Cognitive changes in asymptomatic drug-naïve human immunodeficiency virus type 1 clade C infection

Abstract

Asymptomatic human immunodeficiency virus (HIV) infection is associated with impaired cognitive functioning in both clade B and C infections. The nature of cognitive change longitudinally has not been studied in asymptomatic clade C infection. The present study evaluated changes in neuropsychological functioning over a 2(1/2)-year period in a cohort of HIV-1 clade C-infected asymptomatic individuals from South India. Participants with CD4 counts below 250 were started on highly active antiretroviral therapy (HAART) as per National AIDS Control Organisation NACO guidelines and hence excluded. The sample consisted of 68 patients (30 men and 38 women), with a mean age of 29.4 years (SD=5.6 years) and a mean education of 10.0 years (SD=2.7 years). A comprehensive neuropsychological assessment with 12 tests yielding 21 variables was used to examine cognitive functioning at baseline and subsequently at 6-monthly intervals for five follow-ups. Shift in CD4 and viral load categories measured by the McNemar's test indicated disease progression. Latent growth curve (LGC) modeling assessed the nature of change in cognition over the 2(1/2)-year study period. Ten variables representing attention, executive functions, and long-term memory fit the LGC model. Excepting visual working memory, the slope was nonsignificant for nine variables, indicating absence of deterioration in cognition over a 2(1/2)-year period. However, CD4 and viral load levels worsened, indicating disease progression. Asymptomatic individuals with HIV-1 clade C infection do not show any significant decline on individual neuropsychological functions over 2(1/2) years despite disease progression, as evidenced by immune suppression and viral loads.

Impact of the HIV Tat C30C31S dicysteine substitution on neuropsychological function in patients with clade C disease

“…Finally, the study is cross-sectional in nature and it will be important to understand the long-term outcome of individuals infected with clade C who do and do not exhibit the C31 substitution. Interestingly, Gopukumar et al (2008) reported no significant decline in cognitive function over a two-year and one half-year period among individuals infected with clade C HIV residing in India. Since the Tat C31 substitution is more conserved in this population than in South Africa (Rao et al 2013) it is unclear how cognitive impairment progresses among individuals with and without the Tat substitution in South Africa and therefore additional studies are needed to address this concern.…”