1
|
Peton B, Taniguchi M, Mangiola M, Al Malki MM, Gendzekhadze K. Specificity of HLA monoclonal antibodies and their use to determine HLA expression on lymphocytes and peripheral blood stem cells. HLA 2024; 103:e15192. [PMID: 37596840 DOI: 10.1111/tan.15192] [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: 12/12/2022] [Revised: 06/30/2023] [Accepted: 07/31/2023] [Indexed: 08/20/2023]
Abstract
HLA Class I and II expression are known to differ locus-to-locus, however, HLA expression on the cell-surface is frequently reported as the total amount of HLA Class I or II antigens. This is despite evidence that indicates the differential expression of HLA can influence patient outcomes post-transplantation. Although numerous commercially available HLA monoclonal antibodies (mAbs) exist to characterize HLA expression, there is currently a lack of detailed information regarding their reactivities to HLA specificities. The specificities of locus-specific HLA mAbs (nine Class I and four Class II mAbs) were evaluated by two solid-phase Luminex single antigen bead assays. The reactivity patterns of these mAbs were then confirmed by flow cytometry using lymphocytes and PBSCs (peripheral blood stem cells). Out of the 13 HLA mAbs tested, only four (one Class I and three Class II mAbs) displayed intra-locus reactivity without also reacting to inter-locus specificities. Epitope analysis revealed the presence of shared epitopes across numerous HLA loci, explaining much of the observed inter-locus reactivity. The specificity of the HLA mAbs seen in solid-phase assays was confirmed against PBSCs and lymphocytes by flow cytometry. Using this method, we observed differences in the cell surface expression of HLA-C, HLA-DR, HLA-DQ, and HLA-DP between PBSCs and lymphocytes. Our results emphasize the need to characterize the reactivity patterns of HLA mAbs using solid-phase assays before their use on cells. Through understanding the reactivity of these HLA mAbs, the cellular expression of HLA can be more accurately assessed in downstream assays.
Collapse
Affiliation(s)
- Benjamin Peton
- HLA Laboratory, Department of Hematology and Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California, USA
| | - Michiko Taniguchi
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
| | - Massimo Mangiola
- Transplant Institute, NYU Langone Medical Center, New York, New York, USA
| | - Monzr M Al Malki
- Department of Hematology and Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California, USA
| | - Ketevan Gendzekhadze
- HLA Laboratory, Department of Hematology and Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California, USA
| |
Collapse
|
2
|
Rocha Y, Jaramillo A, Neumann J, Hacke K, Palou E, Torres J. Crossmatch assays in transplantation: Physical or virtual?: A review. Medicine (Baltimore) 2023; 102:e36527. [PMID: 38115324 PMCID: PMC10727546 DOI: 10.1097/md.0000000000036527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/16/2023] [Accepted: 11/17/2023] [Indexed: 12/21/2023] Open
Abstract
The value of the crossmatch test in assessing pretransplant immunological risk is vital for clinical decisions, ranging from the indication of the transplant to the guidance of induction protocols and treatment with immunosuppressants. The crossmatch tests in transplantation can be physical or virtual, each with its advantages and limitations. Currently, the virtual crossmatch stands out for its sensitivity and specificity compared to the physical tests. Additionally, the virtual crossmatch can be performed in less time, allowing for a reduction in cold ischemia time. It shows a good correlation with the results of physical tests and does not negatively impact graft survival. Proper communication between clinicians and the transplant immunology laboratory will lead to a deeper understanding of each patient's immunological profile, better donor-recipient selection, and improved graft survival.
