Characterization of genotype H hepatitis B virus strain identified for the first time from a Japanese blood donor by nucleic acid amplification test

Hepatitis B Virus Genotype H: Epidemiological, Molecular, and Clinical Characteristics in Mexico

The hepatitis B virus (HBV), comprising of ten genotypes (A-J), has been a silent threat against humanity, constituting a public health problem worldwide. In 2016, the World Health Organization set forth an impressive initiative for the global elimination of viral hepatitis by 2030. As the target date approaches, many nations, particularly in the Latin American region, face challenges in designing and implementing their respective elimination plan. This review aimed to portray the state of knowledge about the epidemiological, molecular, and clinical characteristics of HBV genotype H (HBV/H), endemic to Mexico. PubMed, Scopus, Web of Science, and Google Scholar were searched to compile scientific literature over 50 years (1970-2022). A total of 91 articles were organized into thematic categories, addressing essential aspects such as epidemiological data, risk factors, HBV genotype distribution, HBV mixed infections, clinical characteristics, and vaccination. The prevalence and its associated 95% confidence interval (95% CI) were estimated using the Metafor package in R programming language (version 4.1.2). We provide insights into the strengths and weaknesses in diagnostics and prevention measures that explain the current epidemiological profile of HBV/H. Training, research, and awareness actions are required to control HBV infections in Mexico. These actions should contribute to creating more specific clinical practice guides according to the region's characteristics. Mexico's elimination plan for HBV will require teamwork among the government health administration, researchers, physicians, specialists, and civil society advocates to overcome this task jointly.

Long-term follow-up of a Japanese patient with hepatitis B virus genotype H and human immunodeficiency virus coinfection

Hepatitis B virus (HBV) genotypes affect the pathogenesis of disease progression during the course of HBV infection. In Japan, HBV genotype H is one of the rare HBV genotypes. We recovered HBV genotype H from a blood sample from a Japanese HIV-infected patient with acute exacerbation of chronic HBV infection. Due to the development of drugs for treating HBV and HIV, HBV genotype H and HIV coinfection has been well controlled by nucleos(t)ide analogs and highly active antiretroviral therapy, respectively, from 2002 to 2019. Further study is needed with regard to HBV genotype H and its pathogenesis.

An adolescent female having hepatocellular carcinoma associated with hepatitis B virus genotype H with a deletion mutation in the pre-S2 region

The genotypes of hepatitis B virus (HBV) have a distinct geographical distribution, with HBV genotype H being very rare in East Asia, including Japan. We herein report the case of a 12-year-old Japanese female with hepatocellular carcinoma (HCC) who exhibited HBV genotype H. Notably, the HBV isolated from the patient had a deletion mutation in the pre-S2 region. The genome of HBV genotype H in the patient with HCC has not been analyzed in detail. The deletion mutations in the pre-S2 region, which may play an important role in hepatocarcinogenesis in children, can also present in genotype H.

Acute hepatitis B of genotype H resulting in persistent infection

A 47-year-old man presented with general fatigue and dark urine. The laboratory data showed increased levels of hepatic transaminases. The patient was positive for hepatitis B virus (HBV) markers and negative for anti-human immunodeficiency virus. The HBV-DNA titer was set to 7.7 log copies/mL. The patient was diagnosed with acute hepatitis B. The HBV infection route was obscure. The serum levels of hepatic transaminases decreased to normal ranges without any treatment, but the HBV-DNA status was maintained for at least 26 mo, indicating the presence of persistent infection. We isolated HBV from the acute-phase serum and determined the genome sequence. A phylogenetic analysis revealed that the isolated HBV was genotype H. In this patient, the elevated peak level of HBV-DNA and the risk alleles at human genome single nucleotide polymorphisms s3077 and rs9277535 in the human leukocyte antigen-DP locus were considered to be risk factors for chronic infection. This case suggests that there is a risk of persistent infection by HBV genotype H following acute hepatitis; further cases of HBV genotype H infection must be identified and characterized. Thus, the complete determination of the HBV genotype may be essential during routine clinical care of acute hepatitis B outpatients.

