Peripheral clearance of amyloid beta peptide by complement C3-dependent adherence to erythrocytes

Neurobiol Aging. 2006 Dec;27(12):1733-9. doi: 10.1016/j.neurobiolaging.2005.09.043. Epub 2005 Nov 14.


Brain deposits of amyloid beta peptide (Abeta) have been a diagnostic hallmark of Alzheimer's disease (AD) for nearly a century. Recent studies have demonstrated that Abeta is also present in peripheral blood. Here, we present evidence that circulating Abeta42 is subject to complement C3b-dependent adherence to complement receptor 1 (CR1) on erythrocytes, a classical set of mechanisms by which pathogens and proteins recognized as foreign are cleared from the bloodstream. Levels of Abeta42 targeted by this pathway differ significantly in AD compared to mild cognitive impairment and nondemented elderly controls.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / blood
  • Amyloid beta-Peptides / blood*
  • Cell Adhesion / immunology
  • Complement C3 / physiology*
  • Erythrocytes / metabolism*
  • Humans
  • Peptide Fragments / blood*
  • Protein Transport / immunology


  • Amyloid beta-Peptides
  • Complement C3
  • Peptide Fragments
  • amyloid beta-protein (1-42)