Change of hepatitis B virus genotypes in acute and chronic infections in Japan

Acute and chronic HBV infection in central Argentina: High frequency of sub-genotype F1b, low detection of clinically relevant mutations and first evidence of HDV

Introduction

Genomic analysis of hepatitis B virus (HBV) identifies phylogenetic variants, which may lead to distinct biological and clinical behaviors. The satellite hepatitis D virus (HDV) may also influence clinical outcomes in patients with hepatitis B. The aim of this study was to investigate HBV genetic variants, including clinically relevant mutations, and HDV infection in acute and chronic hepatitis B patients in central Argentina.

Methods

A total of 217 adult HBV infected patients [acute (AHB): n = 79; chronic (CHB): n = 138] were studied; 67 were HBV/human immunodeficiency virus (HIV) coinfected. Clinical and demographic data were obtained from medical records. Serological markers were determined. Molecular detection of HBV and HDV was carried out by RT-Nested PCR, followed by sequencing and phylogenetic analysis.

Results

Overall, genotype (gt) F [sub-genotype (sgt) F1b] was the most frequently found. In AHB patients, the gts/sgts found were: F1b (74.7%) > A2 (13.9%) > F4 (7.6%) > C (2.5%) > A1 (1.3%). Among CHB patients: F1b (39.1%) > A2 (23.9%) > F4 (18.2%) > D (9.4%) > C and F6 (3.6% each) > A1, A3 and B2 (0.7% each). The distribution of sgt A2 and gt D was significantly different between HBV mono and HBV/HIV coinfected patients [A2: 15.9% vs. 35.7% (p < 0.05), respectively and D: 14.6% vs. 1.8% (p < 0.05), respectively]. Mutation frequency in basal core promoter/pre-Core (BCP/pC) region was 35.5% (77/217) [AHB: 20.3% (16/79), CHB: 44.2% (61/138)]. In the open reading frame (ORF) S, mutations associated with vaccine escape and diagnostic failure were detected in 7.8% of the sequences (17/217) [AHB: 3.8% (3/79), CHB: 10.1% (14/138)]. ORF-P amino acid substitutions associated with antiviral resistance were detected in 3.2% of the samples (7/217) [AHB: 1.3% (1/79), CHB 4.3%, (6/138)]. The anti-HDV seropositivity was 5.2% (4/77); one sample could be sequenced, belonging to gt HDV-1 associated with sgt HBV-D3.

Discussion

We detected an increase in the circulation of genotype F in Central Argentina, particularly among AHB patients, suggesting transmission advantages over the other genotypes. A low rate of mutations was detected, especially those with antiviral resistance implications, which is an encouraging result. The evidence of HDV circulation in our region, reported for the first time, alerts the health system for its search and diagnosis.

Viral Kinetics of an Acute Hepatitis B Virus Subgenotype F1b Infection in a Mexican Subject

Content available: Author Interview and Audio Recording.

Factors influencing the durability of hepatitis B vaccine responses

The World Health Organization recommends the implementation of universal hepatitis B (HB) vaccination, and global coverage for this vaccine reached 84% in 2015. In Japan, the policy aimed at preventing mother-to-child transmission of HB virus (HBV) initially commenced as a specific vaccination program for infants born to mothers who were positive for HB surface antigen. In 2016, universal HB vaccination was implemented in this country to cover unvaccinated individuals at risk of horizontal HBV transmission. Although HB vaccination has been shown to be highly efficacious and safe, the issues of vaccine non-responders and of the loss of antibodies directed against HB surface antigen (anti-HBs) in HB vaccine recipients remain. To gain better insight into these problems, we previously performed an immunological analysis on adult vaccine recipients after they received an initial HB vaccination. We found that the course of successful HB vaccination is composed of the following distinct phases: 1) acquisition of anti-HBs antibody, 2) attainment of high anti-HBs antibody titers, and 3) maintenance of acquired anti-HBs antibody levels. In this review, we describe the significance of HB vaccination and suggest a potential means of improving the impact of HB vaccination based on our immunological analysis.

Estimating the proportion of people with chronic hepatitis B virus infection eligible for hepatitis B antiviral treatment worldwide: a systematic review and meta-analysis

BACKGROUND

In 2016, of the estimated 257 million people living with chronic hepatitis B virus (HBV) infection worldwide, only a small proportion was diagnosed and treated. The insufficiency of information on the proportion of people infected with HBV who are eligible for treatment limits the interpretation of global treatment coverage. We aimed to estimate the proportion of people with chronic HBV infection who were eligible for antiviral treatment worldwide, based on the WHO 2015 guidelines.

METHODS

In this systematic review and meta-analysis, we searched Medline, EMBASE, and the Cochrane databases from Jan 1, 2007, to Jan 31, 2018, for studies describing HBsAg-positive people in the population or health-care facilities. We extracted information from published studies using a standardised form to estimate the frequency of cirrhosis, abnormal alanine aminotransferase (ALT), HBV DNA exceeding 2000 IU/mL or 20 000 IU/mL, presence of HBeAg, and eligibility for treatment as per WHO and other guidelines as reported in the studies. We pooled proportions through meta-analysis with random effects. The study was registered with PROSPERO, CRD42020132345.

