1
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Ramos LA, Schiavo T, Montagner J, Bundcher C, Kist R, Garcia VD, Neumann J, Keitel E. Waiting time for kidney transplantation based on calculated panel reactive antibodies: experience of a southern Brazilian center. J Bras Nefrol 2024; 46:79-84. [PMID: 37791791 PMCID: PMC10962418 DOI: 10.1590/2175-8239-jbn-2022-0132en] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 04/07/2023] [Indexed: 10/05/2023] Open
Abstract
INTRODUCTION The aim of this study was to analyze the waiting list for kidney transplantation in our hospital according to candidate's panel reactive antibodies (cPRA) and its outcomes. METHODS One thousand six hundred forty patients who were on the waiting list between 2015 and 2019 were included. For the analysis, hazard ratios (HR) for transplant were estimated by Fine and Gray's regression model according to panel reactivity and HR for graft loss and death after transplantation. RESULTS The mean age was 45.39 ± 18.22 years. Male gender was predominant (61.2%), but the proportion decreased linearly with the increase in cPRA (p < 0.001). The distribution of patients according to panels were: 0% (n = 390), 1% - 49% (n = 517), 50% - 84% (n = 269), and ≥ 85% (n = 226). Transplantation was achieved in 85.5% of the sample within a median time of 8 months (CI 95%: 6.9 - 9.1). The estimated HRs for transplantation during the follow-up were 2.84 (95% CI: 2.51 - 3.34), 2.41(95%CI: 2.07 - 2.80), and 2.45(95%CI: 2.08 - 2.90) in the cPRA range of 0%, 1%-49%, and 50%-84%, respectively, compared to cPRA ≥ 85 (p < 0.001). After transplantation, the HR for graft loss was similar in the different cPRA groups, but the HR for death (0.46 95% CI 0.24-0.89 p = 0.022) was lower in the 0% cPRA group when adjusted for age, gender, and presence of donor specific antibodies (DSA). CONCLUSION Patients with cPRA below 85% are more than twice as likely to receive a kidney transplantation with a shorter waiting time. The risk of graft loss after transplantation was similar in the different cPRA groups, and the adjusted risk of death was lower in nonsensitized recipients.
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Affiliation(s)
| | - Tiago Schiavo
- Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS,
Brazil
| | - Juliana Montagner
- Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS,
Brazil
| | - Cristiane Bundcher
- Universidade de Ciências da Saúde de Porto Alegre, Porto Alegre, RS,
Brazil
| | - Roger Kist
- Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS,
Brazil
| | - Valter Duro Garcia
- Universidade de Ciências da Saúde de Porto Alegre, Porto Alegre, RS,
Brazil
- Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS,
Brazil
| | - Jorge Neumann
- Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS,
Brazil
| | - Elizete Keitel
- Universidade de Ciências da Saúde de Porto Alegre, Porto Alegre, RS,
Brazil
- Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS,
Brazil
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2
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Forbes S, Halpin A, Lam A, Grynoch D, Parker R, Hidalgo L, Bigam D, Anderson B, Dajani K, Kin T, O'Gorman D, Senior PA, Campbell P, Shapiro AJ. Islet transplantation outcomes in type 1 diabetes and transplantation of HLA-DQ8/DR4: results of a single-centre retrospective cohort in Canada. EClinicalMedicine 2024; 67:102333. [PMID: 38169703 PMCID: PMC10758748 DOI: 10.1016/j.eclinm.2023.102333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 01/05/2024] Open
Abstract
Background In solid organ transplantation, HLA matching between donor and recipient is associated with superior outcomes. In islet transplantation, an intervention for Type 1 diabetes, HLA matching between donor and recipient is not performed as part of allocation. Susceptibility to Type 1 diabetes is associated with the presence of certain HLA types. This study was conducted to determine the impact of these susceptibility antigens on islet allograft survival. Methods This is a single-centre retrospective cohort study. This cohort of transplant recipients (n = 268) received islets from 661 donor pancreases between March 11th, 1999 and August 29th, 2018 at the University of Alberta Hospital (Edmonton, AB, Canada). The frequency of the Type 1 diabetes susceptibility HLA antigens (HLA-A24, -B39, -DQ8, -DQ2 and-DQ2-DQA1∗05) in recipients and donors were determined. Recipient and donor HLA antigens were examined in relation to time to first C-peptide negative status/graft failure or last observation point. Taking into account multiple transplants per patient, we fitted a Gaussian frailty survival analysis model with baseline hazard function stratified by transplant number, adjusted for cumulative islet dose and other confounders. Findings Across all transplants recipients of donors positive for HLA-DQ8 had significantly better graft survival (adjusted HRs 0.33 95% CI 0.17-0.66; p = 0.002). At first transplant only, donors positive for HLA-DQ2-DQA1∗05 had inferior graft survival (adjusted HR 1.96 95% CI 1.10-3.46); p = 0.02), although this was not significant in the frailty analysis taking multiple transplants into account (adjusted HR 1.46 95% CI 0.77-2.78; p = 0.25). Other HLA antigens were not associated with graft survival after adjustment for confounders. Interpretation Our findings suggest islet transplantation from HLA-DQ8 donors is associated with superior graft outcomes. A donor positive for HLA-DQ2-DQA1∗05 at first transplant was associated with inferior graft survival but not when taking into account multiple transplants per recipient. The relevance of HLA-antigens on organ allocation needs further evaluation and inclusion in islet transplant registries and additional observational and interventional studies to evaluate the role of HLA-DQ8 in islet graft survival are required. Funding None.
