TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: AMPIP    
Amyloid Protein Identification, Paraffin, Mass Spectrometry

Useful For Suggests clinical disorders or settings where the test may be helpful

Definitive identification of amyloid proteins

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

In all cases with adequate tissue, an initial Congo red stain is performed before mass spectrometry testing to confirm positivity and 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, a PATHC / Pathology Consultation may be added if appropriate, upon client approval.

 

See Laboratory Approach to the Diagnosis of Amyloidosis in Special Instructions.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Amyloidosis is a group of hereditary and acquired diseases that are 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.

Interpretation Provides information to assist in interpretation of the test results

An interpretation will be provided.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

No significant cautionary statements.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Theis JD, Dasari S, Vrana JA, et al: 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 Sep;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: Amyloid neuropathy type is distinguished by mass spectrometric based proteomic analysis of nerve tissue. Arch Neurol. 2011:68(2):195-199

5. Vrana JA, Gamez JD, Madden BJ, et al: Classification of amyloidosis by laser microdissection and mass spectrometry-based proteomic analysis in clinical biopsy specimens. Blood. 2009;114(24):4957-4959

Special Instructions Library of PDFs including pertinent information and forms related to the test