Key words : Donor selection criteria, Kidney transplant

Introduction
Kidney transplant is the best treatment option for patients with end-stage renal disease.¹ Preparation of living related kidney donors and recipients is the major factor to achieve best long-term outcomes for these patients. Kidney donor criteria may differ between transplant centers.² Some centers seem to be conservative for donor criteria, and some may be liberal, such as centers that accept expanded donor criteria. The Baskent University donor criteria were established on the principles of Prof. Haberal, which always prioritize the donor’s health. In our study, we present Baskent University evaluation criteria for living kidney donors and recipients.

Materials and Methods
The Baskent University transplantation team has performed more than 2000 kidney transplants from 1985 to 2022 under the leadership of Professor Mehmet Haberal, who remains a pioneer of transplantation in Turkey. During this long period, Baskent University became an exceptional transplant center in Turkey, the Middle East, Europe, and the world. Baskent University has established its own donor criteria for patient assessment prior to both kidney and liver transplant. Prof. Haberal is also the architect of the Turkish transplantation law, which passed in Turkish Parliament on June 3, 1979, and established legislation on procurement, storage, engraftment, and transplant of organs and tissues in Turkey and has been deemed sufficiently progressive to be used as a model by many other countries.^3,4 Here, we summarize the Baskent University approach for evaluation of living kidney transplant donors. Although the main frame is similar, we have constant principles in kidney donation. Our excellent long-term results for kidney transplant recipients and donors support our recent criteria.^5,6

Results
The main rule of living kidney donation is volunteerism, regardless of any criteria. At Baskent University, protection of the donor from social, psychological, and health problems is paramount. Benefit-to-risk ratio and risk of transplant should be assessed for every case. Donors must be followed up, and remedies sought for failed criteria. The set of principles established by Prof. Haberal has been the basis of the Baskent University donation criteria, and we do not accept unrelated kidney transplant donors except in cases of cross-donation.

The Baskent University living related donor criteria are as follows.

(1) An informed consent form is clearly explained by professionals, and the donor candidates are provided sufficient decision time, the opportunity to withdraw from donation at any time before surgery, psychiatric support and evaluation, and mental and social support. Informed consent must also be signed by the donor’s spouse, if married.

(2) Crossmatch tests for blood group and human leukocyte antigen compatibilities are performed at the immunology laboratory of the Baskent University transplantation team. High-risk recipient candidates who have high panel reactive antibody levels are assigned to the desensitization program under supervision of the Immunology Department and may only receive a transplant kidney after minimization of risks. Nephrological, cardiac, pulmonary, infectious, hematological, psychiatric, dental, radiological, and gynecological (if female) evaluations are meticulously applied prior to transplant.

(3) Donors are evaluated with thyroid and abdominal ultrasonography, dynamic renal scintigraphy, and renal computed tomography angiography. Glomerular filtration rate is evaluated with 24-hour urine creatinine clearance, and we do not accept donor candidates who have a creatinine clearance under 100 mL/min. Tests are performed for hepatitis and other viral markers, patients receive the QuantiFERON-TB tuberculosis blood test, and vaccination is detected by infectious diseases. Biopsy is performed for thyroid nodules with a diameter greater than 6 mm. According to the results of scintigraphy, the kidney to be donated is selected. We evaluate any potential proteinuria in a donor by the ratio of spot urine protein to creatinine and by 24-hour urine collection. Albuminuria is an absolute contraindication for kidney donation. If hematuria is detected in a donor candidate, then urine microscopy, urology consultation, computed tomography scan, cystoscopy, and urine culture are performed to exclude any potential urinary disease. A patient with a single kidney stone without coexisting laboratory anomalies or with simple cortical cysts is accepted after careful examination.

(4) We do not have an upper limit for donor age unless the donor has any medical problems such as low creatinine clearance under 100 mL/min. Hypertension is also an absolute contraindication for donation according to Baskent University criteria, and normal blood pres-sure must be proved by 24-hour ambulatory pressure measurement and normal fundoscopic evaluation without any antihypertensive drug.

(5) Obesity with a body mass index (measured as body weight in kilograms divided by height in meters squared) higher than 30, fasting blood glucose higher than 100 mg/dL with a positive oral glucose tolerance test, and diabetic fundoscopic findings are also contraindications according to our criteria. Female donor candidates are evaluated in gynecology and with mammography and breast ultrasonography. Genetic tests are applied in cases of suspected hereditary diseases and disposition to diseases such as atypical hemolytic uremic syndrome. Fertile female donor candidates should not be planning to give a birth during their life after donation. Complications of pregnancy should be carefully questioned, especially for gestational diabetes and eclampsia.

At Baskent University, all of the kidney transplant donors are followed by the Transplantation Unit yearly without any fee. Blood pressure measurements, laboratory parameters, and abdominal ultrasonography scans are routinely performed for donors.

Conclusions
The major distinctions of the Baskent University living related donor criteria, compared with other transplant centers, are (1) the absence of unrelated kidney donation (except cross-donation), (2) refusal of compensated hypertensive donor candidates (even with effective single antihypertensive drug treatment), and (3) lower limit of 100 mL/min of creatinine clearance in 24-hour urine collection. This set of intensive donor selection criteria provides excellent long-term outcomes for kidney donors at Baskent University and has been proved by our recent studies.

References:

1. Terasaki PI. A personal perspective: 100-year history of the humoral theory of transplantation. Transplantation. 2012;93(8):751-756. doi:10.1097/TP.0b013e3182483713
   CrossRef - PubMed
   
2. Andrews PA, Burnapp L. British Transplantation Society/Renal Association UK Guidelines for Living Donor Kidney Transplantation 2018: Summary of Updated Guidance. Transplantation. 2018;102(7):e307. doi:10.1097/TP.0000000000002253
   CrossRef - PubMed
   
3. Haberal M, Moray G, Karakay Ali H, Bilgin N. Transplantation legislation and practice in Turkey: a brief history. Transplant Proc. 1998;30(7):3644-3646. doi:10.1016/s0041-1345(98)01173-7
   CrossRef - PubMed
   
4. Haberal M, Moray G, Karakayali H, Bilgin N. Ethical and legal aspects, and the history of organ transplantation in Turkey. Transplant Proc. 1996;28(1):382-383.
   CrossRef - PubMed
   
5. Sayin B, Ozdemir A, Ayvazoglu Soy EH, et al. Over 5 years of excellent graft kidney function determinants: Baskent University experience. Exp Clin Transplant. 2019;17(Suppl 1):75-77. doi:10.6002/ect.MESOT2018.O12
   CrossRef - PubMed
   
6. Sayin B, Akdur A, Karakaya E, Ayvazoglu Soy EH, Haberal M. Long-term follow-up of over 600 living related kidney donors: single-center experience. Exp Clin Transplant. 2022;20(Suppl 1):17-19. doi:10.6002/ect.MESOT2021.O4
   CrossRef - PubMed