HIV
Positive Individuals Are at Higher Risk of Occult Hepatitis B Virus Infection,
but Occult Hepatitis C Virus Is Rare
By
Liz Highleyman Occult
viral hepatitis refers to persistent hepatitis B
virus (HBV) or hepatitis C virus (HCV) infection
in the absence of the usual serological markers (antigens or antibodies in the
blood). Such infections can be identified by testing for viral genetic material
(HBV DNA or HCV RNA). Various
prior studies have estimated the prevalence of occult HBV at 0% to 89%, and the
prevalence of occult HCV at 0% to 13%. As described in a presentation at the XVII
International AIDS Conference this month in Mexico City, Lynn Taylor from
Brown University and colleagues sought to determine the prevalence of occult HBV
and HCV in individuals with HIV. The
investigators conducted a retrospective analysis of data from 549 HIV positive
and 296 at-risk HIV negative women in the HIV Epidemiology Research Study (HERS)
collected between 1993 and 2000. Age, race/ethnicity, and HIV risk factors were
similar in the 2 groups; 60% were black, 22% were white, and 15% were Latina. Hepatitis
B virus (HBV) Structure 
The
women were assessed at 3 time points. Occult HBV was defined as persistent plasma
HBV DNA without detectable hepatitis B surface antigen (HBsAg), but usually with
detectable hepatitis B core antibodies (HBcAb). Occult HCV was defined as detectable
HCV RNA without detectable antibodies to the virus. Two distinct time points were
used to differentiate between occult infection and either acute infection (before
the immune system has produced enough antibodies to detect) or HBV clearance with
HBsAg loss. Results
•
During the
baseline study visit, 2.6% of the women had detectable HBsAg, 52% were positive
for hepatitis B core antibodies, and 54% were positive for HCV antibodies.
•
Among the 44
women initially classified as having potential occult HBV, some progressed to
chronic infection (suggesting previous acute infection) and some spontaneously
cleared the virus, leaving 26 (3.1% of the full tested cohort) with persistent
occult HBV at the final visit.
•
Among the HIV
positive women, the rate of persistent occult HBV infection was higher -- at 4.7%
-- than for HIV negative participants.
•
All the women
with persistent occult HBV were HIV positive, compared with 79% of those with
chronic HBV and 69% who spontaneously cleared the virus.
•
Women with
occult HBV infection were significantly more likely than chronically infected
women to have a history of injection drug use and to currently inject drugs or
drink alcohol heavily.
•
Women with
occult HBV infection were more likely to also have evidence of HCV (88% vs 43%
with HCV antibodies, 77% vs 29% with HCV RNA).
•
Looking at
only the HIV positive women, those with occult HBV had a lower CD4 cell count
(205 vs 326 cells/mm3) and a higher HIV viral load (36,725 vs 4480 copies/mL)
than those who spontaneously cleared the virus.
•
None of the
women whose antiretroviral regimen included lamivudine (3TC; Epivir), which has
activity against both HIV and HBV, had detectable HBV DNA.
•
Occult hepatitis
C was rare.
•
Of the 33 women
initially classified as having potential occult HCV, 24 developed chronic infection,
8 spontaneously cleared the virus, and only 1 (0.12% of the full tested cohort)
had persistent occult HCV at the final visit.
•
The sole woman
with occult HCV had advanced HIV disease, with a CD4 count of 37 cells/mm3.
Occult
HBV infection is associated with HIV infection and may be a particular problem
for women with poor control of HIV," the researchers concluded. They
added that while chronic HBV infection was common in this cohort, occult HCV infection
occurred rarely. Brown
University, Providence, RI; Case Western Reserve University, Cleveland, OH; Johns
Hopkins University School of Medicine, Baltimore, MD; Albert Einstein College
of Medicine, New York, NY; Virginia Commonwealth University, Richmond, VA; Centers
for Disease Control and Prevention, Atlanta, GA. 8/22/08 Reference
L Taylor,
P Gholam, A Delong, and others. Occult hepatitis B virus (HBV) and hepatitis C
virus (HCV) viremia in women with and at-risk for HIV/AIDS. XVII International
AIDS Conference (AIDS 2008). Mexico City. August 3-8, 2008. Abstract
THAB0204.
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