Kidney Week

Abstract: PO1671

Podometrics in Different Cortical Zones and Associations with the Number of Non-Sclerotic Glomeruli

Session Information

• Podocyte Injury in Human Disease: Pathomechanism, Diagnosis, and Therapy
  November 04, 2021 | Location: On-Demand, Virtual Only
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1204 Podocyte Biology

Authors

• Haruhara, Kotaro, Monash University, Clayton, Australia

Kotaro Haruhara, MD, PhD

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

Go Kanzaki,

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

Takaya Sasaki,

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

Saeko Hatanaka,

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

Yusuke Okabayashi,

• Shimizu, Akira, Nihon Ika Daigaku, Bunkyo-ku, Tokyo, Japan

Akira Shimizu,

• Cullen-McEwen, Luise A., Monash University, Clayton, Victoria, Australia

Luise A. Cullen-McEwen,

• 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,

• Bertram, John F., Monash University, Clayton, Victoria, Australia

John F. Bertram,

Background

Reduced nephron and podocyte number are common features in CKD. While it is well known that glomerular volume and glomerular density (glomerular number per cortical area) differ between cortical zones, zonal differences in podometrics and correlations with nephron number have not previously been explored.

Methods

Non-sclerotic glomerular number per kidney was estimated using the physical disector/fractionator combination. Podocyte density, podocyte number, podocyte volume and volumetric density of podocyte to glomerulus in each cortical zone were estimated using model-based stereology on a single histological section immunostained with two podocyte markers and imaged by confocal microscopy.

Results

Fifty autopsy kidneys were studied. The median age was 68 years ranging from 28 to 85 years. Median eGFR was 74 mL/min/1.73m². The median number of non-sclerotic glomeruli per kidney was 421,547 (IQR, 289,095－548,233). Non-sclerotic glomerular number was directly correlated with podocyte number per tuft, podocyte density and volumetric density of podocytes in each cortical zone (Fig). Glomeruli in the superficial cortex were smaller than glomeruli in other zones and had the highest podocyte density and smallest podocyte volume. Podocyte number and volumetric density of podocytes were similar across the cortical zones.

Conclusion

These results demonstrate for the first time that a higher number of non-sclerotic glomeruli is directly associated with three beneficial indices of podocyte and glomerular health. Podocyte number and volumetric density of podocytes were the more reliable indicators of non-sclerotic nephron number, independent of cortical zones.

Funding

• Government Support – Non-U.S.