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Affiliation(s)
- Shareen Forbes
- Clinical Islet Transplant Programme, University of Alberta, Edmonton, Canada
- Department of Surgery, University of Alberta, Edmonton, Canada
- Queen's Medical Research Institute, BHF Centre for Cardiovascular Science, University of Edinburgh, Scotland, UK
| | - Anne Halpin
- Alberta Precision Laboratories, University of Alberta, Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
| | - Anna Lam
- Clinical Islet Transplant Programme, University of Alberta, Edmonton, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, University of Alberta, Edmonton, Canada
- Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Don Grynoch
- Alberta Precision Laboratories, University of Alberta, Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
| | - Richard Parker
- Edinburgh Clinical Trials Unit, Usher Institute, University of Edinburgh, Scotland, UK
| | - Luis Hidalgo
- Department of Surgery, University of Wisconsin, Madison, WI, USA
| | - David Bigam
- Department of Surgery, University of Alberta, Edmonton, Canada
| | - Blaire Anderson
- Department of Surgery, University of Alberta, Edmonton, Canada
| | - Khaled Dajani
- Department of Surgery, University of Alberta, Edmonton, Canada
| | - Tatsuya Kin
- Clinical Islet Transplant Programme, University of Alberta, Edmonton, Canada
| | - Doug O'Gorman
- Clinical Islet Transplant Programme, University of Alberta, Edmonton, Canada
| | - Peter A. Senior
- Clinical Islet Transplant Programme, University of Alberta, Edmonton, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, University of Alberta, Edmonton, Canada
- Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Patricia Campbell
- Alberta Precision Laboratories, University of Alberta, Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
| | - A.M. James Shapiro
- Clinical Islet Transplant Programme, University of Alberta, Edmonton, Canada
- Department of Surgery, University of Alberta, Edmonton, Canada
- Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
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3
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Alvares M, Anwar S, Hashmi SK, Zaman MB, Al Mahri A, Alvares C, Al Katheeri L, Purushothaman A, Ralonya ME, Sangalang MG, Jannang R, Abdulle A, Al Qubaisi A, Al Ahmed M, Khamis AH, Al Seiari M, Al Obaidli A, Al Yafei Z, ElGhazali G. Development of a calculated panel reactive antibody calculator for the United Arab Emirates: a proof of concept study. Sci Rep 2023; 13:8468. [PMID: 37231090 DOI: 10.1038/s41598-023-34860-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 05/09/2023] [Indexed: 05/27/2023] Open
Abstract
Calculated panel reactive antibody (CPRA) is used to help increase sensitized patient's access to transplantation. United Arab Emirates (UAE) has a diverse resident population hence we developed a UAE-CPRA calculator based on HLA antigen frequencies of the different ethnic groups that represent the UAE population. HLA antigen frequencies at serological split antigen level for HLA-A, -B, -C, -DRB1 and -DQB1 of 1002 healthy unrelated donors were performed. We subsequently compared the performance of the UAE CPRA calculator with the Organ Procurement and Transplantation Network (OPTN) and the Canadian CPRA calculators in 110 Kidney Transplant waitlist patients from January 2016 to December 2018. Lin's concordance correlation coefficient showed a moderate agreement between the UAE and OPTN calculator (Rc = 0.949, 95% CI 0.929-0.963) and the UAE and Canadian calculators (Rc = 0.952, 95% CI 0.932-0.965). While there continued to be a moderate agreement (Rc = 0.937, UAE versus OPTN calculator) in the lower sensitized group, a poor agreement (Rc = 0.555, UAE versus OPTN calculator) was observed in the higher sensitized group. In this study, we provide a template for countries to develop their own population-specific CPRA calculator. Implementation of the CPRA algorithm based on HLA frequencies of the multi-ethnic UAE population will be more fitting to increase access to transplantation and improve transplant outcomes. Our study demonstrates that the CPRA calculators developed using the data from the western population had poor correlation in our higher sensitized patients disadvantaging them in potential organ allocations systems. We plan to further refine this calculator by using high resolution HLA typing to address the problem of a genetically diverse population.
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Affiliation(s)
- Marion Alvares
- Transplant Immunology section, Sheikh Khalifa Medical City, Union71 - Purehealth, Abu Dhabi and College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Siddiq Anwar
- Department of Medicine, Sheikh Shakbout Medical City, Abu Dhabi, United Arab Emirates
| | - Shahrukh K Hashmi
- Department of Medicine, Sheikh Shakbout Medical City, Abu Dhabi, United Arab Emirates
- Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
- Clinical Affairs, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Muhammad Badar Zaman
- Renal Transplant Department, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates
| | - Ayeda Al Mahri
- Transplant Immunology section, Sheikh Khalifa Medical City, Union71 - Purehealth, Abu Dhabi and College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | | | - Layla Al Katheeri
- Transplant Immunology section, Sheikh Khalifa Medical City, Union71 - Purehealth, Abu Dhabi and College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | | | - Mesele Emily Ralonya
- Renal Transplant Department, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates
| | - Marie Glo Sangalang
- Transplant Immunology section, Sheikh Khalifa Medical City, Union71 - Purehealth, Abu Dhabi and College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Raysha Jannang
- Transplant Immunology section, Sheikh Khalifa Medical City, Union71 - Purehealth, Abu Dhabi and College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Abdulkadir Abdulle
- Transplant Immunology section, Sheikh Khalifa Medical City, Union71 - Purehealth, Abu Dhabi and College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Alyazia Al Qubaisi
- Transplant Immunology section, Sheikh Khalifa Medical City, Union71 - Purehealth, Abu Dhabi and College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Maitha Al Ahmed
- Renal Transplant Department, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates
| | - Amar Hassan Khamis
- Mohamed Bin Rashed University of Medicine and Medical Sciences, Dubai, United Arab Emirates
| | - Mohamed Al Seiari
- Renal Transplant Department, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates
| | | | - Zain Al Yafei
- Transplant Immunology section, Sheikh Khalifa Medical City, Union71 - Purehealth, Abu Dhabi and College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Gehad ElGhazali
- Transplant Immunology section, Sheikh Khalifa Medical City, Union71 - Purehealth, Abu Dhabi and College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
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4
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Gragert L, Kadatz M, Alcorn J, Stewart D, Chang D, Gill J, Liwski R, Gebel HM, Gill J, Lan JH. ABO-adjusted calculated panel reactive antibody (cPRA): A unified metric for immunologic compatibility in kidney transplantation. Am J Transplant 2022; 22:3093-3100. [PMID: 35975734 PMCID: PMC10087664 DOI: 10.1111/ajt.17175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/17/2022] [Accepted: 08/13/2022] [Indexed: 01/25/2023]
Abstract
Implementation of the kidney allocation system in 2014 greatly reduced access disparity due to human leukocyte antigen (HLA) sensitization. To address persistent disparity related to candidate ABO blood groups, herein we propose a novel metric termed "ABO-adjusted cPRA," which simultaneously considers the impact of candidate HLA and ABO sensitization on the same scale. An ethnic-weighted ABO-adjusted cPRA value was computed for 190 467 candidates on the kidney waitlist by combining candidate's conventional HLA cPRA with the remaining fraction of HLA-compatible donors that are ABO-incompatible. Consideration of ABO sensitization resulted in higher ABO-adjusted cPRA relative to conventional cPRA by HLA alone, except for AB candidates since they are not ABO-sensitized. Within cPRA Point Group = 99%, 43% of the candidates moved up to ABO-adjusted cPRA Point Group = 100%, though this proportion varied substantially by candidate blood group. Nearly all O and most B candidates would have elevated ABO-adjusted cPRA values above this policy threshold for allocation priority, but relatively few A candidates displayed this shift. Overall, ABO-adjusted cPRA more accurately measures the proportion of immune-compatible donors compared with conventional HLA cPRA, especially for highly sensitized candidates. Implementation of this novel metric could enable the development of allocation policies permitting more ABO-compatible transplants without compromising equity.
