Kidney Week

Abstract: TH-PO740

Podocyte Density, Rather than Podocyte Number per Glomerulus, Is Associated with Kidney Outcomes in Obesity-Related Glomerulopathy

Session Information

• Glomerular Diseases: Podocyte Biology - I
  November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1403 Podocyte Biology

Authors

• Haruhara, Kotaro, Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan

Kotaro Haruhara,

• Okabayashi, Yusuke, Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan

Yusuke Okabayashi,

• Sasaki, Takaya, Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan

Takaya Sasaki,

• Kubo, Eisuke, Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan

Eisuke Kubo,

• D'Agati, Vivette D., Columbia University Irving Medical Center, New York, New York, United States

Vivette D. D'Agati,

• Bertram, John F., Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia

John F. Bertram,

• Tsuboi, Nobuo, Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan

Nobuo Tsuboi,

• Yokoo, Takashi, Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan

Takashi Yokoo,

Background

Obesity-related glomerulopathy (ORG) is a slowly progressive glomerular disease occurring in obese individuals. Podocyte injury and subsequent podocyte depletion are regarded as key processes in ORG progression. However, no previous study has assessed the longitudinal association between podometrics and long-term kidney outcomes in ORG.

Methods

Podocyte number per glomerular volume (podocyte density) and podocyte number per glomerulus (podocyte number) in ORG patients were estimated using model-based stereology. The associations between these podometrics at the diagnostic biopsy and subsequent kidney outcomes (30% decline in eGFR) were examined by log-rank tests and Cox proportional hazard analyses.

Results

Forty-one ORG patients with median age of 47 years, eGFR 63 mL/min/1.73m² were analyzed. At biopsy diagnosis, ORG patients with podocyte density below the median value were older, predominantly male, and had larger body surface area, higher proteinuria, larger glomeruli, and lower podocyte number than ORG patients with higher podocyte density. During a median follow-up period of 3.9 years, 16 (39%) ORG patients reached a 30% decline in eGFR. Kidney survival in patients with lower podocyte density was significantly worse than in patients with higher podocyte density (P = 0.001), but there was no significant association between kidney survival and lower vs higher podocyte number (P = 0.3). Cox hazard analyses showed that podocyte density, but not podocyte number, was associated with kidney outcome after adjustment for clinical factors, including age, sex, proteinuria, and eGFR.

Conclusion

Our results indicate that lower podocyte density, rather than lower podocyte number, is a high-risk factor for progression of ORG. Confirmation in other ORG cohorts and potential generalizability to other glomerular diseases will require further studies.

Funding

• Government Support – Non-U.S.