Kidney Week

Abstract: TH-PO1177

Low Nephron Numbers and Larger Glomerular Size Are the Predictors of Long-Term Kidney Function in Kidney Donors

Session Information

• Transplantation: Clinical - Pretransplant Management
  November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

• 1902 Transplantation: Clinical

Authors

• Merzkani, Massini, Mayo Clinic, Rochester, Minnesota, United States

Massini Merzkani,

• Lopez, Camden, Alzheimer's Therapeutic Research Institute, San Diego, California, United States

Camden Lopez,

• Narasimhan, Ramya, Mayo Clinic, Rochester, Minnesota, United States

Ramya Narasimhan,

• Larson, Joseph, Mayo Clinic, Rochester, Minnesota, United States

Joseph Larson,

• Kremers, Walter K., Mayo Clinic, Rochester, Minnesota, United States

Walter K. Kremers,

• Denic, Aleksandar, Mayo Clinic, Rochester, Minnesota, United States

Aleksandar Denic,

• Park, Walter, The Mayo Clinic, Rochester, Minnesota, United States

Walter Park,

• Alexander, Mariam P., Mayo Clinic, Rochester, Minnesota, United States

Mariam P. Alexander,

• Taler, Sandra J., Mayo Clinic, Rochester, Minnesota, United States

Sandra J. Taler,

• Chakkera, Harini A., Mayo Clinic Arizona, Phoenix, Arizona, United States

Harini A. Chakkera,

• Issa, Naim S., Mayo Clinic, Rochester, Minnesota, United States

Naim S. Issa,

• Stegall, Mark D., Mayo Clinic, Rochester, Minnesota, United States

Mark D. Stegall,

• Rule, Andrew D., Mayo Clinic, Rochester, Minnesota, United States

Andrew D. Rule,

Background

Microstructural findings of larger nephron size and nephrosclerosis on kidney biopsy are predictive of kidney function after donation at short-term follow up. Our hypothesis is that kidney structural findings also predict long-term kidney function after donation.

Methods

We contacted living kidney donors who were at least 5 years post-donation to obtain blood pressure and kidney function test results. Microstructural (biopsy) and macrostructural (contrast CT scan) findings of the kidney at the time of donation were assessed as predictors of estimated glomerular filtration rate (eGFR), proteinuria, and hypertension with adjustment for years since donation and baseline clinical characteristics.

Results

Among 1687 donors contacted, 807 (48%) participated a mean 10.5 years after donation. At follow-up, 6.4% had developed an eGFR<45 ml/min/1.73 m², the mean residual eGFR ratio (post-/pre-donation eGFR) was 75%, proteinuria (self-reported) occurred in 5.1 %, and new onset hypertension occurred in 19% (119/653). An eGFR <45 ml/min/1.73 m² was predicted by larger glomerular volume per SD (OR=1.48, p=0.01) and low nephron number (below age-specific 5^th percentile) (OR=3.40, p=0.01). Residual eGFR ratio was predicted by low nephron number (-6.1%, p=0.004) and cortical volume per BSA (1.3%, p=0.03). Proteinuria was predicted by glomerular volume per SD (OR=1.42, p=0.01). Hypertension was not predicted by any structural finding. Nephrosclerosis (glomerulosclerosis, interstitial fibrosis, or arteriosclerosis) did not predict any outcome.

Conclusion

Lower nephron numbers and large glomeruli appear to be the most important structural determinants of long term kidney dysfunction after donation.

Funding

• Other NIH Support