Renal Transplant Donor Workup
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Direct answer
One healthy person volunteers a kidney to another, and the living-donor workup exists to answer three questions in strict order: is the pair immunologically compatible (ABO blood group, HLA typing, and a complement-dependent cytotoxicity crossmatch — a positive crossmatch forbids transplantation because of hyperacute rejection), is the donor safe to lose a kidney (measured GFR — KDIGO regards 90 mL/min or more as acceptable, 60-89 as individualised, below 60 as a contraindication; blood pressure, glucose tolerance, proteinuria under 300 mg a day, body mass index, stone disease, malignancy screening, and CT angiography defining arterial anatomy, since accessory renal arteries occur in roughly a quarter), and is the donation lawful and freely given (the Transplantation of Human Organs Act 1994, amended 2011, permits near-relatives to donate, requires authorisation-committee approval for others, criminalises organ commerce, and underpins NOTTO's coordination of deceased donation and paired kidney exchange for ABO or crossmatch-incompatible pairs). A psychological assessment and an independent donor advocate close the evaluation.
What you must remember
- Immunology sequence: ABO first, then HLA typing, then crossmatch; the positive cytotoxicity crossmatch is an absolute bar — hyperacute rejection on the table is its consequence.
- GFR standards (KDIGO): measured, not merely estimated — 90 mL/min or greater acceptable, 60-89 individualised by age and risk, under 60 declined; Indian programmes commonly seek 80 or above for younger donors.
- CT angiography: maps the number and position of renal arteries (accessory arteries in about 25-30%), early branching, venous variants and collecting system; the left kidney with its longer vein is usually chosen for laparoscopic harvest — unless its anatomy is the more complex, in which case the donor keeps the better kidney.
- Exclusion screens: uncontrolled hypertension, diabetes, proteinuria above 300 mg daily, active or recent malignancy, recurrent or infected stones, obesity by programme threshold, significant psychosocial coercion; HIV infection is an absolute contraindication.
- Indian infections panel: hepatitis B and C with viral loads (management per current guidance rather than blanket exclusion), syphilis, and cytomegalovirus serostatus — a donor-positive, recipient-negative mismatch shapes post-transplant prophylaxis.
- The legal frame: THOA 1994 with the 2011 amendment (which recognised swapped and paired transplants and widened near-relatives); authorisation committees for unrelated donors; NOTTO-ROTTO-SOTTO as the national-regional-state hierarchy; punishment for trading in organs.
- Paired kidney exchange: ABO- or crossmatch-incompatible couples swap donors through NOTTO's registry, sometimes in chains — the exam's favourite Indian answer to incompatibility.
- Long-term donor care: slightly raised but low absolute end-stage renal disease risk, annual blood pressure and creatinine checks for life — a follow-up commitment, not a farewell.
Walking a real pair through the pathway
A 32-year-old wife wishes to donate to her 40-year-old husband with chronic kidney disease stage 5. Step one: blood groups — she is O, he is A; incompatible. The options fork here: ABO-incompatible transplantation with desensitisation (plasmapheresis and rituximab, higher rejection risk and cost) or registration for paired exchange through NOTTO, waiting for a compatible swap. Assume a swap succeeds: step two is tissue typing and crossmatch against the new recipient — negative. Step three is her medical file: measured GFR, glucose tolerance test, blood pressure including ambulatory readings, urine protein, CT angiography showing two left arteries — the right kidney is chosen. Step four is institutional: the hospital authorisation committee verifies identity, relationship documents and absence of inducement, as THOA requires. Step five is laparoscopic donor nephrectomy with the described post-operative course, and step six is lifelong annual donor review. Every refusal point along this ladder — immunological, medical, legal — is a potential exam stem.
Where students slip
The first error is trusting estimated GFR: guidelines require measured clearance (isotopic or 24-hour creatinine), and the MCQ phrases the trap as a normal creatinine in a young hypertensive. The second is treating the positive crossmatch as negotiable — it is the one result that stops a transplant outright. The third is forgetting law in a clinical paper: THOA's near-relative definition, authorisation-committee approval for unrelated donors and NOTTO's exchange registry are recurring one-liners. The fourth is the side-choice question — the left kidney is usual for its longer vein, but anatomy and split function decide, and the donor keeps the better kidney.
Frequently asked questions
Which test prevents hyperacute rejection?
The complement-dependent cytotoxicity crossmatch between donor cells and recipient serum. A positive crossmatch is an absolute contraindication to proceeding.
What GFR can a living kidney donor have?
Measured GFR of 90 mL/min or more is acceptable, 60-89 is individualised, and below 60 declines the donor — per KDIGO guidance. Estimation alone is insufficient.
Which law governs organ donation in India?
The Transplantation of Human Organs Act 1994, amended in 2011, with NOTTO coordinating nationally. Unrelated donation requires authorisation-committee approval.
What is paired kidney exchange?
Swapping donors between ABO- or crossmatch-incompatible pairs through the NOTTO registry. It converts two impossible transplants into two possible ones.
Why is CT angiography essential in donor workup?
It maps accessory arteries, early branching, veins and the collecting system, deciding which kidney is harvested. The donor keeps the better-functioning kidney.