HBV genotypes and response to tenofovir disoproxil fumarate in HIV/HBV-coinfected persons

Not uncommon: HBV genotype G co-infections among healthy European HBV carriers with genotype A and E infection

BACKGROUND & AIMS

HBV genotype G (HBV/G) is mainly found in co-infections with other HBV genotypes and was identified as an independent risk factor for liver fibrosis. This study aimed to analyse the prevalence of HBV/G co-infections in healthy European HBV carriers and to characterize the crosstalk of HBV/G with other genotypes.

METHODS

A total of 560 European HBV carriers were tested via HBV/G-specific PCR for HBV/G co-infections. Quasispecies distribution was analysed via deep sequencing, and the clinical phenotype was characterized regarding qHBsAg-/HBV-DNA levels and frequent mutations. Replicative capacity and expression of HBsAg/core was studied in hepatoma cells co-expressing HBV/G with either HBV/A, HBV/D or HBV/E using bicistronic vectors.

RESULTS

Although no HBV/G co-infection was found by routine genotyping PCR, HBV/G was detected by specific PCR in 4%-8% of patients infected with either HBV/A or HBV/E but only infrequently in other genotypes. In contrast to HBV/E, HBV/G was found as the quasispecies major variant in co-infections with HBV/A. No differences in the clinical phenotype were observed for HBV/G co-infections. In vitro RNA and DNA levels were comparable among all genotypes, but expression and release of HBsAg was reduced in co-expression of HBV/G with HBV/E. In co-expression with HBV/A and HBV/E expression of HBV/G-specific core was enhanced while core expression from the corresponding genotype was markedly diminished.

CONCLUSIONS

HBV/G co-infections are common in European inactive carriers with HBV/A and HBV/E infection, but sufficient detection depends strongly on the assay. HBV/G regulated core expression might play a critical role for survival of HBV/G in co-infections.

Hepatitis B Virus (HBV) Genotype Mixtures, Viral Load, and Liver Damage in HBV Patients Co-infected With Human Immunodeficiency Virus

Hepatitis B virus (HBV) co-infection is possible in patients who are positive for human immunodeficiency virus (HIV) since both share similar transmission routes. Furthermore, through the continuous risk of exposure, they potentially can be infected by mixtures of distinct HBV genotypes which can result in the presence of two or more genotypes in a single patient. This study aimed to specify the frequency of mixtures of HBV genotypes and their potential clinic importance in HIV-infected Mexican patients. HBV infection was assessed by serological testing and molecular diagnostics. HBV mixtures were detected by multiplex PCR and DNA sequencing. Liver fibrosis was evaluated using transitional elastography, the Aspartate aminotransferase to Platelets Ratio Index score, and Fibrosis-4 score. Among 228 HIV-infected patients, 67 were positive for HBsAg. In 25 HBV/HIV co-infected patients, 44 HBV genotypes were found: H (50.0%, 22/44), G (22.7%, 10/44), D (15.9%, 6/44), A (9.1%, 4/44), and F (2.3%, 1/44). Among these, 44.0% (11/25) were single genotype, 36.0% (9/25) were dual and 20.0% (5/25) were triple genotype. The most frequent dual combination was G/H (44.4%, 4/9), while triple-mixtures were H/G/D (60.0%, 3/5). The increase in the number of genotypes correlated positively with age (Spearman's Rho = 0.53, p = 0.0069) and negatively with platelet levels (Spearman's Rho = - 0.416, p = 0.039). HBV viral load was higher in triply-infected than dually infected (31623.0 IU/mL vs. 1479.0 IU/mL, p = 0.029) patients. Triple-mixed infection was associated with significant liver fibrosis (OR = 15.0 95%CI = 1.29 - 174.38, p = 0.027). In conclusion, infection with mixtures of HBV genotypes is frequent in HIV patients causing significant hepatic fibrosis related to high viral load, especially in triple genotype mixtures.

The evolution and clinical impact of hepatitis B virus genome diversity

The global burden of hepatitis B virus (HBV) is enormous, with 257 million persons chronically infected, resulting in more than 880,000 deaths per year worldwide. HBV exists as nine different genotypes, which differ in disease progression, natural history and response to therapy. HBV is an ancient virus, with the latest reports greatly expanding the host range of the Hepadnaviridae (to include fish and reptiles) and casting new light on the origins and evolution of this viral family. Although there is an effective preventive vaccine, there is no cure for chronic hepatitis B, largely owing to the persistence of a viral minichromosome that is not targeted by current therapies. HBV persistence is also facilitated through aberrant host immune responses, possibly due to the diverse intra-host viral populations that can respond to host-mounted and therapeutic selection pressures. This Review summarizes current knowledge on the influence of HBV diversity on disease progression and treatment response and the potential effect on new HBV therapies in the pipeline. The mechanisms by which HBV diversity can occur both within the individual host and at a population level are also discussed.