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Affiliation(s)
- Loren Gragert
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Matthew Kadatz
- Vancouver Coastal Health Research Institute, Vancouver, Canada.,Division of Nephrology, University of British Columbia, Vancouver, Canada
| | - James Alcorn
- United Network for Organ Sharing, Richmond, Virginia, USA
| | - Darren Stewart
- United Network for Organ Sharing, Richmond, Virginia, USA
| | - Doris Chang
- Providence Health Research Institute, Vancouver, Canada
| | - Jagbir Gill
- Division of Nephrology, University of British Columbia, Vancouver, Canada.,Providence Health Research Institute, Vancouver, Canada.,Centre for Health Evaluation and Outcomes Sciences, University of British Columbia, Vancouver, Canada
| | - Robert Liwski
- Department of Pathology, Dalhousie University, Halifax, Canada
| | - Howard M Gebel
- Department of Pathology, Emory University, Atlanta, Georgia, USA
| | - John Gill
- Division of Nephrology, University of British Columbia, Vancouver, Canada.,Providence Health Research Institute, Vancouver, Canada
| | - James H Lan
- Vancouver Coastal Health Research Institute, Vancouver, Canada.,Division of Nephrology, University of British Columbia, Vancouver, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada
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5
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Mohammadzadeh S, Jaladat AR, Mohammadi M, Geramizadeh B, Anbardar MH, Soleimani N, Amirinezhad Fard E, Tehrani NJ. Evaluation of the Iranian panel reactive antibody calculator and potential usefulness: A retrospective study. Clin Transplant 2022; 36:e14789. [PMID: 35933599 DOI: 10.1111/ctr.14789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 06/08/2022] [Accepted: 07/29/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND OBJECTIVES There are several cPRA websites based on large enough samples in Eurotransplant, the United Network for Organ Sharing (UNOS), and the Canadian Transplant Registry (CTR). On the other hand, those calculators can differ based on the ethnicity to which they are applied. We developed the Iranian PRA calculator and compared it with UNOS and CTR calculators. METHODS The allele and haplotype frequencies of the Iranian donor pool were estimated using the HLA typing of 523 deceased Iranian kidney donors. The Organ Procurement and Transplantation Network formula was used to generate cPRA (cPRA frequency). We also used a computer script to compare the undesirable antigens of patients with the human leukocyte antigen (HLA) phenotype of donors (cPRA filtering). A total of 100 anti-HLA antibody profiles were determined in 100 sensitized individuals on the waiting list, and cPRA was estimated using various PRA calculators. RESULTS Variable allelic frequencies were obtained from population heterogeneity in each calculator's donor panel. However, no significant changes in cPRA were identified between the Iranian calculator, UNOS, and the Canadian online calculators. Lin's concordance correlation coefficient of .98 showed that cPRA (freq) and cPRA (filter) values had almost perfect agreement. INTERPRETATION AND CONCLUSION The cPRA values from the Iranian calculator are comparable to those from UNOS and CTR calculators. The donor filtering method was more useful because of factors like cost and flexibility. It also makes it easier to update cPRA on a regular basis.
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Affiliation(s)
- Sahand Mohammadzadeh
- Shiraz Transplant Center, Abu-Ali Sina Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Abdul Reza Jaladat
- Shiraz Transplant Center, Abu-Ali Sina Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Maryam Mohammadi
- Faculty of Electrical and Computer Engineering, Shiraz University, Shiraz, Iran
| | - Bita Geramizadeh
- Shiraz Transplant Center, Abu-Ali Sina Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Hossein Anbardar
- Shiraz Transplant Center, Abu-Ali Sina Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Neda Soleimani
- Shiraz Transplant Center, Abu-Ali Sina Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Elahe Amirinezhad Fard
- Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Narges Jamshidian Tehrani
- Shiraz Transplant Center, Abu-Ali Sina Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
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6
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Timofeeva O, Brown J. Immunological considerations—HLA matching and management of high immunological risk recipients. Indian J Thorac Cardiovasc Surg 2022; 38:248-259. [DOI: 10.1007/s12055-021-01201-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/09/2021] [Accepted: 04/13/2021] [Indexed: 10/20/2022] Open
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7
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HLA Homozygosity and Likelihood of Sensitization in Kidney Transplant Candidates. Transplant Direct 2022; 8:e1312. [PMID: 35415215 PMCID: PMC8989785 DOI: 10.1097/txd.0000000000001312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/09/2022] [Indexed: 11/10/2022] Open
Abstract
Background. Homozygosity for HLAs has been associated with adverse outcomes after viral infection as well as pregnancy-induced HLA sensitization. We sought to assess the relationship between HLA locus homozygosity and the level of HLA antibody sensitization. Methods. We measured sensitization using the calculated panel reactive antibody value for a large cohort of 147 461 patients added to the US OPTN/United Network for Organ Sharing kidney transplant waitlist between December 2014 and December 2019. We used multinomial logistic modeling to compare 62 510 sensitized patients to 84 955 unsensitized controls. Results. We found that the number of homozygous HLA loci was strongly associated with the level of sensitization. Within mildly, highly, or extremely sensitized candidates, women displayed a higher relative abundance of HLA homozygosity at multiple HLA loci as compared with men, with attenuation of this effect in Black candidates. In a multivariable logistic model, the number of homozygous HLA loci interacted with female sex but not with other factors associated with sensitization, including recipient ethnicity and a history of prior kidney transplant. Conclusions. This study shows that HLA homozygosity is an innate genetic factor that affects the likelihood of HLA sensitization. Further research is needed to identify the immunologic mechanisms that underlie this observation.
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8
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KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation. Transplantation 2021; 104:S11-S103. [PMID: 32301874 DOI: 10.1097/tp.0000000000003136] [Citation(s) in RCA: 249] [Impact Index Per Article: 83.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.
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9
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Lemieux W, Mohammadhassanzadeh H, Klement W, Daniel C, Sapir-Pichhadze R. Matchmaker, matchmaker make me a match: Opportunities and challenges in optimizing compatibility of HLA eplets in transplantation. Int J Immunogenet 2021; 48:135-144. [PMID: 33426788 DOI: 10.1111/iji.12525] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/12/2020] [Accepted: 12/20/2020] [Indexed: 12/20/2022]
Abstract
The development of donor-specific antibodies (DSAs) is a major complication in transplantation, which is associated with inferior graft survival, impaired quality of life, and increased healthcare costs. DSA develop upon recognition of nonself HLA by the recipient's immune system. HLA molecules contain epitopes, which are the surface regions of HLA molecules recognized by antibodies. HLAMatchmaker is an algorithm for assessing donor:recipient HLA compatibility at the level of structurally defined HLA targets called eplets. The consideration of eplets, rather than the whole HLA molecule, could offer some advantages when classifying the immune risk associated with particular donor:recipient pairs. Assessing compatibility at the level of HLA eplets could decrease misclassification of post-transplant immune risk by improving specificity, when antibodies are confirmed to be directed against donor eplets missing from the recipient's repertoire of eplets. Consideration of eplets may also increase the sensitivity of immune risk assessment, when identifying mismatched eplets that could give rise to new, not previously detected, donor-specific antibodies post-transplant. Eplet matching can serve as a rational strategy for immune risk mitigation. Herein, we review the evolution of HLA (in) compatibility assessment for organ allocation. We outline challenges in the implementation of eplet-based donor:recipient matching, including unavailability of allele-level donor genotypes for 11 HLA loci at the time of organ allocation and difficulty in assessing the hierarchy of immune risk associated with particular HLA eplet mismatches. Opportunities to address some of the current shortcomings of donor genotyping and HLAMatchmaker are also discussed. While there is a demonstrated benefit in the application of HLAMatchmaker for donor: recipient HLA (in)compatibility assessment, evolving long-read genotyping methods, compilation of large data sets with allele-level genotypes, and standardization of methods to verify eplets as determinants of immune-mediated injuries are required before HLA eplet matching is implemented in organ allocation to improve upon transplant outcomes.