FINDINGS

Of the 13 497 studies, 162 were eligible and included in our analysis. These studies included 145 789 participants. The pooled estimate of the proportion of cirrhosis was 9% (95% CI 8-10), ranging from 6% (4-8) in community settings to 10% (9-11) in clinic settings. Examining the proportion of participants who had characteristics used to determine eligibility in the WHO guidelines, 1750 (10·1%) of 17 394 had HBV DNA exceeding 20 000 IU/mL, and 20 425 (30·8%) of 66 235 had ALT above the upper limit of normal. 32 studies reported eligibility for treatment according to WHO or any other guidelines, with a pooled estimate of eligibility at 19% (95% CI 18-20), ranging from 12% (6-18) for studies in community settings to 25% (19-30) in clinic settings.

INTERPRETATION

Many studies described people with HBV infection, but few reported information in a way that allowed assessment of eligibility for treatment. Although about one in ten of the 257 million people with HBV infection (26 million) might be in urgent need of treatment because of cirrhosis, a larger proportion (12-25%) is eligible for treatment in accordance with different guidelines. Future studies describing people with HBV infection should report on treatment eligibility, according to broadly agreed definitions.

FUNDING

WHO and US Centers for Disease Control and Prevention.

Countermeasures against viral hepatitis B and C in Japan: An epidemiological point of view

Although the mortality rate due to hepatocellular carcinoma (HCC) has been gradually decreasing in Japan, approximately 30 000 people died of HCC in 2016. In 2007, the dominant etiology was persistent hepatitis C virus (HCV) infection, which accounted for 65% of total HCC deaths, and 15% of cases were due to chronic hepatitis B virus (HBV) infection. In managing chronic HBV and HCV infection, it is critically important to know the exact number of infected individuals in a particular country, which then assists in evaluating medical and financial needs in the foreseeable future. Therefore, from an epidemiological perspective, we estimated the numbers of HBV and HCV carriers in four categories: (i) undiagnosed carriers; (ii) carriers who were already hospitalized as patients or were receiving outpatient medical attention; (iii) diagnosed carriers who had not consulted any medical facility, or had discontinued consultation; and (iv) newly infected carriers. From these estimates we determined the current HBV and HCV burden and then reviewed the existing countermeasures for their prevention and control in Japan. While continuing the surveillance on the dynamics of hepatitis virus infections linked with preventive measures against hepatitis virus infection, it is crucially important to promote appropriate measures for each of the four groups of hepatitis virus carriers in society.

Evaluation of in vitro screening and diagnostic kits for hepatitis B virus infection

BACKGROUND

For the diagnosis of hepatitis B virus (HBV) infection, the detection and quantification of hepatitis B surface antigen (HBsAg) and HBV DNA are used. Several kits are available for this purpose, and there is a growing need for the evaluation of these kits because their performance may be affected by HBV genotype- or strain-specific polymorphisms.

OBJECTIVES AND STUDY DESIGN

In this study, we used International Standards and the established regional reference panel to evaluate the performance of two HBV DNA quantitative kits, five HBsAg qualitative kits, seven HBsAg quantitative kits and three rapid immune-chromatographic tests for HBsAg.

RESULTS

The quantification values of two HBV DNA quantitative kits exhibited excellent correlation. In the evaluation of HBsAg qualitative and quantitative kits, the titers of several specimens in the HBV-positive panel were below the detection limits of a few kits, and the specimens were determined as HBV-negative. Notably, the quantitative kit results exhibited low correlation values. However, when these data were analyzed for each genotype, the correlations improved. These results suggest that the HBsAg quantification data are influenced by HBV genotypes. The novel rapid immune-chromatographic test exhibited the comparable level of sensitivity to the HBsAg quantitative kits.

CONCLUSIONS

We evaluated the performance of kits for the detection of HBV infection. The HBV DNA quantification data correlated with an excellent agreement, whereas the HBsAg quantification data were affected by HBV genotype. Such evaluations will be useful for estimating the quality of currently available and new HBV assay kits, and for the quality control of these kits.

Hepatitis B Vaccination Status among Japanese Travelers

This study clarified the characteristics of travelers who received hepatitis B vaccinations. Subjects were 233 Japanese travelers who visited our clinic prior to travel. We summarized the characteristics of the clients and performed two comparative studies: first, we compared a hepatitis B-vaccinated group with an unvaccinated group; second, we compared a group that had completed the hepatitis B vaccine series with a group that did not complete the series. The hepatitis B vaccine was administered to 152 clients. Factors positively associated with the hepatitis B vaccination (after adjusting for age and sex) included the following: travel for business or travel as an accompanying family member; travel to Asia; travel for a duration of a month or more; and, inclusion of the vaccine in a company or organization's payment plan. Meanwhile, factors negatively associated with the vaccination were travel for leisure or education, and travel to North America or Africa. Among 89 record-confirmed cases, only 53 completed 3 doses. The completion rate was negatively associated with the scheduled duration of travel if it was from a month to less than a year (after adjusting for age and sex). The present study provides a basis for promoting vaccination compliance more vigorously among Japanese adults.

Clinical characteristics and molecular analysis of hepatitis B virus reactivation in hepatitis B surface antigen-negative patients during or after immunosuppressive or cytotoxic chemotherapy

BACKGROUND AND AIM

Reactivation of hepatitis B virus (HBV) in hepatitis B surface antigen (HBsAg)-positive patients treated with immunosuppressive or cytotoxic chemotherapy is well known and has emerged as an important clinical issue. The risk is low, but reactivation of HBV in HBsAg-negative patients after resolution of HBV infection also occurs; however, the clinical and virological characteristics remain somewhat unclear. We investigated HBsAg-negative patients who developed HBV reactivation during or after immunosuppressive or cytotoxic chemotherapy to clarify the clinical and virological features.

METHODS

Reactivation of HBV in 30 previously infected that is HBsAg-negative patients during or after immunosuppressive or cytotoxic chemotherapy was examined. Direct sequencing at the time of reactivation was used to evaluate 11 patients.