Complex genetic encoding of the hepatitis B virus on-drug persistence

Tenofovir disoproxil fumarate (TDF) is one of the nucleotide analogs capable of inhibiting the reverse transcriptase (RT) activity of HIV and hepatitis B virus (HBV). There is no known HBV resistance to TDF. However, detectable variation in duration of HBV persistence in patients on TDF therapy suggests the existence of genetic mechanisms of on-drug persistence that reduce TDF efficacy for some HBV strains without affording actual resistance. Here, the whole genome of intra-host HBV variants (N = 1,288) was sequenced from patients with rapid (RR, N = 5) and slow response (SR, N = 5) to TDF. Association of HBV genomic and protein polymorphic sites to RR and SR was assessed using phylogenetic analysis and Bayesian network methods. We show that, in difference to resistance to nucleotide analogs, which is mainly associated with few specific mutations in RT, the HBV on-TDF persistence is defined by genetic variations across the entire HBV genome. Analysis of the inferred 3D-structures indicates no difference in affinity of TDF binding by RT encoded by intra-host HBV variants that rapidly decline or persist in presence of TDF. This finding suggests that effectiveness of TDF recognition and binding does not contribute significantly to on-drug persistence. Differences in patterns of genetic associations to TDF response between HBV genotypes B and C and lack of a single pattern of mutations among intra-host variants sensitive to TDF indicate a complex genetic encoding of the trait. We hypothesize that there are many genetic mechanisms of on-drug persistence, which are differentially available to HBV strains. These pervasive mechanisms are insufficient to prevent viral inhibition completely but may contribute significantly to robustness of actual resistance. On-drug persistence may reduce the overall effectiveness of therapy and should be considered for development of more potent drugs.

Immunological Efficacy of Tenofovir Disproxil Fumarate-Containing Regimens in Patients With HIV-HBV Coinfection: A Systematic Review and Meta-Analysis

Background: Hepatitis B virus (HBV) coinfection is common in HIV-positive patients. HIV infection modifies the natural course of HBV infection, leading to a faster progression of liver-related morbidity and mortality than is observed in HBV mono-infected patients. This systematic review and meta-analysis evaluates the current clinical evidence regarding the use of oral tenofovir disproxil fumarate (TDF)-based treatments in patients coinfected with HIV and HBV.

Methods: We performed a comprehensive literature search in PubMed and Web of Science. Supplementary searches were conducted in Google Scholar and Clinicaltrials.gov. We conducted a random effects meta-analysis using the event rate (ER) to estimate the incidence of HBV seroconversion. A subgroup meta-analysis was performed to assess the moderate effects of demographic and disease-related variables on HBsAg loss. This review is registered in the PROSPERO database (CRD42018092379).

Results: We included 11 studies in the review. The immunological effects of oral TDF-based Pre-exposure prophylaxis (PrEP) treatment in patients with HIV-HBV coinfection were 0.249 for HBeAg loss, 0.237 for HBeAg conversion, 0.073 for HBsAg loss, and 0.055 for HBsAg conversion. The factors associated with HBsAg loss were the baseline HBV viral load, participant’s location, and a history of exposure to lamivudine/emtricitabine (3TC/FTC) (all p < 0.05). A trend toward a negative relationship between the baseline CD4⁺ T-cell count and HBsAg loss was observed (p = 0.078).

Conclusion: This systematic review and meta-analysis demonstrated that TDF-containing regimens are effective at stimulating HBeAg loss (24.9%), HBeAg conversion (23.7%), HBsAg loss (7.3%), and HBsAg conversion (5.5%) in HIV-HBV coinfected patients. The moderator analysis showed that HBV viral load, the location of participants, and prior exposure to 3TC/FTC are factors associated with HBsAg loss. Asian ethnicity, prior exposure to 3TC, and a nondetectable baseline HBV viral load are associated with lower odds of HBsAg loss. Well-designed prospective cohort studies and randomized controlled trials (RCTs) with large sample sizes are required for the investigation of potential predictors and biological markers associated with strategies for achieving HBV remission in patients with HIV-HBV coinfection, which is a matter of considerable importance to clinicians and those responsible for health policies.

