CSF biomarkers of neuroinflammation and cerebrovascular dysfunction in early Alzheimer disease

Neurology. 2018 Aug 28;91(9):e867-e877. doi: 10.1212/WNL.0000000000006082. Epub 2018 Jul 27.

Abstract

Objective: To measure CSF levels of biomarkers reflecting microglia and astrocytes activation, neuroinflammation, and cerebrovascular changes and study their associations with the core biomarkers of Alzheimer disease (AD) pathology (β-amyloid [Aβ] and tau), structural imaging correlates, and clinical disease progression over time.

Methods: The study included cognitively unimpaired elderly (n = 508), patients with mild cognitive impairment (MCI, n = 256), and patients with AD dementia (n = 57) from the longitudinal Swedish BioFINDER cohort. CSF samples were analyzed for YKL-40, interleukin (IL)-6, IL-7, IL-8, IL-15, IP-10, monocyte chemoattractant protein 1, intercellular adhesion molecule 1 (ICAM-1), vascular adhesion molecule 1 (VCAM-1), placental growth factor, and fms-related tyrosine kinase 1 (Flt-1). MRI data were available from 677 study participants. Longitudinal clinical assessments were conducted in control individuals and patients with MCI (mean follow-up 3 years, range 1-6 years).

Results: CSF levels of YKL-40, ICAM-1, VCAM-1, IL-15, and Flt-1 were increased during the preclinical, prodromal, and dementia stages of AD. High levels of these biomarkers were associated with increased CSF levels of total tau, with the associations, especially for YKL-40, being stronger in Aβ-positive individuals. The results were similar for associations between phosphorylated tau and YKL-40, ICAM-1, and VCAM-1. High levels of the biomarkers were also associated with cortical thinning (primarily in the precuneus and superior parietal regions) and with subsequent cognitive deterioration in patients without dementia as measured with Mini-Mental State Examination (YKL-40) and Clinical Dementia Rating Sum of Boxes (YKL-40, ICAM-1, VCAM-1 and IL-15). Finally, higher levels of CSF YKL-40, ICAM-1, and Flt-1 increased risk of development of AD dementia in patients without dementia.

Conclusions: Neuroinflammation and cerebrovascular dysfunction are early events occurring already at presymptomatic stages of AD and contribute to disease progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Amyloid beta-Peptides / cerebrospinal fluid
  • Apolipoprotein E4 / genetics
  • Biomarkers / cerebrospinal fluid*
  • Cerebrovascular Disorders / cerebrospinal fluid*
  • Cerebrovascular Disorders / diagnostic imaging
  • Cerebrovascular Disorders / etiology*
  • Chitinase-3-Like Protein 1 / cerebrospinal fluid
  • Cognitive Dysfunction / complications*
  • Cognitive Dysfunction / diagnostic imaging
  • Cytokines / cerebrospinal fluid
  • Encephalitis / cerebrospinal fluid*
  • Encephalitis / diagnostic imaging
  • Encephalitis / etiology*
  • Female
  • Humans
  • Intercellular Adhesion Molecule-1 / cerebrospinal fluid
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Placenta Growth Factor / cerebrospinal fluid
  • Vascular Cell Adhesion Molecule-1 / cerebrospinal fluid
  • Vascular Endothelial Growth Factor Receptor-1 / cerebrospinal fluid
  • tau Proteins / cerebrospinal fluid

Substances

  • Amyloid beta-Peptides
  • Apolipoprotein E4
  • Biomarkers
  • CHI3L1 protein, human
  • Chitinase-3-Like Protein 1
  • Cytokines
  • MAPT protein, human
  • Vascular Cell Adhesion Molecule-1
  • tau Proteins
  • Intercellular Adhesion Molecule-1
  • Placenta Growth Factor
  • FLT1 protein, human
  • Vascular Endothelial Growth Factor Receptor-1