RESULTS

The majority of patients had diffuse large B cell lymphoma treated by rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisolone. Fulminant hepatic failure developed in three patients, who did not survive. HBV subgenotypes A2/Ae (n = 1), B1/Bj (n = 2), and C2/Ce (n = 8) were detected. There were no significant differences in the prevalence of BCP/PC variants between HBV reactivation and acute self-limited hepatitis patient groups. BCP and PC variants were not associated with development of fulminant hepatic failure from HBV reactivation. The prevalence of HBV S region variants, including immune-escape mutants, among reactivation patients was significantly higher than that in acute self-limited hepatitis patients.

CONCLUSIONS

Reactivation risk factors included male sex, advanced age, and hematological malignancy. HBV S gene immune-escape mutants were frequently found in the HBsAg-negative reactivation patients during or after immunosuppressive or cytotoxic chemotherapy.

Analysis of the Molecular Evolution of Hepatitis B Virus Genotypes in Symptomatic Acute Infections in Argentina

Hepatitis B virus (HBV) is a globally distributed human pathogen that leads to both self-limited and chronic infections. At least eight genotypes (A-H) with distinct geographical allocations and phylodynamic behaviors have been described. They differ substantially in many virological and probably some clinical parameters. The aim of this study was to analyze full-length HBV genome sequences from individuals with symptomatic acute HBV infections using phylogenetic and coalescent methods. The phylogenetic analysis resulted in the following subgenotype distribution: F1b (52.7%), A2 (18.2%), F4 (18.2%) and A1, B2, D3 and F2a 1.8% each. These results contrast with those previously reported from chronic infections, where subgenotypes F1b, F4, A2 and genotype D were evenly distributed. This differential distribution might be related to recent internal migrations and/or intrinsic biological features of each viral genotype that could impact on the probability of transmission. The coalescence analysis showed that after a diversification process started in the 80s, the current sequences of subgenotype F1b were grouped in at least four highly supported lineages, whereas subgenotype F4 revealed a more limited diversification pattern with most lineages without offspring in the present. In addition, the genetic characterization of the studied sequences showed that only two of them presented mutations of clinical relevance at S codifyng region and none at the polymerase catalytic domains. Finally, since the acute infections could be an expression of the genotypes currently being transmitted to new hosts, the predominance of subgenotype F1b might have epidemiological, as well as, clinical relevance due to its potential adverse disease outcome among the chronic cases.

The Hepatitis B Virus Genotype Affects the Persistence of Viral Replication in Immunodeficient NOG Mice

Background & Aims

At least eight genotypes of Hepatitis B virus (HBV) have been identified. HBV genotype C is the most common genotype in Japan, although the incidence of HBV genotype A is increasing. The reason underlying the differences in viral multiplication of the HBV genotypes is unclear, especially in vivo. The purpose of this study was to elucidate the differences in HBV load and the persistence of viremia in vivo between genotypes A and C.

Methods

Immunodeficient NOG mice were transfected by hydrodynamic injection with the HBV expression plasmids pHBA1.2 or pHBC1.2, which contain overlength (1.2-mer) copies of the genomes of HBV genotype A or C, respectively.

Results

One day after transfection, the number of HBcAg-positive hepatocytes and serum HBV DNA levels were similar between mice transfected with pHBA1.2 and pHBC1.2. Serum levels of HBV DNA, HBsAg and HBeAg in mice transfected with pHBA1.2 were maintained over 5 months. In contrast, those in mice with pHBC1.2 gradually decreased over time and reached undetectable levels within 3 months after transfection. HBcAg-stained hepatocytes were detected in mice transfected with pHBA1.2, but not pHBC1.2, 5 months post-transfection. Double-staining immunohistochemistry revealed that the number of cleaved caspase3-stained, HBcAg-positive hepatocytes in the pHBC1.2-transfected mice was higher than in the pHBA1.2-transfected mice 3 days post-transfection. Moreover, the plasmid DNA and covalently closed circular DNA levels were decreased in the livers of pHBC1.2-transfected mice. These results suggested that hepatocytes expressing HBV genotype C were eliminated by apoptosis in the absence of immune cells more often than in hepatocytes expressing HBV genotype A.

Conclusions

Immunodeficient mice transfected with HBV genotype A develop persistent viremia, whereas those transfected with HBV genotype C exhibit transient viremia accompanied by apoptosis of HBV-expressing hepatocytes. This differences may affect the clinical courses of patients infected with HBV genotypes A and C.

Characterization of Acute and Chronic Hepatitis B Virus Genotypes in Canada

Objective

The prevalence and distribution of hepatitis B virus (HBV) genotypes in Canada is not known. Genotypic analysis may contribute to a better understanding of HBV strain distribution and transmission risk.

Methods

HBV surface antigen (HBsAg) positive samples of acute (n = 152) and chronic (n = 1533) HBV submitted for strain analysis or reference genotype testing between 2006 and 2012 were analyzed. The HBsAg coding region was amplified to determine the HBV genotype by INNO-LiPA assay or sequence analysis. Single and multivariate analyses were used to describe genotypes’ associations with known demographic and behavioral risk factors for 126 linked cases of acute HBV.

Results

Nine genotypes were detected (A to I), including mixed infections. Genotype C (HBV/C) dominated within chronic infections while HBV/D and A prevailed among acute HBV cases. History of incarceration and residing with a chronic HBV carrier or injection drug user were the most frequently reported risks for acute HBV infection. Over time, HBV/A increased among both acute and chronic infections, and HBV/C and HBV/D decreased among chronic infections.