Management of Virologic Failure and HIV Drug Resistance

Approximately 20% of people with HIV in the United States prescribed antiretroviral therapy are not virally suppressed. Thus, optimal management of virologic failure has a critical role in the ability to improve viral suppression rates to improve long-term health outcomes for those infected and to achieve epidemic control. This article discusses the causes of virologic failure, the use of resistance testing to guide management after failure, interpretation and relevance of HIV drug resistance patterns, considerations for selection of second-line and salvage therapies, and management of virologic failure in special populations.

Long-term virological and serologic responses of chronic hepatitis B virus infection to tenofovir disoproxil fumarate-containing regimens in patients with HIV and hepatitis B coinfection

BACKGROUND

Data regarding the durability of HBV viral suppression with combination antiretroviral therapy (cART) containing tenofovir disoproxil fumarate (TDF) combined with lamivudine (3TC) or emtricitabine (FTC) in HIV/HBV-coinfected patients are scarce in hyperendemic areas of chronic HBV infection.

METHODS

Between 2004 and 2016, HIV/HBV-coinfected Taiwanese with available baseline HBV DNA load were retrospectively reviewed. Determinations of plasma HBV DNA load, HBV serologic markers (HBsAg, anti-HBs, HBeAg, and anti-HBe), and liver function were performed after initiation of cART. Factors associated with time to undetectable HBV DNA load were explored.

RESULTS

A total of 366 patients were included according to cART history: Group 1, 3TC as the only anti-HBV therapy (n = 73); Group 2, TDF-containing cART as initial therapy (n = 127); and Group 3, switch of 3TC-based to TDF-containing cART (n = 166). At year 5, HBV suppression was achieved in 77.8%, 95.7%, and 95.7% of Groups 1, 2 and 3, respectively. In multivariate Cox regression analysis, TDF ( ± 3TC or FTC) but not 3TC alone as initial anti-HBV therapy was significantly associated with HBV suppression (adjusted hazard ratio [aHR] 2.635; 95% CI 1.720-4.037), while HBeAg positivity at baseline was associated with failure to achieve HBV suppression (aHR 0.293; 95% CI 0.178-0.482). Loss of HBsAg occurred in 15 patients (4.1%), with 7 (1.9%) seroconversion to anti-HBs positivity, while HBeAg seroconversion occurred in 11 (16.9%) of 65 HBeAg-positive patients.

CONCLUSIONS

TDF-containing cART achieved durable HBV viral suppression in HIV/HBV-coinfected patients and HBeAg positivity at baseline was associated with failure to achieve HBV suppression despite long-term TDF-containing cART.

Current progress in the prevention of mother-to-child transmission of hepatitis B and resulting clinical and programmatic implications

There is currently no cure for hepatitis B chronic infections. Because new hepatitis B infections result mainly from perinatal transmission, preventing mother-to-child transmission is essential to reach by 2030 the goal of hepatitis B elimination set by the World Health Organization. The universal administration of hepatitis B vaccine to all infants, regardless of maternal status, starting with the birth dose, is the cornerstone of the strategy for elimination. Additional interventions, such as hepatitis B immune globulin administered to newborns and antiviral prophylaxis administered to hepatitis B infected pregnant women, may contribute to reaching the goal earlier. Hepatitis B immune globulin may remain out for reach of many pregnant women in low- and middle-income countries due to cost and logistic issues, but antivirals are cheap and do not require a cold chain for distribution. However, it has been observed that some viruses harbor mutations associated with escape from vaccine-elicited antibodies following immunization or administration of hepatitis B immune globulin. Also, resistance associated mutations have been described for several drugs used for treatment of hepatitis B infected patients as well as for the prevention of mother-to-child transmission. Whether these mutations have the potential to compromise the prevention of mother-to-child transmission or future treatment of the mother is a question of importance. We propose a review of important recent studies assessing tenofovir disoproxil fumarate for the prevention of mother-to-child transmission, and provides detailed information on the mutations possibly relevant in this setting.

High Prevalence of HBV Lamivudine-Resistant Mutations in HBV/HIV Co-Infected Patients on Antiretroviral Therapy in the Area with the Highest Prevalence of HIV/HBV Co-Infection in China

OBJECTIVES

We aimed to determine the prevalence of hepatitis B virus (HBV) drug-resistant mutations in patients co- infected with HBV/human immunodeficiency virus (HIV), including both drug-naïve subjects and those who received antiretroviral therapy (ART) in Guangxi, where the prevalence of HIV/HBV co-infection is highest in China.

METHODS

Two hundred and three subjects co-infected with HBV/HIV were recruited, including 123 drug-naïve patients (group 1) and 80 who received ART (group 2). The polymerase gene of HBV in the serum of all study subjects was analysed.

