# Living  Donor  Extended  Time  Outcomes  (LETO) Study

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2022 · $564,733

## Abstract

PROJECT SUMMARY
We submit this proposal titled “Living donor Extended Time Outcomes (LETO)” as an ancillary study to the newly
initiated “APOL1 Long-term Kidney Transplantation Outcomes” (APOLLO) Network. The APOLLO Consortium
represents the most ambitious national study addressing the implications of donor apolipoprotein L1 gene
(APOL1) renal-risk variants on kidney transplant outcomes. However, the prospective design of the parent
APOLLO is underpowered to assess postdonation kidney health in living donors and outcomes in recipients of
their kidneys due to due to short follow-up duration and secular trends resulting in diminishing numbers of
persons with 2 APOL1 renal-risk variants donating in recent calendar years. We propose a cost-effective “hybrid”
study design—jointly analyzing data collected at home-based research visits together with data collected as part
of clinical care (as entered into a national registry)—that will greatly increase the number of person-years of
follow-up and enhance study power. We will enroll 1,100 living donors who donated from 2001-2005 to generate
data that will have a major impact on the clinical practice of living kidney donation in African Americans. Our
specific aims are:
Aim 1: To determine in a nationally representative sample whether African American living kidney donors with 2
APOL1 renal-risk variants are at higher risk of developing clinically significant chronic kidney disease (estimated
glomerular filtration rate <45 ml/min/1.73m2) approximately two decades after donation.
Aim 2: To determine whether other independent (or APOL1 interactive) gene variants associate with increased
risk of clinically significant chronic kidney disease (estimated glomerular filtration rate <45 ml/min/1.73m2) in
African American living kidney donors.
Aim 3: To determine the impact of donor APOL1 renal-risk variants and other novel genetic risk factors on graft
survival and recipient outcomes in a nationally representative sample of living donor kidney transplant recipients
from African American living donors.

## Key facts

- **NIH application ID:** 10413009
- **Project number:** 5R01DK120551-04
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Chi-yuan Hsu
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $564,733
- **Award type:** 5
- **Project period:** 2019-06-01 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10413009

## Citation

> US National Institutes of Health, RePORTER application 10413009, Living  Donor  Extended  Time  Outcomes  (LETO) Study (5R01DK120551-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10413009. Licensed CC0.

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