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  AIDS 2010
18th International AIDS Conference (IAC)
July 18-23 2010
Vienna, Austria
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Nadir CD4 Count Strongly Predicts Neurocognitive Impairment in CHARTER
  XVIII International AIDS Conference, July 18-23, 2010, Vienna
Mark Mascolini
"Low nadir CD4 could represent a 'legacy event' in HIV infection that establishes slow or nonreversible brain damage," according to CHARTER Group investigators who analyzed neurocognitive impairment in 1525 HIV-infected people according to their lowest-ever CD4 count [1].
CHARTER cohort members all had comprehensive standardized neuropsychological assessment for seven cognitive domains. The investigators diagnosed HIV-associated neurocognitive disorder (HAND) according to published criteria [2]. Nadir CD4 count was determined either by record review or by patient report.
This cross-sectional study assessed the relationship between nadir CD4 count and neurocognitive impairment, first, with no adjustment for other risk factors, and then after adjustment for several demographic and HIV-related variables including antiretroviral history, viral suppression, duration of HIV infection, age, and other conditions that may affect a relationship with nadir CD4 count.
Testing showed that 799 people (52%) had cognitive impairment and 726 did not. CD4 nadir was significantly lower in people with cognitive impairment (155 versus 187 in those without impairment, P = 0.002). Current CD4 count did not differ significantly between the two groups (409 versus 438). Impaired and unimpaired people did not differ significantly in age, education, gender, race, time since CD4 nadir, viral load, or duration of HIV infection. In the unadjusted analysis, lower nadir CD4 count strongly predicted neurocognitive impairment (P = 0.004). That correlation remained significant after statistical adjustment for nearly all variables, except antiretroviral use.
Cohort members taking antiretrovirals had a significantly lower CD4 count than those not taking antiretrovirals (146 versus 343, P < 0.0001). Therefore the CHARTER team repeated the analysis focusing only on 589 antiretroviral-treated people with an undetectable viral load. In this analysis nadir CD4 count significantly predicted neurocognitive impairment after adjustment for age, other conditions that affect neurocognition, and duration of HIV infection (all P < 0.05). The correlation held true when the investigators considered only people with the fewest other conditions.
The CHARTER team concluded that "HIV-associated neurocognitive disorders persist in many patients despite good immune recovery" on antiretroviral therapy. They proposed that "prevention of severe immunosuppression may lead to more favorable neurocognitive outcomes."
1. Ellis R, Badiee J, Letendre S, et al. Nadir CD4 is a predictor of HIV neurocognitive impairment (NCI) in the era of combination antiretroviral therapy (cART): results from the CHARTER study. XVIII International AIDS Conference. July 18-23, 2010. Vienna. Abstract THLBB109.
2. Antinori A, Arendt G, Becker JT, et al. Updated research nosology for HIV-associated neurocognitive disorders. Neurology. 2007;69:1789-1799.