Collapse
Affiliation(s)
| | - Andrés Jaramillo
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Phoenix, AZ
| | - Jorge Neumann
- Transplant Immunology Laboratory, Santa Casa Hospital, Porto Alegre, Brazil
| | - Katrin Hacke
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Phoenix, AZ
| | - Eduard Palou
- Department of Immunology, Centre de Diagnòstic Biomèdic, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Juan Torres
- Department of Immunology, Centre de Diagnòstic Biomèdic, Hospital Clínic de Barcelona, Barcelona, Spain
| |
Collapse
|
3
|
Bray RA, Morris AB, Sullivan HC, Gebel HM. The Virtual Crossmatch: What's in a Name? Transplantation 2023; 107:e273. [PMID: 37749816 DOI: 10.1097/tp.0000000000004723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Affiliation(s)
- Robert A Bray
- Department of Pathology, Emory University, Atlanta, GA
| | | | | | | |
Collapse
|
4
|
Hod-Dvorai R, Philogene MC, Timofeeva O, Gimferrer I, Dunckley H, Greenshields A, Jindra P. Utilizing proficiency testing survey data to create advanced educational content: the virtual crossmatch challenge model. Front Genet 2023; 14:1256498. [PMID: 37811147 PMCID: PMC10552184 DOI: 10.3389/fgene.2023.1256498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 09/11/2023] [Indexed: 10/10/2023] Open
Abstract
Proficiency testing (PT) surveys include data from laboratories across the world and are ideal for creating advanced educational content, beyond just consensus grading. Educational challenges provide a unique opportunity to probe common laboratory practices and risk assessment, especially in cases where there is no "analyte" tested. Human leukocyte antigen (HLA) compatibility evaluation between donor and recipient pairs has been traditionally assessed using T-cell and B-cell physical crossmatches. However, advancements in our ability to identify and characterize HLA antibodies using solid phase assays, in combination with changing deceased donor allocation schemes and improved HLA typing, have shifted the paradigm from performing physical crossmatches to the use of the virtual crossmatch (VXM). VXM is a compatibility assessment relying on the interpretation of pre-transplant HLA laboratory data and as such, it is not an "analyte". However, VXM results are used in clinical decision-making. The VXM assessment depends on patient characteristics as well as laboratory and transplant center practices but must ensure safe transplantation outcomes while maintaining equity in access to transplantation. In this manuscript, we describe the American Society for Histocompatibility and Immunogenetics (ASHI) PT Educational VXM Challenge, as a model for creating educational content using PT survey data. We discuss the different components of the VXM Challenge and highlight major findings and learning points acquired from ASHI VXM Challenges performed between 2018-2022, such as the lack of correlation between the VXM and the physical crossmatch in the presence of low level donor-specific antibodies (DSA), or when the DSA were aimed against donor alleles that are not present on the antibody panel, and in the presence of an antibody to a shared eplet. Finally, we show that the VXM Educational Challenge serves as a valuable tool to highlight the strengths and pitfalls of the VXM assessment and reveals differences in testing and result interpretation among participating HLA laboratories.
Collapse
Affiliation(s)
- Reut Hod-Dvorai
- Department of Pathology, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Mary Carmelle Philogene
- Department of Surgery, Virginia Commonwealth University Medical Center, Richmond, VA, United States
| | - Olga Timofeeva
- Department of Pathology, MedStar Georgetown University Hospital, Georgetown University Medical Center, Washington, DC, United States
| | - Idoia Gimferrer
- Department of Immunogenetics/HLA, BloodworksNW, Seattle, WA, United States
| | - Heather Dunckley
- New Zealand Transplantation and Immunogenetics Laboratory, New Zealand Blood Service, Auckland, New Zealand
| | | | - Peter Jindra
- Immune Evaluation Laboratory, Department of Surgery, Baylor College of Medicine, Houston, TX, United States
| |
Collapse
|
5
|
Locke AF, Hickey M, Valenzuela NM, Butler C, Sosa R, Zheng Y, Gjertson D, Reed EF, Zhang Q. Virtual and Reality: An Analysis of the UCLA Virtual Crossmatch Exchanges. Transplantation 2023; 107:1776-1785. [PMID: 36944607 PMCID: PMC10358445 DOI: 10.1097/tp.0000000000004586] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 01/05/2023] [Accepted: 01/29/2023] [Indexed: 03/23/2023]
Abstract
The "virtual" crossmatch (VXM) has become a critical tool to predict the compatibility between an organ donor and a potential recipient. Yet, nonstandardized laboratory practice can lead to variability in VXM interpretation. Therefore, UCLA's VXM Exchange survey was designed to understand factors that influence the variability of VXM prediction in the presence of HLA donor-specific antibody (DSA). Thirty-six donor blood samples and 72 HLA reference sera were sent to 35 participating laboratories to perform HLA antibody testing, flow crossmatch (FXM), and VXM from 2014 to 2019, consisting of 144 T/B-cell FXM pairs and 112 T/B-cell VXM pairs. In the FXM survey, 86% T-cell FXM and 84% B-cell FXM achieved >80% concordance among laboratories. In the VXM survey, 81% T-cell VXM and 80% VXM achieved >80% concordance. The concordance between FXM and VXM was 79% for T cell and 87% for B cell. The consensus between VXM and FXM was high with strong DSA. However, significant variability was observed in sera with (1) very high titer antibodies that exit prozone effect; (2) weak-to-moderate DSA, particularly in the presence of multiple weak DSAs; and (3) DSA against lowly expressed antigens. With the increasing use the VXM, standardization and continuous learning via exchange surveys will provide better understanding and quality controls for VXM to improve accuracy across all centers.