Distribution of HBV genotypes F and H in Mexico and Central America

The distribution of HBV genotypes is associated with populations of specific geographical regions of the world. We show data from the GenBank sequence database and medical reports, which indicate that HBV genotype H (HBV/H) is mainly distributed in Mexico, whereas HBV genotype F (HBV/F) is distributed in countries from Central America. The phylogenetic analysis and historical records suggest that HBV/H has been present in Mexico even before the arrival of the Spaniards. Interestingly, occult hepatitis B is a common finding in both natives and patients with chronic liver disease in Mexico. This suggests that an immunogenic background could be important during the natural history of liver diseases. The estimated large number of HBV/H-infected patients in Mexico does not correlate with the total number of patients with chronic liver disease and cirrhosis reported in the country. This may be because of the fact that HBV infection is often masked by alcoholic liver disease, HCV coinfection and/or obesity. Here, we analyse the data concerning the distribution of HBV/F and HBV/H genotypes in Central America and Mexico. Specifically, we focus on the effect of molecular epidemiology and pathogenesis of HBV/H. These recent findings reveal new areas of study with therapeutic potential in viral liver diseases.

Age- and gender-specific distributions of hepatitis B virus (HBV) genotypes in Japanese HBV-positive blood donors

BACKGROUND

There are an increasing number of reports on the hepatitis B virus (HBV) genotype distribution in acute or chronic HBV-infected patients in Japan; however, reports on the HBV genotype of blood donors are few. To compare the HBV genotypes of hepatitis B surface antigen (HBsAg)-positive blood donors with infected patients, all the HBsAg-positive donors' genotypes were determined.

STUDY DESIGN AND METHODS

Data on Japanese blood donors from October 2006 to September 2007 were obtained from the Japanese Red Cross database. The number of available samples was 1979, and the HBV genotypes were determined in 1887 samples. The six major genotypes of HBV (A-F) were determined by enzyme-linked immunosorbent assay. The presence of the immunoglobulin M (IgM) antibody against the HBV core antigen was determined by enzyme immunoassay among all HBsAg-positive donors.

RESULTS

A significant difference in the HBV genotype distribution between donors and patients was in the C/B genotype ratio. The ratios were low in blood donors (2.0-3.9) and high in patients (5.3-18.2). The genotype B ratio increases from 13.8% in teenage donors to 42.4% in those in their 50s; however; the genotype C ratio decreases from 83.1% in teenage donors to 55.1% in those in their 50s. In both IgM antibody against hepatitis B core antigen and nucleic acid test-positive donors, genotypes A and B were restricted to male donors.

CONCLUSIONS

The age-specific distribution of HBV genotypes in Japanese blood donors was observed in the B/C genotype ratio. The gender-specific distribution of HBV genotype A, which originated from the US or Western countries, was observed in male Japanese donors.

Genotype D amongst injection drug users with acute hepatitis B virus infection in British Columbia

The eight genotypes of hepatitis B virus (HBV) exhibit distinct geographical distributions. This study identified HBV genotypes and transmission modes associated with acute infection in British Columbia (BC), Canada, from 2001 to 2005. Seventy cases of acute HBV in BC were identified from laboratory reports using a standardized case definition. Interviews for risk factors and hepatitis history were conducted for each case. HBV genotypes were determined by BLAST comparison analysis of the surface (S) or preS gene sequence. To illustrate the distribution of genotypes identified amongst acute cases in BC, an annotated map was produced showing the global occurrence of HBV genotypes. The majority of acute HBV cases occurred in Caucasian, Canadian-born males, with 30% of cases reporting injection drug use (IDU) and 21% reporting incarceration. The most common genotype observed was genotype D (62.9%), followed by genotypes A (18.6%), C (11.4%), B (4.3%), and E (1.4%). A significant association was observed between Genotype D and IDU (P = 0.0025) and previous incarceration (P = 0.0067). Phylogenetic analysis of the S gene sequence demonstrated identical or high genetic relatedness amongst genotype D viral strains (86% sub-genotype D3), thus verifying transmission clustering amongst BC injection drug users. The association between acute HBV genotype and reported transmission modes has not been previously described in North America. Tracking of genotypes can help identify disease transmission patterns and target at-risk populations for preventive immunization.

Sequential accumulation of the mutations in core promoter of hepatitis B virus is associated with the development of hepatocellular carcinoma in Qidong, China

BACKGROUND/AIMS

To investigate the mutations in hepatitis B virus (HBV) that might be related to hepatocellular carcinoma (HCC) in the high-risk area Qidong, China.

