Beta-Amyloid 4240 Ratio CSF
- Laboratory
- Quest Diagnostics
- Test code
- 94627
- Specimen
- Csf
- Fasting
- Not required
Laboratory assay overview
This LC-MS/MS assay measures beta-amyloid 40 (AB40) as well as AB42 in cerebrospinal fluid (CSF), rather than AB42 alone. This permits the normalization of beta amyloid levels circulating in CSF in different patients. Using the ratio of beta-amyloid 42/beta-amyloid 40, improves sensitivity and specificity for detecting Alzheimer's disease.
Quest Diagnostics population reference ranges
Quest Diagnostics calculates these statistical intervals for this specific assay and demographic group, not as universal optimal targets.
| Population | Range |
|---|---|
| ABeta 42 | No Reference Range available |
| ABeta 40 | No Reference Range available |
| ABeta 42/40 Ratio | not stated |
| ≥0.16 | Low Risk of Alzheimer's disease |
| <0.16 | Increased risk of Alzheimer's disease |
View complete laboratory reference notes
ABeta 42 | No Reference Range available ABeta 40 | No Reference Range available ABeta 42/40 Ratio ≥0.16 | Low Risk of Alzheimer's disease <0.16 | Increased risk of Alzheimer's disease
Quest Diagnostics test directory, test code 94627