Molecular diagnosis of viral hepatitis

Clinical diagnosis of viral hepatitis: Current status and future strategies

Viral hepatitis (VH) is a significant public health issue with tremendous potential to aggravate into chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Recent decade has witnessed remarkable uprising in the drug development and effective treatment of VH. An upsurge is seen in identification of antiviral therapies with low rates of viral resistance, the improvement of Hepatitis B Virus (HBV) vaccination and the development of direct-acting antivirals for Hepatitis C Virus (HCV). But unfortunately, the "2030 worldwide eradication" objective of World Health Organization (WHO) is still unmet. It can be largely attributed to the deficit faced by the healthcare system concerning screening and diagnosis. A timely, accurate and comprehensive screening; encompassing maximum population coverage is essential to combat this disease. However, advancements in VH diagnostics remain inadequate and with a marginal use in routine practice. This paper deliberates upon the lacunae in traditional and prevailing diagnostic methodology of viral hepatitis, especially their inadequacy in meeting the unique situations prevailing low- and middle-income countries (LMIC).

Advanced Theranostic Strategies for Viral Hepatitis Using Carbon Nanostructures

There are several treatment protocols for acute viral hepatitis, and it is critical to recognize acute hepatitis in its earliest stages. Public health measures to control these infections also rely on rapid and accurate diagnosis. The diagnosis of viral hepatitis remains expensive, and there is no adequate public health infrastructure, while the virus is not well-controlled. New methods for screening and detecting viral hepatitis through nanotechnology are being developed. Nanotechnology significantly reduces the cost of screening. In this review, the potential of three-dimensional-nanostructured carbon substances as promising materials due to fewer side effects, and the contribution of these particles to effective tissue transfer in the treatment and diagnosis of hepatitis due to the importance of rapid diagnosis for successful treatment, were extensively investigated. In recent years, three-dimensional carbon nanomaterials such as graphene oxide and nanotubes with special chemical, electrical, and optical properties have been used for the diagnosis and treatment of hepatitis due to their high potential. We expect that the future position of nanoparticles in the rapid diagnosis and treatment of viral hepatitis can be better determined.

Applying next-generation sequencing to unravel the mutational landscape in viral quasispecies

Next-generation sequencing (NGS) has revolutionized the scale and depth of biomedical sciences. Because of its unique ability for the detection of sub-clonal variants within genetically diverse populations, NGS has been successfully applied to analyze and quantify the exceptionally-high diversity within viral quasispecies, and many low-frequency drug- or vaccine-resistant mutations of therapeutic importance have been discovered. Although many works have intensively discussed the latest NGS approaches and applications in general, none of them has focused on applying NGS in viral quasispecies studies, mostly due to the limited ability of current NGS technologies to accurately detect and quantify rare viral variants. Here, we summarize several error-correction strategies that have been developed to enhance the detection accuracy of minority variants. We also discuss critical considerations for preparing a sequencing library from viral RNAs and for analyzing NGS data to unravel the mutational landscape.

Prevention and management of viral hepatitis in inflammatory bowel disease: a clinical practice guideline by the Korean Association for the Study of Intestinal Diseases

The treatment of inflammatory bowel disease (IBD) has been revolutionized for the last 10 years by the increasing use of immunomodulators and biologics. With immunosuppression of this kind, opportunistic infection is an important safety concern for patients with IBD. In particular, viral hepatitis is determined by the interaction between the virus and the host's immunity, and the risk of reactivation increases if immunity is compromised by immunosuppression therapy. Parts of Asia, including Korea, still show intermediate endemicity for the hepatitis A virus and hepatitis B virus compared with the United States and Western Europe. Thus, members of IBD research group of the Korean Association for the Study of Intestinal Diseases have produced a guideline on the prevention and management of viral hepatitis in IBD.

Characteristics of acute hepatitis A virus infection before and after 2001: A hospital-based study in Tokyo, Japan

BACKGROUND AND AIM

The incidence of acute hepatitis A [AH (A)] is decreasing because of improvements in hygiene; however, cases of sporadic severe hepatitis are still being reported. We assessed the epidemiology of AH (A) in Japan.

METHODS

This was a hospital-based retrospective study, in which 126 AH (A) patients (96 men [76%], median age 39 [range, 19-66] years) were enrolled. Patients diagnosed with AH (A) before 2001 (n = 79) and after 2001 (n = 47) were compared.

RESULTS

The incidence of AH (A) showed peaks in 1990, 1999, and 2018. After 2001, one patient had hepatitis B virus, four had human immunodeficiency virus, and three had syphilis coinfections. Before and after 2001, HAV was transmitted, respectively, by raw oysters (28% and 26%), overseas travel (19% and 28%), and sexual contact (0% and 19%) (P < 0.01). The frequencies of symptoms were appetite loss (51% and 32%), fever (63% and 81%), and diarrhea (3% and 13%) (all P < 0.05), respectively. On admission, the median levels of alanine aminotransferase (1455 and 3069 U/L) and γ-glutamyl transpeptidase (221 and 345 U/L) were significantly higher (P < 0.01), and the prothrombin time (77.5% and 65.9%) and platelet count (22.7 and 16.4 × 10/μL) were significantly lower after 2001 (P < 0.05). A time to normalization of the bilirubin level ≥ 30 days was associated with older age and a diagnosis of AH (A) after 2001.

CONCLUSIONS

Outbreaks and severe AH (A) cases due to sexual transmission have been reported recently. It is necessary to examine their sexual behavior and other sexual infection.

Interferon-Free Regimen: Equally Effective in Treatment Naive and Experienced HCV Patients

INTRODUCTION AND AIM

Interferon-free regimen has been reported to be highly efficient in treatment of HCV infection, including patients with compensated cirrhosis. We compared the efficacy of Ombitasvir, Paritaprevir, Ritonavir, Dasabuvir and Ribavirin (OBT/PTV/r, with DSV and RBV) therapy in patients with chronic HCV genotype 1b infection and compensated cirrhosis with and without prior treatment experience with pegylated interferon and ribavirin (IFN/RBV).

MATERIAL AND METHODS

A prospective two-center study was conducted in Mures County Hospital and Brasov County Hospital, Romania in period November 2015-July 2016. Both treatment naïve and PegIFN/RBV experienced patients with chronic HCV genotype 1b infection received 12 weeks of OBT/PTV/r, with DSV and RBV. Sustained virologic response 12 weeks after the treatment and eventual discontinuation of therapy due to adverse events were assessed in order to estimate safety and efficiency of therapeutic regimen.