Conclusion

Chronic and acute HBV genotypes in Canada differ in the relative distribution and their associations with known risk factors, suggesting different routes of transmission and clinical progression of infection.

Identification of Novel Recombinant Forms of Hepatitis B Virus Generated from Genotypes Ae and G in HIV-1-Positive Japanese Men Who Have Sex with Men

The rare hepatitis B virus (HBV) genotype G (HBV/G) coinfects HIV-1-positive individuals along with HBV/A and generates recombinants. However, the circulation of HBV A/G recombinants remains poorly understood. This molecular epidemiologic study examined HBV A/G recombinants in Japanese HIV-1-positive men who have sex with men (MSM). Initially, blood specimens submitted for confirmatory tests of HIV infection in Osaka and Tokyo, Japan, from 2006 to 2013 were examined for HIV-1, and HIV-1-positive specimens were screened for HBV. Among 817 specimens from HIV-1-positive individuals, HBsAg was detected in 59 specimens; of these, HBV/Ae (alternatively A2), a subgenotype of HBV/A prevalent in Europe and North America, was identified in 70.2%, HBV/C in 17.5%, and HBV/G in 10.5%, and HBV/E in 1.8% according to the core gene sequence. The full-length genome analysis of HBV was performed on HBV/G-positive specimens because some HBV A/G recombinants were historically overlooked by genotyping based on a partial genome analysis. It revealed that five of the specimens contained novel Ae/G recombinants, the core gene of which had a high sequence similarity to HBV/G. Detailed analyses showed that novel recombinants were coinfected with HBV/Ae in a recombinant-dominant fashion. No major drug-resistant mutations were found in the newly identified HBV Ae/G recombinants. Some of the individuals asymptomatically coinfected with HIV/HBV suffered mild liver injury. This study demonstrated that novel Ae/G HBV recombinants were identified in Japanese HIV-1-positive MSM. The pathogenicity of novel HBV Ae/G recombinants should be examined in a future longitudinal study. Surveillance of such viruses in HIV-1-positive individuals should be emphasized.

Analysis of HBV genotype, drug resistant mutations, and pre-core/basal core promoter mutations in Korean patients with acute hepatitis B

Acute hepatitis B, caused by hepatitis B virus (HBV) strains with drug resistant mutations or pre-core/basal core promoter (PC/BCP) mutations, is a public health concern, because this infection is often associated with poor disease outcome or difficulty in therapeutic choice. The HBV genotype, the prevalence of drug resistant mutations, and PC/BCP mutations in Korean patients with acute hepatitis B were studied. From 2006 to 2008, 36 patients with acute hepatitis B were enrolled prospectively in four general hospitals. Among them, 20 showed detectable HBV DNA (median value was 4.8 log copies/mL). HBV genotyping and analysis of HBV mutations that conferred resistance against lamivudine, adefovir, or entecavir and of PC/BCP mutations were performed using highly sensitive restriction fragment mass polymorphism (RFMP) analysis. All 20 patients were infected with HBV genotype C, which causes almost all cases of chronic hepatitis B in Korea. No patient showed mutations that conferred resistance against lamivudine (L180M, M204V/I), adefovir (A181T, N236S), or entecavir (I169M, A184T/V, S202I/G, M250V/I/L). However, four patients had BCP mutations, and two had PC mutations. Platelet counts were significantly lower in the four patients with PC/BCP mutations compared to those with wild type. In this study, all acute hepatitis B patients had genotype C HBV strains with no drug resistant mutations. However, 20% showed PC/BCP mutations. This highlights the need for further study on the significance of PC/BCP mutations.

Estimating numbers of persons with persistent hepatitis B virus infection transmitted vertically and horizontally in the birth cohort during 1950-1985 in Japan

AIM

We estimated numbers of persons, born between 1950 and 1985 in Japan, who were persistently infected with hepatitis B virus (HBV) through vertical and horizontal infections.

METHODS

HBV carrier rates with vertical and horizontal infections were computed using sex- and age-specific prevalence rates of hepatitis B surface antigen (HBsAg) and hepatitis B e-antigen (HBeAg) by mathematical model. Probabilities of vertical HBV transmission in babies born to carrier mothers with and without HBeAg were presumed to be 90% and 10%, respectively.

RESULTS

HBV carrier rates with vertical infection stayed contrast at approximately 0.3% in birth cohorts through 36 years (1950-1985), both in men and women. By a remarkable constant, HBV carrier rates with horizontal infection decreased steadily from 1.43% to 0.10% in men and from 0.95% to 0.03% in women. The estimated total number of HBV carriers born between 1950 and 1985 was 522 500 (355 488-693 606). Of them, the numbers of HBV carriers with vertical and horizontal infections were 197 574 (149 505-288 709) and 324 926 (205 983-404 896); they accounted for 37.81% and 62.19%, respectively, with a ratio of 1:1.64. The ratio between vertical and horizontal infections was 1:2.20 in men and 1:1.06 in women.

CONCLUSION

Vertical HBV infection had stayed constant until immunoprophylaxis of mother-to-baby transmission was implemented in 1986 in Japan. In contrast, horizontal HBV infection decreased over years. The decrease would be due to many factors, including improved socioeconomic environments, advanced medical maneuvers and equipment, and careful vaccination procedures.

