Hepatitis C Not Culprit of Mental Impairment in HIV Patients

Study finds hepatitis C co-infection not related to decreased mental function.

Impaired mental function in HIV patients with long-term infection is not related to hepatitis C virus (HCV) co-infection, a recent study finds.

In an analysis appearing in the December 10, 2014 issue of Neurology, researchers sought to prevent long-term mental degradation in HIV patients by considering how the infection, along with other pathogens that are common in HIV-positive patients, affect the brain. HCV, which infects approximately 1 in 3 HIV-positive patients in the United States, was ruled out as a cause of the decreased mental function.

"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," said lead author David Clifford, MD, in a press release.

HCV is common among injection drug users, which makes it difficult to evaluate whether drug use or the virus contributes to brain impairment in patients with HIV and HCV co-infection.

To evaluate this question, the researchers studied 1582 HIV patients, of which 408 had an HCV co-infection. The patients received a detailed neuropsychological exam designed to detect signs of decreased mental function associated with HIV.

The test includes written exams taken by the patient and physical exams administered by health care professionals. The patients were tested for their ability to express themselves, make decisions, learn and retain new information utilizing multiple memory types, body movement and muscle control.

The patients with hepatitis C were older, less educated, and had lower test scores for reading, comprehension, spelling, and math.

"In all, we looked at seven domains of mental function," Dr. Clifford said. "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 are now seeking to evaluate whether the immune responses in the brain and the bowel triggered by HIV during the initial stages of infection lead to chronic inflammation that causes the brain function to deteriorate.

"If a hepatitis C infection gets to the point where it damages liver function, the resulting inflammation might well contribute to mental impairment," Clifford said. "Beyond that, though, it doesn't seem to be an active collaborator in the harm HIV does to the brain."