Lamivudine for chronic hepatitis B and HIV co-infection

Predictors of loss of hepatitis B surface antigen in HIV-infected patients

AIM: To study factors associated with loss of hepatitis B surface antigen (HBsAg) in patients co-infected with human immunodeficiency virus (HIV) and hepatitis B virus (HBV).

METHODS: We retrospectively reviewed the medical records of 5681 patients followed up at two New York City HIV clinics from January 1999 to May 2007. Clinical and laboratory parameters including baseline and follow-up HIV viral loads, CD4 cell counts, alanine transaminase levels, demographics, presence of hepatitis C infection, and treatment with highly active antiretroviral therapy dually active against both HIV and HBV infection, were analyzed to determine factors associated with loss of HBsAg.

RESULTS: Three hundred and fifty five patients (355/5681, 6.84%) were co-infected with HIV and HBV and were evaluated. Of these, 226 patients with more than 12 mo follow-up were included in further analysis to determine factors associated with loss of HBsAg in the long-term follow-up. In the univariate analysis, baseline CD4 cell count was associated with loss of HBsAg (P = 0.052). Cox regression analysis revealed that loss of HBsAg was associated with baseline CD4 cell count > 500 cells/mm³ (P = 0.016, odds ratio: 76.174, 95% confidence interval: 2.233-2598.481).

CONCLUSION: Our study showed an interesting association of loss of HBsAg in HIV-HBV co-infected patients with higher CD4 cell count, suggesting that T-cell cytolytic activity against HBV may still be effective in clearing HBV infection.

Impact of highly active antiretroviral therapy (HAART) on the natural history of hepatitis B virus (HBV) and HIV coinfection: relationship between prolonged efficacy of HAART and HBV surface and early antigen seroconversion

BACKGROUND

Coinfection with hepatitis B virus (HBV) in human immunodeficiency virus (HIV)-infected patients is common. However, little is known about the natural history of chronic hepatitis B in HIV-infected populations, especially the impact of highly active antiretroviral therapy (HAART) on the outcome of HBV early antigen (HBeAg) and HBV surface antigen (HBsAg) status.

METHODS

The characteristics of 92 patients coinfected with HIV and HBV were retrospectively assessed before and after HAART and lamivudine treatment to determine the impact of treatment on chronic hepatitis B and factors associated with HBeAg and/or HBsAg seroconversion.

RESULTS

During follow-up, 82 patients received antiretroviral therapy, 79 of whom received HAART. Twenty-eight of the 76 patients who were administered lamivudine therapy developed lamivudine resistance mutations. While receiving antiretroviral therapy, 10 of 59 HBeAg-positive patients developed antibody to HBeAg, 3 of 10 cleared HBsAg, and 2 of 3 developed antibody to HBsAg. Two of 23 HBeAg-negative patients cleared HBsAg and developed antibody to HBsAg. HBeAg and/or HBsAg seroconversion combined with an undetectable HBV DNA level (i.e., an HBV response) correlated with a sustained HIV response (P=.001), shorter duration of antiretroviral therapy (P=.058), and more-severe disease, as evaluated by Centers for Disease Control and Prevention staging (for stage B vs. stage A, P=.029; for stage C vs. stage A, P=.069). For patients with elevated baseline alanine aminotransferase levels, the HBV response correlated significantly with a greater increase in CD4 cell count while receiving HAART.

CONCLUSIONS

In HIV-HBV-coinfected patients, HBV response correlated with a sustained HIV response to antiretroviral therapy, usually HAART including lamivudine.

Impact of viral hepatitis co-infection on response to antiretroviral therapy and HIV disease progression in the HIV-NAT cohort

OBJECTIVE

To examine the impact of viral hepatitis co-infection on HIV disease outcomes following commencement of combination antiretroviral therapy in a developing country setting.

METHODS

HIV RNA suppression, CD4 cell count recovery, and HIV disease progression were examined within a cohort of Thai HIV-infected patients enrolled in eight HIV-NAT randomized controlled trials of antiretroviral therapy (n = 692). Hepatitis B virus (HBV) and hepatitis C virus (HCV) testing was performed on stored serum.

RESULTS

Mean age was 32.3 years, 52% were male, 11% had CDC category C HIV disease at baseline, and 22% had received prior antiretroviral therapy. Prevalence of HBV, HCV and HBV/HCV co-infection was 8.7, 7.2 and 0.4%, respectively. Median HIV RNA reductions (log10 copies/ml) were approximately 1.5 for HIV, HIV-HBV, HIV-HCV subgroups from week 4 up to week 48. Mean increases in CD4 cell count were significantly lower among HIV-HBV and HIV-HCV subgroups at week 4 (HIV, 62 x 10(6) cells/l; HIV-HBV, 29 x 10(6) cells/l; HIV-HCV, 33 x 10(6) cells/l), however, by week 48 CD4 cell increases were similar (HIV, 115 x 10(6) cells/l; HIV-HBV, 113 x 10(6) cells/l; HIV-HCV, 97 x 10(6) cells/l). Cox regression analyses showed that HIV-HBV or HIV-HCV co-infection were not associated with a CD4 cell count increase of 100 x 10(6) cells/l over 48 weeks. Estimated progression to AIDS event or death at week 48 was 3.3% (95% confidence interval, 2.0-5.1%) for HIV, 6.7% (2.5-14.6%) for HIV-HBV, and 8.0% (2.2-20.5%) for HIV-HCV subgroups (P > 0.05).

CONCLUSIONS

An early delayed CD4 count recovery among HIV/viral hepatitis co-infected patients was not sustained, and was not associated with increased HIV disease progression.