Risk factors for long-term persistence of serum hepatitis B surface antigen following acute hepatitis B virus infection in Japanese adults

The proportion of patients who progress to chronicity following acute hepatitis B (AHB) varies widely worldwide. Moreover, the association between viral persistence after AHB and hepatitis B virus (HBV) genotypes in adults remains unclear. A nationwide multicenter study was conducted throughout Japan to evaluate the influence of clinical and virological factors on chronic outcomes in patients with AHB. For comparing factors between AHB patients with viral persistence and those with self-limited infection, 212 AHB patients without human immunodeficiency virus (HIV) coinfection were observed in 38 liver centers until serum hepatitis B surface antigen (HBsAg) disappeared or a minimum of 6 months in cases where HBsAg persisted. The time to disappearance of HBsAg was significantly longer for genotype A patients than that of patients infected with non-A genotypes. When chronicity was defined as the persistence of HBsAg positivity for more than 6 or 12 months, the rate of progression to chronicity was higher in patients with genotype A, although many cases caused by genotype A were prolonged cases of AHB, rather than chronic infection. Multivariate logistic regression analysis revealed only genotype A was independently associated with viral persistence following AHB. A higher peak level of HBV DNA and a lower peak of alanine aminotransferase (ALT) levels were characteristics of AHB caused by genotype A. Treatment with nucleotide analogs (NAs) did not prevent progression to chronic infection following AHB overall. Subanalysis suggested early NA initiation may enhance the viral clearance.

CONCLUSION

Genotype A was an independent risk factor for progression to chronic infection following AHB. Our data will be useful in elucidating the association between viral persistence after AHB, host genetic factors, and treatment with NAs in future studies.

Causes of vertical transmission of hepatitis B virus under the at-risk prevention strategy in Japan

The number of hepatitis B virus (HBV) carrier babies has decreased markedly since the introduction in Japan of an "at-risk" strategy for preventing HBV infection. However, elimination of HBV infection from our country appears difficult. To clarify the limitations of the at-risk strategy for preventing vertical transmission of HBV, causes of vertical transmission in a single hospital were retrospectively analyzed. The following causes were presumed in 17 carrier pediatric cases: five patients had prenatal HBV infection, HBV infection during/after the immunization program was confirmed in five cases, two patients had prenatal infection or infection during the immunization program and three cases were caused by human error (by the patients' guardians). Because their mothers were HBV-negative at screening and only developed acute hepatitis B in the perinatal period, another two cases (Cases 3 and 10) did not undergo immunization because they were not subjects of the at-risk strategy. Sequence analyses in ten patients revealed genotype C (subgenotype, C2/Ce) in nine cases and genotype A (subgenotype, A2/Ae) in one case (Case 3). In Japan, HBV subgenotype Ae has recently been found more frequently among sexually active men with acute hepatitis. There are concerns that horizontal transmission of HBV from these men to their pregnant partners could increase. These data suggest clear limitations to the at-risk strategy in Japan and the possibility that the increase in genotype A may influence vertical transmission of HBV.

Degenerate polymerase chain reaction strategy with DNA microarray for detection of multiple and various subtypes of virus during blood screening

BACKGROUND

The risk of transferring blood-borne infections during transfusion is continually increasing because of newly emerging and reemerging viruses. Development of a rapid screening method for emerging viruses that might be transmitted by transfusion is required to eliminate such pathogens during blood donor screening. Owing to increased use of human materials in organ transplants and cell therapy, the risk of donor-transmitted viral infections is also increasing. Although nucleic acid amplification technology (NAT) is dedicated to blood screening, a small, convenient detection system is needed at the laboratory and hospital level.

STUDY DESIGN AND METHODS

We developed a new pathogen detection system that can detect multiple viruses simultaneously, using originally designed degenerate polymerase chain reaction primers to amplify a wide range of viral genotypes. Amplified samples were identified using a DNA microarray of pathogen-specific probes.

RESULTS

We detected very low copy numbers of multiple subtypes of viruses, such as human hepatitis C virus (HCV), human hepatitis B virus (HBV), human parvovirus B19 (PVB19), and West Nile virus (WNV), using a single plate. We also detected all genotypes of human immunodeficiency virus (HIV) but sensitivity was less than for the other viruses.

CONCLUSION

We developed a microarray assay using novel primers for detection of a wide range of multiple pathogens and subtypes. Our NAT system was accurate and reliable for detection of HIV, HBV, HCV, PVB19, and WNV, with respect to specificity, sensitivity, and genotype inclusivity. Our system could be customized and extended for emerging pathogens and is suitable as a future NAT system.

Prophylactic effect of antiretroviral therapy on hepatitis B virus infection

BACKGROUND

Hepatitis B virus (HBV) infection is common in individuals infected with human immunodeficiency virus, especially in men who have sex with men (MSM). Almost all currently used regimens of antiretroviral therapy (ART) contain lamivudine (LAM) or tenofovir disoproxil fumarate (TDF), both of which have significant anti-HBV activity. However, the prophylactic effect of ART on HBV infection has not been assessed previously.

METHODS

Non-HBV-vaccinated HIV-infected MSM were serologically evaluated for HBV infection using stocked serum samples. Cases negative for HBV surface antigen (HBsAg), antibody to HBsAg (anti-HBs), and antibody to HBV core antigen (anti-HBc) in first serum samples were serologically followed until last available stocked samples. HBV genotype and LAM-resistant mutation (rtM204V/I) were analyzed in cases that became HBsAg-positive.

RESULTS

The first stocked samples were negative for all analyzed HBV serological markers in 354 of 1434 evaluated patients. The analysis of their last samples indicated HBV incident infection in 43 of them during the follow-up period. The rate of incident infections was lower during LAM- or TDF-containing ART (0.669 incident infections in 100 person-years) than during no ART period (6.726 incident infections in 100 person-years) and other ART (5.263 incident infections in 100 person-years) (P < .001). Genotype A was most prevalent (76.5%), and LAM-resistant HBV was more frequent in incident infections during LAM-containing ART (50.0%) than in those during no ART and other ART (7.1%) (P = .029).

