Kidney Week

Abstract: PO0955

In Patients with Biopsy-Proven Diabetic Nephropathy, 38% Have a Second Significant Diagnosis

Session Information

• Diabetic Kidney Disease: Clinical - 1
  October 22, 2020 | Location: On-Demand
  Abstract Time: 10:00 AM - 12:00 PM

Category: Diabetic Kidney Disease

• 602 Diabetic Kidney Disease: Clinical

Authors

• Walker, Patrick D., Arkana Laboratories, Little Rock, Arkansas, United States

Patrick D. Walker,

• Charu, Vivek, Stanford University School of Medicine, Stanford, California, United States

Vivek Charu,

• Dai, Dao-Fu, The University of Iowa Roy J and Lucille A Carver College of Medicine, Iowa City, Iowa, United States

Dao-Fu Dai,

Background

AIM: determine the renal biopsy (Bx) incidence of a second kidney disease (2^nd DX) in patients (Pts) with diabetic nephropathy (DN) Bx'ed for various clinical indications.

Methods

Of 45,422 non-transplant cases received from 2001-2014 (2222 nephrologists, 39 states), 7,746 Pts with DN were found. 1,749 cases were excluded for insufficient data. 1,398 cases with FSGS were excluded (separate study). 4,599 cases were analyzed (age range: 8 - >89 years; males 53.5%). Bx indication: acute kidney injury (AKI), acute nephritic syndrome (ANS), rapidly progressive renal failure (RPRF), hematuria (Heme), suspect a non-DN renal disease (Non-DN), sudden increase in proteinuria (Prot) or chronic kidney disease (CKD). We recorded a specific rule out (r/o) diagnosis if one was given. BX DN Grade: I EM changes; II Mesangial increase; III Nodular Sclerosis; IV >50% Global Sclerosis.

Results

A 2^nd DX was found in 1750 (38%) cases. Overall, there were 40 2^nd DXs: ATI 41%, acute interstitial nephritis 14%, infection-related glomerulopathy (GN) 7%, etc. There were multiple unexpected 2^nd DXs: fibrillary GN, amyloid, dense deposit disease, among others. The highest odds ratio (OR) of a 2^nd DX was in Pts with AKI at 3.25 whereas CKD had an OR of 0.03 (Table). Age correlated with a 2^nd DX (p<0.001) with the Bx incidence ranging from 29% in Pts <30 to 56% for those ≥ 80. In 1,589 cases, a specific DX was to be ruled out. A 2nd Dx was found in 48% of Bx's with a r/o Dx versus 33% when no r/o Dx was given (OR=1.83, CI (1.62, 2.08), p<0.001). Lesser grades of DN significantly correlated with a 2^nd DX; I - 75%, II - 64%, III - 38%, IV - 20% (p<0.001).

Conclusion

In Bx proven DN, a significant 2^nd DX was found in 38%, with AKI and ANS most likely to yield a 2^nd DX. Age and a r/o DX can further differentiate patient groups most likely to have a 2nd DX. Given the worldwide toll of diabetes, the finding of a potentially treatable 2^nd DX in diabetics already at high-risk of end stage kidney disease should provide significant savings in morbidity, mortality and health care expense.