title: A4 protein in Alzheimer's disease: primary and secondary cellular events in extracellular amyloid deposition.
abstract: This study was designed to investigate the role of serum proteins, microglia, glial fibrillary acidic protein (GFAP) positive cells and dystrophic neurites in the genesis of cerebral amyloid. Using A4 protein antisera, we found an amorphous non-congophilic, form of plaque, which was not seen in Bielschowsky silver staining or Bodian impregnations. GFAP-positive glial cells, cells immunolabelled for some macrophage markers and dystrophic neurites were detected in congophilic plaques with crystalline amyloid, but not in the amorphous, non-congophilic plaques. The presence of alpha l-antichymotrypsin, complement factors and P component, but not of common serum proteins in both the amorphous and congophilic plaques, indicates that these three proteins may have a pathogenetic role in amyloid formation. Amorphous plaques may be the earlier forms of plaque and consequently, the presence of reactive cells and dystrophic neurites may be secondary phenomena.
authors.affiliation: Department of Neuropathology, Academic Hospital Free University, Amsterdam, The Netherlands.
authors.forename: J M
authors.initials: JM
authors.lastname: Rozemuller
authors.forename: P
authors.initials: P
authors.lastname: Eikelenboom
authors.forename: F C
authors.initials: FC
authors.lastname: Stam
authors.forename: K
authors.initials: K
authors.lastname: Beyreuther
authors.forename: C L
authors.initials: CL
authors.lastname: Masters
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology; D000682:Amyloid / Q000032:analysis*; D016229:Amyloid beta-Peptides; D001369:Axons / Q000473:pathology; D015922:Complement C1q / Q000032:analysis; D015932:Complement C3c / Q000032:analysis; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D008264:Macrophages / Q000473:pathology; D008297:Male; D009454:Neurofibrils / Q000473:pathology; D009457:Neuroglia / Q000473:pathology; D000683:Serum Amyloid P-Component / Q000032:analysis; D000514:alpha 1-Antichymotrypsin / Q000032:analysis
chemical_list: D000682:Amyloid; D016229:Amyloid beta-Peptides; D005904:Glial Fibrillary Acidic Protein; D000683:Serum Amyloid P-Component; D000514:alpha 1-Antichymotrypsin; D015922:Complement C1q; D015932:Complement C3c