RESULTS

Fifty nine patients were included in study, 35 (59.3%) of them were previously treated with IFN/RBV. Forty four (74.5%) patients were previously diag-nosed with cirrhosis Child Pugh score 5, while 15 (25.4%) with Child Pugh score 6. All 59 patients achieved a SVR12 of 100% and one patient from treatment naïve cohort discontinued the therapy due to hyperbilirubinemia and encephalopathy. However viral load assessed at 12 weeks after discontinuation of therapy in this patient was undetectable. Conclusion An all-oral regimen of co-for-mulated OBT/PTV/r with DSV and RBV results in high rate of sustained virologic response at post-treatment week 12 among HCV GT1b infected patients associated with compensated cirrhosis, regardless of previous treatment experience with PegIFN/RBV.

Prevalence of hepatitis C virus infection and the IL28B genotype polymorphism among blood donors and high-risk populations

INTRODUCTION

To study the prevalence of hepatitis C virus (HCV) infection in blood donor (BD), haemodialysis (HD) and intravenous drug user (IVDU) populations in Singapore and assess the IL28B polymorphism if HCV positive.

METHODS

The BD population were healthy volunteers, the HD population were patients who were on haemodialysis for at least six months of follow-up between January 2009 and December 2014. IVDU population was from inmates at halfway houses who consented.

RESULTS

Between 2011 and 2014, of 161,658 individuals who underwent screening prior to blood donation, 95 (0.059%) were positive for HCV. Of the 42 sera available, common genotypes (GTs) were GT-3 (47.6%) and GT-1 (31.0%). Of 1,575 HD patients, 2.2% were anti-HCV positive. The HCV GT distribution was HCV GT-1 (32.4%), HCV GT-3 (20.5%) and GT-6 (8.8%). 83 halfway house inmates were screened. Of the 47 IVDUs, 36.2% were anti-HCV positive with predominant GT-3 (%). IL28B polymorphism was noted to be CC predominantly 85.3%.

CONCLUSION

Prevalence of HCV infection has decreased in both the BD and HD populations. However, it remains high in the IVDU population. GT-1 remains the most common in the HD population; however, GT-3 infection is now more common among the BD population in Singapore. IL28B - CC is the predominant variant among the HCV-infected individuals in Singapore.

Hepatic Encephalopathy in Patients in Lviv (Ukraine)

Background and Objectives

Hepatic encephalopathy (HE) research has long been impeded by the vague definition of this disabling complication of liver failure. This article provides an overview of the etiology and impact of HE on neuromuscular functions as well as its role in the development of infections and anemia.

Materials and Methods

This was a descriptive study conducted in 36 patients with HE. Close monitoring of these patients was done by checking on several parameters.

Results

The etiological distribution: alcohol (67%), hepatitis C virus (HCV; 17%), HCV and alcohol (8%), hepatitis B virus (HBV; 3%), HBV and alcohol (3%), HBV and HCV (6%), and cryptogenic (3%). The laboratory results indicated an elevation of De Ritis level in 69% of cases and in 92% of total bilirubin values. The Halstead-Reitan (H-R) test score with regards to gender indicated that more than half of the patients had a score of 2, while only few cases received the scores 3 and 4. The frequency of H-R score with regards to Child-Pugh score showed the significant preponderance of Child-Pugh score of 7–9 (B): 58.3% compared to others groups of results, and these results indicated patients’ poor prognosis.

Conclusion

Findings showed the preponderance of female patients towards developing HE and the poor survival rate of patients older than 65 years. Alcohol and hepatitis C were the main causes associated with the development of HE. The neurological assessment marked the preponderance of Child-Pugh grades B and C and also the prevalence in female patients with neuropsychological disabilities through the assessment of H-R test.

Detection and quantification of hepatitis E virus in the absence of IgG and IgM anti-HEV in HIV-positive patients

AIMS

To improve RT-qPCR with an internal control and a synthetic standard curve to detect HEV in HIV co-infected patients.

METHODS AND RESULTS

A single-stranded RNA (ssRNA) and a double-stranded DNA (dsDNA) synthetic curve were designed, compared to the international reference panel for HEV genotypes, and tested to quantify and detect a reference panel for HEV genotypes. The detection limit of the RNA synthetic curve (50 copies per ml) was better than the DNA synthetic curve (100 copies per ml) and the WHO standard curve (250 copies per ml). Then, 280 serum samples from HIV-positive patients were tested for HEV RNA, which was detected in 3·6% of serum samples. The viral load ranged from 2 × 10² copies per ml to 4·78 × 10⁸ copies per ml. HEV IgM/IgG antibodies were not detected in the RNA-positive patients. Sequencing analysis of HEV showed that the virus belongs to genotype 3 (HEV GT3).

CONCLUSIONS

Real-time PCR was a useful tool to estimate co-infection with HEV/HIV, even in patients with low viral loads and undetectable anti-HEV IgG and IgM antibodies.

SIGNIFICANCE AND IMPACT OF THE STUDY

Hepatitis E virus genotype 3 (HEV GT3) has been associated with silent chronic hepatitis and cirrhosis in HIV-positive subjects worldwide, but there is a lack of data on this co-infection in Brazil.

Semiquantitative Nucleic Acid Test with Simultaneous Isotachophoretic Extraction and Amplification

Nucleic acid amplification tests (NAATs) provide high diagnostic accuracy for infectious diseases and quantitative results for monitoring viral infections. The majority of NAATs require complex equipment, cold chain dependent reagents, and skilled technicians to perform the tests. This largely confines NAATs to centralized laboratories and can significantly delay appropriate patient care. Low-cost, point-of-care (POC) NAATs are especially needed in low-resource settings to provide patients with diagnosis and treatment planning in a single visit to improve patient care. In this work, we present a rapid POC NAAT with integrated sample preparation and amplification using electrokinetics and paper substrates. We use simultaneous isotachophoresis (ITP) and recombinase polymerase amplification (RPA) to rapidly extract, amplify, and detect target nucleic acids from serum and whole blood in a paper-based format. We demonstrate simultaneous ITP and RPA can consistently detect 5 copies per reaction in buffer and 10 000 copies per milliliter of human serum with no intermediate user steps. We also show preliminary extraction and amplification of DNA from whole blood samples. Our test is rapid (results in less than 20 min) and made from low-cost materials, indicating its potential for detecting infectious diseases and monitoring viral infections at the POC in low resource settings.

Role of Age and Race in the Risk of Hepatocellular Carcinoma in Veterans With Hepatitis B Virus Infection

BACKGROUND & AIMS

Hepatocellular (HCC) surveillance guidelines for patients with chronic hepatitis B virus (HBV) infection are based on race- and age-specific estimates of HCC risk, derived from studies conducted in areas in which HBV is endemic.

METHODS

We conducted a retrospective cohort study using the national Veterans Administration data to identify patients with chronic HBV infection from 2001 through 2013. We examined the effect of race and age on HCC risk while adjusting for baseline clinical characteristics.