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Affiliation(s)
- William Lemieux
- Centre for Outcomes Research and Evaluation (CORE), Research Institute of McGill University Health Centre, Montréal, QC, Canada
| | - Hossein Mohammadhassanzadeh
- Centre for Outcomes Research and Evaluation (CORE), Research Institute of McGill University Health Centre, Montréal, QC, Canada
| | - William Klement
- Centre for Outcomes Research and Evaluation (CORE), Research Institute of McGill University Health Centre, Montréal, QC, Canada.,Canadian Blood Services, Ottawa, Ontario, Canada
| | - Claude Daniel
- Division of Hematology, McGill University Health Centre, Montréal, QC, Canada
| | - Ruth Sapir-Pichhadze
- Centre for Outcomes Research and Evaluation (CORE), Research Institute of McGill University Health Centre, Montréal, QC, Canada.,Division of Nephrology and the Multi-Organ Transplant Program, Royal Victoria Hospital, McGill University Health Centre, Montréal, QC, Canada.,Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, QC, Canada
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10
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Kransdorf EP, Pando MJ, Stewart D, Lindblad K, Bray R, Murphey C, Kaur N, Patel JK, Kim I, Zhang X, Maiers M, Kobashigawa JA, Gragert L. Stem cell donor HLA typing improves CPRA in kidney allocation. Am J Transplant 2021; 21:138-147. [PMID: 32558252 DOI: 10.1111/ajt.16156] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/19/2020] [Accepted: 06/13/2020] [Indexed: 01/25/2023]
Abstract
The Organ Procurement and Transplantation Network (OPTN) Kidney Allocation System provides a priority to sensitized candidates based on the calculated panel reactive antibody (CPRA) value. The human leukocyte antigen (HLA) haplotype reference panel used for calculation of the CPRA by the United Network for Organ Sharing (UNOS), the OPTN contractor, has limitations. We derived a novel panel from the National Marrow Donor Program HLA haplotype data set and compared the accuracy of CPRA values generated with this panel (NMDP-CPRA) to those generated from the UNOS panel (UNOS-CPRA), using predicted and actual deceased donor kidney offers for a cohort of 24 282 candidates. The overall accuracy for kidney offers was similar using NMDP-CPRA and UNOS-CPRA. Accuracy was slightly higher for NMDP-CPRA than UNOS-CPRA for candidates in several highly sensitized CPRA categories, with deviations in linkage disequilibrium for Caucasians and the smaller size of the UNOS panel as contributing factors. HLA data derived from stem cell donors yields CPRA values that are comparable to those derived from deceased kidney donors while improving upon several problems with the current reference panel. Consideration should be given to using stem cell donors as the reference panel for calculation of CPRA to improve equity in kidney transplant allocation.
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Affiliation(s)
- Evan P Kransdorf
- Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Marcelo J Pando
- Transplant Immunology Laboratory, Scott & White Medical Center, Temple, Texas, USA
| | - Darren Stewart
- Research Department, United Network for Organ Sharing, Richmond, Virginia, USA
| | - Kelsi Lindblad
- Research Department, United Network for Organ Sharing, Richmond, Virginia, USA
| | - Robert Bray
- HLA Laboratory, Emory University Medical Center, Atlanta, Georgia, USA
| | - Cathi Murphey
- HLA Laboratory, Southwest Immunodiagnostics, San Antonio, Texas, USA
| | - Navchetan Kaur
- Department of Pathology, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Jignesh K Patel
- Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Irene Kim
- Comprehensive Transplant Center, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Xiaohai Zhang
- Comprehensive Transplant Center, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Martin Maiers
- National Marrow Donor Program, Minneapolis, Minnesota, USA
| | - Jon A Kobashigawa
- Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA.,Comprehensive Transplant Center, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Loren Gragert
- Department of Pathology, Tulane University School of Medicine, New Orleans, Louisiana, USA.,National Marrow Donor Program, Minneapolis, Minnesota, USA
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11
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Donor-Specific Human Leukocyte Antigen Antibody Formation After Distal Tibia Allograft and Subsequent Graft Resorption. Clin J Sport Med 2020; 30:e156-e158. [PMID: 30707112 DOI: 10.1097/jsm.0000000000000715] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The association between donor-specific human leukocyte antigen (HLA) antibody formation and small bone allograft resorption has not been studied. We present the case of a patient treated for glenoid bone loss using a distal tibial allograft with Bankart repair who formed donor-specific HLA antibodies against the allograft and had subsequent graft resorption. X-ray and computed tomography (CT) scans were performed before and after surgery at standard checkpoints. Patient blood and serum samples were collected before and after surgery for HLA typing and HLA antibody testing. Human leukocyte antigen antibodies against the donor-specific HLA-A2 antigens were identified 6 weeks after surgery and were still detected at 5 months after surgery. At 6 months after surgery, a CT arthrogram revealed significant graft resorption. This case shows a temporal correlation between HLA antibody formation and clinical findings, potentially suggesting an association between HLA antibody formation and graft resorption. Further study is required to confirm this.
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12
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Sullivan HC, Gragert L, Smith GH, Lindblad K, Gebel HM, Bray RA. A simple electronic tool for assessing amino acid sequence polymorphisms within exon-2 of HLA-DPB1 alleles. Hum Immunol 2020; 81:430-436. [PMID: 32684412 DOI: 10.1016/j.humimm.2020.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 10/23/2022]
Abstract
In November 2014, the OPTN/UNOS Board of Directors mandated that HLA-DPB1 typing be performed for all deceased donors. Currently, there are over 1,000 known HLA DPB1 alleles, yet fewer than 30 are represented on commonly used single antigen bead (SAB) solid phase antibody assays. Moreover, the official World Health Organization (WHO) nomenclature for the DPB1 locus does not permit assessment of structural relationships between alleles based on their names. Thus, for donor DPB1 alleles lacking a corresponding SAB, determining the compatibility between a donor-recipient pair when the recipient possesses DPB1 antibodies currently requires the use of manual sequence alignments. Multiple studies have reported that DPB1 alleles can be classified into serological-defined categories based on shared protein sequence motifs residing in distinct hypervariable regions. To date, six such motifs have been recognized. To address this problem, we developed a computer-assisted tool to compare donor and recipient DPB1 allele sequences, specifically those defined by DPB1 hypervariable region motifs located in exon 2 (http://dpreport.hlatools.org). This tool quickly identifies mismatched DPB1 motifs, and easily permits the identification of motif-based donor-specific antibodies (DSA) to DPB1.
