title: Impact of the HIV Tat C30C31S dicysteine substitution on neuropsychological function in patients with clade C disease.
abstract: Previous animal studies have identified a C31S residue substitution in the C30C31 dicysteine motif of the Tat protein that is associated with reduced neurovirulence in clade C human immunodeficiency virus (HIV). However, clinical studies of patients infected with clade C HIV have reported significant levels of cognitive impairment. To date, no study has specifically examined cognitive function in clade C-infected patients as a function of the presence or absence of the Tat C31 substitution. The present study investigated the impact of the Tat C30C31S genetic substitution among individuals residing in South Africa infected with clade C HIV that either exhibited the C30C31 motif (n = 128) or the C31S motif (n = 46). A control group of seronegative individuals was included to examine the overall impact of HIV on cognitive performance. All individuals completed a comprehensive neuropsychological battery consisting of tests sensitive to HIV. Results revealed that clade C-infected individuals performed significantly worse across cognitive tests compared to seronegative controls. However, there were no significant differences in cognitive performances between individuals with the C31S motif versus those without the C31S substitution. Proximal CD4 cell count and plasma viral load were unrelated to cognitive performances for either group. Results confirm that the C31S dicysteine motif substitution of the Tat protein does not appreciably moderate neuropsychological outcomes in clade C. Further, these findings highlight the importance of clinical management of cognitive symptoms among individuals infected with this viral clade worldwide.
authors.affiliation: Department of Psychology and Behavioral Neuroscience, University of Missouri-St. Louis, University Boulevard, St. Louis, USA, paulro@umsl.edu.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Paul
authors.forename: John A
authors.initials: JA
authors.lastname: Joska
authors.forename: Carol
authors.initials: C
authors.lastname: Woods
authors.forename: Soraya
authors.initials: S
authors.lastname: Seedat
authors.forename: Susan
authors.initials: S
authors.lastname: Engelbrecht
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Hoare
authors.forename: Jodi
authors.initials: J
authors.lastname: Heaps
authors.forename: Victor
authors.initials: V
authors.lastname: Valcour
authors.forename: Beau
authors.initials: B
authors.lastname: Ances
authors.forename: Laurie M
authors.initials: LM
authors.lastname: Baker
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Salminen
authors.forename: Dan J
authors.initials: DJ
authors.lastname: Stein
mesh_terms: D000293:Adolescent; D000328:Adult; D019943:Amino Acid Substitution; D000818:Animals; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D003071:Cognition; D056344:Executive Function; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy / Q000503:physiopathology* / Q000821:virology; D015497:HIV-1 / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011930:Reaction Time; D013019:South Africa; D019562:Viral Load; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000235:genetics*
chemical_list: D054322:tat Gene Products, Human Immunodeficiency Virus