A-beta-40 - Simoa Assay - 96 tests

αβ40 is a 40 amino acid proteolytic product from the amyloid precursor protein (APP) that has gained attention as a biomarker correlating with Alzheimer disease (AD) onset, mild cognitive impairment, vascular dementia, and other cognitive disorders. Beta-secretase cleavage of APP initially results in the production of an APP fragment that is further cleaved by gamma-secretase at residues 40-42 to generate two main forms of amyloid beta, αβ40 and αβ42.

Amyloid beta (αβ) peptides (including a shorter αβ38 isoform) are produced by different cell types in the body, but the expression is particularly high in the brain. Accumulation of αβ in the form of extracellular plaques is a neuropathological hallmark of Alzhiemer's Disease (AD) and believed to play a central role in the neurodegenerative process. αβ40 is the major amyloid component in these plaques and is thought to be an initiating factor of AD plaques. In healthy and disease states αβ40 is the most abundant form of the amyloid peptides in both cerebrospinal fluid (CSF) and plasma (10-20X higher than αβ42). Recent studies suggest that a decrease in the ratio of αβ42/αβ40 may indicate AD progression.