RESULTS

The study cohort had 8329 patients; 3498 patients (42.0%) were white, 3248 (39%) were African Americans, and 659 (7.9%) were Asian Pacific Islanders. The annual HCC incidence was highest in Asian Pacific Islanders (0.65%), followed by whites (0.57%) and African Americans (0.40%). After adjusting for clinical and viral factors, the risk of HCC was significantly higher in Asian Pacific Islanders compared with whites (adjusted hazard ratio [HR] = 2.04; 95% CI, 1.31-3.17). There was no difference in HCC risk between African Americans and whites (adjusted HR, 0.77; 95% CI, 0.58-1.02). HCC risk increased with age: adjusted HR was 1.97 (95% CI, 0.99-3.87) for 40-49 years; adjusted HR was 3.00 (95% CI, 1.55-5.81) for 50-59 years; and adjusted HR was 4.02 (95% CI, 2.03-7.94) for more than 60 years vs less than 40 years. Patients with cirrhosis had higher risk of HCC than patients without cirrhosis (adjusted HR = 3.69; 95% CI, 2.82-4.83). However, even among patients without cirrhosis, the annual incidence of HCC was more than 0.2% for all patients older than 40 years with high levels of alanine aminotransferase-regardless of race.

CONCLUSIONS

In a sample of male veterans with chronic HBV infection, risk of HCC is highest among Asian Pacific Islanders, followed by whites and African Americans. Cirrhosis increased HCC risk. Among patients without cirrhosis, male patients who are older than 40 years and have increased levels of alanine aminotransferase might benefit from HCC surveillance, regardless of race.

Empirical validation of the Horowitz Multiple Systemic Infectious Disease Syndrome Questionnaire for suspected Lyme disease

PURPOSE

Lyme disease is spreading worldwide, with multiple Borrelia species causing a broad range of clinical symptoms that mimic other illnesses. A validated Lyme disease screening questionnaire would be clinically useful for both providers and patients. Three studies evaluated such a screening tool, namely the Horowitz Multiple Systemic Infectious Disease Syndrome (MSIDS) Questionnaire. The purpose was to see if the questionnaire could accurately distinguish between Lyme patients and healthy individuals.

METHODS

Study 1 examined the construct validity of the scale examining its factor structure and reliability of the questionnaire among 537 individuals being treated for Lyme disease. Study 2 involved an online sample of 999 participants, who self-identified as either healthy (N=217) or suffering from Lyme now (N=782) who completed the Horowitz MSIDS Questionnaire (HMQ) along with an outdoor activity survey. We examined convergent validity among components of the scale and evaluated discriminant validity with the Big Five personality characteristics. The third study compared a sample of 236 patients with confirmed Lyme disease with an online sample of 568 healthy individuals.

RESULTS

Factor analysis results identified six underlying latent dimensions; four of these overlapped with critical symptoms identified by Horowitz - neuropathy, cognitive dysfunction, musculoskeletal pain, and fatigue. The HMQ showed acceptable levels of internal reliability using Cronbach's coefficient alpha and exhibited evidence of convergent and divergent validity. Components of the HMQ correlated more highly with each other than with unrelated traits.

DISCUSSION

The results consistently demonstrated that the HMQ accurately differentiated those with Lyme disease from healthy individuals. Three migratory pain survey items (persistent muscular pain, arthritic pain, and nerve pain/paresthesias) robustly identified individuals with verified Lyme disease. The results support the use of the HMQ as a valid, efficient, and low-cost screening tool for medical practitioners to decide if additional testing is warranted to distinguish between Lyme disease and other illnesses.

Identification of hepatitis B virus A1762T/G1764A double mutant strain in patients in Southern Brazil

Infection by hepatitis B virus (HBV) is a worldwide public health problem. Chronic HBV infection with high viral replication may lead to cirrhosis and/or hepatocellular carcinoma. Mutant HBV strains, such as the HBV A1762T/G1764A double mutant, have been associated with poor prognosis and higher risk of the patient for developing cirrhosis and/or hepatocellular carcinoma. This study analyzed the presence of the HBV A1762T/G1764A double mutant in patients with chronic HBV and its association with clinical parameters such as viral load, aminotransferases, and HBV antigens. A total of 49 patients with chronic hepatitis B were included in the study, and the HBV A1762T/G1764A double mutant strain was detected in four samples (8.16%) by polymerase chain reaction followed by restriction fragment length analysis (PCR-RFLP). The viral load was not significantly different between patients with or without the double mutant strain (p=0.43). On the other hand, carriers of the HBV A1762T/G1764A double mutant had higher levels of ALT (p=0.0028), while AST levels did not differ between groups (p=0.051). In this study, 75% of the samples with the HBV A1762T/G1764A double mutation were HBeAg negative and anti-HBe positive, reflecting seroconversion even though they still displayed high viral loads. Our study has shown that the HBV A1762T/G1764A double mutant strain circulates in Brazilian patients, and is associated with elevated levels of ALT and HBeAg seroconversion.

Molecular diagnosis of the human immunodeficiency, Hepatitis B and C viruses among blood donors in Lomé (Togo) by multiplex real time PCR

This study aimed to compare the sensitivity of multiplex PCR to ELISA technique in the instantaneous detection of HBV, HCV and HIVin blood samples from donors of the National blood Transfusion Centre in Togo. A total of 440 blood samplesfrom volunteer were collected and tested by ELISA and multiplex PCR for HBV, HCV and HIV detection. Among the 440 volunteer blood donors, 83% were female and 17% were male. Age range of 20-29 years was more represented (73%). Whereas, multiplex PCR detected more cases of HBV than ELISA (50% vs 33%, P=0.0155);ELISA more detected HCV than PCR (34% vs 3%, P<0.0001) and HIV (26% vs 7%, P<0.0001). Confirming these observations our data showed that multiplex PCR was more sensitive in the detection of HBV. The sensitivity of ELISA for the detection of HCV and HIV was elevated compared to multiplex PCR. Multiplex PCR was more specific that ELISA for the detection of HCV and HIV.Interestingly, our data showed that the gender do not influenced the sensitivity of either ELISA or multiplex PCR to detect these viruses. This study showed the limit of both ELISA and multiplex PCR in the detection of HBV, HCV and HIV.

A novel real-time reverse transcription-polymerase chain reaction assay with partially double-stranded linear DNA probe for sensitive detection of hepatitis C viral RNA

The detection and quantification of HCV RNA is very helpful for the management and treatment of HCV related diseases. Detection of low HCV viral load is a great challenge in HCV RNA detection. Here, we developed a novel real-time RT-PCR assay with partially double-stranded linear DNA probe which can detect all HCV genotypes and improve the detection performance. The novel assay has a wide linear dynamic range of HCV RNA quantification (1×10(2)-1×10(11)IU/ml) and a limit of detection of 78IU/ml. The assay exhibits an excellent reproducibility with 2.52% and 1.33% coefficients of variations, for inter- and intra-assays, respectively. To evaluate the viability of the assay, a comparison with a commercial HCV RNA detection kit was performed using 106 serum samples. The lineared correlation coefficient between the novel assay and the commercial HCV RNA detection kit was 0.940. Meanwhile, the deviation between the two methods was tolerable. Therefore, the novel real-time RT-PCR assay was applicable for laboratory diagnosis and monitoring of HCV infection.

