A new study published in the journal Neurology entitled “Absence of neurocognitive effect of hepatitis C infection in HIV-coinfected people” examined the effect of hepatitis C virus (HCV) on neurocognitive performance in patients with HIV.
Hepatitis C virus (HCV) infection is often linked to HIV infection, with estimations indicating that nearly 170 million people are infected with HCV, while 33 million have HIV.
Neurocognitive impairment is a prevalent in HIV infection, with 40%–50% patients with HIV performing poorly in neurocognitive tests. However, the reasons for these neurocognitive impairments remain unknown. Neural injury before HIV treatment, toxicity due to antiretroviral therapy, ongoing low-level CNS infection with neurologic loss, or comorbid disorders may all be underlying causes of neurocognitive impairment.
In a recent press release, lead author of the study David Clifford, MD, of Washington University said, “Hepatitis C infection has serious long-term side effects, such as damage to the liver, but our research indicates that it does not affect the brain.”
The team of researchers analyzed a sample of 1,582 participants enrolled in CNS HIV Antiretroviral Therapy Effects Research (CHARTER) study. Of these, 408 were also infected with hepatitis C. Each patient performed a neurocognitive assessment to detect signs of HIV-associated mental deficits.
Multivariate analysis revealed that neurocognitive performance was characterized by global deficit scores and the proportion of individuals who were impaired were the same in the HCV-seropositive and HCV-seronegative groups.
Analysis of the whole sample revealed that only verbal domain scores showed a better performance in the HCV+ group. In the subgroup without comorbidities, scores in all 7 domains of neurocognitive functioning did not differ by HCV serostatus. In the HCV-seropositive group, analysis did not reveal an association between neurocognitive performance and serum HCV RNA concentration.
“In all, we looked at seven domains of mental function,” said Clifford. “We studied their overall performance and looked at each domain individually and found no evidence that the group with hepatitis C performed worse.”
The researchers concluded that in patients with HIV, HCV coinfection is not linked with neurocognitive impairment, at least when HCV-associated liver damage is absent.
In the press release, Dr. Clifford said regarding the results “If a hepatitis C infection gets to the point where it damages liver function, the resulting inflammation might well contribute to mental impairment. Beyond that, though, it doesn’t seem to be an active collaborator in the harm HIV does to the brain.”