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Test Code MSFGN Fibrillary Glomerulonephritis Confirmation, Paraffin, LC-MS/MS


Necessary Information


1. Preliminary pathology report and history are required.

2. A brief explanatory note or consultative letter is also recommended.



Specimen Required


Supplies: Pathology Packaging Kit (T554)

Specimen Type: Formalin-fixed or B5-fixed, paraffin-embedded tissue block

Container/Tube: Pathology Packaging Kit

Collection Instructions:

1. Do not send fixed tissue slides. Testing can only be done on paraffin-embedded tissue blocks.

2. Attach the green pathology address label included in the kit to the outside of the transport container.


Secondary ID

113012

Useful For

Diagnosis of fibrillary glomerulonephritis

Testing Algorithm

A pathology consultation is typically not required. If the Fibrillary GN Confirm, LC MS/MS results do not support the clinical findings, a PATHC/Path Consultation may be added if appropriate, upon client approval.

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Fibrillary GN Confirm, LC MS/MS

Specimen Type

AMYLOID

Specimen Stability Information

Specimen Type Temperature Time
AMYLOID Ambient (preferred)
  Refrigerated 

Reject Due To

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

Fixed tissue slides

wet or frozen tissue

Cytological smears

nonformalin fixed tissue

nonparaffin embedded tissue

Clinical Information

Fibrillary glomerulonephritis (FGN) is a rare kidney disease with fibrillary deposits in the glomeruli that contain polyclonal IgG and complement, indicating immune complex deposition. Although usually Congo-red negative, more recently cases with weak Congo-red positivity have been observed, making the distinction from amyloid more challenging. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) performed on microdissected glomeruli from patients with FGN demonstrate a unique proteomic profile including the protein DNAJB9 (Mayo Clinic unpublished observations). The presence of DNAJB9 was found to be highly sensitive and specific for FGN, distinguishing it from other glomerular diseases including amyloid, immunotactoid glomerulopathy, and immune complex-mediated proliferative glomerulonephritis. The presence of DNAJB9, in the appropriate clinical and pathological context, can be useful to establish a diagnosis of FGN.

Interpretation

An interpretation will be provided.

Clinical Reference

1. 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

2. 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

3. Rosenstock JL, Markowitz GS, Valeri AM, et al: Fibrillary and immunotactoid glomerulonephritis: Distinct entities with different clinical and pathologic features. Kidney Int 2003;63:1450-1461

4. Casanova S, Donini U, Zucchelli P, et al: Immunohistochemical distinction between amyloidosis and fibrillar glomerulopathy. Am J Clin Pathol 1992;97:787-795

5. Rosenmann E, Eliakim M: Nephrotic syndrome associated with amyloid-like glomerular deposits. Nephron 1977;18:301-308

Day(s) and Time(s) Performed

Monday through Friday

Analytic Time

7-15 days

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

82542

88380

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MSFGN Fibrillary GN Confirm, LC MS/MS In Process

 

Result ID Test Result Name Result LOINC Value
BA0389 Interpretation In Process
BA0390 Participated in the Interpretation In Process
BA0391 Report electronically signed by In Process
BA0392 Material Received In Process
BA0393 Disclaimer 62364-5
BA0394 Case Number In Process