Definitive identification of amyloid proteins
Test Id | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
MLCPC | Microdissection, Laser Capture | No, (Bill Only) | No |
MSPTC | Mass Spectrometry | No, (Bill Only) | No |
In all cases with adequate tissue, an initial Congo red stain is performed before mass spectrometry testing to confirm positivity, and the pattern of amyloid deposition can be considered when interpreting mass spectrometry results.
In some instances, per pathologist discretion, a different initial Congo red stain may be performed using SS2PC / Special Stain, Group II, Other (Bill Only).
-If the stain is negative for amyloid, then this test will not be performed, and only the SS2PC will be charged.
-If the stain is positive for amyloid, this test will be performed, and the SS2PC billing charge will be credited.
A pathology consultation is typically not required. If the amyloid subtyping results do not fit the clinical findings, PATHC / Pathology Consultation may be added if appropriate, upon client approval.
For more information see Amyloidosis: Laboratory Approach to Diagnosis.
Histological Stain/Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
GPAMYPROPAR
GPMSCBB
Amyloid AA
Amyloid AL
Amyloid ATTR
Amyloid LECT-2
Amyloid
In all cases with adequate tissue, an initial Congo red stain is performed before mass spectrometry testing to confirm positivity, and the pattern of amyloid deposition can be considered when interpreting mass spectrometry results.
In some instances, per pathologist discretion, a different initial Congo red stain may be performed using SS2PC / Special Stain, Group II, Other (Bill Only).
-If the stain is negative for amyloid, then this test will not be performed, and only the SS2PC will be charged.
-If the stain is positive for amyloid, this test will be performed, and the SS2PC billing charge will be credited.
A pathology consultation is typically not required. If the amyloid subtyping results do not fit the clinical findings, PATHC / Pathology Consultation may be added if appropriate, upon client approval.
For more information see Amyloidosis: Laboratory Approach to Diagnosis.
AMYLOID
This test should only be ordered on patients for whom a primary diagnosis has already been established. If a patient does not have a primary diagnosis, order PATHC / Pathology Consultation or refer to the Pathology Consultation Ordering Algorithm.
If a pathology consultation is desired in addition to this test, order PATHC / Pathology Consultation alone and send the required paperwork with specimen. Indicate that amyloid protein identification is desired. If needed, this test will be added by the reviewing pathologist and will be reported with the consultation. For more information see PATHC / Pathology Consultation.
Attach the green pathology address label included in the kit to the outside of the transport container.
1. Preliminary pathology report and history are required.
2. Include performed Congo red slide
3. A brief explanatory note or consultative letter is also recommended.
Specimen Type: Formalin-fixed or B5-fixed paraffin-embedded tissue block
Collection Instructions:
1. Do not send fixed tissue slides for testing. Testing can only be done on paraffin-embedded tissue blocks.
2. If Congo red stain has already been performed, send Congo red stained slide along with the tissue block.
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Cardiovascular Test Request (T724)
-Hematopathology/Cytogenetics Test Request (T726)
-Renal Diagnostics Test Request (T830)
Fixed tissue slides Wet/frozen tissue Cytological smears Nonformalin fixed tissue Nonparaffin embedded tissue | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
AMYLOID | Ambient (preferred) | ||
Refrigerated |
Definitive identification of amyloid proteins
In all cases with adequate tissue, an initial Congo red stain is performed before mass spectrometry testing to confirm positivity, and the pattern of amyloid deposition can be considered when interpreting mass spectrometry results.
In some instances, per pathologist discretion, a different initial Congo red stain may be performed using SS2PC / Special Stain, Group II, Other (Bill Only).
-If the stain is negative for amyloid, then this test will not be performed, and only the SS2PC will be charged.
-If the stain is positive for amyloid, this test will be performed, and the SS2PC billing charge will be credited.
A pathology consultation is typically not required. If the amyloid subtyping results do not fit the clinical findings, PATHC / Pathology Consultation may be added if appropriate, upon client approval.
For more information see Amyloidosis: Laboratory Approach to Diagnosis.
Amyloidosis is a group of hereditary and acquired diseases unified by extracellular tissue deposition of misfolded proteins resulting in end organ damage. Amyloidosis can be a systemic or localized disease. Although many cases of amyloidosis are hereditary, most are acquired as the result of an underlying monoclonal B-cell/plasma cell malignancy, as a phenomenon of aging, or as the result of long-standing chronic inflammation. Specific amyloid-related diseases are therefore associated with specific amyloid proteins. These include kappa or lambda immunoglobulin light chains (AL amyloid), transthyretin (ATTR amyloid), serum amyloid A (SAA amyloid), and other uncommon subtypes. Because treatment of amyloidosis patients differs radically for the different amyloid subtypes, it is critically important to accurately identify the proteins that constitute the amyloid deposits.
The basic diagnosis of amyloidosis is typically achieved by Congo red staining of paraffin-embedded tissue biopsy specimens obtained from diverse anatomic sites and demonstrating Congo red-positive, apple-green birefringent, amyloid deposits in the tissues. The next step is to definitively subtype the amyloid deposits. This test fulfills that need. It relies on laser microdissection of Congo red-positive amyloid deposits followed by analysis by liquid chromatography tandem mass spectrometry to accurately determine the identity of the proteins that constitute the amyloid.
An interpretive report will be provided.
An interpretation will be provided.
In rare instances amyloid deposits may show a false-negative result by Congo red staining. Because this test depends on the presence of Congo red-positive amyloid, these cases may not be identified as amyloid by this testing algorithm. Correlation with clinical and pathologic features and other laboratory test results is recommended to definitively exclude a diagnosis of amyloidosis.
1. Theis JD, Dasari S, Vrana JA, Kurtin PJ, Dogan A. Shotgun-proteomics-based clinical testing for diagnosis and classification of amyloidosis. J Mass Spectrom. 2013;48(10):1067-1077
2. Said SM, Sethi S, Valeri AM, et al. Renal amyloidosis: origin and clinicopathologic correlations of 474 recent cases. Clin J Am Soc Nephrol. 2013;8(9):1515-1523
3. Dasari S, Theis JD, Vrana JA, et al. Amyloid typing by mass spectrometry in clinical practice: a comprehensive review of 16,175 samples. Mayo Clin Proc. 2020;95(9):1852-1864. doi:10.1016/j.mayocp.2020.06.029
4. Klein CJ, Vrana JA, Theis JD, et al. Mass spectrometric-based proteomic analysis of amyloid neuropathy type in nerve tissue. Arch Neurol. 2011;68(2):195-199
5. Vrana JA, Gamez JD, Madden BJ, Theis JD, Bergen HR III, Dogan A. Classification of amyloidosis by laser microdissection and mass spectrometry-based proteomic analysis in clinical biopsy specimens. Blood. 2009;114(24):4957-4959
Affected areas are removed from paraffin-embedded tissues by laser microdissection. Protein digestion is performed, followed by liquid chromatography tandem mass spectrometry.(Unpublished Mayo method)
Monday through Friday
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
88313
82542 (if appropriate)
88380 (if appropriate)
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
AMPIP | Amyloid Protein ID, Par, LC MS/MS | 101405-9 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
71185 | Interpretation | 50595-8 |
71186 | Participated in the Interpretation | No LOINC Needed |
71187 | Report electronically signed by | 19139-5 |
71189 | Material Received | 81178-6 |
71592 | Disclaimer | 62364-5 |
72109 | Case Number | 80398-1 |