Diagnosing fibrillary glomerulonephritis
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.
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
GPFGNMS
GPMSCBB
ISFGNMSST
FGN
DNAJB9
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.
AMYLOID
1. Preliminary pathology report and history are required.
2. A brief explanatory note, or consultative letter, is recommended.
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.
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
Fixed tissue slides wet or frozen tissue Cytological smears Nonformalin fixed tissue Nonparaffin embedded tissue | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
AMYLOID | Ambient (preferred) | ||
Refrigerated |
Diagnosing fibrillary glomerulonephritis
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.
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glomeruli from patients with FGN demonstrates a unique proteomic profile including the protein DNAJB9 (Mayo Clinic unpublished observations).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.
An interpretation will be provided.
No significant cautionary statements
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;8(9):1515-1523
2. Vrana JA, Gamez JD, Madden BJ, Theis JD, Bergen HR 3rd, Dogan A. 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, Sacchi G, Appel GB, D'Agati VD. Fibrillary and immunotactoid glomerulonephritis: Distinct entities with different clinical and pathologic features. Kidney Int. 2003;63(4):1450-1461
4. Casanova S, Donini U, Zucchelli P, Mazzucco G, Monga G, Linke RP. Immunohistochemical distinction between amyloidosis and fibrillar glomerulopathy. Am J Clin Pathol. 1992;97(6):787-795
5. Rosenmann E, Eliakim M. Nephrotic syndrome associated with amyloid-like glomerular deposits. Nephron. 1977;18(5):301-308
6. Nasr SH, Vrana JA, Dasari S, et al. DNAJB9 is a specific immunohistochemical marker for fibrillary glomerulonephritis. Kidney Int Rep. 2017;3(1):56-64
7. Dasari S, Alexander MP, Vrana JA, et al. DnaJ Heat Shock Protein Family B Member 9 is a Novel Biomarker for Fibrillary GN. J Am Soc Nephrol. 2018;29(1):51-56
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.
82542
88380
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
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.
|
---|---|---|
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 |