CONCLUSIONS

LAM- and TDF-containing ART regimens seem to provide prophylaxis against HBV infection, although drug-resistant strains seem to evade these effects.

Prevalence and epidemiological traits of HIV infections in populations with high-risk behaviours as revealed by genetic analysis of HBV

The prevalence and epidemiological traits of human immunodeficiency virus (HIV)/hepatitis B virus (HBV) infections in high-risk populations (HRPs) remained unclarified in Japan. We determined the prevalence of HIV, HBV and Treponema pallidum (TP) and the viral genotypes in HRPs who attended primary sexually transmitted infection (STI) clinics in Osaka province during 2006-2011. Of 7898 specimens, 133 (1·7%) were HIV positive, which was significantly higher than the figures reported by Japanese Red Cross (0·0019%) and public health centres (0·27%) in Japan. The frequency of HIV-1 subtype B was 88·7%, followed by CRF01_AE (2·3%) and C (0·8%), which were almost identical to the national trend. HBV seroprevalence was surprisingly high in the HIV-positive group (63·2%), which was significantly higher than that in the HIV-negative group (25·6%). By contrast, there was no statistical correlation between HIV and TP infection. Interestingly, the distinct HBV genotypes Ae and G were prevalent in the HIV-positive population (60·0% and 20·0%, respectively), although both were rarely detected during nationwide surveillance. The transmission of HIV and HBV appeared to occur largely within a closed community early in life. Of note, about one-quarter of HIV-positive cases would have remained untested if health professionals had not motivated individuals to undergo HIV testing. This is the first evidence-based assessment of HIV positivity and HIV/HBV co-infection in HRPs at primary STIs in Japan and the effect of the involvement of health professionals in the diagnosis of HIV infections in asymptomatic carriers. The genotyping of HBV provided valuable information for understanding HIV epidemical traits.

Determinants of the clinical outcome of patients with severe acute exacerbation of chronic hepatitis B virus infection

BACKGROUND

Severe acute exacerbation of chronic hepatitis B can sometimes occur and lead to hepatic failure and death. The objective of this study was to elucidate the predictors of progression to hepatic decompensation during severe acute exacerbation.

METHODS

We prospectively analyzed 37 consecutive patients with acute exacerbation of chronic hepatitis B (accompanied by jaundice and coagulopathy) for clinical outcome and factors that influenced the development of severe acute exacerbation, including viral kinetics.

RESULTS

Fourteen (37.8%) patients progressed to severe acute exacerbation (accompanied by encephalopathy). Multivariate analysis identified serum bilirubin (>5 mg/dl, P = 0.002) as a significant determinant of progression to hepatic failure and prothrombin activity (<45%, P = 0.028) and as a determinant of liver-related death. The hepatitis B virus (HBV) DNA level before therapy was measured in 25 patients. HBV DNA levels increased or did not change from before commencement of treatment in all 11 patients who progressed to severe acute exacerbation. On the other hand, HBV DNA levels did not change or increased in 8 of 14 patients (57%) with acute exacerbation (P = 0.02).

CONCLUSIONS

Serum bilirubin and prothrombin activities were significant predictors of clinical outcome in patients with severe acute exacerbation of chronic hepatitis B. Viral kinetics until commencement of therapy can predict the severity of acute exacerbation of chronic hepatitis B.

Genome-wide association study confirming association of HLA-DP with protection against chronic hepatitis B and viral clearance in Japanese and Korean

Hepatitis B virus (HBV) infection can lead to serious liver diseases, including liver cirrhosis (LC) and hepatocellular carcinoma (HCC); however, about 85–90% of infected individuals become inactive carriers with sustained biochemical remission and very low risk of LC or HCC. To identify host genetic factors contributing to HBV clearance, we conducted genome-wide association studies (GWAS) and replication analysis using samples from HBV carriers and spontaneously HBV-resolved Japanese and Korean individuals. Association analysis in the Japanese and Korean data identified the HLA-DPA1 and HLA-DPB1 genes with P_meta = 1.89×10⁻¹² for rs3077 and P_meta = 9.69×10⁻¹⁰ for rs9277542. We also found that the HLA-DPA1 and HLA-DPB1 genes were significantly associated with protective effects against chronic hepatitis B (CHB) in Japanese, Korean and other Asian populations, including Chinese and Thai individuals (P_meta = 4.40×10⁻¹⁹ for rs3077 and P_meta = 1.28×10⁻¹⁵ for rs9277542). These results suggest that the associations between the HLA-DP locus and the protective effects against persistent HBV infection and with clearance of HBV were replicated widely in East Asian populations; however, there are no reports of GWAS in Caucasian or African populations. Based on the GWAS in this study, there were no significant SNPs associated with HCC development. To clarify the pathogenesis of CHB and the mechanisms of HBV clearance, further studies are necessary, including functional analyses of the HLA-DP molecule.

An adult patient with acute infection with hepatitis B virus genotype C that progressed to chronic infection

In 2008, a 28-year-old woman consulted our hospital due to general fatigue. Her ALT level was within normal range but she was positive for hepatitis B surface antigen (HBsAg). Her ALT level was nearly within normal range thereafter and she was consistently positive for HBeAg. Later, it was proven that she was negative for HBsAg in 1999. She had been a sex worker in 2007-2008. Complete genome sequencing revealed that her HBV was genotype C. The present case may indicate that it is possible for acute infection with HBV genotype C to progress to chronic infection in adults.

