Standardized Classification and Reporting of Glomerulonephritis

Sanjeev Sethi; Fernando C. Fervenza


Nephrol Dial Transplant. 2019;34(2):193-199. 

In This Article

What Should Kidney Biopsy Diagnosis Look Like?

Putting it Together With Clinical Modifiers

A clinical modifier is the clinical and/or laboratory findings that, together with the renal biopsy findings, point to the correct etiology of the GN; for example clinical modifiers include, hepatitis C in the setting of immune-complex GN with a membranoproliferative GN pattern of injury, the presence of positive anti-GBM titers in the setting of a severe crescentic and necrotizing anti-GBM GN, positive anti-PR3 titers in the setting of a pauci-immune necrotizing and crescentic GN, staphylococcal abscess in the setting of IgA-dominant infection-related GN, positive monoclonal Ig in serum and urine in the setting of monoclonal Ig–associated proliferative GN, etc.

In order to incorporate four of the five most important questions raised by the nephrologist, the kidney biopsy diagnosis should include

  • Primary diagnosis, with clinical modifiers

  • Pattern of injury

  • Established score/class/grade of disease entities, such as IgA nephropathy and lupus nephritis

  • Secondary diagnosis, such as ATN, interstitial nephritis and thrombotic microangiopathy

  • Ancillary studies if done, such as IgG subtyping, pronase retrieval techniques and mass spectrometry

  • Chronicity grade and score

Simply enumerating the kidney biopsy findings in a numerical order, in particular labelling the primary diagnosis simply in terms of pattern of injury, is inadequate and incomplete.

A comment section that includes a summary of the diagnostic features, prognostic findings and differential diagnosis is needed, along with key references. The details of LM, IF microscopy and EM to be included in the kidney biopsy report are given in the Mayo Clinic consensus report on GN.[4] Some examples of the diagnosis are shown in Table 1.