Transplant donor evaluation is a comprehensive process used to assess the suitability and safety of individuals who wish to donate a kidney, particularly living kidney donors. The primary goal is to protect the donor from unacceptable short-term and long-term health risks while ensuring the donated kidney provides optimal outcomes for the recipient.

Living kidney donation requires careful assessment of the donor’s medical, surgical, psychological, and social status. Risk assessment and clear communication are essential early steps to ensure that donor candidates make an informed decision without coercion, pressure, or undue influence.

The policies and protocols of the transplant centre should guide donor selection, evaluation, acceptance, and exclusion decisions. Regardless of whether a donor candidate is accepted or excluded, appropriate follow-up care and counselling should be arranged.

Epidemiology

Living kidney donation contributes significantly to kidney transplantation programs worldwide by increasing organ availability and reducing waiting times for patients with end-stage kidney disease.

Compared with dialysis, successful kidney transplantation provides improved survival and quality of life for suitable recipients. However, donor safety remains the highest priority because donors are generally healthy individuals undergoing surgery without direct medical benefit.

Long-term follow-up of donors is important to monitor kidney function, cardiovascular health, blood pressure, metabolic disease, and overall wellbeing.

Principles of Donor Evaluation

The evaluation process aims to:

• Confirm voluntary informed consent.

• Assess medical and psychological suitability.

• Identify conditions that increase donor risk.

• Ensure adequate kidney function after donation.

• Reduce perioperative and long-term complications.

• Ensure compatibility between donor and recipient.

A complete history and physical examination should be documented for every donor candidate.

Eligibility Criteria

Adults aged 18 years and above may be considered for living related kidney donation.

Assessment should determine:

• Medical suitability.

• Surgical suitability.

• Psychological readiness.

• Ability to understand risks and benefits.

• Long-term ability to maintain follow-up care.

Clinical Assessment

History and Physical Examination

A detailed evaluation should include:

• Medical history.

• Surgical history.

• Medication history.

• Family history of kidney disease.

• Cardiovascular risk assessment.

• Lifestyle assessment.

• Psychological and social assessment.

Physical examination should assess:

• Body mass index.

• Blood pressure.

• Cardiovascular status.

• Peripheral vascular disease.

• Signs of chronic illness.

Psychosocial Assessment

Psychosocial evaluation should assess:

• Voluntary nature of donation.

• Understanding of risks and benefits.

• Emotional readiness.

• Family and social support.

• Financial or social pressures influencing decision-making.

• Ability to comply with lifelong follow-up.

The donor must be able to make an independent decision without coercion.

Investigations

Investigations are guided by donor age, medical history, risk factors, and transplant centre protocols.

Surgical Assessment

Assessment should evaluate factors affecting surgical safety and kidney removal.

Important considerations include:

Obesity

• Increased surgical and anaesthetic risks.

• Assessment of body mass index and associated metabolic risks.

Anticoagulation

• Review indication for anticoagulant therapy.

• Assess bleeding risk.

• Requirement for anticoagulation is not an absolute contraindication but requires specialist evaluation.

Vascular anatomy

Assessment of:

• Renal arteries.

• Renal veins.

• Anatomical variations.

Imaging may be required before surgery.

Native kidney assessment

Important in patients with:

• Polycystic kidney disease.

• Structural kidney abnormalities.

Urological assessment

Evaluation for:

• Urinary tract abnormalities.

• Previous urological disease.

• Surgical suitability.

Diabetes Screening

All donor candidates should be assessed for diabetes risk.

Evaluation may include:

• Fasting blood glucose.

• HbA1c.

• Additional testing where indicated.

Patients with significant diabetes-related risk require careful assessment because donation may increase future kidney disease risk.

Cancer Screening

Cancer screening should be performed according to age and risk factors.

Assessment may include:

• Imaging studies.

• Cystoscopy where indicated.

• Colonoscopy for candidates with increased colorectal cancer risk.

Important considerations:

• Previous cured malignancy does not automatically exclude donation.

• The required waiting period depends on the type, stage, and recurrence risk of the malignancy.

Pulmonary Disease Assessment

Assessment includes:

• History of respiratory disease.

• Physical examination.

• Pulmonary function testing when clinically indicated.

Candidates with significant uncontrolled pulmonary disease require specialist assessment.

Cardiovascular Disease Assessment

Cardiovascular evaluation is essential because kidney donation involves major surgery.

Assessment includes:

• Medical history and physical examination.

• Electrocardiogram (ECG).

