Beta-Amyloid 42/40 Ratio, CSF

Test Code

94627

CPT Codes
82542 <br><strong>This test is not available for New York patient testing.</strong>

Preferred Specimen

1.2 mL CSF collected in a polypropylene tube

Minimum Volume

0.6 mL

Instructions

Collect and transport CSF in a 12x75 mm polypropylene tube. Store frozen.

Note: Quest Diagnostics does not perform this test for individuals under the age of 18. Pre-test and post-test counseling is strongly recommended.

Transport Temperature

Frozen

Specimen Stability

Room tempurature: 72 hours
Refrigerated: 5 days
Frozen: 31 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Hemolysis • Grossly lipemic • Specimen collected in a glass, polystyrene, or polycarbonate tube • Moderately and grossly icteric

Methodology
Liquid Chromotography/Tandem Mass Spectrometry (LC/MS/MS)

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Night Sets up 1 day a week.

Clinical Significance

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.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.