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HelpTest Code MSFGN Fibrillary Glomerulonephritis Confirmation, Mass Spectrometry, Paraffin Tissue
Necessary Information
1. Preliminary pathology report and history are required.
2. A brief explanatory note, or consultative letter, is recommended.
Specimen Required
Supplies: Pathology Packaging Kit (T554)
Specimen Type: Formalin-fixed or B5-fixed, paraffin-embedded tissue block
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.
Useful For
Diagnosing fibrillary glomerulonephritis
Testing Algorithm
A pathology consultation is typically not required. If the results of this test do not support the clinical findings, PATHC / Pathology 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/MSSpecimen Type
AMYLOIDSpecimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| AMYLOID | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
| Fixed tissue slides wet or frozen tissue Cytological smears Nonformalin fixed tissue Nonparaffin embedded tissue |
Reject |
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, 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glomeruli from patients with FGN demonstrates a unique proteomic profile including the protein DNAJB9 (Mayo Clinic unpublished observations).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.
Cautions
No significant cautionary statements
Method Description
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)
Day(s) Performed
Monday through Friday
Report Available
7 to 15 daysSpecimen Retention Time
Until reportedPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
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.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 | 59465-5 |
| BA0390 | Participated in the Interpretation | No LOINC Needed |
| BA0391 | Report electronically signed by | 19139-5 |
| BA0392 | Material Received | 81178-6 |
| BA0393 | Disclaimer | 62364-5 |
| BA0394 | Case Number | 80398-1 |
Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.