|Year : 2020 | Volume
| Issue : 2 | Page : 230-231
An algorithm of pretransplant compatibility testing for deceased-donor kidney transplant program
Aseem K Tiwari, Geet Aggarwal, Rajni Chauhan
Department of Transfusion Medicine, Medanta-The Medicity, Gurgaon, Haryana, India
|Date of Submission||28-Sep-2020|
|Date of Decision||30-Sep-2020|
|Date of Acceptance||30-Sep-2020|
|Date of Web Publication||13-Nov-2020|
Aseem K Tiwari
Department of Transfusion Medicine, Medanta-The Medicity, Gurgaon, Haryana
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Tiwari AK, Aggarwal G, Chauhan R. An algorithm of pretransplant compatibility testing for deceased-donor kidney transplant program. Glob J Transfus Med 2020;5:230-1
|How to cite this URL:|
Tiwari AK, Aggarwal G, Chauhan R. An algorithm of pretransplant compatibility testing for deceased-donor kidney transplant program. Glob J Transfus Med [serial online] 2020 [cited 2020 Nov 27];5:230-1. Available from: https://www.gjtmonline.com/text.asp?2020/5/2/230/300645
One of the most serious challenges in kidney transplants is organ shortage; hence, using deceased donor is increasingly encouraged. In deceased-donor program, recipient needs to be appropriately selected from a wait-list of recipients, waiting for long period of approximately 4 years. The allocation of organ is a complex process, influenced by a number of factors, including medical urgency, age of recipient, and donor-recipient compatibility under “expanded criteria.” A structured deceased-donor program could have a positive impact by reducing the dependence on live-related donor program and is especially useful for highly sensitized recipients. One of the major challenges currently faced in deceased-donor program by laboratories is the lack of uniform testing techniques/algorithm across laboratories, which are sensitive and can provide quick results.
| Pretransplant Compatibility Testing in Human Leukocyte Antigen Laboratories|| |
One of the major factors in pretransplant compatibility assessment is the evaluation of donor-specific antibody (DSA) in the recipient for optimal donor selection and graft survival. There are numerous conventional “physical” techniques involving recipient serum and donors' lymphocytes or antigens from lysed cells, that are classified as cell-based methods (complement dependent micro-lymphocytotoxicity cross-match [CDCXM] and flow-cytometric cross-match [FCXM]) and solid-phase methods (panel reactive antibody, Luminex cross-match [LXM] and single-antigen bead [SAB]) for identifying DSA. Conventional technique like CDCXM is less sensitive, cumbersome to perform, subjective in interpretation, and due to low B-cell numbers.
Many laboratories are shifting from conventional physical techniques to virtual crossmatch (VXM) technique using SAB testing to identify anti-human leukocyte antigen (HLA) antibodies and matching it virtually with high-resolution HLA typing of prospective live-donor/deceased-donor. There are centers in developed countries which have omitted the physical cross-match, completely, in favor of VXM.
| Testing Algorithm for Deceased-Donor Program|| |
In deceased-donor program, the algorithm should be simple to understand and easy to follow. The algorithm should be designed to reduce waiting time of recipients without impacting allograft survival, recipient survival, or early rejection rates. Tests like antibody screen can be performed, even before the organ is available for better decision-making in “organ allocation” across various transplant centers; for example, as shown in the suggested algorithm [Figure 1], there could be three different transplant centers (Bangalore, Mangalore, and Manipal) in a state (Karnataka) with a unified list of wait-listed patients. Since majority of recipients (81%) have negative antibody screen, organ allocation is easy and only a routine pretransplant physical crossmatch (LXM/FCXM) can be performed to establish recipient-donor compatibility, just before the transplant.
In recipients with positive antibody screen (19%), SAB should be done to identify the specificity of antibody. VXM can be performed to establish recipient-donor compatibility without the need to transport organ or samples to the transplant center. Later, when the organ is available, physical crossmatch (LXM/FCXM) can be performed just before the transplant, at the center to which the organ is allocated on the basis of VXM.
This algorithm [Figure 1] involving VXM helps to identify the most appropriate recipient from multiple patients in waiting-list at different locations, in a time-efficient manner. The algorithm is especially helpful for highly sensitized recipients in finding a matched donor, which is otherwise, extremely difficult. Since SAB is performed only in a minority of recipients (19%), cost-effectiveness of this algorithm is also very reasonable.
| References|| |
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