Immunohistochemical Demonstration of Amyloid P Component in Cerebro‐vascular Amyloidosis

Abstract

The presence of amyloid P component (AP) in cerebral amyloid deposits was sought using a direct immunoperoxidase technique. AP was detected in the amyloid deposits in the vessel walls but was absent from the intracerebral plaques in tissue from patients with senile cerebral amyloidosis. AP was also present in the amyloid deposits in the vessel walls of patients with the Icelandic form of hereditary cerebral haemorrhage associated with amyloidosis.

Immunohistochemical characterization of the amyloid deposits and quantitation of pertinent cerebrospinal fluid proteins in hereditary cerebral hemorrhage with amyloidosis.

“…No immunoreactivity against other known amyloidogenic proteins (amyloid fibril protein AA, 33 K and X light immunoglobulin chains, 34 or prealbumin 3536 ) was detected. As in other types of amyloidosis and consistent with an earlier study 37 the amyloid P component was demonstrated to occur in the amyloid deposits.…”

Preferential association of serum amyloid P component with fibrillar deposits in familial British and Danish dementias: Similarities with Alzheimer's disease

“…SAP has been found associated in vivo with animal and human amyloid deposits irrespective of the biochemical nature of the amyloid subunit (reviewed in [1]) and colocalizing with neurofibrillary pathology in a various neurodegenerative conditions including Creutzfedt-Jacob disease, Parkinson's and diffuse Lewy body disorders, and in the parkinsonism-dementia complex of Guam [4,[9][10][11]. SAP immunoreactivity is also commonly observed in Down's syndrome, AD, and in amyloid disorders with primarily cerebrovascular compromise such as Hereditary Cerebral Hemorrhage with Amyloidosis, Icelandic-type [12][13][14][15][16]. In AD brains, the widespread SAP immunoreactivity is evident in association with plaques and amyloid-laden vessels as well as with neurofibrillary tangles, but its presence in diffuse pre-amyloid deposits is controversial (reviewed in [4]).…”

Degradation of Amyloid A Precursor Protein SAA by Macrophage Cell Lines Obtained from Amyloid Resistant and Susceptible Strains of Mice

“…Moreover, SDS-PAGE analysis of culture medium did not show any appearance of the 8 kDa protein band which would further suggest that AA fibrils were not formed. Other components present in vivo, such as the different common elements found in several types of amyloid deposits (serum amyloid P, heparan sulphate proteoglycan, Apo-E) [30][31][32][33][34][35], may be required for inducing a partial degradation and/or fibril formation. These common elements may be relevant to test in vitro to determine whether they play a role in the initiation phase of fibril formation.…”

“…However, when we consider that macrophages from susceptible mice show a slower SAA degradative processing between 24 and 48 h, one can wonder whether a similar intermittent block in SAA degradation occurring in vivo, where co-factors are present, may represent a 'window of opportunity' for the extracellular fibril formation and deposition. In vivo, co-factors such as heparan sulphate proteoglycans, amyloid P component and/or Apolipoprotein-E (Apo-E) could play a role in the initiation or perpetuation of the fibril formation in the presence of SAA [30][31][32][33][34][35].…”