RESULTS

The results showed that the prevalence of HBV drug-resistant mutations in group 2 (76.5%, 95% CI 56.3-96.7) was significantly higher than that in group 1 (1.4%, 95% CI -1.4 to 4.2; χ2 = 50.955, p < 0.05). The major pattern of lamivudine (3TC)-resistant mutations is L180M+M204I+L80I (35.7%). In total, 95% of subjects with resistant mutations had cross-resistance to telbivudine and entecavir. No putative tenofovir disoproxil fumarate (TDF) resistance change was found. Five subjects (6.5%) in group 2 had HBV viral loads over 10 × 106 copies/mL. Four of them had 3TC-resistant mutations. Multivariate analysis showed that ART was the only factor associated with the development of drug-resistant mutations.

CONCLUSION

Treating HIV in HIV/HBV co-infection with antiretroviral agents may result in a very high prevalence of HBV 3TC-resistant mutations. TDF could not completely suppress HBV replication.

Population-based outcome analysis of diffuse large B-cell lymphoma in people living with HIV infection and competent individuals

The prognostic factors and outcome of 58 acquired immunodeficiency syndrome-related diffuse large B-cell lymphoma (AR-DLBCL) patients from the Swiss HIV Cohort Study, diagnosed from 2004 to 2011, were compared with those of 326 immunocompetent (IC)-DLBCL from the Hematology Division of the Amedeo Avogadro University (Italy) and the Oncology Institute of Southern Switzerland. Median follow-up was 6 years; 5-year overall survival (OS) was 68% (95% CI: 63%-73%) in IC-DLBCL and 63% (95% CI: 49%-75%) in AR-DLBCL (P = .220). The acquired immunodeficiency syndrome-related lymphoma international prognostic index predicted OS in AR-DLBCL. Among 148 patients younger than 61 years (40 AR-DLBCL and 108 IC-DLBCL) treated with RCHOP/RCHOP-like regimens, 20 IC-DLBCL and 9 AR-DLBCL patients died and OS was not significantly different. A higher proportion of early deaths occurred in the AR-DLBCL: indeed, 1-year OS was 94% (95% CI: 87%-97%) in IC-DLBCL and 82% (95% CI: 66%-91%) in AR-DLBCL patients. After rituximab and active antiretroviral therapy introduction, AR-DLBCL and IC-DLBCL patients treated with curative intent have similar long-term survival.

Comparison of Hepatitis B Virus Infection in HIV-Infected and HIV-Uninfected Participants Enrolled in a Multinational Clinical Trial: HPTN 052

OBJECTIVE

Data comparing hepatitis B virus (HBV) infection in HIV-infected [HIV(+)], and HIV-uninfected [HIV(-)] individuals recruited into the same study are limited. HBV infection status and chronic hepatitis B (cHB) were characterized in a multinational clinical trial: HIV Prevention Trials Network (HPTN 052).

METHOD

HBV infection status at enrollment was compared between HIV(+) (N = 1241) and HIV(-) (N = 1232) from 7 HBV-endemic countries. Hepatitis B e antigen and plasma HBV DNA were determined in cHB. Median CD4, median plasma HIV RNA, and prevalence of transaminase elevation were compared in HIV(+) with and without cHB. Significance was assessed with χ, Fisher exact, and median tests.

RESULTS

Among all participants, 33.6% had HBV exposure without cHB (8.9% isolated HBV core antibody, "HBcAb"; 24.7% HBcAb and anti-HB surface antibody positive, "recovered"), 4.3% had cHB, 8.9% were vaccinated, and 53.5% were uninfected. Data were similar among HIV(+) and HIV(-) except for isolated HBcAb, which was more prevalent in HIV(+) than HIV(-) [10.1% vs. 7.7%, P = 0.046]. Median HBV DNA trended higher in HIV(+) than in HIV(-). In HIV(+) with cHB versus those without cHB, transaminase elevations were more prevalent (alanine aminotransferase ≤ grade 2, 12% vs. 5.2%, P = 0.037; aspartate aminotransferase ≤ grade 2, 26% vs. 6.0%, P < 0.001), CD4 trended lower, and HIV RNA was similar.

CONCLUSIONS

HBV infection status did not differ by HIV infection status. HIV co-infection was associated with isolated HBcAb and a trend of increased HBV DNA. In HIV, cHB was associated with mild transaminase elevations and a trend toward lower CD4.

