Serum Amyloid P component (SAP)

LASA filenames: C868

Contact: Natasja van Schoor

Background
In people with Alzheimer’s disease several changes take place in the brain. One of these changes includes deposition of amyloid (plaques), which contains a number of proteins, such as amyloid beta-peptide. Amyloid beta-peptide is converted from the amyloid precursor protein (APP). In addition, plaques consist of some other proteins such as α1-antichymotrypsine (ACT) and serum amyloid P component (SAP). Recently it was shown with LASA data that plasma ACT is associated with an increased risk of cognitive decline (Dik et al., 2005), suggesting that plasma levels of plaque-associated proteins impose a higher risk of the incidence of Alzheimer’s disease. Whether plasma SAP levels are associated with higher risk of AD has never been investigated.

Measurements in LASA

Blood collection
At cycle C, morning blood samples were drawn in 1352 respondents. Subjects were only allowed to take tea and toast, but no dairy products. The samples were centrifuged and stored at -20°C until determination in 2005.

Measurement procedure & variable information
SAP levels were measured in plasma samples using an ELISA, validated by the department of Clinical Chemistry, VU University Medical Center.

Availability of data per wave

Number of respondents in wave C:

Serum Amyloid P component (SAP): 1244

Previous use in LASA
None

Reference

Dik, M. G., Jonker, C., Hack, C. E., Smit, J. H., Comijs, H. C., & Eikelenboom, P. Serum inflammatory proteins and cognitive decline in older persons. Neurology, 2005;64(8), 1371-1377.

Date of last update: April 2, 2020