Prolonged use of tenofovir in HIV/hepatitis B virus (HBV)-coinfected individuals does not lead to HBV polymerase mutations and is associated with persistence of lamivudine HBV polymerase mutations

Long-Term TDF-Inclusive ART and Progressive Rates of HBsAg Loss in HIV-HBV Coinfection-Lessons for Functional HBV Cure?

BACKGROUND

Tenofovir disoproxil fumarate (TDF) is effective in suppressing HIV and hepatitis B virus (HBV) replication in HIV-HBV coinfection although HBV DNA can persist in some individuals on TDF-containing antiretroviral therapy (ART). We initiated a prospective longitudinal study to determine durability of HBV virological control and clinical outcomes after prolonged TDF-based ART in HIV-HBV coinfection.

METHODS

Ninety-two HIV-HBV coinfected participants on, or about to commence, TDF-containing ART from Australia (n = 41) and Thailand (n = 52) were enrolled. Participants were followed 6-monthly for 2 years, then annually to 5 years. Laboratory and clinical assessments and a serum sample were collected at each study visit. These analyses compare follow-up at 2 and 5 years.

RESULTS

12.0% (95% confidence interval 6.8 to 20.2) of total study entry cohort (n = 92) or 15.3% (95% confidence interval: 8.8 to 25.3) of those with data to year 5 (n = 72) lost hepatitis B surface antigen (HBsAg). The only statistically significant association with HBsAg loss was lower study entry quantitative HBsAg. CD4 T-cell count increased by a median 245 cells/mm3 between the preTDF sample and 5 years of follow-up. By year 5, 98.5% of the cohort had undetectable HBV DNA (<15 IU/mL) and 91.4% had undetectable HIV RNA (<20 copies/mL).

CONCLUSIONS

HBsAg loss was high and ongoing over 5 years of follow-up in HIV-HBV coinfected individuals on TDF-containing ART and undetectable HBV was almost universal. Although the pattern of HBsAg loss temporarily parallels immune reconstitution, we could not identify predictive immune markers. The high rate of HBsAg loss in HIV-HBV coinfection may offer valuable insights into the search for a functional HBV cure.

Consensus document of the Spanish Association for Study of the Liver on the treatment of hepatitis B virus infection (2020)

Hepatitis B virus (HBV) infection remains a global public health problem. HBV vaccination is the most effective tool to reduce the incidence of HBV disease. Despite there has not been new clinical developments for the treatment of chronic hepatitis B in the last few years, changing epidemiology and current insights on natural history, diagnostic tools and therapy indications make necessary an update of the former version of the consensus document of the Spanish Association for Study of the Liver on the treatment of hepatitis B infection published in 2012. The current document updates the management of chronic hepatitis B. The treatment of choice is the long-term administration of a nucleos(t)ide analogue with high barrier to resistance (entecavir, tenofovir or tenofovir alafenamide). Pegylated interferon may be an option in patients with non-advanced liver disease, but its applicability is limited due to the low efficacy and poor tolerability. All patients must be monitored for the risk of progression to advanced liver disease and development of hepatocellular carcinoma.

Antiretroviral Effects on HBV/HIV Co-infection and the Natural History of Liver Disease

Hepatitis B virus (HBV) coinfection is common in persons with human immunodeficiency virus (HIV) infection, contributing significantly to morbidity and mortality. Many currently used HIV antiretroviral therapy (ART) regimens provide potent anti-HBV activity and it is recommended that HBV-HIV coinfected persons be treated with ART regimens containing tenofovir. ART has multiple benefits, including increasing rates of HBV clearance after initial infection and potent suppression of HBV DNA in chronic infection. Nevertheless, long-term studies have yet to demonstrate a profound positive impact of ART on HBV-related fibrosis progression and development of endstage liver disease.