Collapse
Affiliation(s)
- Arlene F. Locke
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, UCLA Health, Los Angeles, CA
| | - Michelle Hickey
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, UCLA Health, Los Angeles, CA
| | - Nicole M. Valenzuela
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, UCLA Health, Los Angeles, CA
| | - Carrie Butler
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, UCLA Health, Los Angeles, CA
| | - Rebecca Sosa
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, UCLA Health, Los Angeles, CA
| | - Ying Zheng
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, UCLA Health, Los Angeles, CA
| | - David Gjertson
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, UCLA Health, Los Angeles, CA
| | - Elaine F. Reed
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, UCLA Health, Los Angeles, CA
| | - Qiuheng Zhang
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, UCLA Health, Los Angeles, CA
| |
Collapse
|
6
|
Silva C, Aires P, Santo P, Xavier P. Low Expression Loci and the Use of Pronase in Flow Cytometry Crossmatch. Transplant Proc 2023; 55:1383-1389. [PMID: 37173263 DOI: 10.1016/j.transproceed.2023.03.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 03/31/2023] [Indexed: 05/15/2023]
Abstract
Pronase treatment of lymphocytes has been used to improve the specificity and sensitivity of flow cytometric crossmatch, especially B-cell flow cytometric crossmatch, due to the presence of Fc receptors on the cell surface. Some limitations have been reported in the literature: false negatives due to the reduction of major histocompatibility complex expression and false-positive T cells in HIV+ patients due to exposure to cryptic epitopes. This study aimed to evaluate the effect of pronase in our assays, using untreated and treated cells with 2.35 U/mL of pronase to improve flow cytometric crossmatch specificity and sensitivity. The study was carried out with donor-specific IgG antibodies (DSAs) to low expression loci (HLA-C, -DQ, or -DP) because, in our laboratory practice, patients with virtual crossmatch (LABScreen single antigen assays) to DSA against antigen HLA-A, B, and DR are excluded from cellular crossmatch. Our results showed that, for T-cell flow cytometry crossmatch (FCXM), a cutoff value of 1171 median fluorescence intensity (MFI), an area under the curve (AUC) of 0.926 (P < .0001), and 0.834 (P < .0001), a sensitivity of 100% and 85.7%, and a specificity of 77.5% and 74.4%, without and with pronase treatment, respectively. For B-cell FCXM without pronase treatment, the best cutoff was 2766 MFI, an AUC of 0.731 (P < .0001), a sensitivity of 69.6%, and a specificity of 66.7%, whereas for B cells treated with pronase, the cutoff value was 4496 MFI, an AUC of 0.852 (P < .0001), a sensitivity of 86.4%, and a specificity of 77.8%. Our analysis of 128 FCXM showed a better performance using the untreated lymphocytes for FCXM with the prerequisite of a higher cutoff value (≈5000 MFI) to reach a better sensitivity and specificity due to the loss of HLA expression.
