Live Kidney Donor Study -Renal Function Study

Study Overview
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Brief Summary
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Kidney transplantation from living donors has been shown to carry many benefits over deceased donor transplantation. Because of benefits such as shorter waiting times and improved outcome for transplant recipients, living kidney donation accounts for an increasing number of kidney transplants nationwide. Most published studies about living kidney donation demonstrate that the procedure is safe, but they also emphasize concerns that long-term data on live donor outcomes are insufficient. In particular, data concerning the extent of renal function decline after donation are inadequate. This study will measure glomerular filtration rate (GFR) in previous living donors and aims to more accurately describe renal function after kidney donation.

Detailed Description
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Previous studies poorly describe renal function after kidney donation. Most published studies of renal function after donation are based on predictive equations, which were not designed for living kidney donors. One concern is that use of these equations may underestimate glomerular filtration rate (GFR) following donation. Systematic underestimation of GFR may cause previous kidney donors to be inaccurately categorized as having chronic kidney disease (CKD). While data for the entire kidney donor population are insufficient, there is even less available information about renal function after donation in black renal donors. In the general population, the incidence of end stage renal disease is higher among blacks compared to whites. Whether this pattern carries over to the black renal donor population is unclear. The primary objectives of this study are to more accurately measure current GFR; evaluate the change in GFR before and after donation; compare measured GFR in donors matched by race, age, sex, time from donation, presence of hypertension, and presence of obesity; and evaluate differences between predictive equations and measured GFR. This is an observational study to look at the long term outcomes in living kidney donors. Participants in this study will also be participants in DAIT RELIVE-04. As a part of this study, participants will have a brief medical history taken and a glomerular filtration rate test performed.

Official Title
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Live Kidney Donor Study -Renal Function Study

Conditions
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Kidney Donation, Kidney Failure, Kidney Transplantation

Intervention / Treatment
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* Other: Glomerular Filtration Rate with Iothalamate
* Other: Glomerular Filtration Rate with Iohexol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Underwent unilateral donor nephrectomy between 5 and 50 years ago; but no later than June 30, 2005 at Mayo Clinic or University of Minnesota Alive at the time of study recruitment Underwent GFR measurement before and early after donor nephrectomy (Mayo Clinic participants only) Underwent GFR measurement late after donor nephrectomy and 3 or more years prior to the invitation to participate in this study (UMN participants only) Self reported black race (UAB participants only) Negative serum pregnancy test (Total Beta Human Chorionic Gonadotropin (HCG) <5) for women of child-bearing potential Exclusion Criteria: Less than 5 years out from time of kidney donation Inability to contact donor Inability or unwillingness to provide informed consent Iodine or iodinated contrast allergy. Pregnant or breast feeding women
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 1<br>Caucasians who donated a kidney at Mayo Clinic in Rochester, Minnesota (MN) | Other: Glomerular Filtration Rate with Iothalamate<br>* used to determine kidney function<br>* Other names: GFR;|
| 2<br>Caucasians who donated a kidney at the University of Minnesota | Other: Glomerular Filtration Rate with Iohexol<br>* used to determine kidney function<br>* Other names: GFR;|
| 3<br>African-Americans who donated a kidney at the University of Alabama | Other: Glomerular Filtration Rate with Iothalamate<br>* used to determine kidney function<br>* Other names: GFR;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in measured GFR from before donor nephrectomy compared to early (within first 2 years) after donor nephrectomy. |  | Throughout study | 
| Change in measured GFR from early after donor nephrectomy compared to late donor nephrectomy. Change in measured GFR from early to late after donor nephrectomy stratified by: time since donation, hypertensive donors, obese donors, and age of donors |  | Throughout study | 
| Differences in measured GFR in black donors compared to white donors matched by age, sex and time from donation |  | Throughout study | 
| Incremental differences between measured GFR and estimated GFR before donor nephrectomy, early after donor nephrectomy, and late after donor nephrectomy |  | Throughout study | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in measured GFR between hypertensive donors and normotensive donors |  | Throughout study | 
| Differences in measured GFR between donors with familial history of renal disease (LRD) and donors without familial history of renal disease (LURD) |  | Throughout study | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Glomerular Filtration Rate