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Publication Abstract Display
Type: Published Abstract
Title: Nadir CD4 is a predictor of HIV neurocognitive impairment (NCI) in the era of combination antiretroviral therapy: results from the CHARTER Study.
Authors: Ellis R, Badiee J, Letendre S, Vaida F, Franklin D, Heaton R, Clifford D, Collier A, Marra C, Gelman B, McArthur J, Morgello S, Simpson D, McCutchan JA, Grant I, for the CHARTER Group
Year: 2010
Publication: XVIII International AIDS Conference, July 18-23, Vienna, Austria
Volume: Issue: Pages:
Abstract:Introduction: NCI continues to be prevalent in the ART era but its predictors are not entirely clear. Higher nadir CD4 counts have been associated with lower risk of NCI. This study provides a more detailed analysis of the association with nadir CD4 by controlling for factors that may affect both nadir CD4 and NCI. Methods: The relationship between nadir CD4 count on NCI was examined in 1525 HIV-infected individuals after correcting for several demographic and disease-related covariates, including ART history, viral suppression, duration of HIV infection, age, and comorbid conditions that might confound the observed relationship. CD4 nadir was square-root-transformed to improve the symmetry of its distribution for parametric analyses. Results: Unadjusted, lower nadir CD4 counts were strongly associated with NCI (p = 0.004). This relationship remained statistically significant after adjusting for nearly all demographic and disease-related covariates. After adjusting for ART use, however, nadir CD4 was no longer statistically significant. Since those taking ART had a lower nadir CD4 counts than those not taking ART (146 vs. 343, p < .0001), analyses were repeated in those on ART with an undetectable viral load in plasma (n=589). In this subgroup, nadir CD4 count remained a significant correlate of NCI after adjusting for age, comorbidity, and duration of infection (all p < .05). Results were similar when examining only those with the fewest comorbidities. Conclusions: Nadir CD4 count is strongly associated with NCI even after adjusting for variables that can influence both nadir CD4 and NCI. This association is attenuated with ART use, but is still present when only examining those on ART with an undetectable viral load. These findings suggest that low nadir CD4 could represent a legacy event in HIV infection and that prevention of severe immunosuppression may lead to more favorable neurocognitive outcomes.

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