Amyloid Protein Identification, Paraffin, Mass Spectrometry
Use
Amyloidosis is a hereditary and acquired diseases group characterized by extracellular deposition of misfolded proteins leading to end organ damage. Specific amyloid-related diseases are associated with specific amyloid proteins, such as kappa or lambda immunoglobulin light chains (AL amyloid), transthyretin (ATTR amyloid), and serum amyloid A (SAA amyloid). Accurate protein identification is crucial since treatment varies based on amyloid subtype. This test employs Congo red staining followed by laser microdissection and mass spectrometry to reliably determine the identity of proteins constituting the amyloid.
Special Instructions
This test should only be ordered on patients with an established primary diagnosis. If a diagnosis is unclear, consider ordering PATHC / Pathology Consultation or referring to the Pathology Consultation Ordering Algorithm. Include preliminary pathology report, history, and, if applicable, Congo red-stained slide with the specimen. Attach the green pathology address label on the transport container.
Limitations
False-negative results may occur with Congo red staining. Cases not recognized as amyloid may require correlation with clinical and pathological features for definitive diagnosis. The test relies on laser microdissection and mass spectrometry, which requires Congo red-positive samples.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 101405-9
- 50595-8
- 19139-5
- 81178-6
- 62364-5
- 80398-1
Result Turnaround Time
7-15 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Collection Instructions
Do not send fixed tissue slides. Testing requires paraffin-embedded tissue blocks. If Congo red stain has been performed, send stained slide with tissue block.
Causes for Rejection
Fixed tissue slides, wet/frozen tissue, cytological smears, nonformalin fixed tissue, nonparaffin embedded tissue
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Ambient (preferred) |
| Refrigerated | Refrigerated |