Collapse
Affiliation(s)
- Cláudia Silva
- Instituto Português Do Sangue E Da Transplantação-Área Transplantação, Porto, Portugal
| | - Paula Aires
- Instituto Português Do Sangue E Da Transplantação-Área Transplantação, Porto, Portugal
| | - Paula Santo
- Instituto Português Do Sangue E Da Transplantação-Área Transplantação, Porto, Portugal
| | - Paula Xavier
- Instituto Português Do Sangue E Da Transplantação-Área Transplantação, Porto, Portugal.
| |
Collapse
|
7
|
Pandey P, Pande A, Mandal S, Marik A, Devra AK, Sinha VK, Bhatt AP, Gajway SY, Singh RK, Mishra S, Jha S. Detection of donor-specific HLA antibodies: A retrospective observation in 350 renal transplant cases. Transpl Immunol 2023; 77:101783. [PMID: 36608831 DOI: 10.1016/j.trim.2022.101783] [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: 09/14/2022] [Revised: 12/02/2022] [Accepted: 12/31/2022] [Indexed: 01/05/2023]
Abstract
BACKGROUND The main objective of this study was to determine the results of the cell-based assay (CDC-XM and FC-XM), and correlate with the results of solid phase assay (L-SAB). METHODS In this retrospective study, 350 prospective renal transplant recipients were tested for the presence of HLA antibodies by CDC-XM, FC-XM and L-SAB screening with their corresponding donor. RESULTS T-cell-FC-XM showed a sensitivity of 71.43% and a specificity of 91.50% for detecting class I L-SAB (+), while B-cell-FCXM showed a sensitivity of 94.94% and a specificity of 61.99% for detecting class II L-SAB (+). On the other hand, T-CDC-XM showed a sensitivity of 32.14% and a specificity of 98.64% for detecting class I L-SAB (+), while B-CDC-XM showed a sensitivity of 44.30% and a specificity of 94.83% for detecting class II L-SAB (+). In this study, the results indicated that DSA class I MFI value of 2845 and above significantly (p ≤0.001) correlated with T-cell-FC-XM positivity, while MFI value of 4585 and above (p ≤0.001) showed strong predictive accuracy of a positive T-cell-CDC-XM. However, DSA class II MFI cut-off of 1988 and above significantly (p ≤0.001) correlated with B-cell-FC-XM positivity, while MFI value of 5986 and above (p ≤0.001) showed strong predictive accuracy of a positive B-cell-CDC-XM. CONCLUSIONS Our study showed that CDC-XM has poor sensitivity, while FC-XM has poor specificity to detect DSA. L-SAB has good correlation with T-cell-FC-XM (p < 0.0001) but not with B-cell-FC-XM (P = 0.31). DSA strength >2845 and > 1988 significantly correlated with T-cell-FC-XM positivity and B-cell-FC-XM positivity, respectively. While, a MFI value of >4585 and > 5986 significantly correlated with T-cell-CDC-XM positivity and B-cell-CDC-XM positivity, respectively. These MFI cut-off values could serve as a surrogate marker for CDC-XM and FC-XM tests and may help in resolving the limitations of cell-based techniques. In conclusion, we found that L-SAB is more sensitive and specific than CDC-XM and FC-XM and therefore may be used as a test of choice.
Collapse
Affiliation(s)
- Prashant Pandey
- Department of Transfusion Medicine, Histocompatibility and Molecular Biology, Jaypee Hospital, Noida, UP 201301, India
| | - Amit Pande
- Department of Histocompatibility and Molecular Biology, Jaypee Hospital, Noida,UP 201301, India.
