Test Catalog

Test ID: DNJB9    
DNAJB9 Immunostain, Technical Component Only

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

Diagnosis of fibrillary glomerulonephritis

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

For the initial technical component only immunohistochemical (IHC) stain performed, the appropriate bill-only test ID will be reflexed and charged (IHTOI). For each additional technical component only IHC stain performed, an additional bill-only test ID will be reflexed and charged (IHTOA).

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

DNAJB9 (Dnaj [hsp40] homolog, subfamily b, member 9) is a heat shock protein that plays a role in protein folding. Proteomic analysis indicates that the DNAJB9 protein is specifically identified in glomeruli of patients with fibrillary glomerulonephritis (FGN). By immunohistochemistry there is an intense smudgy staining of extracellular glomerular deposits for DNAJB9 in patients with FGN.

Interpretation Provides information to assist in interpretation of the test results

This test does not include pathologist interpretation; only technical performance of the stain is performed. If an interpretation is required, order PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case.


The positive and negative controls are verified as showing appropriate immunoreactivity and documentation is retained at Mayo Clinic Rochester. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request, call 855-516-8404.


Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

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

Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen-dependent. Best practice is for paraffin sections to be cut within 6 weeks.

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

1. Nasr SH, Vrana JA, Dasari S, et al: DNAJB9 is a specific immunohistochemical marker for fibrillary glomerulonephritis. Kidney Int Rep. 2018 Jan;3(1):56-64

2. 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 Jan;29(1):51-56

3. Liang S, Chen D, Liang D, et al: Clinicopathological characteristics and outcome of patients with fibrillary glomerulonephritis: DNAJB9 is a valuable histologic marker. J Nephrol. 2020 Jun 18. doi: 10.1007/s40620-020-00783-4