METHODS

DNA sequences of HBV basal core promoter (BCP) and the overlapping X gene were determined in 58 HCC and 71 chronic hepatitis (CH) patients. In addition, a consecutive series of plasma samples from 15 HCC cases were employed to compare the CP/X sequences before and after the occurrence of HCC.

RESULTS

T1762/A1764 double mutation was frequently found in Qidong patients, regardless of clinical status (65.5% in HCC and 73.2% in CH, P>0.05). Unexpectedly, the adjacent T1766/A1768 mutation significantly increased the risk of HCC (P<0.05). Moreover, the prevalence of triple mutations in BCP was significantly higher in patients with HCC than those with CH (P<0.05). The longitudinal study demonstrated that the mutations in BCP were gradually accumulated during the development of HCC. Colony formation assay showed while A1764 mutation alone did not alter the colony-inhibitory activity of HBx, double or triple mutations largely abrogated this effect.

CONCLUSIONS

The complex mutation involving T1766/A1768 was closely related to HCC. The enhanced risk of HCC caused by BCP variants could be attributable partially to the aberrant activity of HBx.

Hepatitis B virus DNA in unusual serological profiles of hepatitis B surface antigen-positive sera

On the basis of a seroepidemiological survey of hepatitis B virus (HBV) infection conducted on 6208 random serum samples from four provinces of Thailand, we found 19 of 246 (7.7%) hepatitis B surface antigen (HBsAg)-positive samples with unusual serological constellations of HBV infection. Ten samples tested positive for HBsAg, anti-HBc (anti-hepatitis B core antibody), and anti-HBs (anti-hepatitis B surface antibody) markers (group I), 3 specimens were HBsAg and anti-HBs positive without detectable anti-HBc (group II), and the remaining 6 specimens showed only HBsAg (group III). In group I, 7 of 10 HBsAg-positive sera could be confirmed by HBsAg neutralization, yielding positive results for all samples. None of the group II sera were available in sufficient amounts for confirmation. In group III, five of six sera were confirmed by HBsAg neutralization, with four showing a positive reaction. HBV DNA was detected in 7 of 10 (70%) specimens in group I, in 1 of 3 (33.3%) specimens in group II, and in 3 of 6 (50%) specimens in group III. On the basis of HBsAg neutralization, HBV DNA was found in five of seven (71.4%) HBsAg-positive samples in group I and in three of four (75%) HBsAg-positive samples in group III, whereas the one confirmed HBsAg-negative sample in group III also remained negative for HBV DNA. Amino acid sequences were compared with those specifying the "a" determinant of the wild-type virus, particularly focusing on HBV-S protein variations between positions 110 and 160. Among 11 HBV DNA-positive sera, G145A was detected in 2 samples in group I, with the remaining samples identical to the wild-type virus. These unusual serological profiles may be due to the altered immune response of the host or to HBV variants.

A male patient with severe acute hepatitis who was domestically infected with a genotype H hepatitis B virus in Iwate, Japan

Although all eight genotypes of hepatitis B virus (HBV) strains are circulating in Japan, no cases of acute hepatitis with foreign HBV strains of genotype H have thus far been reported in Japan. Here, we report a 35-year-old Japanese patient with severe acute hepatitis who was domestically infected with genotype H HBV. On admission, he had a high HBV load of 1.0 x 10(9) copies/ml, elevated levels of total bilirubin (7.0 mg/dl) and alanine aminotransferase (3606 IU/l), and reduced prothrombin activity of 39.0%. The HB-JAIW05 isolate obtained in the present study was composed of 3215 nucleotides and had the highest similarity of 99.7% with the reported genotype H HBV isolate recovered from a Japanese blood donor. The HB-JAIW05 isolate had neither precore (A1896) nor core promoter (T1762/A1764) mutations. However, upon comparison with the consensus sequence of ten reported HBV isolates of the same genotype, the HB-JAIW05 isolate had 17 nucleotide substitutions including five missense mutations in the P gene, which may be related to vigorous replication of HBV in this case. He had no history of traveling abroad, but had had extramarital sexual contact with two Japanese women living in Iwate, Japan, 2 weeks and 2 months before the disease onset, respectively. Our results suggest that rare HBV genotypes such as H may be spreading in Japan via sexual contact. Further molecular epidemiological studies on HBV to clarify the exact changing profiles of de novo HBV infection in Japan in relation to genotype and genomic variability are warranted.