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Affiliation(s)
- H Clifford Sullivan
- Department of Pathology & Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, United States
| | - Loren Gragert
- Department of Pathology & Laboratory Medicine, Tulane University School of Medicine, New Orleans, LA, United States
| | | | - Kelsi Lindblad
- United Network for Organ Sharing, Richmond, VA, United States
| | - Howard M Gebel
- Department of Pathology & Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, United States
| | - Robert A Bray
- Department of Pathology & Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, United States.
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13
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De Santis D, Truong L, Martinez P, D'Orsogna L. Rapid high‐resolution
HLA
genotyping by
MinION
Oxford nanopore sequencing for deceased donor organ allocation. HLA 2020; 96:141-162. [DOI: 10.1111/tan.13901] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/23/2020] [Accepted: 04/08/2020] [Indexed: 01/20/2023]
Affiliation(s)
- Dianne De Santis
- Department of Clinical ImmunologyPathWest, Fiona Stanley Hospital Perth Western Australia Australia
| | - Linh Truong
- Department of Clinical ImmunologyPathWest, Fiona Stanley Hospital Perth Western Australia Australia
| | - Patricia Martinez
- Department of Clinical ImmunologyPathWest, Fiona Stanley Hospital Perth Western Australia Australia
| | - Lloyd D'Orsogna
- Department of Clinical ImmunologyPathWest, Fiona Stanley Hospital Perth Western Australia Australia
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14
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Dean CL, Krummey SM, Gebel HM, Bray RA, Sullivan HC. Identification of a recurrent pattern of false-positivity by Luminex HLA MHC class I single antigen bead testing. Hum Immunol 2020; 81:73-78. [PMID: 31917024 DOI: 10.1016/j.humimm.2019.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/12/2019] [Accepted: 12/26/2019] [Indexed: 02/07/2023]
Abstract
Previously, a distinct MHC class II Luminex-single antigen bead (SAB) pattern was described and attributed to antibodies targeting denatured antigens. In this study, we describe a distinct MHC class I reactivity pattern observed in 1.8% (105/5992) of samples resulted in 2017. The pattern displays reactivity to the following Luminex-SABs: HLA-A*33:03, A*36:01, A*80:01, B*54:01, B*53:01, C*06:02, C*07:02, C*18:02, C*14:02, C*03:03, C*03:04, and C*15:02. This pattern was identified in patients with no sensitization history, negative FlowPRA results, and antibody to self-antigen(s). Epitope analysis failed to reveal a common determinant(s) to explain this pattern of reactivity. Additionally, we found this pattern to be prevalent in female patients (62%) and also those with systemic lupus erythematosus (62%). Given these findings, we speculate this pattern likely represents false-positive reactivity, possibly due to antibody targeting denatured antigens or a specific peptide, molecular mimicry, autoimmunity, or a combination thereof.
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Affiliation(s)
- Christina L Dean
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, United States
| | - Scott M Krummey
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, United States
| | - Howard M Gebel
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, United States
| | - Robert A Bray
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, United States
| | - Harold C Sullivan
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, United States.
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15
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Gordon WJ, Ainsworth L, Aronson S, Baronas J, Kaufman RM, Guleria I, Milford EL, Oates M, Paz RD, Yeung MY, Lane WJ. Development of a Calculated Panel Reactive Antibody Web Service with Local Frequencies for Platelet Transfusion Refractoriness Risk Stratification. J Pathol Inform 2019; 10:26. [PMID: 31463162 PMCID: PMC6686574 DOI: 10.4103/jpi.jpi_29_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 07/01/2019] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Calculated panel reactive antibody (cPRA) scoring is used to assess whether platelet refractoriness is mediated by human leukocyte antigen (HLA) antibodies in the recipient. cPRA testing uses a national sample of US kidney donors to estimate the population frequency of HLA antigens, which may be different than HLA frequencies within local platelet inventories. We aimed to determine the impact on patient cPRA scores of using HLA frequencies derived from typing local platelet donations rather than national HLA frequencies. METHODS We built an open-source web service to calculate cPRA scores based on national frequencies or custom-derived frequencies. We calculated cPRA scores for every hematopoietic stem cell transplantation (HSCT) patient at our institution based on the United Network for Organ Sharing (UNOS) frequencies and local frequencies. We compared frequencies and correlations between the calculators, segmented by gender. Finally, we put all scores into three buckets (mild, moderate, and high sensitizations) and looked at intergroup movement. RESULTS 2531 patients that underwent HSCT at our institution had at least 1 antibody and were included in the analysis. Overall, the difference in medians between each group's UNOS cPRA and local cPRA was statistically significant, but highly correlated (UNOS vs. local total: 0.249 and 0.243, ρ = 0.994; UNOS vs. local female: 0.474 and 0.463, ρ = 0.987, UNOS vs. local male: 0.165 and 0.141, ρ = 0.996; P < 0.001 for all comparisons). The median difference between UNOS and cPRA scores for all patients was low (male: 0.014, interquartile range [IQR]: 0.004-0.029; female: 0.0013, IQR: 0.003-0.028). Placement of patients into three groups revealed little intergroup movement, with 2.96% (75/2531) of patients differentially classified. CONCLUSIONS cPRA scores using local frequencies were modestly but significantly different than those obtained using national HLA frequencies. We released our software as open source, so other groups can calculate cPRA scores from national or custom-derived frequencies. Further investigation is needed to determine whether a local-HLA frequency approach can improve outcomes in patients who are immune-refractory to platelets.
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Affiliation(s)
- William J. Gordon
- Department of Medicine, Division of General Internal Medicine and Primary Care, Brigham and Women's Hospital, Boston, MA, USA
- Department of Medicine, Division of General Internal Medicine, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
- Partners HealthCare, Somerville, MA, USA
| | | | | | - Jane Baronas
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Richard M. Kaufman
- Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Indira Guleria
- Harvard Medical School, Boston, MA, USA
- Department of Medicine, Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - Edgar L. Milford
- Harvard Medical School, Boston, MA, USA
- Department of Medicine, Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | | | | | - Melissa Y. Yeung
- Harvard Medical School, Boston, MA, USA
- Department of Medicine, Division of Renal Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - William J. Lane
- Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
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16
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Greenshields AL, Liwski RS. The ABCs (DRDQDPs) of the prozone effect in single antigen bead HLA antibody testing: Lessons from our highly sensitized patients. Hum Immunol 2019; 80:478-486. [DOI: 10.1016/j.humimm.2019.04.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 04/19/2019] [Accepted: 04/26/2019] [Indexed: 11/15/2022]
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17
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Does the Canadian allocation system for highly sensitized patients work? Curr Opin Organ Transplant 2019; 24:239-244. [PMID: 31090630 DOI: 10.1097/mot.0000000000000635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The number of sensitized heart transplant candidates is rising. Highly sensitized patients are disadvantaged because they encounter longer waiting times to heart transplant. Strategies to reduce their waiting times include waitlist prioritization and desensitization therapies. The purpose of this review is to describe the listing category for highly sensitized patients in the Canadian allocation system, examine the advantages and limitations of this strategy and provide an approach to the management of the highly sensitized patient awaiting heart transplant. RECENT FINDINGS Analysis of data from the United Network of Organ Sharing shows that the incidence of death or removal from the waitlist in patients listed for heart transplant increases as the calculated panel reactive antibody (cPRA) increases and is independent of medical urgency. In the Canadian allocation system, patients with cPRA more than 80% have a similar incidence of death on the waitlist as less sensitized patients, suggesting they survive to be transplanted. Furthermore, prioritizing and transplanting highly sensitized patients has been associated with acceptable post-transplant outcomes. SUMMARY The Canadian allocation system prioritizes highly sensitized patients to increase equity and access to transplantation while maintaining good post-transplant outcomes. Not all highly sensitized patients can wait for an organ, even if prioritized. A pragmatic individualized approach would consider the medical stability of the patient, the likelihood of transplant with a negative crossmatch and then determine whether waitlist prioritization or desensitization is the more appropriate strategy.