Naturally occurring hepatitis B virus reverse transcriptase mutations related to potential antiviral drug resistance and liver disease progression

The annual number of deaths caused by hepatitis B virus (HBV)-related disease, including cirrhosis and hepatocellular carcinoma (HCC), is estimated as 887000. The reported prevalence of HBV reverse transcriptase (RT) mutation prior to treatment is varied and the impact of preexisting mutations on the treatment of naïve patients remains controversial, and primarily depends on geographic factors, HBV genotypes, HBeAg serostatus, HBV viral loads, disease progression, intergenotypic recombination and co-infection with HIV. Different sensitivity of detection methodology used could also affect their prevalence results. Several genotype-dependent HBV RT positions that can affect the emergence of drug resistance have also been reported. Eight mutations in RT (rtL80I, rtD134N, rtN139K/T/H, rtY141F, rtM204I/V, rtF221Y, rtI224V, and rtM309K) are significantly associated with HCC progression. HBeAg-negative status, low viral load, and genotype C infection are significantly related to a higher frequency and prevalence of preexisting RT mutations. Preexisting mutations are most frequently found in the A-B interdomain of RT which overlaps with the HBsAg “a” determinant region, mutations of which can lead to simultaneous viral immune escape. In conclusion, the presence of baseline RT mutations can affect drug treatment outcomes and disease progression in HBV-infected populations via modulation of viral fitness and host-immune responses.

HIV-hepatitis B virus coinfection: epidemiology, pathogenesis, and treatment

: HIV infection has a significant impact on the natural history of chronic hepatitis B virus (HBV) infection, with increased levels of HBV DNA, accelerated progression of liver disease and increased liver-associated mortality compared with HBV monoinfection. Widespread uptake and early initiation of HBV-active antiretroviral therapy has substantially improved the natural history of HIV-HBV coinfection but the prevalence of liver disease remains elevated in this population. In this paper, we review recent studies examining the natural history and pathogenesis of liver disease and seroconversion in HIV-HBV coinfection in the era of HBV-active antiretroviral therapy and the effects of HIV directly on liver disease. We also review novel therapeutics for the management of HBV with a particular emphasis on clinical strategies being developed for an HBV cure and an HIV cure and their impact on HIV-HBV coinfected individuals.

Molecular epidemiology of co-infection with hepatitis B virus and human immunodeficiency virus (HIV) among adult patients in Harare, Zimbabwe

The objective of this study was to determine the prevalence of co-infection with hepatitis B virus (HBV) and human immunodeficiency virus (HIV) and the genetic characteristics of both viruses among pre-HIV-treatment patients in Harare, Zimbabwe. This cross-sectional survey involved 176 remnant plasma samples collected from consenting HIV patients (median age 35 [18-74]) between June and September 2014. HBV seromarkers were determined by high-sensitivity chemiluminescence assays. Molecular evolutionary analyses were conducted on the basal core promoter/precore (BCP/PC) and S regions of HBV, as well as part of the HIV pol region. Of the 176 participants (65.7% female), 19 (10.8%) were positive for HBsAg (median 0.033 IU/ml (IQR 0.01-415). The HBsAg incidence was higher in men than women (P = 0.009). HBsAg-positive subjects had lower median CD4 counts (P = 0.016). HBV DNA was detectable in 12 HBsAg-positive samples (median 3.36 log cp/ml (2.86-4.51), seven being amplified and sequenced. All isolates were subgenotype A1 without HBV drug resistance mutations but each had at least one BCP/PC mutation. PreS deletion mutants and small S antigen variants M133I/T and D144G were identified. Of the 164 HIV isolates successfully genotyped, 163 (99.4%) were HIV-1 subtype C and only one was HIV-1 subtype F1. Sixteen (9.8%) had at least one drug resistance mutation, predominantly non-nucleoside reverse transcriptase inhibitor-related mutations, observed mostly among female participants. This study shows that co-infection with HBV is present among HIV patients enrolling into HIV care in Zimbabwe, suggesting that HBV screening and monitoring programmes be strengthened in this context. J. Med. Virol. 89:257-266, 2017. © 2016 Wiley Periodicals, Inc.

Effects of long-term tenofovir-based combination antiretroviral therapy in HIV-hepatitis B virus coinfection on persistent hepatitis B virus viremia and the role of hepatitis B virus quasispecies diversity

OBJECTIVE

Hepatitis B virus (HBV) can persist in some HIV-HBV coinfected individuals on tenofovir disoproxil fumarate (TDF)-containing combination antiretroviral therapy (cART) but HBV resistance to TDF has not been reported and the source of persistent HBV DNA on TDF is poorly understood. The aims of this study were to assess long-term HBV suppression in HIV-HBV coinfected individuals receiving TDF and investigate quasispecies variation using ultradeep pyrosequencing (UDPS).

