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Editorial
Board:
Emmet B. Keeffe, MD (Chair); |
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HBV Watch™ |
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Timely Information for Practicing Physicians |
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July
2004
Coinfection
WITH Hepatitis B virus (HBV) AND Human Immunodeficiency Virus (HIV)
Topic
review. Coinfection with HBV and HIV is common,
stemming from similar routes of transmission.
A consequence of longer survival of patients with HIV infection after
institution of highly active antiretroviral therapy (HAART) has been the
development of chronic liver disease due to hepatitis B and C. Despite the suggestion that HBV may increase
HIV replication, chronic HBV infection does not seem to influence the
progression of HIV disease or the response to HAART. In contrast, studies have shown an increased
risk of chronic HBV infection after acute hepatitis B in HIV-infected
individuals, particularly in those with lower CD4+ counts. Others have
demonstrated higher rates of viral replication, and also decreased rates of HBV
DNA clearance and HBeAg seroconversion in HIV patients. Similar to hepatitis C virus-HIV coinfection,
there is an increased risk of progression to cirrhosis in HBV-HIV
patients. Furthermore, the risk of HBeAg
reactivation was found to be higher in HIV-infected patients. Although HAART is associated with a potential
risk for hepatotoxicity, the development of clinical hepatitis in coinfected
individuals is often related to flare of HBV due to immune reconstitution.
Thus, it is clear that the morbidity and mortality associated with chronic
hepatitis B is increased in HIV-infected patients. However, HBV is preventable by vaccination. Although the response to vaccination is
poorer among those infected with HIV, it is important to administer a complete
series of vaccinations to prevent HBV infection in susceptible individuals.
Impact of HBV coinfection on outcomes of HIV
patients. In Western countries where sharing needles
and homosexuality are the 2 major routes of HIV transmission, the prevalence of
chronic HBV coinfection in HIV patients ranges from 6% to 10%. However, the prevalence of HBV coinfection in
HIV patients has rarely been reported in countries where vertical transmission
of HBV is common. In addition,
coinfection with HIV and HBV may result in complex interactions that adversely
affect patient outcomes because HIV impairs cellular immunity allowing
increased replication of HBV and HBV in turn enhances HIV replication. Due to these findings, Wang-Huei Sheng and
colleagues at the National Taiwan University Hospital conducted a prospective
observational study between June 1994 and February 2003 of 498 HIV-infected patients
(111 patients with chronic HBV coinfection and 387 patients without HBV or HCV
coinfection) to assess the impact of HBV coinfection on clinical outcomes of
HIV-infected patients in a region where HBV infection is hyperendemic. Similar proportions of patients in both
treatment groups experienced an increase in CD4 counts and developed new
opportunistic infections. However,
coinfected patients were at greater risk to develop hepatitis and hepatic
decompensation. Furthermore, despite
treatment with HAART, coinfected patients were at increased risk for
virological failure and death. These
results demonstrated that HBV coinfection has an adverse impact on the outcomes
of HIV-infected patients. Patients with HIV infection should undergo HBV
vaccination regular monitoring of liver function tests. (Sheng W-H, et al. Clin Infect Dis 2004;38:1471-1477)
HEPATITIS A AND B VACCINATION PRACTICES
Adherence to guidelines. Although vaccinations for hepatitis A and
B have been recommended by the Advisory Committee on Immunization Practices
(ACIP) for several years, few studies have examined the adherence to these
guidelines. Thus, Ellen Tedaldi and
others retrospectively reviewed data obtained from 9 clinic sites located in 7
PEDIATRIC CHRONIC HBV INFECTION
Predictors of virological response to
lamivudine therapy. Children with chronic HBV infection are often
asymptomatic, but may develop cirrhosis or hepatocellular carcinoma. The therapeutic goal of antiviral therapy is
HBeAg loss or seroconversion. HBeAg
seroconversion is usually preceded by a decrease in serum HBV DNA levels to
<105 genome copies/mL which correlates with normalization of ALT
levels and histological improvement. The
availability of an oral agent with minimal toxicity such as lamivudine is an
attractive alternative to interferon for children. Xenia Hom et al. analyzed data from a
double-blind international study in which 297 children aged 2-17 years with
chronic HBV infection were randomized in a 2:1 ratio to receive either
lamivudine 3 mg/kg (up to a maximum of 100 mg) once daily or matching placebo
for 52 weeks. Treatment with lamivudine
was associated with a higher virological response rate than placebo
administration (23% vs. 13%; p = 0.039).
Univariate analysis revealed that higher ALT level, higher histologic
activity index (HAI) score, and lower HBV DNA level at baseline predicted a
greater likelihood for virological response to lamivudine. Multivariate analysis identified only
baseline ALT level and HAI score to be predictive for response. These data allow for a more precise patient
selection for the use of lamivudine to treat children with chronic HBV
infection. (Hom X, et al. Pediatr Infect Dis J 2004;23:441-445)
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