CHAPTER 37: Evaluation of the Living Kidney Donor

INTRODUCTION

The evaluation of the living donor is a complex process, including medical, psychosocial, and ethical/legal considerations. Although society guidelines exist, there is considerable center-specific variation in the approval of a living donor.^1–3 The following chapter includes essential components of a living donor evaluation and commonly cited exclusion criteria.

Donor evaluation can be divided into the following categories:

• (1) Assessments to protect the health and safety of the donor

  • (A) Medical assessment

    • (i) Age

      • Advanced age (defined as age above 65), may be associated with decreased recipient graft and patient survival; both recipient and donor should be fully informed with regard to potential long-term disadvantages

      • Potential donors less than 18 years are generally excluded due to uncertain future long-term consequences of donation and possible maturity level of the potential donor

    • (ii) Diabetes mellitus

      • Initiate screening with hemoglobin A1C (HbA1c) and/or fasting blood glucose (FBG)

      • A 2-hour oral glucose tolerance test (2h-OGTT) should be performed in donors with:

        • Glucose intolerance by HbA1c

        • History of gestational diabetes

        • Family history of diabetes mellitus

      • Diabetic donors should be excluded (HbA1c ≥6.5%, fasting glucose ≥126 mg/dL [7.0 mmol/L], 2h-OGTT ≥200 mg/dL [11.1 mmol/L]) due to long-term risk of chronic kidney disease.

      • Prediabetic donors (HbA1c of 5.7–6.4%, fasting glucose of 100 mg/dL [5.6 mmol/l] to 125 mg/dL [6.9 mmol/L]) or a 2h-OGTT value of 140 mg/dL [7.8 mmol/L] to 199 mg/dL [11.0 mmol/L]) can be considered acceptable candidates; however, they must be counseled appropriately on weight loss, dietary modifications, and exercise.

    • (iii) Hypertension

      • Obtain two blood pressure readings on separate occasions

      • 24-hour ambulatory blood pressure monitoring can confirm any abnormal blood pressure reading or concern for white coat hypertension.

      • Prehypertensives (blood pressure ranging from 120–139 mm Hg systolic and/or 80–89 mm Hg diastolic) should be easily identified and counseled. There is uncertainty on whether to exclude them as potential donors, as they are at increased risk of developing hypertension and cardiovascular disease.

      • Candidates with hypertension that can be controlled to systolic <140, diastolic <90 using one antihypertension agent without evidence of organ damage may be acceptable for donation. Such candidates should be screened for:

        • Microalbuminuria

        • Left ventricular hypertrophy or other cardiac disease

      • A donor with a history of hypertension on two or more medications should generally be excluded

      • Caution with accepting donors with prehypertension or hypertension who are African American or Hispanic

    • (iv) Prehypertensives or hypertensives must be counseled that blood pressure typically increases after kidney donation.

    • (v) Pregnancy

      • Pregnant patients are excluded.

      • All female potential donors of childbearing age who are contemplating future pregnancies should be counseled on the potential risks of donating, including increased risk for:

        • Gestational hypertension

        • Preeclampsia

        • Prematurity

      • A high level of surveillance and monitoring is suggested for all pregnant women post donation.

  • (B) Renal assessment

    • (i) Glomerular filtration rate (GFR)

      • Obtain a 24-hour urine for creatinine clearance on all donors; ensure accurate collection.

      • Further evaluation with radionuclide methods can be performed.

      • The majority of transplant centers’ ...