Genotypic distribution of hepatitis C virus in Thailand and Southeast Asia

The majority of hepatitis C virus (HCV) infection results in chronic infection, which can lead to liver cirrhosis and hepatocellular carcinoma. Global burden of hepatitis C virus (HCV) is estimated at 150 million individuals, or 3% of the world's population. The distribution of the seven major genotypes of HCV varies with geographical regions. Since Asia has a high incidence of HCV, we assessed the distribution of HCV genotypes in Thailand and Southeast Asia. From 588 HCV-positive samples obtained throughout Thailand, we characterized the HCV 5' untranslated region, Core, and NS5B regions by nested PCR. Nucleotide sequences obtained from both the Core and NS5B of these isolates were subjected to phylogenetic analysis, and genotypes were assigned using published reference genotypes. Results were compared to the epidemiological data of HCV genotypes identified within Southeast Asian. Among the HCV subtypes characterized in the Thai samples, subtype 3a was the most predominant (36.4%), followed by 1a (19.9%), 1b (12.6%), 3b (9.7%) and 2a (0.5%). While genotype 1 was prevalent throughout Thailand (27-36%), genotype 3 was more common in the south. Genotype 6 (20.9%) constituted subtype 6f (7.8%), 6n (7.7%), 6i (3.4%), 6j and 6m (0.7% each), 6c (0.3%), 6v and 6xa (0.2% each) and its prevalence was significantly lower in southern Thailand compared to the north and northeast (p = 0.027 and p = 0.030, respectively). Within Southeast Asia, high prevalence of genotype 6 occurred in northern countries such as Myanmar, Laos, and Vietnam, while genotype 3 was prevalent in Thailand and Malaysia. Island nations of Singapore, Indonesia and Philippines demonstrated prevalence of genotype 1. This study further provides regional HCV genotype information that may be useful in fostering sound public health policy and tracking future patterns of HCV spread.

Biomarkers in HCV Infection

Liver-related biomarkers have been developed and validated mainly in patients with chronic hepatitis C for the prediction of liver fibrosis or cirrhosis, which is a final pathway of chronic liver injury. They are noninvasive, traceable, and easy-to-use. Biomarkers provide implications related to screening, diagnosis, treatment, and prognosis of chronic hepatitis. For the improvement of performance and coverage, biomarker panels, imaging biomarkers, and even genetic biomarkers have been developed. With the advancement of genomics and proteomics, earlier and more precise prediction is expected in the near future. In this review, multiple biomarker panels for the estimation of the degree of fibrosis in chronic hepatitis C, biomarkers for the screening and diagnosis of hepatitis C, biomarkers for the treatment of hepatitis C, biomarkers for the prediction of complications related to the chronic hepatitis C, and future perspectives will be summarized.

[Microbiological diagnosis of viral hepatitis]

Liver inflammation or hepatitis has many different causes, both infectious and non-infectious. Among the former, viral infection is responsible for at least half of all hepatitis worldwide. Different viruses have been described with primary tropism for liver tissue. These microorganisms have been successively named with letters of the alphabet: A, B, C, D, E and G. The aim of this paper is to review this heterogeneous group of viruses in its most basic aspects, including clinical implications, treatment, main control, and prophylactic measures and, of special interest, diagnostic approaches, both serological and molecular, which are used for their detection, quantification and characterization.

Evaluation of a Rapid One-step Real-time PCR Method as a High-throughput Screening for Quantification of Hepatitis B Virus DNA in a Resource-limited Setting

Virological monitoring is the best predictor for the management of chronic hepatitis B virus (HBV) infections. Consequently, it is important to use the most efficient, rapid and cost-effective testing systems for HBV DNA quantification. The present study compared the performance characteristics of a one-step HBV polymerase chain reaction (PCR) vs the two-step HBV PCR method for quantification of HBV DNA from clinical samples. A total of 100 samples consisting of 85 randomly selected samples from patients with chronic hepatitis B (CHB) and 15 samples from apparently healthy individuals were enrolled in this study. Of the 85 CHB clinical samples tested, HBV DNA was detected from 81% samples by one-step PCR method with median HBV DNA viral load (VL) of 7.50 × 103 lU/ml. In contrast, 72% samples were detected by the two-step PCR system with median HBV DNA of 3.71 × 103 lU/ml. The one-step method showed strong linear correlation with two-step PCR method (r = 0.89; p < 0.0001). Both methods showed good agreement at Bland-Altman plot, with a mean difference of 0.61 log10 IU/ml and limits of agreement of -1.82 to 3.03 log10 IU/ml. The intra-assay and interassay coefficients of variation (CV%) of plasma samples (4-7 log10 IU/ml) for the one-step PCR method ranged between 0.33 to 0.59 and 0.28 to 0.48 respectively, thus demonstrating a high level of concordance between the two methods. Moreover, elimination of the DNA extraction step in the one-step PCR kit allowed time-efficient and significant labor and cost savings for the quantification of HBV DNA in a resource limited setting.

HOW TO CITE THIS ARTICLE

Rashed-Ul Islam SM, Jahan M, Tabassum S. Evaluation of a Rapid One-step Real-time PCR Method as a High-throughput Screening for Quantification of Hepatitis B Virus DNA in a Resource-limited Setting. Euroasian J Hepato-Gastroenterol 2015;5(1):11-15.

Comparison of HCV core antigen and anti-HCV with HCV RNA results

BACKGROUND

The measurement of anti-HCV antibodies using immunological methods and the confirmation of viral nuclear acid based on molecular methods is important in diagnosis and follow-up of the HCV infection.

OBJECTIVES

In this study, we aimed to analyse HCV core Antigen positivity among anti-HCV antibody positive sera to determine the significance of testing of HCV core Ag for the laboratory diagnosis of HCV infection, by considering the correlation between serum HCV core Ag and HCV RNA levels.

METHODS

115 patients suspected of having hepatitis C and who were positive for anti-HCV antibody were investigated using chemiluminescent and molecular methods. Anti-HCV antibody, HCV core Ag and HCV RNA levels were detected by the Vitros ECiQ immunodiagnostic system, Architect i2000 system and RT-PCR, respectively.

RESULTS

The sensitivity, specificity, positive and negative predictive values and accuracy rate of HCV core Antigen assay were detected as 86.5%(83/96), 100%(19/19), 100%(83/83), 59.4%(19/32), 88.7%(102/115) respectively.

CONCLUSION

HCV core Ag assay could be used for diagnosis of HCV infection as it is easy to perform, cost-effective, has high specificity and positive predictive value. However, it should be kept in mind that it may have lack of sensitivity and negative predictive value.