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18
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Patients with immunological diseases or on peritoneal dialysis are prone to false positive flow cytometry crossmatch. Hum Immunol 2019; 80:487-492. [PMID: 30904438 DOI: 10.1016/j.humimm.2019.03.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 02/25/2019] [Accepted: 03/19/2019] [Indexed: 11/22/2022]
Abstract
Despite implementation of virtual crossmatches, flow cytometry crossmatches (FCXM) are still used by many transplant centers to determine immunological risk before kidney transplantation. To determine if common profiles of patients prone to false positive FCXM exist, we examined the demographics and native diseases of kidney patients tested with autologous FCXM (n = 480). Improvements to FCXM and cell isolation methods significantly reduced the positive rate from 15.1% to 5.3%. Patients with native diseases considered 'immunological' (vasculitis, lupus, IgA nephropathy) had more positive autologous FCXM (OR = 3.36, p = 0.003) vs. patients with all other diseases. Patients who were tested using our updated method (n = 321) still showed that these immunological diseases were a significant predictor for positive autologous FCXM (OR = 4.79, p = 0.006). Interestingly, patients on peritoneal dialysis (PD) also had significantly more positive autologous FCXM than patients on hemodialysis or waiting for pre-emptive kidney transplants (OR = 3.27, p = 0.02). These findings were confirmed in patients who had false positive allogeneic FCXM. Twenty of 24 (83.3%) patients with false positive allogeneic FCXM tested with updated method either had immunological diseases originally or were on PD. Our findings are helpful when interpreting an unexpected positive FCXM, especially for transplantation from deceased donors.
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19
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Lima BA, Alves H. Portuguese calculated panel reactive antibodies online estimator. HLA 2019; 93:445-450. [PMID: 30838808 DOI: 10.1111/tan.13516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 02/17/2019] [Accepted: 03/01/2019] [Indexed: 11/29/2022]
Abstract
Calculated panel reactive antibodies (CPRA) is a sensitization measure used to classify and prioritize transplant candidates in different kidney transplant allocation systems. CPRA is based on identification of HLA unacceptable on potential organ donors making a transplant candidate ineligible for transplantation. Here, we present a CPRA online estimator based on HLA allelic and haplotypic frequencies from Portuguese donors. We also compare the values we obtained from our CPRA estimator (Portuguese [PT]-CPRA) against CPRA values obtained from: Eurotransplant virtual PRA calculator (ET-CPRA); Canadian CPRA calculator (Canadian [CN]-CPRA) and Organ Procurement and Transplantation Network CPRA calculator (United States [US]-CPRA). When we analyzed correlations between CPRA values obtained from pairs of calculators, we observed that they are significantly and highly correlated. Bland-Altman plots for the comparison between PT-CPRA calculator against the other calculators, show higher differences between PT and CN than between PT and ET and PT and US. Also, the lowest value for Lin's concordance coefficient was obtained for the comparison between PT and CN calculators. CPRA values reliability depend on donors' pool from which it is calculated and it is crucial for classify correctly highly sensitized patients. A CPRA calculator must use donors' HLA frequencies similar from those who would be actual organ donors.
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Affiliation(s)
- Bruno A Lima
- Data Science Department, Oficina de Bioestatistica, Vilar Formoso, Portugal
| | - Helena Alves
- Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis, Instituto Nacional de Saúde Dr. Ricardo Jorge, Vilar Formoso, Portugal
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20
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Histocompatibility leukocyte antigen and organ transplantation: love and hate relationship. Curr Opin Organ Transplant 2018; 23:467-469. [PMID: 29957722 DOI: 10.1097/mot.0000000000000552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Abstract
The HLA region is the most polymorphic genes in the human genome and is associated with an increasing number of disease states. Historically, HLA typing methodology has been governed by phenotypic determination. This practice has evolved into the use of molecular methods such as real-time PCR, sequence-specific oligonucleotides, and sequencing-based methods. Numerous studies have identified HLA matching as a key determinate to improve patient outcomes from transplantation. Solid-organ transplants focus on HLA-DRB1 in renal organ allocation while hematopoietic cell transplants focus on HLA-A, -B, -C, -DRB1 matching. The role of HLA typing in the future will be driven by HLA expression, understanding of HLA haplotypes, and rapid HLA typing.
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Affiliation(s)
- Claire H Edgerly
- Department of Pathology and Laboratory Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Eric T Weimer
- Department of Pathology and Laboratory Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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22
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Shen SW, Chang CK, Gao YS, Hsu PJ, Cheng SC, Liu FY, Lo SC. Establishment of calculated panel reactive antibody and its potential benefits in improving the kidney allocation strategy in Taiwan. J Formos Med Assoc 2017; 116:956-963. [PMID: 29037453 DOI: 10.1016/j.jfma.2017.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/26/2017] [Accepted: 09/18/2017] [Indexed: 10/18/2022] Open
Abstract
BACKGROUND/PURPOSE Renal transplant candidates who are highly sensitized to human leukocyte antigens (HLAs) tend to wait longer to find a matched donor and have poor outcomes. Most organ-sharing programs prioritize highly sensitized patients in the allocation scoring system. The HLA sensitization status is traditionally evaluated by the panel-reactive antibody (PRA) assay. However, this assay is method dependent and does not consider the ethnic differences in HLA frequencies. A calculated PRA (cPRA), based on a population's HLA frequency and patients' unacceptable antigens (UAs), correctly estimates the percentage of donors suitable for candidates. The Taiwan Organ Registry and Sharing Center does not prioritize sensitized patients. We propose that the incorporation of the cPRA and UAs into the renal allocation program will improve the local kidney allocation policy. METHODS We established a cPRA calculator using 6146 Taiwanese HLA-A, -B, -C, -DR, and -DQ phenotypes. We performed simulated allocation based on the concept of acceptable mismatch for 76 candidates with cPRA values exceeding 80%. RESULTS We analyzed 138 waitlisted renal transplant candidates at our hospital, and we determined that the concordance rate of the cPRA and PRA for highly sensitized (%PRA > 80%) candidates was 92.5%, which decreased to 20% for those with %PRA < 80%. We matched 76 highly sensitized patients based on acceptable mismatch with the HLA phenotypes of 93 cadaver donors. Forty-six patients (61%) found at least one suitable donor. CONCLUSION The application of the cPRA and acceptable mismatch can benefit highly sensitized patients and reduce positive lymphocyte cytotoxicity crossmatch.
