Current trends in requirements for a donor organ in kidney transplantation

Background. Kidney transplantation is the gold standard for treating patients suffering from end-stage renal failure. The main problem, which is typical for all countries, is the shortage of donor organs. Thus, an imbalance between the number of recipients in need of a kidney transplant and the number of available donor organs develops, which increases and thereby significantly limits the possibilities of using this type of treatment. In order to increase the pool of donor organs, there are current trends towards reducing the requirements for a transplant. In this regard, the number of transplanted kidneys from elderly donors, as well as after resection for identified tumors, is increasing.

Material and methods. When writing the literature review, data on modern requirements for a donor organ during kidney transplantation, published in the databases PubMed (https://www.ncbi.nlm.nih.gov/pubmed/), Scientific Electronic Library of the Russian Federation - eLibrary.ru (https ://elibrary.ru/) and websites of professional endourological associations were used. The databases were searched using the keywords “kidney transplantation”, “renal cell carcinoma”, “elderly donor”. At the first stage, 93 sources no older than 5 years were found that were relevant to the topic of the review. Conference abstracts, short communications, and duplicate publications were excluded. After this, based on the relevance of the data, the reliability of the sources, the impact factors of the journals and the sequence of presentation of the material in the manuscript, 36 articles in scientific international peer-reviewed journals, practical guidelines and clinical recommendations were selected directly for citation in the review.

Results. Kidney transplantation has proven advantages over hemodialysis. The main groups through which it is planned to increase the number of donor organs include elderly people and donors with both newly diagnosed and previously established renal cell carcinoma (RCC). The disease-free median follow-up in the recipient group was 69 months, and graft survival with tumors up to 4 cm after 5 years was 93%. The use of ex vivo resection of a donor kidney with a tumor is justified in a group of patients with numerous concomitant diseases who will not be able to survive to the stage of kidney transplantation on a standard waiting list. The use of donor kidneys from elderly patients and donors with an incidental diagnosis or history of RCC in combination with chronic use of immunosuppressive therapy increases the risk of graft tumors. However, despite this, the advantages of using this group of donors with the growing need for kidney transplants in patients with end-stage renal failure, the undeniable advantages of transplantation in terms of survival and quality of life over other types of renal replacement therapy, prevail over the possible risks for the recipient and make this direction is promising. Despite the existing differences in the interpretation of risk categories, all modern guidelines unanimously recognize that kidney tumors <4 cm in diameter (stage pT1a) with Fuhrman risk grade I to II, despite a certain risk, can and should be used for transplantation. Transmission of RCC through a transplanted kidney was quite rare (0.015 to 1%).

Conclusion. In recent decades, against the backdrop of a shortage of transplants, there has been a steady trend towards the use of “recovered” kidneys and elderly donors to increase the pool of donor organs. At the same time, the risk of developing RCC of the transplant significantly increases, which should lead to a revision of the frequency of screening of the transplanted kidney, as well as the development and improvement of organ-preserving techniques in identifying these tumors.