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Kidney Week

Abstract: PO2292

Application of the Renal Chronicity Score on Native Kidney Biopsies: Results from the FCGG Biopsy Registry

Session Information

Category: CKD (Non-Dialysis)

  • 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention


  • Deleersnijder, Dries, Katholieke Universiteit Leuven Universitaire Ziekenhuizen Leuven, Leuven, Flanders, Belgium
  • Laurens, Wim, AZ Nikolaas, Sint-Niklaas, Oost-Vlaanderen, Belgium
  • De Meester, Johan MJ, AZ Nikolaas, Sint-Niklaas, Oost-Vlaanderen, Belgium
  • Dendooven, Amélie, Universitair Ziekenhuis Gent, Gent, Oost-Vlaanderen, Belgium
  • Sprangers, Ben, Katholieke Universiteit Leuven Universitaire Ziekenhuizen Leuven, Leuven, Flanders, Belgium

Chronic changes on kidney biopsy strongly predict renal outcome and have important treatment implications. Sethi et al. recently proposed the renal chronicity score (RCS), a standardized pathology scoring system which uniformly scores chronic changes on kidney biopsies. We report the RCS of the biopsies included in the FCGG registry in 2018 and 2019.


The RCS is derived from the sum of the degree of glomerulosclerosis, tubular atrophy, interstitial fibrosis and arteriosclerosis, and ranges from 0 (no/minimal chronic changes) to 10 (severe chronic changes). The FCGG registry is a population-based native kidney biopsy registry in Flanders (Northern part of Belgium) that covers a population of approximately 6.5 million inhabitants.


In 2018 and 2019, the RCS was reported in 1106 of 1403 adult biopsies (78,83%), with a median value of 4 (mild chronic changes, Fig. 1A). Minimal change disease (MCD) and lupus nephritis (LN) showed mostly minimal to mild signs of disease chronicity (Fig. 1B). Membranous nephropathy (MN), tubulointerstitial nephritis (TIN), ANCA-associated vasculitis (AAV) and IgA-nephropathy (IgAN) showed an increasing proportion of moderate to severe chronic changes (26%, 35%, 37%, 45%, respectively, Fig. 1B). Finally, in focal segmental glomerulosclerosis (FSGS), nephrosclerosis and diabetic kidney disease (DKD) the proportion of biopsies with moderate to severe chronic changes exceeded 50% (60%, 79%, 80%, respectively, Fig. 1B). The RCS was also higher in biopsies from older patients (Fig. 1C), although this observation is likely confounded by the etiology of kidney disease in the older age categories (i.e., more nephrosclerosis in older patients).


We report on the first large population-based kidney biopsy registry that systematically scores chronic changes on kidney biopsy in a standardized manner, using the RCS. Future research should validate this score by assessing the correlation with prognosis and treatment outcome in individual kidney diseases and determine whether disease-specific modifications in the chronicity classification should be made.