Resting cerebral blood flow: a potential biomarker of the effects of HIV in the brain.
OBJECTIVE
HIV enters the brain soon after infection causing neuronal damage and microglial/astrocyte dysfunction leading to neuropsychological impairment. We examined the impact of HIV on resting cerebral blood flow (rCBF) within the lenticular nuclei (LN) and visual cortex (VC).


METHODS
This cross-sectional study used arterial spin labeling MRI (ASL-MRI) to measure rCBF within 33 HIV+ and 26 HIV- subjects. Nonparametric Wilcoxon rank sum test assessed rCBF differences due to HIV serostatus. Classification and regression tree (CART) analysis determined optimal rCBF cutoffs for differentiating HIV serostatus. The effects of neuropsychological impairment and infection duration on rCBF were evaluated.


RESULTS
rCBF within the LN and VC were significantly reduced for HIV+ compared to HIV- subjects. A 2-tiered CART approach using either LN rCBF < or =50.09 mL/100 mL/min or LN rCBF >50.09 mL/100 mL/min but VC rCBF < or =37.05 mL/100 mL/min yielded an 88% (29/33) sensitivity and an 88% (23/26) specificity for differentiating by HIV serostatus. HIV+ subjects, including neuropsychologically unimpaired, had reduced rCBF within the LN (p = 0.02) and VC (p = 0.001) compared to HIV- controls. A temporal progression of brain involvement occurred with LN rCBF significantly reduced for both acute/early (<1 year of seroconversion) and chronic HIV-infected subjects, whereas rCBF in the VC was diminished for only chronic HIV-infected subjects.


CONCLUSIONS
Resting cerebral blood flow (rCBF) using arterial spin labeling MRI has the potential to be a noninvasive neuroimaging biomarker for assessing HIV in the brain. rCBF reductions that occur soon after seroconversion possibly reflect neuronal or vascular injury among HIV+ individuals not yet expressing neuropsychological impairment.
Ances
B M
BM
Department of Neurology, Washington University in St. Louis, MO, USA. bances@wustl.edu
Sisti
D
D
Vaida
F
F
Liang
C L
CL
Leontiev
O
O
Perthen
J E
JE
Buxton
R B
RB
Benson
D
D
Smith
D M
DM
Little
S J
SJ
Richman
D D
DD
Moore
D J
DJ
Ellis
R J
RJ
D015526:AIDS Dementia Complex / Q000175:diagnosis / Q000503:physiopathology*; D000328:Adult; D001479:Basal Ganglia / Q000098:blood supply / Q000503:physiopathology / Q000821:virology; D020144:Basal Ganglia Cerebrovascular Disease / Q000175:diagnosis / Q000503:physiopathology / Q000821:virology; D015415:Biomarkers / Q000032:analysis; D001921:Brain / Q000098:blood supply* / Q000503:physiopathology* / Q000821:virology; D002536:Cerebral Arteries / Q000473:pathology / Q000503:physiopathology / Q000821:virology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000503:physiopathology* / Q000821:virology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014793:Visual Cortex / Q000098:blood supply / Q000503:physiopathology / Q000821:virology
D015415:Biomarkers