Recent advances in molecular diagnostics of hepatitis B virus

Hepatitis B virus (HBV) is one of the important global health problems today. Infection with HBV can lead to a variety of clinical manifestations including severe hepatic complications like liver cirrhosis and hepatocellular carcinoma. Presently, routine HBV screening and diagnosis is primarily based on the immuno-detection of HBV surface antigen (HBsAg). However, identification of HBV DNA positive cases, who do not have detectable HBsAg has greatly encouraged the use of nucleic acid amplification based assays, that are highly sensitive, specific and are to some extent tolerant to sequence variation. In the last few years, the field of HBV molecular diagnostics has evolved rapidly with advancements in the molecular biology tools, such as polymerase chain reaction (PCR) and real-time PCR. Recently, apart of PCR based amplification methods, a number of isothermal amplification assays, such as loop mediated isothermal amplification, transcription mediated amplification, ligase chain reaction, and rolling circle amplification have been utilized for HBV diagnosis. These assays also offer options for real time detection and integration into biosensing devices. In this manuscript, we review the molecular technologies that are presently available for HBV diagnostics, with special emphasis on isothermal amplification based technologies. We have also included the recent trends in the development of biosensors and use of next generation sequencing technologies for HBV.

Re-appraisal of old and new diagnostic tools in the current management of chronic hepatitis B

Hepatitis B virus (HBV) is a very complex and intricate DNA structure associated with a particular genomic organization and replication cycle. However, many years of investigations allowed clarification of the real HBV natural history, through a deeper knowledge of the behavior of HBV antigens and viral structures. Several of the old diagnostic tools, such as HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) determinations, gained prominence now, since the variation of both HBsAg and HBeAg plasma levels was shown to predict treatment response. In addition, the availability of more sensitive methods, such as HBV DNA detection by real-time PCR, has improved the current knowledge of the relationships between HBV replication levels and the natural history of the disease. It is now well established that some HBV genotypes are associated with a better response to treatment with pegylated interferon. Despite the widely accepted value of liver biopsy as a staging tool, transient elastography is being increasingly acknowledged as a non-invasive method to assess liver stiffness, chiefly for detection of advanced fibrosis. Current international guidelines for the management of chronic hepatitis B have provided several accurate biochemical and serological criteria for selecting patients for treatment, allowing a higher number of cases to be enrolled into antiviral therapy. This review describes the different serological markers used for the study of HBV and their clinical significance. It also deals with methods used for detection of genotypes and HBV DNA, emphasizing the effectiveness of such determinations for both patient selection and chronic hepatitis B therapy/monitoring.

Comparison of the Abbott RealTime HBV assay with the Roche Cobas AmpliPrep/Cobas TaqMan HBV assay for HBV DNA detection and quantification

BACKGROUND

Measurement of hepatitis B virus (HBV) DNA levels is essential in the clinical management of patients with chronic HBV infection. Performance and accuracy of quantitation for HBV DNA are therefore critical in clinical practice.

OBJECTIVES

We aimed to compare and evaluate the performance characteristics of two HBV DNA quantitative assays: Abbott RealTime HBV (RealTime assay) and Cobas AmpliPrep/Cobas TaqMan HBV assays 2.0 (TaqMan assay).

STUDY DESIGN

Serum samples from 220 HBV-infected patients were collected. Performance characteristics of the HBV DNA quantitative assays, including sensitivity, linearity, and reproducibility were measured. The assays were compared based on the viral status, including HBeAg, genotype, core promoter and pre-core region mutations.

RESULTS

The RealTime assay had a sensitivity and specificity of 98.2% and 100%, respectively. The intra-assay coefficients of variation of serum samples ranged from 0.00% to 11.25% for the RealTime assay and 1.22% to 8.22% for TaqMan assay. Paired quantitative results showed excellent correlation by linear regression analysis (R(2)=0.961), good level of agreement with a mean difference of 0.31log10IU/mL, and limits of agreement of -0.62 to 1.24log10IU/mL, irrespective of HBeAg, genotype, core promoter and pre-core region mutation-specific differences. In this study, a difference of ≥1log10IU/mL between the two assays was observed in 8.6% of the samples. Genotype B and average HBV DNA levels of <3log10IU/mL were significant associated factors of this discordance.

CONCLUSIONS

The Abbott assay delivered high performance for HBV DNA quantification and correlated extremely well with the TaqMan assay, irrespective of viral status.

Drug resistance of a viral population and its individual intrahost variants during the first 48 hours of therapy

Using hepatitis C virus (HCV) and interferon (IFN) resistance as a proof of concept, we have devised a new method for calculating the effect of a drug on a viral population, as well as the resistance of the population's individual intrahost variants. By means of next-generation sequencing, HCV variants were obtained from sera collected at nine time points from 16 patients during the first 48 h after injection of IFN-α. IFN-resistance coefficients were calculated for individual variants using changes in their relative frequencies, and for the entire intrahost viral population using changes in viral titer. Population-wide resistance and presence of IFN-resistant variants were highly associated with pegylated IFN-α2a/ribavirin treatment outcome at week 12 (P = 3.78 × 10(-5) and 0.0114, respectively). This new method allows an accurate measurement of resistance based solely on changes in viral titer or the relative frequency of intrahost viral variants during a short observation time.

Epidemiological characteristics and genotype distribution of hepatitis C virus in Guangxi

AIM: To investigate the distribution characteristic of HCV genotypes in Guangxi, and to explore the correlations of ethnicity, gender, age, route of infection and HCV-RNA load with HCV genotypes.

METHODS: The NS5B region was amplified from 137 HCV-RNA positive serum samples and sequenced. The sequences obtained were compared with the sequences deposited in Genebank to construct a HCV NS5B phylogenetic tree.

RESULTS: The major genotype of HCV in Guangxi was 1b (58.4%), followed by 6a (12.4%), 3b (10.2%), 1a (7.3%), 2a (7.3%), and 3a (4.4%). There were no significant correlations between HCV genotype and ethnicity or gender (P > 0.05 for both). Significant correlations were found between HCV genotype and age, route of infection and HCV-RNA load (P < 0.05 for all).

CONCLUSION: Accurate HCV genotypes and subgenotypes can be obtained by establishing a phylogenetic tree of the HCV NS5B region. At least seven subgenotypes were detected in Guangxi and the main genotypes are 1b, 6a and 3b. Compared with previous reports, our results indicated that the prevalence of genotype 1b seems to decline, and the prevalence of 6a tends to increase gradually. Genotypes 3 and 6a were mainly found in young intravenous drug users. The distribution of HCV genotypes changes with the change in the route of infection.

Hepatitis C virus infection in Egyptian children with type 1 diabetes mellitus: A single center study

BACKGROUND

Only few studies have evaluated the epidemiology and risk factors of hepatitis C virus (HCV) infection in Egyptian children with type 1 diabetes mellitus (T1DM). The present study aimed at measurement of the rates of anti-HCV positivity by Enzyme-Linked Immuno-Sorbent Assay (ELISA) test and of HCV-Ribonucleic acid (RNA) positivity by polymerase chain reaction (PCR) among children with T1DM and to study the possible risk factors of infection.