New strains of hepatitis B virus genotype E circulating in Nigeria

OBJECTIVE

Hepatitis B virus (HBV) is not uncommon among persons infected with human immunodeficiency virus (HIV). Severity of HBV infection and treatment outcome are associated with specific HBV genotypes. No study has reported the types of HBV genotypes circulating among HIV-infected subjects in Nigeria. This study was designed to determine the prevalence of HBV, as well as its genotypic distribution among HIV-infected subjects in Benin City, Nigeria.

METHODS

Whole blood was collected from a total of 564 HIV-infected and 250 apparently healthy HIV-negative subjects. Serodiagnosis of HBV infection was done using an immunochromatographic kit. Detection of HBV-DNA and sequencing of amplicons were done using standard molecular techniques.

RESULTS

HIV status was not significantly associated with HBV seroinfection (HIV vs. non-HIV: 4.6% vs. 4.0%; odds ratio = 1.168, 95% confidence interval = 0.550, 2.444, and P = 0.854). HIV-infected subjects were observed to have an insignificantly (P = 0.645) higher prevalence of true HBV infection than their non-HIV-infected counterparts (HIV positive vs. HIV negative: 23.1% vs. 10.0%). All patients with true HBV infection were found to harbor HBV genotype E, which did not cluster around other HBV genotype E.

CONCLUSION

This study reports novel strains of HBV genotype E circulating in Nigeria.

Molecular diversity in irregular or refugee immigrant patients with HBV-genotype-E infection living in the metropolitan area of Naples

In a recent testing in the metropolitan area of Naples, Italy, on 945 irregular immigrants or refugees, 87 HBsAg chronic carriers were identified, 53 of whom were infected by HBV-genotype E. The aim of the present study was to identify the genetic diversity of HBV-genotype E in these 53 immigrants. The 53 immigrant patients with HBV-genotype-E infection were born in Africa, central or eastern Asia, eastern Europe or Latin America. These patients had been seen for a clinical consultation at one of the four first-level units from January 2012 to 2013. The first dataset contained 53 HBV-S gene isolates plus 128 genotype/subgenotype specific reference sequences downloaded from the National Center for Biotechnology Information. The second dataset, comprising the 53 HBV-S gene isolates, previously classified as HBV-genotype E, was used to perform the time-scaled phylogeny reconstruction using a Bayesian approach. Phylogenetic analysis showed that all 53 HBV-S isolates belonged to HBV-genotype E. Bayes factor analysis showed that the relaxed clock exponential growth model fitted the data significantly better than the other models. The time-scaled Bayesian phylogenetic tree of the second dataset showed that the root of the tree dated back to the year 1990 (95% HPD:1984-2000). Four statistically supported clusters were identified. Cluster A dated back to 2012 (95% HPD:1997-2012); cluster B dated back to 2008 (95% HPD:2001-2015); cluster C to 2006 (95% HPD:1999-2013); cluster D to 2004 (95% HPD:1998-2011). This study disclosed the genetic evolution and phylogenesis in a group of HBV-genotype-E-infected immigrants. J. Med. Virol. 89:1015-1024, 2017. © 2016 Wiley Periodicals, Inc.

Hepatitis B virus genotypes A and D in Uganda

BACKGROUND

The prevalence of hepatitis B virus (HBV) infection in Uganda is 10%. Hepatitis B virus genotypes impact on treatment response, rate of spontaneous recovery and progression of chronic HBV infection and hepatocellular carcinoma. There is little information on the HBV genotypic distribution in Uganda.

OBJECTIVES

To determine HBV genotypes in Uganda.

METHODS

The MBN clinical laboratory performs HBV viral load and genotype testing in Uganda. It receives hepatitis B surface antigen (HBsAg)-positive samples from all over the country for additional HBV testing. Samples are stored for 6 months before being discarded. Our study used delinked stored samples. PCR-positive samples had DNA extracted and used as template for HBV genome amplification by nested PCR. Reverse hybridisation was performed and genotypes were determined by the line probe assay method (INNO-LiPA).

RESULTS

One hundred stored HBsAg-positive plasma samples with detectable viral loads were analysed. Of these, 93 samples showed PCR amplification products and gave genotype-specific probe lines on the INNO-LiPA assay. Of the patients, where gender was recorded, 60.9% were female, and the overall median age (IQR) was 25 (2-60) years. There was a predominance of HBV genotype D (47 patients; 50.5%), followed by genotype A, (16 patients; 17.2%). One patient (1.1%) had genotype E. In 28% of the samples mixed infections were detected with genotypes A/E (9.7%) and A/D (6.5%) being most common. Genotypes B, C, E and H only occurred as part of mixed infections.

CONCLUSION

Hepatitis B genotypes D and A were predominant in our study population.