METHODS

Ninety-two HIV-HBV coinfected participants on, or about to commence, TDF-containing cART were enrolled [Australia (n = 40), Thailand (n = 52)] and followed for 2 years with study visits every 6 months. HBV reverse transcriptase sequencing was performed on samples with HBV DNA more than 400 IU/ml by population-based methods and UDPS. Quasispecies diversity was assessed using Shannon entropy.

RESULTS

Over 24 months, viremia was detected at least once in 17% (n = 16) of the cohort. Novel mutations were not identified in on TDF samples tested by population-based sequencing (n = 19). Using UDPS, the median Shannon entropy value in samples prior to TDF in patients aviremic on TDF was not statistically different from those who were viremic on TDF (n = 50; 8.4 and 9.1, respectively, P = 0.9). Longitudinal Shannon entropy analysis of on TDF samples from five participants showed three individuals with significant changes in viral diversity over time.

CONCLUSION

Persistent viremia on TDF-containing cART is common but TDF-resistance was not detected. In some individuals, changes in viral diversity over time were observed on TDF which could potentially be active viral replication. Further follow-up will be needed to determine the clinical significance of detectable HBV DNA on TDF-containing cART.

A computational chemistry perspective on the current status and future direction of hepatitis B antiviral drug discovery

Computational chemical biology, applied to research on hepatitis B virus (HBV), has two major branches: bioinformatics (statistical models) and first-principle methods (molecular physics). While bioinformatics focuses on statistical tools and biological databases, molecular physics uses mathematics and chemical theory to study the interactions of biomolecules. Three computational techniques most commonly used in HBV research are homology modeling, molecular docking, and molecular dynamics. Homology modeling is a computational simulation to predict protein structure and has been used to construct conformers of the viral polymerase (reverse transcriptase domain and RNase H domain) and the HBV X protein. Molecular docking is used to predict the most likely orientation of a ligand when it is bound to a protein, as well as determining an energy score of the docked conformation. Molecular dynamics is a simulation that analyzes biomolecule motions and determines conformation and stability patterns. All of these modeling techniques have aided in the understanding of resistance mutations on HBV non-nucleos(t)ide reverse-transcriptase inhibitor binding. Finally, bioinformatics can be used to study the DNA and RNA protein sequences of viruses to both analyze drug resistance and to genotype the viral genomes. Overall, with these techniques, and others, computational chemical biology is becoming more and more necessary in hepatitis B research. This article forms part of a symposium in Antiviral Research on "An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for hepatitis B."

High incidence of lamivudine-resistance-associated vaccine-escape HBV mutants among HIV-coinfected patients on prolonged antiretroviral therapy

BACKGROUND

Worldwide, frequent emergence of lamivudine (3TC)-resistant HBV mutants has been reported in HIV-HBV-coinfected patients during long-term antiretroviral therapy (ART) that contains 3TC as the sole anti-HBV drug. Three major patterns of mutations in HBV polymerase gene, namely single (rtM204V), double (rtL180M+rtM204V) and triple (rtV173L+rtL180M+rtM204V) mutations, are associated with 3TC-resistance; additionally, the triple mutation has vaccine-escape potential due to a corresponding change in overlapping surface gene. Data from India, a major reservoir for HIV and HBV infection, is lacking. Here we investigated the effect of long-term 3TC treatment on virological response for HBV and characterized the 3TC-resistant HBV mutations in a cohort of HIV-HBV-coinfected patients from eastern India.

METHODS

A cross-sectional study was performed in HIV-infected patients (n=563) receiving 3TC-containing ART for ≥6 months from the major ART centre of eastern India during 2011-2012. The hepatitis B surface antigen-positive HIV-infected patients (n=62) were categorized into four groups with comparable sample size according to the 3TC exposure for ≥6-<12 months (group I; n=15), ≥12-<24 months (group II; n=20), ≥24-<48 months (group III; n=13) and ≥48 months (group IV; n=14). Patients' plasma samples were examined for hepatitis B e antigen (HBeAg), HBV DNA, viral load and covalently closed circular DNA (cccDNA). HBV reverse transcriptase region was sequenced.

