Lowest-ever CD4 Cell Count Predicts Neurocognitive Impairment in People with HIV

By Liz Highleyman

AIDS dementia complex (also known as AIDS-related dementia and HIV-associated dementia) is a condition in people with AIDS that results in the loss of cognitive capacity, affecting the ability to function in a social or occupational setting.

Serious AIDS-related dementia has become less common since the advent of HAART, but neurocognitive impairment is still observed.

As reported in the October 2008 issue of AIDS Research and Human Retroviruses, Spanish researchers studied whether nadir (lowest-ever) CD4 cell count is a predictor of neurocognitive changes in people with HIV.

This cross-sectional study analyzed 64 HIV-infected participants in 2 groups. Group 1 consisted of 26 patients with a nadir CD4 count of 200 cells/mm3 or less, while Group 2 included 38 patients whose CD4 count had always remained above 200 cells/mm3. Within Group 2, the researchers also looked at the subgroup receiving antiretroviral therapy and compared them with patients in Group 1, all of whom received treatment.

Percentages of patients with evidence of neurocognitive impairment were compared according to different nadir CD4 cutoffs (200, 250, 300, and 350 cells/mm3). Demographic and clinical variables were evaluated, as were differences in neurocognitive function.

Results

• Neurocognitive impairment tended to be more prevalent in the low CD4 nadir group (19 patients, or 73.1%) than in the high CD4 nadir group (20 patients, or 52.6%) (P = 0.123).

• When nadir CD4 cutoffs were compared, there was a trend toward more impairment as CD4 nadir decreased, though this did not reach statistical significance.

• Significant differences in function were observed, however, in attention/working memory (digit span backward test; P = 0.032) and executive function (trail making test part B; P = 0.020), with the high CD4 nadir group performing better.

• Comparison between the low CD4 nadir group and the treated high CD4 nadir patients confirmed these findings.

In conclusion, the study authors wrote, "We found differences in neurocognitive functioning in relation to nadir CD4 count in HIV-infected patients."

They added that, "Attention should be given to this value in the management of neurocognitive protection in HIV infection."

Lluita contra la SIDA Foundation, Germans Trias i Pujol University Hospital, Badalona, Barcelona, Catalonia, Spain; Autònoma de Barcelona University, Barcelona, Catalonia, Spain; Consorci Sanitari de Terrassa Hospital, Terrassa, Barcelona, Catalonia, Spain; Politècnica de Catalunya University, Barcelona, Catalonia, Spain; IrsiCaixa Foundation, Badalona, Barcelona, Catalonia, Spain.

10/21/08

Reference
JA Moreno-Munoz, CR Fumaz, MJ Ferrer, and others. Nadir CD4 cell count predicts neurocognitive impairment in HIV-infected patients. AIDS Research and Human Retroviruses 24(10): 1301-1307. October 2008. (Abstract).