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Affiliation(s)
- Ssu-Wen Shen
- Department of Laboratory Medicine, National Taiwan University Hospital, Taiwan
| | - Chun-Kai Chang
- Department of Laboratory Medicine, National Taiwan University Hospital, Taiwan
| | - Yi-Shun Gao
- Department of Laboratory Medicine, National Taiwan University Hospital, Taiwan
| | - Pin-Jou Hsu
- Department of Laboratory Medicine, National Taiwan University Hospital, Taiwan
| | - Shuo-Chueh Cheng
- Department of Laboratory Medicine, National Taiwan University Hospital, Taiwan
| | - Fei-Yun Liu
- Department of Laboratory Medicine, National Taiwan University Hospital, Taiwan
| | - Shyh-Chyi Lo
- Department of Laboratory Medicine, National Taiwan University Hospital, Taiwan; Department of Laboratory Medicine, National Taiwan University College of Medicine, Taiwan.
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23
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Abstract
HLAs are fundamental to the adaptive immune response and play critical roles in the cellular and humoral response in solid organ transplantation. The genes encoding HLA proteins are the most polymorphic within the human genome, with thousands of different allelic variants known within the population. Application of the principles of population genetics to the HLA genes has resulted in the development of a numeric metric, the calculated panel-reactive antibody (CPRA) that predicts the likelihood of a positive crossmatch as a function of a transplant candidate's unacceptable HLA antigens. The CPRA is an indispensible measure of access to transplantation for sensitized candidates and is used as the official measure of sensitization for allocation of points in the US Kidney Allocation System and Eurotransplant. Here, we review HLA population genetics and detail the mathematical basis of the CPRA. An understanding of these principles by transplant clinicians will lay the foundation for continued innovation in the care of sensitized patients.
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24
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Montgomery MC, Petraroia R, Weimer ET. Buccal swab genomic DNA fragmentation predicts likelihood of successful HLA genotyping by next-generation sequencing. Hum Immunol 2017; 78:634-641. [DOI: 10.1016/j.humimm.2017.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 08/07/2017] [Accepted: 08/08/2017] [Indexed: 10/19/2022]
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25
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Wehmeier C, Hönger G, Cun H, Amico P, Hirt-Minkowski P, Georgalis A, Hopfer H, Dickenmann M, Steiger J, Schaub S. Donor Specificity but Not Broadness of Sensitization Is Associated With Antibody-Mediated Rejection and Graft Loss in Renal Allograft Recipients. Am J Transplant 2017; 17:2092-2102. [PMID: 28245084 DOI: 10.1111/ajt.14247] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 02/13/2017] [Accepted: 02/17/2017] [Indexed: 01/25/2023]
Abstract
Panel-reactive antibodies are widely regarded as an important immunological risk factor for rejection and graft loss. The broadness of sensitization against HLA is most appropriately measured by the "calculated population-reactive antibodies" (cPRA) value. In this study, we investigated whether cPRA represent an immunological risk in times of sensitive and accurate determination of pretransplantation donor-specific HLA antibodies (DSA). Five hundred twenty-seven consecutive transplantations were divided into four groups: cPRA 0% (n = 250), cPRA 1-50% (n = 129), cPRA 51-100% (n = 43), and DSA (n = 105). Patients without DSA were considered as normal risk and received standard immunosuppression without T cell-depleting induction. Patients with DSA received an enhanced induction therapy and maintenance immunosuppression. Surveillance biopsies were performed at 3 and 6 months. Median follow-up was 5.7 years. Among the three cPRA groups, there were no differences regarding the 1-year incidence of ABMR (p = 0.16) and TCMR (p = 0.75). The 5-year allograft survival rates were similar and around 87% (p = 0.28). The estimated glomerular filtration rate at last follow-up was 50-53 mL/min (p = 0.45). On multivariable Cox proportional hazard analysis, the strongest independent predictor for ABMR and (death-censored) graft survival was pretransplantation DSA. cPRA were not predictive for ABMR, TCMR, or (death-censored) graft survival. We conclude that with current DSA assignment, the broadness of sensitization measured by cPRA does not imply an immunological risk.
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Affiliation(s)
- C Wehmeier
- Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland
| | - G Hönger
- Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland.,HLA-Diagnostic and Immunogenetics, Department of Laboratory Medicine, University Hospital Basel, Basel, Switzerland.,Transplantation Immunology and Nephrology, Department of Biomedicine, University Basel, Basel, Switzerland
| | - H Cun
- Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland
| | - P Amico
- Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland.,HLA-Diagnostic and Immunogenetics, Department of Laboratory Medicine, University Hospital Basel, Basel, Switzerland
| | - P Hirt-Minkowski
- Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland
| | - A Georgalis
- Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland
| | - H Hopfer
- Institute for Pathology, University Hospital Basel, Basel, Switzerland
| | - M Dickenmann
- Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland
| | - J Steiger
- Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland
| | - S Schaub
- Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland.,HLA-Diagnostic and Immunogenetics, Department of Laboratory Medicine, University Hospital Basel, Basel, Switzerland.,Transplantation Immunology and Nephrology, Department of Biomedicine, University Basel, Basel, Switzerland
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26
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27
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Asensio E, López-Hoyos M, Romón Í, Ontañón J, San Segundo D. Assessment of Spanish Panel Reactive Antibody Calculator and Potential Usefulness. Front Immunol 2017; 8:540. [PMID: 28553286 PMCID: PMC5425465 DOI: 10.3389/fimmu.2017.00540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 04/24/2017] [Indexed: 11/25/2022] Open
Abstract
Background and objectives The calculated panel reactive of antibodies (cPRAs) necessary for kidney donor-pair exchange and highly sensitized programs are estimated using different panel reactive antibody (PRA) calculators based on big enough samples in Eurotransplant (EUTR), United Network for Organ Sharing (UNOS), and Canadian Transplant Registry (CTR) websites. However, those calculators can vary depending on the ethnic they are applied. Here, we develop a PRA calculator used in the Spanish Program of Transplant Access for Highly Sensitized patients (PATHI) and validate it with EUTR, UNOS, and CTR calculators. Methods The anti-human leukocyte antigen (HLA) antibody profile of 42 sensitized patients on waiting list was defined, and cPRA was calculated with different PRA calculators. Results Despite different allelic frequencies derived from population differences in donor panel from each calculator, no differences in cPRA between the four calculators were observed. The PATHI calculator includes anti-DQA1 antibody profiles in cPRA calculation; however, no improvement in total cPRA calculation of highly sensitized patients was demonstrated. Interpretation and conclusion The PATHI calculator provides cPRA results comparable with those from EUTR, UNOS, and CTR calculators and serves as a tool to develop valid calculators in geographical and ethnic areas different from Europe, USA, and Canada.
