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Geneugelijk K, Spierings E. PIRCHE-II: an algorithm to predict indirectly recognizable HLA epitopes in solid organ transplantation. Immunogenetics 2019; 72:119-129. [PMID: 31741009 PMCID: PMC6971131 DOI: 10.1007/s00251-019-01140-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 10/16/2019] [Indexed: 12/14/2022]
Abstract
Human leukocyte antigen (HLA) mismatches between donors and recipients may lead to alloreactivity after solid organ transplantation. Over the last few decades, our knowledge of the complexity of the HLA system has dramatically increased, as numerous new HLA alleles have been identified. As a result, the likelihood of alloreactive responses towards HLA mismatches after solid organ transplantation cannot easily be assessed. Algorithms are promising solutions to estimate the risk for alloreactivity after solid organ transplantation. In this review, we show that the recently developed PIRCHE-II (Predicted Indirectly ReCognizable HLA Epitopes) algorithm can be used to minimize alloreactivity towards HLA mismatches. Together with the use of other algorithms and simulation approaches, the PIRCHE-II algorithm aims for a better estimated alloreactive risk for individual patients and eventually an improved graft survival after solid organ transplantation.
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Affiliation(s)
- Kirsten Geneugelijk
- Laboratory of Translational Immunology, University Medical Center Utrecht, Heidelberglaan 100, 3584, CX, Utrecht, The Netherlands.
| | - Eric Spierings
- Laboratory of Translational Immunology, University Medical Center Utrecht, Heidelberglaan 100, 3584, CX, Utrecht, The Netherlands
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Sapir-Pichhadze R, Zhang X, Ferradji A, Madbouly A, Tinckam KJ, Gebel HM, Blum D, Marrari M, Kim SJ, Fingerson S, Bashyal P, Cardinal H, Foster BJ. Epitopes as characterized by antibody-verified eplet mismatches determine risk of kidney transplant loss. Kidney Int 2019; 97:778-785. [PMID: 32059998 DOI: 10.1016/j.kint.2019.10.028] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/26/2019] [Accepted: 10/17/2019] [Indexed: 01/01/2023]
Abstract
To optimize strategies that mitigate the risk of graft loss associated with HLA incompatibility, we evaluated whether sequence defined HLA targets (eplets) that result in donor-specific antibodies are associated with transplant outcomes. To define this, we fit multivariable Cox proportional hazard models in a cohort of 118 382 United States first kidney transplant recipients to assess risk of death-censored graft failure by increments of ten antibody-verified eplet mismatches. To verify robustness of our findings, we conducted sensitivity analysis in this United States cohort and assessed the role of antibody-verified eplet mismatches as autonomous predictors of transplant glomerulopathy in an independent Canadian cohort. Antibody-verified eplet mismatches were found to be independent predictors of death-censored graft failure with hazard ratios of 1.231 [95% confidence interval 1.195, 1. 268], 1.268 [1.231, 1.305] and 1.411 [1.331, 1.495] for Class I (HLA-A, B, and C), -DRB1 and -DQB1 loci, respectively. To address linkage disequilibrium between HLA-DRB1 and -DQB1, we fit models in a subcohort without HLA-DQB1 eplet mismatches and found hazard ratios for death-censored graft failure of 1.384 [1.293, 1.480] for each additional antibody-verified HLA-DRB1 eplet mismatch. In a subcohort without HLA-DRB1 mismatches, the hazard ratio was 1.384 [1.072, 1.791] for each additional HLA-DQB1 mismatch. In the Canadian cohort, antibody-verified eplet mismatches were independent predictors of transplant glomerulopathy with hazard ratios of 5.511 [1.442, 21.080] for HLA-DRB1 and 3.640 [1.574, 8.416] for -DRB1/3/4/5. Thus, donor-recipient matching for specific HLA eplets appears to be a feasible and clinically justifiable strategy to mitigate risk of graft loss.
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Affiliation(s)
- Ruth Sapir-Pichhadze
- Division of Nephrology, Royal Victoria Hospital, McGill University Health Centre, Montreal, Quebec, Canada; The Multi Organ Transplant Program, Royal Victoria Hospital, McGill University Health Centre, Montreal, Quebec, Canada; Centre for Outcomes Research and Evaluation (CORE), McGill University Health Centre, Montreal, Quebec, Canada; Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada.
