Abstract: FR-PO669

Renal Histology Does Not Predict Progression of Diabetic Nephropathy

Session Information

Category: Diabetes

  • 502 Diabetes Mellitus and Obesity: Clinical

Authors

  • Misra, Paraish Shivam, University of Toronto, Toronto, Ontario, Canada
  • Krizova, Adriana, St Michael's Hospital, Toronto, Ontario, Canada
  • Gilbert, Richard E., Keenan Research Centre for Biomedical Sciences, St. Michael's Hospital, Toronto, Ontario, Canada
  • Yuen, Darren A., Keenan Research Centre for Biomedical Sciences, St. Michael's Hospital, Toronto, Ontario, Canada
Background

The ability to predict renal disease progression in diabetes remains limited, despite the identification of well-established risk factors including glycemic control, blood pressure, and albuminuria. The consensus pathologic classification system developed by the Renal Pathology Society (RPS) was designed to assist clinical and research assessment of diabetic nephropathy. While some reports have suggested that the RPS classification correlates with disease progression, its predictive potential has not yet been completely evaluated. Our aim was to determine the relationship between the RPS score and progression of diabetic renal disease.

Methods

Slope of estimated glomerular filtration rate (eGFR) decline was calculated for patients with biopsy-proven diabetic kidney disease, and correlated with RPS histologic classification scores. Results were adjusted for baseline eGFR and urine albumin-to-creatinine ratios (ACR) at the time of biopsy. Additionally, the correlation between slope of eGFR decline and histologic and clinic parameters was assessed, and renal survival curves (time off dialysis) were generated for subgroups of ACR, eGFR, and histology scores.

Results

26 patients with biopsy-proven diabetic kidney disease and at least 6 months of eGFR follow-up data were identified among 394 biopsies performed at St. Michael’s Hospital between 2011 and 2016. While renal survival was significantly worse with increasing glomerular and interstitial fibrosis/tubular atrophy scores (p <0.0001 and p = 0.0124, respectively), patients with higher fibrosis scores had lower eGFR at the time of biopsy (r = -0.6623, p = 0.0002). Slope of eGFR decline did not correlate with either histologic classification or baseline clinical parameters on univariate or multivariate analyses.

Conclusion

Beyond establishing the diagnosis of diabetic nephropathy, our results suggest that renal biopsy does not provide any additional information regarding the rate of disease progression. While patients with higher fibrosis scores on biopsy tended to have poorer renal survival, such individuals also had lower baseline eGFR. Importantly, histologic scores did not correlate with future changes in eGFR. Larger studies are needed to confirm these observations.

Funding

  • Private Foundation Support