11C-PiB Imaging of Human Immunodeficiency Virus-Associated Neurocognitive Disorder

Arch Neurol. 2012 Jan;69(1):72-7. doi: 10.1001/archneurol.2011.761.

Abstract

Objective: To evaluate whether the amyloid-binding agent carbon 11-labeled Pittsburgh Compound B ((11)C-PiB) could differentiate Alzheimer disease (AD) from human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) in middle-aged HIV-positive participants.

Design: (11)C-PiB scanning, clinical assessment, and cerebrospinal fluid (CSF) analysis were performed. Both χ(2) and t tests assessed differences in clinical and demographic variables between HIV-positive participants and community-living individuals observed at the Knight Alzheimer's Disease Research Center (ADRC). Analysis of variance assessed for regional differences in amyloid-β protein 1-42 (Aβ42) using (11)C-PiB.

Setting: An ADRC and HIV clinic.

Participants: Sixteen HIV-positive participants (11 cognitively normal and 5 with HAND) and 19 ADRC participants (8 cognitively normal and 11 with symptomatic AD).

Main outcome measures: Mean and regional (11)C-PiB binding potentials.

Results: Participants with symptomatic AD were older (P < .001), had lower CSF Aβ42 levels (P < .001), and had higher CSF tau levels (P < .001) than other groups. Regardless of degree of impairment, HIV-positive participants did not have increased (11)C-PiB levels. Mean and regional binding potentials were elevated for symptomatic AD participants (P < .001).

Conclusions: Middle-aged HIV-positive participants, even with HAND, do not exhibit increased (11)C-PiB levels, whereas symptomatic AD individuals have increased fibrillar Aβ42 deposition in cortical and subcortical regions. Observed dissimilarities between HAND and AD may reflect differences in Aβ42 metabolism. (11)C-PiB may provide a diagnostic biomarker for distinguishing symptomatic AD from HAND in middle-aged HIV-positive participants. Future cross-sectional and longitudinal studies are required to assess the utility of (11)C-PiB in older individuals with HAND.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / cerebrospinal fluid
  • Alzheimer Disease / diagnostic imaging
  • Alzheimer Disease / genetics
  • Amyloid beta-Peptides / cerebrospinal fluid
  • Apolipoproteins E / genetics
  • Benzothiazoles*
  • Case-Control Studies
  • Cerebral Cortex / diagnostic imaging
  • Cerebral Cortex / pathology
  • Cognition Disorders / cerebrospinal fluid
  • Cognition Disorders / diagnostic imaging*
  • Cognition Disorders / etiology*
  • Cognition Disorders / genetics
  • Female
  • HIV Infections / cerebrospinal fluid
  • HIV Infections / complications*
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Peptide Fragments / cerebrospinal fluid
  • Positron-Emission Tomography

Substances

  • 2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole
  • Amyloid beta-Peptides
  • Apolipoproteins E
  • Benzothiazoles
  • Peptide Fragments
  • amyloid beta-protein (1-42)