SETTINGS AND DESIGN

Cross-sectional controlled study.

MATERIALS AND METHODS

The study included 150 children with T1DM (Group 1) (mean age 14. 76 ± 6.4 years). Fifty children age and sex-matched were included as control group (Group 2) (mean age 13.62 ± 2.11 years). They were screened for HCV antibodies using third generation ELISA and HCV-RNA positivity by PCR.

RESULTS

The frequency of anti-HCV positivity by ELISA was significantly higher in children with T1DM (n = 150) in comparison wiith control group (n = 50) (12% vs 6%; P<0.001), while the frequency of HCV-RNA positivity by PCR among the cases testing positive by ELISA was 75% for both diabetic group and control group. There were no significant differences in serum levels of liver biochemical profile in diabetic children with anti-HCV positivity (n = 18) in comparison to those with anti-HCV negativity (n = 132). Residence in rural area, low socioeconomic class and prior hospitalization were significant risk factors for anti-HCV positivity by ELISA.

CONCLUSIONS

The frequency of HCV infection in children with T1DM in Upper Egypt appears to be high and is mainly related to residence in rural area, low socioeconomic class and prior hospitalization. HCV infection in these children is not associated with significant changes in hepatic biochemical parameters.

RECOMMENDATIONS

Implementation of strict infection control measures are highly recommended to reduce the frequency of HCV infection. Furthermore, the silent evolution of HCV infection in children makes periodic screening of HCV in diabetic children mandatory.

Hepatitis C virus RNA tests: performance attributes and their impact on clinical utility

The diagnostic market is driven by the burden of disease in the population and the ease or difficulty of disease diagnosis. The efficacy of available therapeutics determines the need for monitoring. Hepatitis C virus currently affects approximately 3% of the world's population, although the overall response rate to the best available therapies is 56%. Research regarding hepatitis C virus remains elusive due to lack of an efficient cell culture system. Diagnosis and monitoring of active hepatitis C virus infection therefore rely on sophisticated molecular tests. This review will focus on current molecular tests for hepatitis C virus RNA and the performance attributes that these tests require for accurate diagnosis and monitoring of infection.

Combined adenovirus-mediated artificial microRNAs targeting mfgl2, mFas, and mTNFR1 protect against fulminant hepatic failure in mice

Hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) has a poor prognosis with high in-hospital mortality. Hepatic and circulating inflammatory cytokines, such as fibrinogen like protein 2 (fgl2), FasL/Fas, and TNFα/TNFR1, play a significant role in the pathophysiology of ACLF. This study aimed to investigate the therapeutic effect of recombinant adenoviral vectors carrying constructed DNA code for non-native microRNA (miRNA) targeting mouse fgl2 (mfgl2) or both mFas and mTNFR1 on murine hepatitis virus (MHV)-3-induced fulminant hepatitis in BALB/cJ mice. Artificial miRNA eukaryotic expression plasmids against mfgl2, mFas, and mTNFR1 were constructed, and their inhibitory effects on the target genes were confirmed in vitro. pcDNA6.2-mFas-mTNFR1- miRNA，which expresses miRNA against both mFas and mTNFR1 simultaneously，was constructed. To construct a miRNA adenovirus expression vector against mfgl2, pcDNA6.2-mfgl2-miRNA was cloned using Gateway technology. Ad-mFas-mTNFR1- miRNA was also constructed by the same procedure. Adenovirus vectors were delivered by tail-vein injection into MHV-3-infected BALB/cJ mice to evaluate the therapeutic effect. 8 of 18 (44.4%) mice recovered from fulminant viral hepatitis in the combined interference group treated with Ad-mfgl2-miRNA and Ad-mFas-mTNFR1-miRNA. But only 4 of 18 (22.2%) mice receiving Ad-mfgl2-miRNA and 3 of 18 (16.7%) mice receiving Ad-mFas-mTNFR1- miRNA survived. These adenovirus vectors significantly ameliorated inflammatory infiltration, fibrin deposition, hepatocyte necrosis and apoptosis, and prolonged survival time. Our data illustrated that combined interference using adenovirus-mediated artificial miRNAs targeting mfgl2, mFas, and mTNFR1 might have significant therapeutic potential for the treatment of fulminant hepatitis.

Advances in the Diagnosis and Monitoring of Hepatitis C Virus Infection

Hepatitis C virus (HCV) infection represents a major health problem worldwide. Approximately 350,000 people die every year from hepatitis C related diseases. Antiviral therapy is given to prevent such complications. Advances in serological and molecular assays greatly improved the diagnosis of hepatitis C virus infection and the management of chronically infected patients. Sensitive real-time PCR methods are currently used to monitor the response to antiviral therapy, to guide treatment decisions, and to assess the sustained virological response 24 weeks after the end of therapy. HCV genotyping is part of the pretreatment evaluation. Determination of HCV genotype is important both for tailoring antiviral treatment and for determining treatment duration. It predicts also response to therapy. With the recent introduction of the serine protease inhibitors telaprevir and boceprevir, approved for the treatment of genotype 1 chronic hepatitis C in combination with INF-a and ribavirin, subtyping has become clinically relevant. Indeed, subtypes 1a and 1b may respond differently to current telaprevir-based or boceprevir-based triple therapy. This review summarizes the most recent advances in the diagnosis and monitoring of HCV chronic infection.

The importance of HCV RNA measurement for tailoring treatment duration

The introduction of telaprevir and boceprevir in the treatment of chronically HCV genotype 1 infected patients has led to substantially improved sustained virologic response rates and shorter treatment duration for a growing group of patients. Management and monitoring of patients receiving protease inhibitor-based triple therapy is of major importance and has become more complicated. Close monitoring of HCV RNA levels for patients on protease inhibitor-based therapy to identify subjects who are eligible for shortening of treatment duration, are virological non-responders or are in danger of experiencing a viral breakthrough is strongly recommended. Several virological tools including qualitative and quantitative HCV RNA assays for detection and quantification of HCV RNA are commercially available. We review these methods and their implications for HCV therapy as well as current sustained virologic response definition, stopping rules and recommendations for protease inhibitor-based treatment durations.

Hepatitis C virus (HCV) infection in Africa: a review

Hepatitis C virus (HCV) is a viral pandemic and a leading cause of chronic liver disease. This review highlights the epidemiology and management of Hepatitis C in Africa. We searched for articles on medline using the terms, "Hepatitis C", "Prevalence", "Epidemiology", "Africa" and "Treatment". The bibliographies of the articles found were used to find other references. We included articles published after 1995 only. The data was summarized and presented in tables and figures. Africa has the highest WHO estimated regional HCV prevalence (5.3%). Egypt has the highest prevalence (17.5%) of HCV in the world. Genotypes commonly found in Africa are 1, 4 and 5. Genotype 3 is found in Egypt and parts of Central Africa. Blood transfusion is a major means of acquisition of HCV infection. While treatment with peginterferon and ribavirin is recommended for patients with chronic HCV, no data were found on their use in Africa. Neither were there any data on definitive management (liver transplantation) for those with end stage disease. Data on HCV infection in Africa are scarce. This suggests that hepatitis C is still a neglected disease in many countries. Limited data exist in literature on HCV in Africa.