• Echocardiography.

Additional assessment:

For candidates above 40 years or those with risk factors for coronary artery disease:

• Stress ECG.

• Dobutamine stress echocardiography.

Peripheral Arterial Disease Assessment

All candidates should be assessed by:

• Medical history.

• Physical examination.

Further imaging may be required if vascular disease is suspected.

Consultation with a vascular surgeon may be necessary before transplantation.

Neurological Disease Assessment

Assessment includes:

• History of neurological disease.

• Previous stroke or transient ischaemic attack (TIA).

Considerations:

• Delay transplantation assessment for approximately 6 months after stroke or TIA.

Patients with high-risk autosomal dominant polycystic kidney disease may require screening for:

• Intracranial aneurysms.

Gastrointestinal and Liver Disease Assessment

History and examination should exclude active:

• Peptic ulcer disease.

• Diverticulitis.

• Pancreatitis.

• Cholelithiasis.

• Inflammatory bowel disease.

• Liver disease.

Additional investigations should be performed when clinically indicated.

Haematological Assessment

Assessment may include:

• Screening for thrombophilia in high-risk individuals.

• Antiphospholipid antibody testing where indicated.

Requirement for anticoagulation therapy is not an absolute contraindication to kidney donation but requires careful risk assessment.

Immunological Assessment

Evaluation includes documentation of sensitizing events such as:

• Previous blood transfusions.

• Pregnancy or miscarriage.

Testing includes:

• Human leukocyte antigen (HLA) antibody testing.

Results should be documented and communicated to the transplant team.

Infection Screening

Donor candidates should be screened for infections including:

• Hepatitis B virus.

• Hepatitis C virus.

• Human immunodeficiency virus (HIV).

• Cytomegalovirus (CMV).

Additional infection screening may be performed according to local protocols.

Compatibility Testing

Compatibility assessment includes:

Blood group testing

• ABO blood typing.

Tissue compatibility testing

Assessment of:

• Human leukocyte antigen (HLA) compatibility.

• Major histocompatibility complex (MHC) Class I and Class II typing.

Recipient antibody testing

Includes:

• Donor-specific anti-HLA antibody testing.

These tests help estimate immunological compatibility and rejection risk.

Pre-donation Kidney Function Assessment

Adequate kidney function is essential before donation.

Assessment includes:

Serum kidney function tests

• Serial serum creatinine measurements.

• Estimated glomerular filtration rate (eGFR).

Measurement of filtration capacity

Options include:

• Measured creatinine clearance.

• Measured GFR.

Specialized assessment

In selected cases:

• Single kidney GFR measurement.

Methods may include radioactive tracer studies such as:

• Technetium-99m DTPA (99mTc-diethylenetriamine pentaacetic acid).

Differential Diagnosis of Abnormal Donor Evaluation Findings

Abnormal findings during donor assessment should prompt evaluation for:

1. Chronic kidney disease

   • Reduced eGFR or abnormal kidney markers.

2. Diabetic kidney disease

   • Diabetes-associated kidney damage.

3. Hypertensive nephropathy

   • Kidney injury related to uncontrolled hypertension.

4. Polycystic kidney disease

   • Structural kidney abnormality affecting suitability.

5. Cardiovascular disease

   • May increase surgical risk.

6. Urinary tract abnormalities

   • Structural or functional abnormalities affecting kidney safety.

7. Malignancy

   • Active cancer may affect eligibility.

Referral and Follow-up

All potential kidney donors should be assessed through an accredited transplant program.

Follow-up should be arranged for:

• Accepted donors after donation.

• Candidates excluded from donation.

Long-term follow-up should include:

• Blood pressure monitoring.

• Kidney function assessment.

• Cardiovascular risk assessment.

• Lifestyle counselling.

Complications and Risks of

Kidney Donation

Potential complications include:

Surgical complications

• Bleeding.

• Infection.

• Anaesthetic complications.

• Wound complications.

Long-term risks

• Hypertension.

• Reduced kidney reserve.

• Proteinuria.

• Chronic kidney disease in high-risk individuals.

Psychological effects

• Emotional stress.

• Anxiety or depression related to donation outcomes.

Prognosis

Most carefully selected kidney donors maintain good health and kidney function after donation.

Long-term outcomes are generally favorable when donors undergo:

• Appropriate pre-donation evaluation.

• Careful surgical procedures.

• Lifelong health monitoring.

Donor safety and informed decision-making remain central to successful transplantation programs.