Amyloid Beta 42/40 Ratio details
What Amyloid Beta 42/40 Ratio shows
The amyloid beta 42/40 ratio is calculated by dividing the level of amyloid beta 42 by amyloid beta 40 in your blood plasma. Amyloid beta 42 is the form that tends to clump into plaques in the brain, one of the hallmarks of Alzheimer's disease, and when this happens less of it appears in the blood. The ratio is used to help evaluate adults with memory or thinking concerns. A lower ratio suggests a higher likelihood of amyloid plaques, while a higher ratio suggests a lower likelihood. It does not diagnose Alzheimer's disease on its own, and it is interpreted by a clinician alongside your symptoms, cognitive testing and, when needed, brain imaging or spinal fluid tests.
Tests that include Amyloid Beta 42/40 Ratio
This LC-MS/MS assay measures beta-amyloid 40 (AB40) as well as AB42 in plasma, rather than AB42 alone. This permits the normalization of beta amyloid levels circulating in plasma in different patients. Using the ratio of beta-amyloid 42/beta-amyloid 40, improves sensitivity and specificity for detecting Alzheimer's disease.
- Amyloid Beta 40 Peptide Measures amyloid beta 40 in plasma, a common protein fragment from the brain used together with amyloid beta 42 to calculate the 42/40 ratio.
- Amyloid Beta 42/40 Ratio A ratio calculated from amyloid beta 42 and amyloid beta 40 in plasma, used to help estimate the likelihood of amyloid plaques in the brain.
- Amyloid Beta 42 Peptide Measures amyloid beta 42 in plasma, the protein fragment that forms plaques in the brain in Alzheimer's disease, used to calculate the 42/40 ratio.
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