RESULTS

With a longer period of 3TC exposure, the frequency of HIV-HBV-coinfected patients having HBV DNA suppression decreased. The prevalence of HBeAg-positivity, serum HBV DNA load >2,000 IU/ml and 3TC-resistant mutations simultaneously increased. Remarkably, the 3TC-resistant triple mutation predominated over the double mutation in this cohort (32.26% versus 19.34%) and prevailed in significantly higher frequency among HBV viraemic patients experiencing 3TC for ≥48 months (60% versus 10%; P=0.03). Patients with 3TC-resistant triple mutants had HBV genotype-D, high serum HBV DNA load and elevated alanine aminotransferase level, and presence of cccDNA in their serum.

CONCLUSIONS

Considering this alarmingly high incidence of 3TC-resistant triple mutation and its possible clinical/public health implications, proper management of 3TC-resistance among HIV-HBV-coinfected patients is an urgent necessity in India.

Factors associated with delayed hepatitis B viral suppression on tenofovir among patients coinfected with HBV-HIV in the CNICS cohort

BACKGROUND

Despite widespread use in HIV and hepatitis B virus (HBV) infection, the effectiveness of tenofovir (TDF) has not been studied extensively outside of small cohorts of coinfected patients with HBV-HIV. We examined the effect of prior lamivudine (3TC) treatment and other factors on HBV DNA suppression with TDF in a multisite clinical cohort of coinfected patients.

METHODS

We studied all patients enrolled in the Centers for AIDS Research Network of Integrated Clinical Systems cohort from 1996 to 2011 who had chronic HBV and HIV infection, initiated a TDF-based regimen continued for ≥ 3 months and had on-treatment HBV DNA measurements. We used Kaplan-Meier curves and Cox-proportional hazards to estimate time to suppression (HBV DNA level <200 IU/mL or <1000 copies/mL) by selected covariates.

RESULTS

Among 397 coinfected patients on TDF, 91% were also on emtricitabine or 3TC concurrently, 92% of those tested were hepatitis B e antigen positive, 196 (49%) had prior 3TC exposure; 192 (48%) achieved HBV DNA suppression over a median of 28 months (interquartile range: 13-71). Median time to HBV DNA suppression was 17 months for those who were 3TC-naive and 50 months for those who were 3TC exposed. After controlling for other factors, prior 3TC exposure, baseline HBV DNA level >10,000 IU/mL, and lower nadir CD4 count were independently associated with decreased likelihood of HBV DNA suppression on TDF.

CONCLUSIONS

These results emphasize the role of prior 3TC exposure and immune response on delayed HBV suppression on TDF.

Case report: management and HBV sequencing in a patient co-infected with HBV and HIV failing tenofovir

Nucleos(t)ide analogs such as tenofovir, lamivudine, or emtricitabine are active against both HBV and HIV. Tenofovir confers potent and durable HBV-DNA suppression but the best strategy in case of resistance of HBV to tenofovir remains unknown. A case of a 22-year-old patient with co-infection with HBV and HIV transmitted perinatally is reported. After prolonged and intermittent treatment of HIV with lamivudine and tenofovir, HBV became resistant to lamivudine. Subsequently, clinical resistance to tenofovir occurred, manifesting as HBV-DNA breakthrough. The non-compliance was reasonable excluded and HIV-RNA remained constantly suppressed. Entecavir (1 mg daily) was added and the combination therapy resulted in a rapid and continuous suppression of HBV-DNA for over 12 months. The treatment was well-tolerated and safe. No known mutations, such as rtA181T/V associated with rtN236T or A194T that are associated with reduced susceptibility or resistance to tenofovir were detected. However, a unique and complex HBV substitution pattern was found: with a development of rtR192PR mutation at the time of virological failure. Adding entecavir to failing therapy with tenofovir and emtricitabine was feasible, well-tolerated and resulted in virological success. The rtR192PR, which is located in the B domain near the rtA194T, occurring in a context of a very complex substitutions patterns, might be associated with resistance to tenofovir.

