Infection with hepatitis C does not affect the cognitive
performance of women with or at risk of HIV, according to data from the Women’s
Interagency HIV Study (WIHS) published in the online edition of the Journal of Acquired Immune Deficiency
“We were unable to show a significant association between
the presence of HCV [hepatitis C virus]…and performance on our cognitive
battery nor that there is an interaction between HIV and HCV in their effect on
cognitive function,” write the
However, their was some evidence that infection with HIV had
an impact on cognition.
A number of earlier studies have suggested that hepatitis
C-infected individuals have an increased risk of neurocognitive impairments.
Moreover, replicating virus has been found in the brains of patients with the
infection. It has also been suggested that co-infection with HIV and hepatitis
C could have a worse impact on cognitive function than either virus alone.
Women have been unrepresented in research exploring the
impact of hepatitis C on cognition. Therefore, investigators from the WIHS
designed a study involving 1338. Just under a fifth (18%) had detectable
hepatitis C virus and 67% were infected with HIV.
“To our knowledge this cohort for our study is over twice as
large as any previously reported study of the effects of HCV and HIV on
cognition,” note the investigators.
The patients were divided into six groups:
Negative for both HIV and hepatitis C RNA (392
HIV-negative/hepatitis C RNA-positive (42 individuals).
HIV-positive/hepatitis C RNA-negative (480
AIDS/hepatitis C RNA-negative (241 individuals).
AIDS/hepatitis C RNA-positive (88 individuals)
The patients had a battery of four tests to assess their
cognitive function. The results were controlled for age, ethnicity, depression,
liver disease status and current or past drug and alcohol abuse, all of which
have been shown to affect cognitive function.
There were significant differences between the patients
according to their hepatitis C and/or HIV-infection status.
Individuals infected with hepatitis C were a significant
nine years older than women who did not have hepatitis C (p < 0.001). Rates
of injecting drug use were also significantly higher among the women with
hepatitis C (85% vs. 12%), and hepatitis C-infected women were also
significantly more likely to report recent use of cocaine (p < 0.001).
As expected, liver function was significantly poorer in
those infected with hepatitis C, and the women with an AIDS diagnosis had lower
CD4 cell counts than other individuals (p = 0.001).
After controlling for potential confounders, the
investigators failed to find any association between hepatitis C viraemia and
In their first set of analysis, they established a significant
connection between poorer liver function and poorer cognitive function (p <
0.001). However, this relationship disappeared after controlling for factors
such as age, ethnicity, depression and general mental health.
Nevertheless, infection with HIV was associated with
impaired speed of information processing and perceptual motor ability (p <
The investigators do not regard their findings as
definitive: “The question of whether HCV has a direct effect on cognition will
require future studies with a complete neuropsychological batter, a large
control group and a large group of HCV-mono-infected subjects.” They also
believe that such studies would need “a cohort that includes both men and