used qualitatively as well as for quantitative detection. Among the molecular techniques version 2.0 of the CobasAmpliprep/CobasTaqMan assay and Abbott’s real time polymerase chain reaction kit were found to be most sensitive with a lower detection limit of only 6.25 IU/mL and 1.48 IU/mL respectively.

CONCLUSION: Serological and molecular assays are predominant and reliable methods for HBV detection. Automated systems are highly sensitive and quantify HBV DNA and serological markers for monitoring.

Epidemiology of Hepatitis B and Hepatitis C Infections and Benefits of Programs for Hepatitis Prevention in Northeastern China: A Cross-Sectional Study

BACKGROUND

To investigate the epidemiology of hepatitis B and C infections and the benefits of programs aimed at hepatitis prevention and control in Northeastern China.

METHODS

Individuals receiving health examinations were recruited to complete a questionnaire and undergo laboratory tests for hepatitis infection. Data on demographic characteristics, results of hepatitis B virus (HBV) and hepatitis C virus (HCV) serological tests, for HBV and HCV infection were analyzed.

RESULTS

Among 227 808 study participants, the hepatitis B surface antigen (HBsAg) and anti-HCV-positive rates were 6.1% and 3.0%, respectively. Among HBsAg-positive participants, 63.8% tested positive for HBV DNA, 20.2% had an abnormal alanine aminotransferase (ALT) level, and 10.7% had cirrhosis. Among anti-HCV-positive participants, 57.2% tested positive for HCV RNA, 29.6% had an abnormal ALT level, and 8.4% had cirrhosis. Among HBsAg- or anti-HCV-positive participants, 47.1% and 32.0%, respectively, were aware of their infection. Among participants infected with HBV or HCV and suitable for antivirus treatment, 23.5% and 16.1%, respectively, had received antivirus treatment. The HBV plus HCV coinfection rate was 0.08%.

CONCLUSIONS

The HBsAg-positive rate decreased significantly after implementation of recently introduced HBV control programs in China. However, the anti-HCV-positive rate showed only a slight decrease, indicating that programs for the prevention and control of hepatitis viruses require continued strengthening.

CHINESE CLINICAL TRIALS REGISTRATION

ChiCTR-ECS-13004009.

Usefulness of in-house PCR methods for hepatitis B virus DNA detection

The aim of the present study was to evaluate the performance of three in-house PCR techniques for HBV DNA detection and compare it with commercial quantitative methods to evaluate the usefulness of in-house methods for HBV diagnosis. Three panels of HBsAg reactive sera samples were evaluated: (i) 50 samples were examined using three methods for in-house qualitative PCR and the Cobas Amplicor HBV Monitor Assay; (ii) 87 samples were assayed using in-house semi-nested PCR and the Cobas TaqMan HBV test; (iii) 11 serial samples obtained from 2 HBV-infected individuals were assayed using the Cobas Amplicor HBV test and semi-nested PCR. In panel I, HBV DNA was detected in 44 samples using the Cobas Amplicor HBV test, 42 samples using semi-nested PCR (90% concordance with Cobas Amplicor), 22 samples using PCR for the core gene (63.6% concordance) and 29 samples using single-round PCR for the pre-S/S gene (75% concordance). In panel II, HBV DNA was quantified in 78 of the 87 HBsAg reactive samples using Cobas TaqMan but 52 samples using semi-nested PCR (67.8% concordance). HBV DNA was detected in serial samples until the 17th and 26th week after first donation using in-house semi-nested PCR and the Cobas Amplicor HBV test, respectively. In-house semi-nested PCR presented adequate concordance with commercial methods as an alternative method for HBV molecular diagnosis in low-resource settings.