Genotyping and molecular characterization of hepatitis B virus from human immunodeficiency virus-infected individuals in southern Africa

Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) are hyperendemic in sub-Saharan Africa. The HBV genotypes prevailing in HIV-infected Africans are unknown. Our aim was to determine the HBV genotypes in HIV-infected participants and to identify clinically significant HBV mutations. From 71 HBV DNA^+ve HIV-infected participants, 49 basic core promoter/precore (BCP/PC) and 29 complete S regions were successfully sequenced. Following phylogenetic analysis of 29 specimens in the complete S region, 28 belonged to subgenotype A1 and one to D3. Mutations affecting HBeAg expression at the transcriptional (1762T1764A), translational (Kozak 1809–1812, initiation 1814–1816, G1896A with C1858T), or post translational levels (G1862T), were responsible for the high HBeAg-negativity observed. The G1862T mutation occurred only in subgenotype A1 isolates, which were found in one third (7/21) of HBsAg^−ve participants, but in none of the 18 HBsAg^+ve participants (p<0.05). Pre-S deletion mutants were detected in four HBsAg^+ve and one HBsAg^−ve participant/s. The following mutations occurred significantly more frequently in HBV isolated in this study than in strains of the same cluster of the phylogenetic tree: ps1F25L, ps1V88L/A; ps2Q10R, ps2 R48K/T, ps2A53V and sQ129R/H, sQ164A/V/G/D, sV168A and sS174N (p<0.05). ps1I48V/T occurred more frequently in females than males (p<0.05). Isolates with sV168A occurred more frequently in participants with viral loads >200 IU per ml (p<0.05) and only sS174N occurred more frequently in HBsAg^−ve than in HBsAg^+ve individuals (p<0.05). Prior to initiation of ART, ten percent, 3 of 29 isolates sequenced, had drug resistance mutations rtV173L, rtL180M+rtM204V and rtV214A, respectively. This study has provided important information on the molecular characteristics of HBV in HIV-infected southern Africans prior to ART initiation, which has important clinical relevance in the management of HBV/HIV co-infection in our unique setting.

Clinical and virological characteristics of hepatitis B or C virus co-infection with HIV in Indonesian patients

Hepatitis virus-related liver disease increases substantially the mortality rate of patients with HIV on highly active antiretroviral therapy (HAART). Therefore, early diagnosis of hepatitis B virus (HBV) and hepatitis C virus (HCV) is important. However, the prevalence of HBV and HCV infection in Indonesian patients infected with HIV is unknown. Therefore, this study examined the molecular and clinical characteristics of HBV and HCV in 126 patients infected with HIV, mostly on HAART, at Dr. Sardjito Hospital, Yogyakarta, Indonesia. The rates of triple infection, HIV/HCV co-infection, HIV/HBV co-infection, and mono-infection were 4.8%, 34.1%, 3.2%, and 57.9%, respectively. Seven HCV genotypes were detected, with genotypes 1a, 1b, 1c, 3a, 3k, 4a, and 6n found in 23 (52%), 1 (2%), 4 (9%), 5 (11%), 7 (16%), 3 (6%), and 1 (2%) patients, respectively, indicating multiple modes of transmission. HBV-DNA was detected in 2/10 patients with hepatitis B surface antigen; both patients were HAART naive. Univariate analysis revealed that male sex, higher education level, injection drug use, sexual contact, alanine aminotransferase ≥40 IU/L, and aspartate aminotransferase-to-platelet ratio index > 0.5 were associated with HCV co-infection. In multivariate analysis, injection drug use (OR: 26.52; 95% CI: 3.52-199.54) and alanine aminotransferase ≥40 IU/L (OR: 6.36; 95% CI: 1.23-32.89) were independently associated with HCV co-infection. HCV co-infection was common among Indonesian patients infected with HIV, particularly among injecting drug users, and was a risk factor for disease progression of HIV.

Long-term outcome of primary non-responders to tenofovir therapy in HIV/HBV-co-infected patients: impact of HBV genotype G

AIM

To evaluate the early virological response (EVR) to combined tenofovir-lamivudine or emtricitabine regimen in HBV/HIV-co-infected patients and the long-term efficacy of tenofovir.

METHODS

In this retrospective monocentric study, among the 166 HIV/HBV-co-infected patients regularly followed from 2003 to 2008 at Bichat Claude Bernard Hospital, 61 patients had received, either de novo combination therapy with tenofovir and lamivudine or emtricitabine (group I, n = 15) or add-on tenofovir to lamivudine therapy (group II, n = 46). The HBV polymerase region was sequenced and analysed for all patients with available samples.