Prolonged hepatitis after acute infection with genotype H hepatitis B virus

We present a case report of a Japanese patient who showed prolonged infection after acute hepatitis B with genotype H. The patient was a 60-year-old man who underwent an annual health care check every year for several years and was never pointed out to have any liver damage, and markers for hepatitis B and C were negative. He was found to be positive for hepatitis B surface antigen (HBsAg) at his health care check in December 2005. After one month, he had an elevated aminotransferase level with hepatitis B e antigen and a high level of serum HBV DNA. He was diagnosed as having acute hepatitis B. On HBV genotype, he had genotype H by the direct sequence method, and he was given a 100 mg of lamivudine daily. However, his acute hepatitis tended to go toward prolonged infection. After two months, he was treated with interferon daily for 28 days. He had negative HBsAg in August 2006. Genotype H, the newest type of hepatitis B, could be the type which shows a poor response to lamivudine. The present paper is the first report, describing the clinical course of acute hepatitis B with genotype H from onset to remission.

Heterogeneity of Hepatitis B Virus Genotype D in Japan

OBJECTIVE

Hepatitis B virus (HBV) genotypes B and C are predominant in Japan. Previously, we reported that approximately 9% of HBV carriers in the Ehime area of western Japan were infected with genotype D (HBV/D) and their sequences closely related. Recently, serum samples from 3 patients with chronic HBV/D infections living in Tokyo and the surrounding area became available for testing. The purpose of this study was to determine whether the HBV/D isolates from these different areas of Japan are closely related.

METHODS

Of the 3 Tokyo area patients infected with HBV/D, 2 had chronic hepatitis, and 1 had hemophilia with a history of frequent coagulation factor injections. The complete HBV/D genome sequences of each were determined, and compared with those of subjects from the Ehime area.

RESULTS

All 3 HBV/D sequences had a genomic length of 3,182 bases, and the hepatitis B surface antigen subtype was ayw3. Phylogenetic analysis revealed that the 1 of the HBV/D isolates was closely related to the isolates from Ehime Prefecture, while 1 was similar and 1 was clearly distinct.

CONCLUSION

Our results indicate that HBV/D infections in Japan are heterogeneous.

Molecular analysis of hepatitis B virus isolates in Mexico: Predominant circulation of hepatitis B virus genotype H

AIM: To determine the genotypes in Mexican hepatitis B virus (HBV) isolates and characterize their precore and core promoter mutations.

METHODS: Forty-nine HBV isolates of Mexico obtained from sera of 15 hepatitis patients, 6 hemodialysis patients, 20 men seeking HIV testing, and 8 AIDS patients were analyzed. HBV isolates were amplified by PCR, and genotyped by line probe assay (INNO-LiPA HBV Genotyping; INNOGENETICS N V, Ghent, Belgium). HBV genotype confirmation was performed by DNA sequencing part of the sAg region. Precore and core promoter mutation characterization was performed by line probe assay (INNO-LiPA HBV PreCore; INNOGENETICS N V, Ghent, Belgium).

RESULTS: Overall, HBV genotype H was found in 37 (75.5%) out of the 49 isolates studied. HBV genotypes G, A, and D were found in 5 (10.2%), 4 (8.2%), and 3 (6.1%) isolates, respectively. HBV genotype H was predominant in isolates from hemodialysis patients (100%), hepatitis patients (80%), and men seeking HIV testing (75%), and accounted for half of infections in AIDS patients (50%). Six (12.2%) out of the 49 HBV isolates showed both wild type and mutant populations at precore codon 28. These mixed wild type and precore mutant populations were observed in one HBV genotype A isolate and in all HBV genotype G isolates. A dual variant core promoter mutation was observed in 1 (2%) of the isolates, which was genotype H.

CONCLUSION: HBV genotype H is highly predominant in HBV isolates of Mexico followed by genotypes G, A and D. A low frequency of precore and core promoter mutations is observed in HBV Mexican isolates.

