Effects of coinfection with HIV and hepatitis C virus on the nervous system.

We evaluated a cohort of persons with late-stage HIV infection currently enrolled in a longitudinal tracking study to determine whether coinfection with hepatitis C virus (HCV) is associated with a greater prevalence and/or severity of HIV-associated cognitive-motor complex and distal predominantly sensory peripheral polyneuropathy compared with persons with HIV infection alone. Of 159 subjects, 31 tested positive for HCV, and this group was compared with 31 randomly selected subjects with HIV infection alone. All subjects underwent a structured neurological examination and a formal neuropsychological testing battery. Blood and cerebrospinal fluid samples were analyzed for cryoglobulins and glutamine levels, respectively. HIV/HCV-coinfected subjects showed a greater, statistically significant cognitive-motor impairment compared with those not coinfected. Despite the well-recognized neurological manifestations of both HIV infections and more recently hepatitis C, it is still uncertain whether the effects of HIV and HCV augment one another or are partially additive in their deleterious effects on the nervous system.