Seronegative
Chronic Hepatitis C in HIV/HCV Coinfected Patients By
Liz Highleyman Seronegative
chronic hepatitis C refers to patients who have no detectable antibodies against
the hepatitis C virus (HCV), but do have detectable
HCV RNA in their serum. Seronegative HCV infection occurs in some HIV positive
patients, although the associated factors are not well understood. This
"false negative" phenomenon makes it likely that some HIV/HCV
coinfected individuals will not be properly diagnosed using standard HCV
antibody screening tests, and therefore will not receive timely monitoring
of liver disease and, if needed, treatment for hepatitis C. At
the recent XVI International AIDS Conference in Toronto,
Phyllis Tien, MD, and colleagues reported on a study to assess factors associated
with being HCV RNA-positive but anti-HCV antibody-negative. The researchers analyzed
data from HIV positive participants in the Fat Redistribution and Metabolic Changes
in HIV infection (FRAM) cohort and in 3 other previously published studies, for
a total of 1855 subjects. Results
869 of 1151 FRAM participants tested negative for HCV antibodies; among these,
15 had detectable HCV RNA.
In a pooled analysis of FRAM plus the other 3 studies, the prevalence of seronegative
HCV infection was 2.0% (37 of 1855 patients).
Among anti-HCV-negative subjects, the prevalence was 3.2% (37 of 1174 patients).
Detectable
HCV RNA in HCV antibody-negative individuals was associated with:
- History
of injection drug use (OR 6.22);
- Elevated alanine aminotransferase (ALT)
levels (OR 1.99 per doubling);
- Current CD4
cell count below 200 cells/mm3 (OR 2.31).
Among HIV positive subjects with detectable HCV RNA, history of injection drug
use (OR 0.26) and older age (OR 0.43 per decade) were associated with a decreased
likelihood of being HCV antibody-negative.
Current CD4 count below 200 cells/mm3 (OR 2.80) was associated with an increased
likelihood of being HCV antibody-negative.
Conclusion
The researchers
concluded that HIV positive individuals without detectable HCV antibodies should
undergo HCV RNA testing if they have elevated ALT levels. This is especially true
for those with low CD4 counts (because their immune systems may be too compromised
to produce anti-HCV antibodies) and those with a history of injection drug use
(because this group is known to be at higher risk for HCV infection). This
study shows that while the standard ELISA antibody test is sufficient to detect
HCV in most coinfected individuals, a subset of patients who would be missed using
standard screening tests may require HCV RNA testing. "Analysis
of HIV positive subjects with detectable HCV RNA suggests that patients with CD4
[counts] below 200 and younger patients, and those without a history of injection
drug use are more likely to be anti-HCV-negative," the researchers added,
and recommend that, "Investigation of how immunosuppression and viral factors
impact serologic detection of HCV in specific populations is therefore needed." 09/08/06 Reference
G
Chamie, M Bonacini, D Bangsberg, and others. Factors associated with seronegative
chronic hepatitis C virus infection in HIV-infection. XVI International AIDS Conference.
Toronto, August 13-18, 2006. Abstract WEPE0046/13774.
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