Real-time PCR assay for detection and quantification of hepatitis B virus genotypes A to G

The detection and quantification of hepatitis B virus (HBV) DNA play an important role in diagnosing and monitoring HBV infection as well as assessing therapeutic response. The great variability among HBV genotypes and the enormous range of clinical HBV DNA levels present challenges for PCR-based amplification techniques. In this study, we describe the development, evaluation, and validation of a novel real-time PCR assay designed to provide accurate quantification of DNA from all eight HBV genotypes in patient plasma specimens. A computer algorithm was used to design degenerate real-time PCR primers and probes based upon a large number (n = 340) of full-length genomic sequences including HBV genotypes A to H from Europe, Africa, Asia, and North and South America. Genotype performance was tested and confirmed using 59 genotype A to G specimens from two commercially available worldwide genotype panels. This assay has a dynamic range of at least 8 log(10) without the need for specimen dilution, good clinical intra- and interassay precision, and excellent correlation with the Bayer Diagnostics VERSANT HBV DNA 3.0 (branched DNA) assay (r = 0.93). Probit analysis determined the 95% detection level was 56 IU/ml, corresponding to 11 copies per PCR well. The high sensitivity, wide linear range, good reproducibility, and genotype inclusivity, combined with a small sample volume requirement and low cost, make this novel quantitative HBV real-time PCR assay particularly well suited for application to large clinical and epidemiological studies.

Acute hepatitis B virus window-period blood donations detected by individual-donation nucleic acid testing: a report on the first two cases found and interdicted in Spain

BACKGROUND

Mathematical models predict that, in Spain, a significant number of blood units will be obtained during the window period of the hepatitis B virus (HBV) infection. Routine nucleic acid testing (NAT) on individual blood units may provide experimental data to evaluate such a theoretical risk.

STUDY DESIGN AND METHODS

Between February and July 2005, a total of 34,631 individual units were screened for HBV DNA by a multiplex transcription-mediated amplification (TMA) test. Units that repeatedly reacted in the test, but did not react for HBV surface antigen (HBsAg), were submitted to additional testing by both molecular and conventional assays, and the donors were recalled for follow-up studies and the collection of clinical and epidemiologic data.

RESULTS

Confirmatory testing and follow-up studies identified 2 blood units donated during the HBV infection window period (1/17,316 units studied). Sequencing of amplification products obtained by nested polymerase chain reaction (n-PCR) revealed two HBV strains from genotypes D/ayw3 and F/adw4q-, but did not identify HBsAg mutants. The HBV DNA concentration in the index donations was estimated to be below the n-PCR detection level (180 IU/mL), in both cases. One donor developed acute hepatitis 2 months after donating blood, but the other remained asymptomatic and displayed normal alanine aminotransferase levels at follow-up.

CONCLUSIONS

The HBV infection window period is a real issue in the setting of Spanish blood transfusions. NAT of individual units by TMA would make a significant contribution to improving the safety of the blood supply in Spain. Additional studies involving a larger number of units and longer periods of time are required, however, to ascertain the true incidence of the problem in this country.

Hepatitis B epidemiology in Latin America

Background

Hepatitis B virus (HBV) is a small DNA-containing virus with 4 genes, C, S, X and P. The S gene codes for the surface antigen (HBsAg), which contains the "a" determinant, the main region for induction of a protective humoral immune response. To compare the genotype and sequence of the "a" determinant between strains isolated from asymptomatic and symptomatic Mexican HBV carriers.

Results

21 asymptomatic (blood donors) and 12 symptomatic (with clinical signs and with >1 year lamivudine treatment) HBV carriers were studied; all patients were positive for the HBsAg in serum. Viral load, genotypes, and subtypes were determined in plasma. A fragment of the S gene including the "a" determinant was PCR amplified and sequenced to determine genotype, subtype and to identify mutations. Mean viral load was 0.7965 × 10⁴ copies/ml in asymptomatic carriers and 2.73 × 10⁶ copies/ml in symptomatic patients. Genotypes H, C, and F were identified in asymptomatic individuals; whereas H was dominant in symptomatic patients. A fragment of 279 bp containing the "a" determinant was amplified from all 33 carriers and sequences aligned with S gene sequences in the GenBank. Mutations identified were Y100N, T126I, Q129H and N146K in the asymptomatic group, and F93I and A128V in the symptomatic group.

Conclusion

Differences in genotype and in mutations in the "a" determinant were found between strains from asymptomatic and symptomatic HBV Mexican carriers.