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Affiliation(s)
- Esther Asensio
- Immunology Service, Marqués de Valdecilla Universitary Hospital-IDIVAL, Santander, Cantabria, Spain.,Tissue Typing Laboratory, Marqués de Valdecilla Universitary Hospital-IDIVAL, Santander, Cantabria, Spain
| | - Marcos López-Hoyos
- Immunology Service, Marqués de Valdecilla Universitary Hospital-IDIVAL, Santander, Cantabria, Spain.,Tissue Typing Laboratory, Marqués de Valdecilla Universitary Hospital-IDIVAL, Santander, Cantabria, Spain
| | - Íñigo Romón
- Tissue Typing Laboratory, Marqués de Valdecilla Universitary Hospital-IDIVAL, Santander, Cantabria, Spain
| | - Jesús Ontañón
- Immunology, Universitary Hospital of Albacete, Castilla la Mancha, Spain
| | - David San Segundo
- Immunology Service, Marqués de Valdecilla Universitary Hospital-IDIVAL, Santander, Cantabria, Spain.,Tissue Typing Laboratory, Marqués de Valdecilla Universitary Hospital-IDIVAL, Santander, Cantabria, Spain
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28
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Maier M, Takano T, Sapir-Pichhadze R. Changing Paradigms in the Management of Rejection in Kidney Transplantation: Evolving From Protocol-Based Care to the Era of P4 Medicine. Can J Kidney Health Dis 2017; 4:2054358116688227. [PMID: 28270929 PMCID: PMC5308536 DOI: 10.1177/2054358116688227] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/17/2016] [Indexed: 12/30/2022] Open
Abstract
PURPOSE OF REVIEW P4 medicine denotes an evolving field of medicine encompassing predictive, preventive, personalized, and participatory medicine. Using the example of kidney allograft rejection because of donor-recipient incompatibility in human leukocyte antigens, this review outlines P4 medicine's relevance to the various stages of the kidney transplant cycle. SOURCES OF INFORMATION A search for English articles was conducted in Medline via OvidSP (up to August 18, 2016) using a combination of subject headings (MeSH) and free text in titles, abstracts, and author keywords for the concepts kidney transplantation and P4 medicine. The electronic database search was expanded further on particular subject headings. FINDINGS Available histocompatibility methods exemplify current applications of the predictive and preventive domains of P4 medicine in kidney transplant recipients' care. Pharmacogenomics are discussed as means to facilitate personalized immunosuppression regimens and promotion of active patient participation as a means to improve adherence. LIMITATIONS For simplicity, this review focuses on rejection. P4 medicine, however, should more broadly address health concerns in kidney transplant recipients, including competing outcomes such as infections, malignancies, and cardiovascular disease. This review highlights how biomarkers to evaluate these competing outcomes warrant validation and standardization prior to their incorporation into clinical practice. IMPLICATIONS Consideration of all 4 domains of the P4 medicine framework when caring for and/or studying kidney transplant recipients has the potential of increasing therapeutic efficiency, minimizing adverse effects, decreasing health care costs, and maximizing wellness. Technologies to gauge immune competency, immunosuppression requirements, and early/reversible immune-mediated injuries are required to optimize kidney transplant care.
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Affiliation(s)
- Mirela Maier
- Division of Nephrology, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada
- Metabolic Disorders and Complications, Research Institute of McGill University Health Centre, Montreal, Quebec, Canada
| | - Tomoko Takano
- Division of Nephrology, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada
- Metabolic Disorders and Complications, Research Institute of McGill University Health Centre, Montreal, Quebec, Canada
| | - Ruth Sapir-Pichhadze
- Division of Nephrology, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada
- Metabolic Disorders and Complications, Research Institute of McGill University Health Centre, Montreal, Quebec, Canada
- Multi-Organ Transplant Program, Royal Victoria Hospital, McGill University Health Centre, Montreal, Quebec, Canada
- Centre for Outcomes Research and Evaluation, McGill University Health Centre, Montreal, Quebec, Canada
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Kransdorf EP, Pando MJ. Calculated panel reactive antibody with decimals: A refined metric of access to transplantation for highly sensitized candidates. Hum Immunol 2017; 78:252-256. [PMID: 28069404 DOI: 10.1016/j.humimm.2016.12.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 12/16/2016] [Accepted: 12/27/2016] [Indexed: 01/03/2023]
Abstract
The use of the calculated panel reactive antibody (CPRA) value and the implementation of allocation points for sensitized candidates by the United Network for Organ Sharing (UNOS) have improved access to kidney transplantation for highly sensitized candidates (98% CPRA and above). Despite this, a large population of highly sensitized candidates remain awaiting transplantation. To better define this population, we propose the use of two refinements of the standard UNOS CPRA, the CPRA with decimals or CPRAd, and the likelihood of a compatible donor (LCD). These refined metrics of the standard UNOS CPRA will allow transplant programs to describe their patients' access to transplantation with increased granularity and will help in decisions regarding the use of desensitization.
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Affiliation(s)
| | - Marcelo J Pando
- Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona, Phoenix, AZ, USA.
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30
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Reynolds BC, Tinckam KJ. Sensitization assessment before kidney transplantation. Transplant Rev (Orlando) 2017; 31:18-28. [DOI: 10.1016/j.trre.2016.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 10/05/2016] [Indexed: 01/28/2023]
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Vogiatzi P. Some considerations on the current debate about typing resolution in solid organ transplantation. Transplant Res 2016; 5:3. [PMID: 26958340 PMCID: PMC4782307 DOI: 10.1186/s13737-016-0032-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 01/28/2016] [Indexed: 11/26/2022] Open
Abstract
Background The shortage of suitable organs and achieved tolerance are uncontested main concerns in transplantation. Long waiting lists for deceased donors and limited numbers of living donors are the current scenarios. Kidney grafts from living donors have better overall survival compared to cadaveric and require less aggressive immunosuppressive regimens. The human leukocyte antigen (HLA) labs have the key role to test the recipient and donors compatibility based on typing and antibody profile. The current standard molecular procedure in solid organ transplantation is low-resolution typing, at the antigen level. Main text In this commentary, the merits of high versus low degree of typing resolution in solid organ transplantation are discussed. Critical questions and reasons to bring high-resolution typing as a routine test in health system are considered. Specifically, with the introduction of the next-generation sequencing (NGS) in HLA, the pros and cons in living donation and benefits after deceased donation are critically evaluated. Conclusion NGS has the potential to improve the transplant rates and the overall graft survival. Alternative strategies to increase in demanding the number of transplants are briefly highlighted.
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Affiliation(s)
- Paraskevi Vogiatzi
- Department of Pathology, Tissue Typing Laboratory, University of Michigan, 2900 Huron Parkway, Ann Arbor, MI 48105 USA
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