Risk stratification for hepatitis B virus related hepatocellular carcinoma

Hepatitis B virus (HBV) infection is the major cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC) worldwide, especially in the Asia-Pacific region. Several hepatitis B viral factors predictive of clinical outcomes in HBV carriers have been identified. The Risk Evaluation of Viral Load Elevation and Associated Liver Disease/Cancer-HBV (REVEAL-HBV) study from Taiwan illustrated the strong association between HBV-DNA level at study entry and risk of HCC over time. In this community-based cohort study, male gender, older age, high serum alanine aminotransferase level, positive hepatitis B e antigen, higher HBV-DNA level, HBV genotype C infection, and core promoter mutation are independently associated with a higher risk of HCC. Another large hospital-based Elucidation of Risk Factors for Disease Control or Advancement in Taiwanese Hepatitis B Carriers cohort of Taiwanese patients further validated the findings of REVEAL-HBV. The risk of HCC started to increase when HBV-DNA level was higher than 2000 IU/mL. Both HBV-DNA and HBsAg levels were shown to be associated with HCC development. While HBV-DNA level had better predictive accuracy than HBsAg level, when investigating the overall cohort in patients with HBV-DNA level < 2000 IU/mL, HBsAg level ≥ 1000 IU/mL was identified as a new independent risk factor for HCC. With the results from REVEAL-HBV, a risk calculation for predicting HCC in non-cirrhotic patients has been developed and validated by independent cohorts (Risk Estimation for Hepatocellular Carcinoma in Chronic Hepatitis B).Taken together, ample evidence indicates that HBsAg level can complement HBV-DNA level in predicting HCC development, especially in HBV carriers with low viral load. In conclusion, HBV treatment guidelines should include the risk stratification of HCC to individualize the management of HBV carriers with different levels of HCC risk.

Introduction of an automated system for the diagnosis and quantification of hepatitis B and hepatitis C viruses

Hepatitis B virus (HBV) and Hepatitis C virus (HCV) infections pose major public health problems because of their prevalence worldwide. Consequently, screening for these infections is an important part of routine laboratory activity. Serological and molecular markers are key elements in diagnosis, prognosis and treatment monitoring for HBV and HCV infections. Today, automated chemiluminescence immunoassay (CLIA) analyzers are widely used for virological diagnosis, particularly in high-volume clinical laboratories. Molecular biology techniques are routinely used to detect and quantify viral genomes as well as to analyze their sequence; in order to determine their genotype and detect resistance to antiviral drugs. Real-time PCR, which provides high sensitivity and a broad dynamic range, has gradually replaced other signal and target amplification technologies for the quantification and detection of nucleic acid. The next-generation DNA sequencing techniques are still restricted to research laboratories.The serological and molecular marker methods available for HBV and HCV are discussed in this article, along with their utility and limitations for use in Chronic Hepatitis B (CHB) diagnosis and monitoring.

High false-negative rate of anti-HCV among Egyptian patients on regular hemodialysis

Routine serological testing for hepatitis C virus (HCV) infection among hemodialysis (HD) patients is currently recommended. A dilemma existed on the value of serology because some investigators reported a high rate of false-negative serologic testing. In this study, we aimed to detect the false-negative rate of anti-HCV among Egyptian HD patients. Seventy-eight HD patients, negative for anti-HCV, anti-HIV, and hepatitis B surface antigen, were tested for HCV RNA by reverse transcriptase polymerase chain reaction (RT-PCR). In the next step, the viral load was quantified by real-time PCR in RT-PCR-positive patients. Risk factors for HCV infection, as well as clinical and biochemical indicators of liver disease, were compared between false-negative and true-negative anti-HCV HD patients. The frequency of false-negative anti-HCV was 17.9%. Frequency of blood transfusion, duration of HD, dialysis at multiple centers, and diabetes mellitus were not identified as risk factors for HCV infection. The frequency of false-negative results had a linear relation to the prevalence of HCV infection in the HD units. Timely identification of HCV within dialysis units is needed in order to lower the risk of HCV spread within the HD units. The high false-negative rate of anti-HCV among HD patients in our study justifies testing of a large scale of patients for precious assessment of effectiveness of nucleic acid amplification technology testing in screening HD patient.

Occult infection with hepatitis C virus: friend or foe?

Hepatitis C virus (HCV) infection is a global pandemic associated with a growing disease burden due to cirrhosis and the consequent morbidity and mortality. Transmission is largely via blood-to-blood contact. Following primary infection, a minority of individuals clear the infection predominantly via cellular immune mechanisms, whereas the majority become chronically infected. Recent data suggest that a third outcome may also be possible, termed 'occult' infection in which subjects who are known, or suspected to have previously been infected with HCV, no longer have viral RNA in their serum at levels detectable by sensitive commercial assays, but do have virus detected by ultra-sensitive techniques. Occult infection has also been detected in peripheral blood mononuclear cells, which may indicate an extra-hepatic reservoir of the virus. Although the clinical significance of occult infection remains unknown, most authors have raised concerns of recrudescent infection. Here we critically review the published literature, suggest further avenues of investigation and propose that occult infection may be beneficial to the host by maintaining immunological memory to protect against reinfection.

The clinical and laboratory characteristics of patients with chronic hepatitis B using current or past antiviral therapy in Korea: a multi-center, nation-wide, cross-sectional epidemiologic study

Background/Aims

The proper assessment of the current disease status of patients with chronic hepatitis B would be valuable for establishing optimal management strategies.

Methods

The clinical and laboratory characteristics of 2,954 patients with current or previous antiviral treatment (46.2±10.8 years, 69.7% male) enrolled from 46 referral hospitals and 129 local hospitals or clinics throughout Korea were analyzed.

Results

The disease status included chronic hepatitis, cirrhosis, and hepatocellular carcinoma in 79.9%, 16.4%, and 3.7% of the patients, respectively. The major mode of hepatitis B virus (HBV) infection was vertical transmission. The hepatitis C virus (HCV) co-infection rate was 1.5%; however, only 50.8% of patients were evaluated for HCV. The use of herbal or complementary medicines was reported in 33.5% of the patients. The majority of patients (97.6%) were treated with oral nucleoside/nucleotide analogues. Several characteristics were different between the patients treated at referral hospitals and local hospitals/clinics, including the disease state, choice of antiviral drug, and methods of HBV DNA measurement.