| | - Xun Zhang
- Centre for Outcomes Research and Evaluation (CORE), McGill University Health Centre, Montreal, Quebec, Canada
| | - Abdelhakim Ferradji
- Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Abeer Madbouly
- Bioinformatics Research, Center for International Blood and Marrow Transplant Research, Minneapolis, Minnesota, USA
| | - Kathryn J Tinckam
- Division of Nephrology, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada; The Kidney Transplant Program, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada; Division of Nephrology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine, University of Toronto, Toronto, Ontario, Canada; Department of Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Howard M Gebel
- Department of Pathology, Emory University, Atlanta, Georgia, USA
| | - Daniel Blum
- Division of Nephrology, St Michael's Hospital, Toronto, Ontario, Canada
| | - Marilyn Marrari
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - S Joseph Kim
- Division of Nephrology, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada; The Kidney Transplant Program, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada; Division of Nephrology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada
| | - Stephanie Fingerson
- Bioinformatics Research, Center for International Blood and Marrow Transplant Research, Minneapolis, Minnesota, USA
| | - Pradeep Bashyal
- Bioinformatics Research, Center for International Blood and Marrow Transplant Research, Minneapolis, Minnesota, USA
| | | | - Bethany J Foster
- Centre for Outcomes Research and Evaluation (CORE), McGill University Health Centre, Montreal, Quebec, Canada; Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada; Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada
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53
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Tambur AR, McDowell H, Hod-Dvorai R, Abundis MAC, Pinelli DF. The quest to decipher HLA immunogenicity: Telling friend from foe. Am J Transplant 2019; 19:2910-2925. [PMID: 31165546 DOI: 10.1111/ajt.15489] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 05/14/2019] [Accepted: 05/15/2019] [Indexed: 01/25/2023]
Abstract
Molecular mismatch load analysis was recently introduced as a means for performing risk stratification following organ transplantation. However, although good correlation was demonstrated between molecular mismatch load and generation of de novo donor-specific HLA antibody (DSA), quite a few exceptions exist, and the underlying factors that define HLA immunogenicity remain unclear. Herein, we present a new paradigm to interrogate differences between molecular mismatches that lead to the generation of de novo DSA and those that do not (the 2MM1DSA cohort). Specifically, patients transplanted across 2 HLA-DQ mismatches, who formed de novo DSA only to one mismatch (foe) but not the other (friend), provide a unique environment in which patient-specific factors that affect the immune response other than immunogenicity, such as infection and immunosuppression, can be controlled for. It further permits focusing on mismatches uniquely exhibited by the de novo DSA allele, rather than mismatches shared by both DSA and non-DSA alleles. This concept paper illustrates several examples, highlights the need for center-specific or population-specific cutoff values for posttransplant risk stratification, and mostly argues that if there is no direct correlation between molecular mismatch load and immunogenicity, then molecular mismatch load must not be adopted as an approach for equitable organ allocation.
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Affiliation(s)
- Anat R Tambur
- Transplant Immunology Laboratory, Comprehensive Transplant Center, Northwestern University, Chicago, Illinois
| | - Hannah McDowell
- Transplant Immunology Laboratory, Comprehensive Transplant Center, Northwestern University, Chicago, Illinois
| | - Reut Hod-Dvorai
- Transplant Immunology Laboratory, Comprehensive Transplant Center, Northwestern University, Chicago, Illinois
| | - Maria A C Abundis
- Transplant Immunology Laboratory, Comprehensive Transplant Center, Northwestern University, Chicago, Illinois
| | - David F Pinelli
- Transplant Immunology Laboratory, Comprehensive Transplant Center, Northwestern University, Chicago, Illinois
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Chong AS, Rothstein D, Safa K, Riella LV. Outstanding questions in transplantation: B cells, alloantibodies, and humoral rejection. Am J Transplant 2019; 19:2155-2163. [PMID: 30803121 PMCID: PMC6691724 DOI: 10.1111/ajt.15323] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 02/06/2019] [Accepted: 02/16/2019] [Indexed: 01/25/2023]
Abstract
Over the past three decades, improved immunosuppression has significantly reduced T cell-mediated acute rejection rates, but long-term graft survival rates have seen only marginal improvement. The cause of late graft loss has been under intense investigation, and chronic antibody-mediated rejection (AMR) has been identified as one of the leading causes, thus providing a strong rationale for basic science investigation into donor-specific B cells and antibodies in transplantation and ways to mitigate their pathogenicity. In 2018, the American Society of Transplantation launched a community-wide online discussion of Outstanding Questions in Transplantation, and the topic of B cell biology and donor-specific antibody prevention emerged as a major area of interest to the community, leading to a highly engaged dialogue, with comments from basic and translational scientists as well as physicians (http://community.myast.org/communities/community-home/digestviewer). We have summarized this discussion from a bedside to bench perspective and have organized this review into outstanding questions within the paradigm that AMR is a leading cause of graft loss in the clinic, and points of view that challenge aspects of this paradigm. We also highlight opportunities for basic and translational scientists to contribute to the resolution of these questions, mapping important future directions for the transplant research field.
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Affiliation(s)
- Anita S. Chong
- Department of Surgery, The University of Chicago,Corresponding author: Anita S. Chong, PhD, 5841 S. Maryland Ave, Chicago, IL 60637, Ofc: 773-702-5521; Fax: 773-702-5517;
| | - David Rothstein
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh
| | - Kassem Safa
- Transplant Center and Division of Nephrology, Massachusetts General Hospital, Harvard Medical School
| | - Leonardo V. Riella
- Schuster Transplantation Research Center, Renal Division, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, USA
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Abstract
Lung transplantation provides a realistic hope of improved survival and enhanced quality of life. However, outcomes can be disappointing, meaning many decisions are highly controversial. Practice is largely based on expert opinion and there is a dearth of high-level evidence. Not surprisingly, this leads to centre-specific practices that may vary considerably in controversial areas. The aim of this review, therefore, is to explore some of those domains and present the available evidence. As the science of lung transplantation approaches its fifth decade, we are only now reaching a critical mass of clinicians and scientific researchers to enable adequately powered studies to assist in informing our approach to some of these controversies. Lung transplantation provides a realistic hope of improved survival and enhanced quality of life. However, outcomes can be disappointing, meaning many decisions are highly controversial. Better evidence is desperately needed.http://ow.ly/Dl4N30maYV9
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Affiliation(s)
- David Abelson
- The Lung Transplant Unit, St Vincent's Hospital, Sydney, Australia
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