1. What are the various categories of living-donor transplants?
n Related donors: Donor and recipient are biologically related.
n Unrelated donors: Donor is not biologically related, but an emotional relationship exists
between the donor and recipient (e.g., coworkers, classmates, friends).
n Directed anonymous donors: Donor has no relationship to the recipient; the donor learned
of the recipient’s situation and decided to donate altruistically.
n Undirected anonymous donors: Donor decides donate his or her kidney to the waiting list.
n Paired exchange donors: A pair of donor–recipient candidates (from the related or
unrelated categories) enters into a scheme in which the donor is exchanged with another
donor–recipient candidate pair so as to achieve donor–recipient biologic compatibility of
the ABO blood group system and/or negative cross-match reactivity.
n Multiple paired exchange donors: A paired exchange donation as described in the preceding
section and involves more than two donor–recipient candidate pairs.
2. What do SCD, ECD, DCD, and DBD stand for?
n SCD 5 standard criteria donor
n ECD 5 expanded criteria donor
n DCD 5 donation after cardiac death
n DBD 5 donation after brain death
3. What is an expanded criteria donor?
An expanded criteria donor is .60 years old or age 50 to 59 years old and has two of the
following: cerebrovascular accident as the cause of death, pre-existing hypertension, or terminal
serum creatinine greater than or equal to 1.5 mg/dL. Expanded criteria donors have a 70%
increased risk of graft failure over standard criteria donors.
Metzger RA, Delmonico FL, Feng S, et al. Expanded criteria donors for kidney transplantation. Am J Transplant
2003;3(Suppl 4):114–125.
4. What is the difference in graft survival among living donor transplants,
standard criteria donor transplants, and expanded criteria donor transplants?
See Figure 56-1.
5. What are some general contraindications for kidney donation?
n Chronic kidney disease (glomerular filtration rate ,80 mL/min/1.73 m2)
n Proteinuria
n Hematuria
n Active infection
n Chronic, active viral infections (e.g., HIV, hepatitis B/C)
n Active malignancy
n Family history of renal cell carcinoma
n Hypertension
n Diabetes
n Urologic abnormalities, including nephrolithiasis
n Substance abuse
n Obesity (body mass index .35 kg/m2)
n Age younger than 18 years
How is a living kidney donor evaluated to determine suitability?
The evaluation of a potential living kidney generally begins with an assessment of the donor
and recipient blood groups and a cross-match. When a potential donor is identified, a crossmatch
is performed prior to transplantation to evaluate for any evidence of preformed
antibodies against the specific donor (human leukocyte antigens [HLA]) that could result in
hyperacute and/or acute humoral rejection. A final cross-match using fresh serum is
performed in all cases immediately preceding transplantation to ensure compatibility between
the donor and recipient. The methods available for cross-match testing include: enzyme-linked
immunosorbent assay (ELISA), flow cytometry, complement-dependent cytotoxicity, and
single antigen bead assay.
The donor and recipient generally must be ABO compatible. This can occur under one of
the following circumstances: the donor and recipient are ABO identical, the donor has blood
type O (universal donor), or the recipient is blood type AB (universal recipient). Given the
distribution of blood group antigens in the United States, the waiting time on the deceased
donor list is prolonged for patients with blood group O and B. The practice of donor swapping
in the case of ABO mismatches with a willing acceptable donor has gained some favor in the
United States. ABO-incompatible transplantations following desensitization strategies have
been performed successfully at some institutions.
Rh antigens are not expressed in kidney tissue; therefore Rh mismatches are not
considered to play a substantial role in allograft rejection. Female Rh-negative recipients ofchildbearing age are at risk for sensitization when the donor is Rh-positive and should receive
anti-Rh immunoglobulin (RhoGAM) at the time of transplantation.
The major histocompatibility complex (MHC) antigens measured routinely in HLA
laboratories include the class I antigens (A, B, and C) and class II antigens (DP, DQ, DR). HLA
matching is an important predictor of survival of deceased donor allografts. However, with the
use of better immunosuppressive agents, the use of HLA matching in allocation policies has
come under considerable debate. A recent study demonstrated that with each successive year
from 1994 to 1998, ever-increasing degrees of HLA mismatching was required to have a
statistically significant adverse effect on graft failure. It also appears that not all HLA
mismatches confer the same risk. HLA-DR matches have been associated with the most
beneficial effect on long-term allograft survival. As a result, some centers advocate matching
schemes to include kidneys without DR mismatches even if mismatched at the A and B loci.
Given the scarcity of kidneys, the reliance on the number of HLA mismatches to determine the
compatibility of a particular donor/recipient pairing is likely to be replaced by a determination
of the significance of each mismatch on future graft survival.
Why are renal imaging tests performed in living kidney donors prior to
transplantation?
n To ensure the presence of two kidneys
n To exclude malignancy involving the urinary tract
n To exclude anatomic abnormalities of the urinary tract
n To assess the vascular supply to the donor kidney
8. What are some common imaging tests performed to evaluate the donor
kidney?
n Helical computed tomography (CT)
n CT angiogram
n Magnetic resonance angiogram
9. What are the surgical risks to the donor?
Laparoscopic surgical techniques have resulted in shorter hospital stays, reduced incisional
pain, and an earlier return to work for living donors when compared to open nephrectomies.
Conversion to open nephrectomy occurs in approximately 2% of the procedures. The
perioperative mortality reported for living kidney donation is approximately 0.03%. Bleeding
and reoperation are more common in laparoscopic techniques, although they are still relatively
rare (0.45% and 1%, respectively).