Prevalence of HBV infection among different HIV-risk groups in Hai Phong, Vietnam

Hepatitis B virus (HBV) infection in Hai Phong, northern Vietnam, was characterized by analyzing the prevalence and genotype distribution of HBV as well as co-infection with human immunodeficiency virus type 1 (HIV-1) among five different risk groups for HIV infection. Plasma samples were collected from intravenous drug users (n=760, anti-HIV-1 antibody positive rate: 35.9%), female sex workers (FSWs; n=91, 23.1%), seafarers (n=94, 0%), pregnant women (n=200, 0.5%), and blood donors (n=210, 2.9%) in 2007 [Ishizaki et al. (2009): AIDS Res Hum Retroviruses 25:175-182]. Samples were screened for the hepatitis B surface antigen (HBsAg) and anti-HBs antibody and analyzed genetically. The cumulative HBV incidence rate (HBsAg+anti-HBs) was 53.2% (10.7+42.5%) in intravenous drug users, 51.6% (11.0+40.6%) in FSWs, 54.3% (9.6+44.7%) in seafarers, 50.5% (12.5+38.0%) in pregnant women, and 51.0% (18.1+32.9%) in blood donors; there was no significant difference among these groups. Of 163 HBsAg-positive samples, 113 could be analyzed genetically. Phylogenetic analysis, based on the preS1 region, revealed genotype B4 was most prevalent (90/113; 79.6%), followed by C1 (17.7%), I1 (1.8%), and B2 (0.9%). There was no significant difference in HBV genotype distribution among different HIV infection-risk groups. The prevalence of HBsAg was 10.3% (31/301) in HIV-1-infected individuals and 12.5% (132/1,054) in non-HIV-1-infected individuals, which was not significant. In addition, no significant difference in HBV genotype distribution was observed between HBV/HIV-1 coinfected and HBV mono-infected groups. These results suggest that, although HBV and HIV-1 share modes of transmission, major transmission routes of HBV have been different from those of HIV-1 in Hai Phong, Vietnam.

Easy-to-use phylogenetic analysis system for hepatitis B virus infection

AIM

  The molecular phylogenetic analysis has been broadly applied to clinical and virological study. However, the appropriate settings and application of calculation parameters are difficult for non-specialists of molecular genetics. In the present study, the phylogenetic analysis tool was developed for the easy determination of genotypes and transmission route.

METHODS

  A total of 23 patients of 10 families infected with hepatitis B virus (HBV) were enrolled and expected to undergo intrafamilial transmission. The extracted HBV DNA were amplified and sequenced in a region of the S gene.

RESULTS

  The software to automatically classify query sequence was constructed and installed on the Hepatitis Virus Database (HVDB). Reference sequences were retrieved from HVDB, which contained major genotypes from A to H. Multiple-alignments using CLUSTAL W were performed before the genetic distance matrix was calculated with the six-parameter method. The phylogenetic tree was output by the neighbor-joining method. User interface using WWW-browser was also developed for intuitive control. This system was named as the easy-to-use phylogenetic analysis system (E-PAS). Twenty-three sera of 10 families were analyzed to evaluate E-PAS. The queries obtained from nine families were genotype C and were located in one cluster per family. However, one patient of a family was classified into the cluster different from her family, suggesting that E-PAS detected the sample distinct from that of her family on the transmission route.

CONCLUSIONS

  The E-PAS to output phylogenetic tree was developed since requisite material was sequence data only. E-PAS could expand to determine HBV genotypes as well as transmission routes.

Epidemiological survey of Japanese children infected with hepatitis B and C viruses

AIM

  The lack of a nationwide survey on hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in Japan led us to investigate the epidemiological profiles of these infections among Japanese children.

METHODS

  We conducted a questionnaire survey of children (<20 years of age) infected with either HBV (n = 136) or HCV (n = 114), who visited 636 pediatric institutions in Japan from 2003 through 2005. Most HBV-infected subjects (94%) were born in 1986 or after when a nationwide immunization program for infants born to HBe antigen-positive carriers was initiated. The transmission routes were divided into five groups: maternal, horizontal (subdivided into intrafamilial, iatrogenic and other horizontal), and unknown transmission.

RESULTS

  Comparison of subjects born in 1990 or after and those born in 1989 or before, when anti-HBc and anti-HCV (c100-3) screening tests of blood donors began, showed a shift in the relative proportions of maternal, intrafamilial, iatrogenic, other horizontal, and unknown transmission from 52%, 19%, 4%, 7% and 19% to 70%, 14%, 6%, 1% and 9%, respectively, for HBV, which was statistically insignificant (P = 0.120), and from 14%, 0%, 76%, 4% and 7% to 89%, 2%, 4%, 0% and 5%, respectively, for HCV, which was statistically significant (P < 0.001). HBV horizontal transmission did not decrease in proportion. No transfusion-acquired HCV infection was reported in subjects born in 1993 or after.

CONCLUSION

  Maternal transmission is a prominent source of HCV infection among Japanese children. The implementation of measures to prevent HBV horizontal infection is also essential, and the present system of selective vaccination should be expanded to universal vaccination.

