Impact of cerebrospinal fluid matrix on the detection of Alzheimer's disease with Aβ42 and influence of disease on the total-Aβ42/Aβ40 ratio.

• The 42 amino acid fragment of amyloid β (Aβ1-42) in cerebrospinal fluid (CSF) has continued to be important for detecting cerebral β-amyloidosis in Alzheimer's disease (AD). However, there are impediments to our ability to fully understand this measurement, including matrix interference and changes linked to APOE ε4 genotype. The current study investigated matrix interference as a contributing factor for detecting AD in APOE ε4-negative patients by comparing total extractable Aβ1-42 to free Aβ1-42. It also examined the ratio of total Aβ1-42 to Aβ1-40, since changes relative to other Aβ peptides may provide a measurement of cerebral β-amyloidosis that is neutral to changes in APP metabolism. Total Aβ1-42 lost diagnostic power for detecting AD, confirming a role for matrix in the diagnostic. However, when total Aβ1-42/Aβ1-40 was examined, the separation between groups was reestablished. This result was confirmed in a second sample set of unknown APOE status. These results confirmed that matrix interference in some CSF samples appears to contribute to identifying AD patients and this can be compensated by using a total extracted Aβ1-42/Aβ1-40 ratio when matrix interference is small. It may be preferable to employ a total Aβ1-42/Aβ1-40 measurement, since this could minimize variability due to matrix and compensate for across patient differences. This article is protected by copyright. All rights reserved.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Neurovetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Neurosciences (hsv//eng)

Publication and Content Type

ref (subject category)

art (subject category)