Conclusions

This study provides a comprehensive picture of the clinical and laboratory characteristics of patients treated in Korea. Efforts to optimize management strategies are warranted.

Incidence of CMV-HCV coinfection in renal transplant recipient

The authors report a case of a 47-year-old cytomegalovirus (CMV) immunoglobulin G (IgG) seropositive male patient with end stage renal disease who received a live renal transplant from a CMV IgG seropositive donor. Six months post-transplantation, the patient presented with reduced renal allograft function associated with fever, severe breathlessness, new onset jaundice and pancytopenia. His CMV DNA PCR came positive. Hepatitis C virus (HCV) RNA PCR also came positive (genotype I) though anti-HCV test performed before and after transplantation was negative. The patient was treated with oral valganciclovir and showed improvement of his clinical condition and was subsequently discharged under supervised therapy. However, the patient could not be treated for HCV because of risk of renal allograft rejection. The authors suggest oral valganciclovir for management of CMV infection and proper detection and eradication of HCV before renal transplantation to avoid future complications and prolongation of allograft survival.

Performance characteristics and comparison of Abbott and artus real-time systems for hepatitis B virus DNA quantification

Virological monitoring of hepatitis B virus (HBV) DNA is critical to the management of HBV infection. With several HBV DNA quantification assays available, it is important to use the most efficient testing system for virological monitoring. In this study, we evaluated the performance characteristics and comparability of three HBV DNA quantification systems: Abbott HBV real-time PCR (Abbott PCR), artus HBV real-time PCR with QIAamp DNA blood kit purification (artus-DB), and artus HBV real-time PCR with the QIAamp DSP virus kit purification (artus-DSP). The lower limits of detection of these systems were established against the WHO international standards for HBV DNA and were found to be 1.43, 82, and 9 IU/ml, respectively. The intra-assay and interassay coefficients of variation of plasma samples (1 to 6 log(10) IU/ml) ranged between 0.05 to 8.34% and 0.16 to 3.48% for the Abbott PCR, 1.53 to 26.85% and 0.50 to 12.89% for artus-DB, and 0.29 to 7.42% and 0.94 to 3.01% for artus-DSP, respectively. Ninety HBV clinical samples were used for comparison of assays, and paired quantitative results showed strong correlation by linear regression analysis (artus-DB with Abbott PCR, r = 0.95; Abbott PCR with artus-DSP, r = 0.97; and artus-DSP with artus-DB, r = 0.94). Bland-Altman analysis showed a good level of agreement for Abbott PCR and artus-DSP, with a mean difference of 0.10 log(10) IU/ml and limits of agreement of -0.91 to 1.11 log(10) IU/ml. No genotype-specific bias was seen in all three systems for HBV genotypes A, C, and D, which are predominant in this region. This finding illustrates that the Abbott real-time HBV and artus-DSP systems show more comparable performance than the artus-DB system, meeting the current guidelines for assays to be used in the management of hepatitis B.

An early decrease in serum HBeAg titre is a strong predictor of virological response to entecavir in HBeAg-positive patients

Quantification of HBeAg levels has been found to be useful in monitoring and predicting the outcomes of interferon and lamivudine treatment in HBeAg-positive patients. The aim of this study was to determine whether quantification of HBeAg at baseline and on treatment could predict which patients would achieve HBeAg seroconversion after 96 weeks of entecavir therapy. Sixty-five HBeAg-positive naïve chronic hepatitis B patients who were treated with entecavir at a dose of 0.5 mg once daily for 96 weeks were evaluated. Serum HBV DNA levels were assessed at baseline, week 24, 48 and 96; serum HBeAg levels were assessed at baseline, week 12, 24, 48, 72 and 96. Serum HBeAg levels were associated with a higher likelihood of HBeAg seroconversion to entecavir at weeks 96 than serum HBV DNA levels both at baseline and on treatment (at baseline: OR = 9.932, P = 0.003 vs. OR = 5.045, P = 0.036; on treatment: OR = 112.5, P < 0.0001 vs. OR = 47.782, P < 0.0001). A maintained reduction in HBeAg > 65% of pretreatment HBeAg values after 24 weeks of entecavir therapy is the strongest predictor for HBeAg seroconversion at week 96 (OR = 70.578, P < 0.0001). Quantification of HBeAg at the start and early during therapy showed a higher predictive value than that of HBV DNA for HBeAg seroconversion by entecavir. A significant decrease in serum HBeAg levels at week 24 may be a useful on-treatment measurement in the early phase for predicting HBeAg seroconversion and identifying patients who will most likely benefit from finite entecavir treatment.

Rapid detection of hepatitis C virus RNA by a reverse transcription loop-mediated isothermal amplification assay

The usefulness of reverse transcription loop-mediated isothermal amplification (RT-LAMP) for the rapid diagnosis of hepatitis C virus (HCV) RNA was evaluated. This assay showed higher sensitivities than that of nested RT-PCR, with a detection limit of 600 IU mL(-1) , and no cross-reactivity was observed with hepatitis A virus, hepatitis B virus and hepatitis E virus. Furthermore, 106 stored sera from recently diagnosed cases were retrospectively investigated with real-time RT-PCR, the nested RT-PCR, in parallel with this new assay. The general detection rates of HCV RT-LAMP, real-time PCR and the nested RT-PCR for 106 stored sera samples were 95%, 96% and 88%, respectively. This study provides the first data on the usefulness of HCV RT-LAMP in the diagnosis of HCV RNA, especially in the early clinical diagnosis of acute HCV infection.

Development of a new duplex real-time polymerase chain reaction assay for hepatitis B viral DNA detection

BACKGROUND

Quantification of hepatitis B virus (HBV) DNA can be used for diagnosing HBV infection and monitoring the effect of antiviral therapy. However, probably because of mismatches between the template and primer/probe, HBV DNA in some HBV infections could not be detected using currently available commercial assays with single primer/probe. By aligning the HBV sequences, we developed a duplex real-time polymerase chain reaction (PCR) assay using two sets of primers/probes and a specific armored DNA as internal control (IC).

RESULTS

The limit of the duplex real-time PCR assay was 29.5 IU/ml, whereas the specificity was 100%. The within-run precision coefficient of variation (CV) ranged from 1.02% to 2.73%, while the between-run CV ranged from 0.83% to 1.25%. The optimal concentration of armored DNA IC in the HBV DNA duplex real-time PCR assay was 1 000 copies/ml. Data from 69 serum samples with HBV infection showed that the performance of the duplex real-time PCR assay was comparable to that of the COBAS Ampliprep/Cobas Taqman (CAP/CTM) HBV assay and was superior to those of the domestic commercial HBV assays.

CONCLUSIONS

The duplex real-time PCR assay is sufficiently sensitive, specific, accurate, reproducible and cost-effective for the detection of HBV DNA. It is suitable for high throughput screening and frequent HBV DNA level monitoring.