RESULTS

All 15 group I patients achieved EVR vs 32 (82%) of group II patients (P = 0.15). Seven adherent group II patients met criteria for primary non-response, but achieved delayed response (DR) to therapy. In these seven patients, when compared with the 39 group II patients, there was a trend to longer duration of lamivudine pre-treatment and to higher rate of lamivudine-resistant mutants; and HBV genotype-G proportion was higher (P = 0.026). No virological breakthrough occurred after a median of 46 months follow up.

CONCLUSION

In these HBV/HIV-co-infected patients, first-line HBV therapy with tenofovir and emtricitabine or lamivudine was associated with EVR. However, DR to tenofovir was observed in 15% of patients who added tenofovir to lamivudine therapy, of whom four of seven (57%) had genotype G-HBV infection. No resistance was evidenced after 46 months of therapy even in patients with DR to tenofovir. At last, a good renal safety profile of TDF was observed after a median follow-up of 4 years of therapy.

Hepatitis B virus drug resistance to current nucleos(t)ide analogs: Mechanisms and mutation sites

Nucleos(t)ide analogs (NAs) have become the mainstream drugs for the treatment of chronic hepatitis B virus infection. Drug resistance to NAs, however, has posed a major obstacle in obtaining sustained viral suppression. Standardized definitions of terms and nomenclature in discussing NAs resistance have been proposed. Drug resistance to NAs is produced by a combination of viral, host and antiviral drug factors. A detailed understanding of the mechanisms and effects of mutation sites that cause resistance to NAs is important for the design of rational treatment and management of patients with existing drug resistance.

Efficacy of tenofovir disoproxil fumarate/emtricitabine compared with emtricitabine alone in antiretroviral-naive HIV-HBV coinfection in Thailand

BACKGROUND

Therapy for chronic hepatitis B with tenofovir disoproxil fumarate (TDF) and lamivudine (3TC) or emtricitabine (FTC) is currently recommended for HIV-HBV coinfection. However, there is limited randomized data on the efficacy of combined therapy with TDF and FTC, especially in antiretroviral (ARV)-naive patients.

METHODS

This was a prospective randomized clinical trial comparing the efficacy of HBV monotherapy with FTC versus TDF/FTC combination therapy in ARV-naive HIV-HBV coinfection. HIV-HBV-coinfected patients initiating ARV were randomized to either FTC/zidovudine/efavirenz (EFV; n=6) or TDF/FTC/EFV (n=10). The primary end point was the time-weighted area under the curve (TWAUC) of HBV DNA at 48 weeks.

RESULTS

The median baseline CD4(+) T-cell count was 64 cells/μl (interquartile range [IQR] 36-172), plasma HIV type-1 RNA was 4.90 log(10) copies/ml (IQR 4.58-5.44) and plasma HBV DNA was 8.76 log(10) copies/ml (IQR -8.45-8.82). A total of 11/16 (69%) patients were hepatitis B e antigen (HBeAg)-positive. The median TWAUC decrease in HBV DNA was -5.32 log(10) copies/ml in the TDF/FTC group compared with -3.25 log(10) copies/ml in the FTC group (P=0.03). At week 48, 90% of the TDF/FTC group and 33% of the FTC group had plasma HBV DNA<170 copies/ml (P=0.036, intention-to-treat analysis). HBeAg loss was observed in 4/11 (36%) HBeAg-positive patients. Hepatic flares were observed in 3/16 (19%) of patients.

CONCLUSIONS

TDF/FTC combination therapy resulted in a significantly greater decrease in HBV DNA than FTC monotherapy, with a greater proportion of patients with undetectable HBV DNA at week 48. Our study supports the current recommendation of ARV containing TDF/FTC as the treatment of choice for patients with HIV-HBV coinfection.

Management and treatment of chronic hepatitis B virus infection in HIV positive and negative patients: the EPIB 2008 study

BACKGROUND & AIMS

To compare the management and the virological and serological efficacy of treatments for chronic hepatitis B (CHB) in HIV positive and negative patients.

METHODS

Two hundred and forty-six HIV positive and 205 HIV negative consecutive patients with past or present CHB, seen in October 2008 in participating departments, were included in a multicenter study. All the data were retrospectively collected from the first visit to October 2008 through a standardized questionnaire.