Prevalence and characterization of lamivudine-resistant hepatitis B virus mutations in HIV-HBV co-infected individuals

OBJECTIVE

To determine the prevalence of hepatitis B virus (HBV) genotypic resistance to lamivudine, identify risk factors associated with lamivudine resistance, and characterize the pattern of HBV polymerase mutations in patients co-infected with HIV.

DESIGN

Retrospective cross-sectional study.

METHODS

Thirty-three chronic HBV-infected patients were identified from a cohort of 1719 HIV-infected individuals. Patient information was collected from case records, HBV DNA was measured on stored serum by polymerase chain reaction, and positive samples underwent sequencing of HBV polymerase, basal core promoter and precore regions.

RESULTS

Three groups of patients were identified: group 1 were viraemic in the absence of lamivudine-resistance mutations, group 2 were viraemic in association with lamivudine-resistance mutations, and group 3 were not viraemic. Group 2 patients with lamivudine-resistant mutations had significantly higher HBV-DNA viral loads but did not differ in duration of lamivudine therapy, HBV genotype, HIV viral load or CD4 cell count compared with patients with wild-type HBV. Group 2 individuals also demonstrated significantly higher serum alanine aminotransferase (ALT) levels than group 1, who were higher than group 3. Unique mutations were detected in HBV polymerase, including rtV173L plus rtL180M plus rtM204V, which occurred in three patients. This virus has the in-vitro characteristics of a 'vaccine escape' mutant of HBV.

CONCLUSION

Genotypic HBV lamivudine resistance was found in 39% of HIV-HBV co-infected individuals treated with lamivudine as part of highly active antiretroviral therapy. These patients exhibited significantly elevated HBV viral loads and serum ALT, and three were infected with a lamivudine-resistant HBV strain that was potentially transmissible to HBV-vaccinated individuals.

Activity of tenofovir on hepatitis B virus replication in HIV-co-infected patients failing or partially responding to lamivudine

Treatment of hepatitis B virus (HBV) with lamivudine may not completely suppress viral replication and often fails as a result of lamivudine resistance. Tenofovir is a new HIV inhibitor with further activity against HBV, which was explored in 12 HBV/HIV-co-infected patients with detectable levels of serum HBV-DNA, despite receiving a lamivudine-containing antiretroviral regimen. Lamivudine-resistance mutations were found in HBV from seven patients. HBV-DNA levels dropped a median of 3.78 logs from baseline to 24 weeks. Tenofovir was very effective at reducing HBV-DNA levels in HIV/HBV-co-infected patients carrying either wild-type or lamivudine-resistant viruses.

[Recommendations of the Spanish AIDS Study Group (GESIDA) and the National Aids Plan (PNS) for antiretroviral treatment in adult patients with human immunodeficiency virus infection in 2002]

OBJECTIVE

To provide an update of recommendation on antiretroviral treatment (ART) in HIV-infected adults.Methods. These recommendations have been agreed by consensus by a committee of the spanish AIDS Study Group (GESIDA) and the National AIDS Plan. To do so, advances in the physiopathology of AIDS and the results on efficacy and safety in clinical trials, cohort and pharmacokinetics studies published in biomedical journals or presented at congresses in the last few years have been reviewed. Three levels of evidence have been defined according to the data source: randomized studies (level A), case-control or cohort studies (level B) and expert opinion (level C). Whether to recommend, consider, or not to recommend ART has been established for each situation.

RESULTS

Currently, ART with combinations of at least three drugs constitutes the treatment of choice in chronic HIV infection. In patients with symptomatic HIV infection, initiation of ART is recommended. In asymptomatic patients initiation of ART should be based on the CD41/mL lymphocyte count and on the plasma viral load (PVL): a) in patients with CD41 lymphocytes < 200 cells/mL, initiation of ART is recommended; b) in patients with CD41 lymphocytes between 200 and 300 cells/mL, initiation of ART should, in most cases, be recommended; however, it could be delayed when the CD41 lymphocyte count remains close to 350 cells/mL and the PVL is low, and c) in patients with CD41 lymphocytes > 350 cells/mL, initiation of ART can be delayed. The aim of ART is to achieve an undetectable PVL. Adherence to ART plays a role in the durability of the antiviral response. Because of the development of cross-resistance, the therapeutic options in treatment failure are limited. In these cases, genotypic analysis is useful. Toxicity limits ART. The criteria for ART in acute infection, pregnancy and postexposure prophylaxis and in the management of coinfection with HIV and hepatitis C and B virus are controversial.

CONCLUSIONS

The current approach to initiating ART is more conservative than in previous recommendations. In asymptomatic patients, the CD41 lymphocyte count is the most important reference factor for initiating ART. Because of the considerable number of drugs available, more sensitive monitoring methods (PVL) and the possibility of determining resistance, therapeutic strategies have become much more individualized.

Hepatitis B

The management of acute HBV infection is supportive. Specific treatment is not indicated for HBV carriers because they often have no evidence of liver injury, and, further, do not respond to currently available therapies. Interferon monotherapy is best indicated for patients with chronic replicating HBV infection and evidence of chronic hepatitis. There is an increased likelihood of clearing HBsAg with interferon monotherapy as compared to lamivudine. Lamivudine is an oral nucleoside analog that is better tolerated than interferon. The clinical situations for its use are far more than interferon monotherapy. Lamivudine should be used in patients with decompensated cirrhosis and also in transplantation, both before and after transplantation. The post-transplant use of hepatitis B immune globulin (HBIG) and lamivudine combination therapy may be better for recipients who are identified in a replicative phase prior to transplantation. Hepatitis B coinfection with one or more viruses, HCV, HDV, or HIV, may occur. Both interferon and lamivudine have been useful in these patients. However, the data are sparse and heterogeneous. Therapy with one or both drugs will have to be tailored to the clinical situation. Combination therapy with immunomodulatory and/or antiviral drugs are what we will be looking toward in the future.