Clinical relevance and public health significance of hepatitis B virus genomic variations

Ten hepatitis B virus (HBV) genotypes (A-J) and 34 HBV subgenotypes have been identified so far. HBV genotypes and subgenotypes have distinct geographical distributions, and have been shown to differ with regard to clinical outcome, prognosis, and response to interferon treatment. Infection with subgenotype A2 is frequently associated with high viral load, resulting in acute infection via horizontal transmission. Genotypes A and B are more sensitive to interferon treatment than genotypes D and C, respectively. Genotype B is more frequent in acute hepatitis than genotype C, whereas genotype C (C2) is more frequently associated with an increased risk of hepatocellular carcinoma (HCC), mostly cirrhotic, as compared with genotype B (B2). Genotype mixture is associated with high viral load and worse outcome of HBV infection. HBV mutations in the S genes, especially amino acids substitution at position 145 (G145R), are associated with immune escape, whereas mutations in the PreS or S genes which impair HBsAg secretion could present a risk to blood safety. HBV variants harboring mutations in the viral polymerase gene that confer resistance to nucleoside analogs may be selected during antiviral therapy. Different genotypes have distinct mutation patterns in the PreS and EnhII/BCP/Precore regions. PreS deletions, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. HCC-associated HBV mutants may not transmit via mother-to-child transmission, and are likely generated during HBV-induced pathogenesis. Examination of HBV mutations alone or in combination and host genetic susceptibility will be helpful in classifying the HBV-infected subjects who will develop HCC and need active anti-viral treatments.

Features and clinical implications of hepatitis B virus genotypes and mutations in basal core promoter/precore region in 507 Chinese patients with acute and chronic hepatitis B

BACKGROUND

The association of hepatitis B virus (HBV) genotypes and basal core promoter (BCP) and precore (PC) mutations with the clinical characteristics is increasingly recognized.

OBJECTIVE

To investigate virologic features and clinical implications of HBV genotypes, BCP and PC mutations between large-size patients with acute hepatitis B (AHB) and chronic hepatitis B (CHB).

STUDY DESIGN

One hundred and eighty-two AHB patients and 325 CHB patients were investigated. HBV genotypes and BCP/PC mutations were determined by direct sequencing. Mutations at 10 interested sites of the BCP/PC region were compared between the two groups of patients.

RESULTS

AHB patients had a significantly higher ratio of genotype B to C than CHB patients (37.4-62.6% vs. 16.6-83.4%, P<0.001). The prevalence of BCP/PC wild-type virus was 60.4% in AHB patients in contrast to 28.9% in CHB patients. Significantly lower prevalence of A1762T, G1764A, G1896A, and G1899A but higher prevalence of T1758C was found in AHB patients. Interestingly, T1758C and A1762T/G1764A appeared mutual restraint. Genotype B virus had lower BCP mutation frequency and similar PC mutation frequency compared to genotype C virus. AHB patients with BCP/PC mutant virus had higher viral load, whereas CHB patients with BCP/PC mutant virus had lower viral load and elevated alanine aminotransferase, in comparison with those with the wild-type virus.

CONCLUSION

Patients with genotype B virus, BCP/PC wild-type virus or T1758C mutant virus were more susceptible to develop AHB, whereas high prevalence of the BCP/PC mutations was associated with CHB development.

Clinical relevance and public health significance of hepatitis B virus genomic variations

Ten hepatitis B virus (HBV) genotypes (A-J) and 34 HBV subgenotypes have been identified so far. HBV genotypes and subgenotypes have distinct geographical distributions, and have been shown to differ with regard to clinical outcome, prognosis, and response to interferon treatment. Infection with subgenotype A2 is frequently associated with high viral load, resulting in acute infection via horizontal transmission. Genotypes A and B are more sensitive to interferon treatment than genotypes D and C, respectively. Genotype B is more frequent in acute hepatitis than genotype C, whereas genotype C (C2) is more frequently associated with an increased risk of hepatocellular carcinoma (HCC), mostly cirrhotic, as compared with genotype B (B2). Genotype mixture is associated with high viral load and worse outcome of HBV infection. HBV mutations in the S genes, especially amino acids substitution at position 145 (G145R), are associated with immune escape, whereas mutations in the PreS or S genes which impair HBsAg secretion could present a risk to blood safety. HBV variants harboring mutations in the viral polymerase gene that confer resistance to nucleoside analogs may be selected during antiviral therapy. Different genotypes have distinct mutation patterns in the PreS and EnhII/BCP/Precore regions. PreS deletions, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. HCC-associated HBV mutants may not transmit via mother-to-child transmission, and are likely generated during HBV-induced pathogenesis. Examination of HBV mutations alone or in combination and host genetic susceptibility will be helpful in classifying the HBV-infected subjects who will develop HCC and need active anti-viral treatments.

Does hepatitis B virus (HBV) genotype influence the clinical outcome of HBV infection?

Between 5 and 10% of adults infected with the hepatitis B virus (HBV) develop a chronic infection lasting longer than 6 months, which may lead to advanced liver disease. HBV can be classified into six genotypic families: A, B, C, D, E and F, but only genotypes A and D are significantly represented in western Europe, where they account for some 90% of cases of infection with HBV. In the present study, we investigated a possible association between HBV genotype A or D and clinical outcome of the infection. We compared the prevalence of these genotypes in a group of patients with chronic active hepatitis to that of a group with acute resolving hepatitis. In patients with chronic active hepatitis, genotype A was found in 28 of 35 patients and genotype D in only four. The remaining three patients were infected with genotype non-A, non-D. In contrast, genotype D was found in 24 of 30 patients with acute hepatitis, whilst genotype A was found in only three patients of this group. Three were infected with genotype non-A, non-D. Our results show a clear association between genotype A and chronic outcome (Ficher's exact test: two-sided P-value, P < 0.0001). They suggest that HBV genotypes may play a role in the virus-host relationship. Possible mechanisms for such a role are discussed.