RESULTS

Compared to HIV negative patients, HIV positive patients more often presented positive HBeAg (46.4% vs. 32.8%, p=0.01), HBV genotype A (54.8% vs. 17.1%, p<0.0001), co-infection with HCV (12.4% vs. 5.9%, p=0.0002) or HDV (12.6% vs. 2.9%, p=0.04). HIV positive patients were more often on HBV therapy (92.7% vs. 57.1%, p<0.0001), leading to undetectable serum HBV DNA levels (71.0% vs. 44.1%, p<0.0001). In HIV positive patients, multivariate analysis showed that older age, lower initial HBV DNA levels, and longer time on HBV therapy significantly correlated with undetectable HBV DNA. No difference in efficacy was observed between tenofovir used alone or in combination. HBsAg (but not HBe) loss was more often observed in HIV positive patients, sometimes followed by HBsAg re-appearance after withdrawal of HBV treatment. Excluding the 37 HBV-HCV-co-infected patients, the last clinical presentation and liver fibrosis scores were similar in HIV positive and negative patients.

CONCLUSIONS

The assessment of CHB and the efficacy of HBV therapy have improved in HIV positive patients. HIV infection did not have a negative impact on the likelihood of HBV therapeutic success.

Virology and clinical sequelae of drug-resistant HBV in HIV-HBV-coinfected patients on highly active antiretroviral therapy

Several of the nucleoside/nucleotide analogues used to treat HIV also inhibit HBV replication, with lamivudine being the oldest of this group. Thus, prior to licensing of tenofovir, many HIV-HBV-coinfected individuals received lamivudine as the only drug active against HBV as part of an anti-HIV regimen, which set the stage for the emergence of drug-resistant HBV. In coinfected persons, lamivudine-resistant HBV develops more rapidly than in HBV-monoinfected persons, but it is not known if this is true for the newer agents. Owing to overlapping reading frames of the HBV polymerase and surface antigens, drug-resistant changes in HBV Pol can lead to mutations in the envelope. This review will discuss studies of drug-resistant HBV in HIV-infected persons including drug-resistant mutations that have been identified and clinical sequelae of these mutations.

Is there Emergence of Clinical HBV Resistance Under Long-Term HBV Combination Therapy? A Challenging Case Report

A first case of clinical tenofovir (TDF) HBV resistance in an HIV/HBV coinfected patient who developed an acute flare of hepatitis B is reported. The clinical course was accompanied by signs of acute liver failure after being on successful HBV treatment with tenofovir and persistently undetectable HBV-DNA viral load for over five years.

Safety and efficacy of telbivudine for the treatment of chronic hepatitis B

Telbivudine was recently approved for the treatment of chronic hepatitis B. Phase III studies indicated its antiviral potency with 6- to 6.5-log copies/mL reductions in hepatitis B DNA levels at year 1, comparable to other potent agents such as entecavir or tenofovir. Genotypic resistance rates, however, reached 25% at year 2 in hepatitis B e-antigen positive subjects and 11% in hepatitis B e-antigen negative subjects, preventing it from becoming a preferred first-line drug for hepatitis B. Furthermore, its signature resistance mutation (a change from methionine to isoleucine at position 204 in the reverse transcriptase domain of the hepatitis B polymerase) also confers cross-resistance to entecavir, lamivudine, and emtricitabine. Telbivudine is well tolerated, with elevations in creatine phosphokinase being the most common abnormality observed in clinical trials. Most often, elevations were asymptomatic. Future research in hepatitis B will focus on the best ways to use existing therapies, including telbivudine, sequentially or in combination in order to maximize viral suppression and minimize the development of antiviral resistance.

The pathogenesis of liver disease in the setting of HIV–hepatitis B virus coinfection

There are many potential reasons for increased liver-related mortality in HIV–hepatitis B virus (HBV) coinfection compared with either infection alone. HIV infects multiple cells in the liver and might potentially alter the life cycle of HBV, although evidence to date is limited. Unique mutations in HBV have been defined in HIV–HBV-coinfected individuals and might directly alter pathogenesis. In addition, an impaired HBV- specific T-cell immune response is likely to be important. The roles of microbial translocation, immune activation and increased hepatic stellate cell activation will be important areas for future study.