| | - Saikat Mandal
- Department of Transfusion Medicine, Jaypee Hospital, Noida, UP 201301, India
| | - Arghyadeep Marik
- Department of Transfusion Medicine, Jaypee Hospital, Noida, UP 201301, India
| | - Amit Kumar Devra
- Kidney Transplant Programme, Department of Urology and Kidney Transplant, Jaypee Hospital, Noida, UP 201301, India
| | - Vijay Kumar Sinha
- Department of Nephrology and Kidney Transplant, Jaypee Hospital, Noida, UP 201301, India
| | - Anil Prasad Bhatt
- Department of Nephrology and Kidney Transplant, Jaypee Hospital, Noida, UP 201301, India
| | | | - Ravi Kumar Singh
- Department of Nephrology and Kidney Transplant, Jaypee Hospital, Noida, UP 201301, India
| | - Smriti Mishra
- Department of Histocompatibility and Molecular Biology, Jaypee Hospital, Noida,UP 201301, India
| | - Shantanu Jha
- Department of Histocompatibility and Molecular Biology, Jaypee Hospital, Noida,UP 201301, India
| |
Collapse
|
8
|
Cornaby C, Weimer ET. HLA Typing by Next-Generation Sequencing: Lessons Learned and Future Applications. Clin Lab Med 2022; 42:603-612. [PMID: 36368785 DOI: 10.1016/j.cll.2022.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Caleb Cornaby
- McLendon Clinical Laboratories, UNC Hospitals, 101 Manning Drive, Chapel Hill, NC 27514, USA
| | - Eric T Weimer
- McLendon Clinical Laboratories, UNC Hospitals, 101 Manning Drive, Chapel Hill, NC 27514, USA; Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27514, USA.
| |
Collapse
|
9
|
Ho CS, Putnam KR, Peiter CR, Herczyk WF, Gerlach JA, Lu Y, Campagnaro EL, Woodside KJ, Cusick MF. Daratumumab Interferes with Allogeneic Crossmatch Impacting Immunological Assessment in Solid Organ Transplantation. J Clin Med 2022; 11:jcm11206059. [PMID: 36294380 PMCID: PMC9605360 DOI: 10.3390/jcm11206059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 10/03/2022] [Accepted: 10/12/2022] [Indexed: 11/07/2022] Open
Abstract
We report the first case of Daratumumab interference of allogeneic crossmatch tests repeatedly causing aberrant false-positive results, which inadvertently delayed transplant for a waitlisted renal patient with multiple myeloma. Daratumumab is an IgG1κ human monoclonal antibody commonly used to treat multiple myeloma, characterized by cancerous plasma cells and often leads to renal failure requiring kidney transplant, by depleting CD38-expressing plasma cells. In this case study, the patient had end-stage renal disease secondary to multiple myeloma and was continuously receiving Daratumumab infusions. The patient did not have any detectable antibodies to human leukocyte antigens but repeatedly had unexpected positive crossmatch by the flow cytometry-based method with 26 of the 27 potential deceased organ donors, implying donor-recipient immunological incompatibility. However, further review and analysis suggested that the positive crossmatches were likely false-positive as a result of interference from Daratumumab binding to donor cell surface CD38 as opposed to the presence of donor-specific antibodies. The observed intensity of the false-positive crossmatches was also highly variable, potentially due to donor- and/or cell-dependent expression of CD38. The variability of CD38 expression was, therefore, for the first time, characterized on the T and B cells isolated from various tissues and peripheral blood of 78 individuals. Overall, T cells were found to have a lower CD38 expression profile than the B cells, and no significant difference was observed between deceased and living individuals. Finally, we show that a simple cell treatment by dithiothreitol can effectively mitigate Daratumumab interference thus preserving the utility of pre-transplant crossmatch in multiple myeloma patients awaiting kidney transplant.
Collapse
Affiliation(s)
- Chak-Sum Ho
- Gift of Hope Organ & Tissue Donor Network, Itasca, IL 60143, USA
- Department of Medicine, College of Human Medicine, Michigan State University, East Lansing, MI 48824, USA
- Gift of Life Michigan, Ann Arbor, MI 48108, USA
- Correspondence: (C.-S.H.); (M.F.C.)
| | | | | | | | - John A. Gerlach
- Gift of Life Michigan, Ann Arbor, MI 48108, USA
- Biomedical Laboratory Diagnostics Program, College of Natural Science, Michigan State University, East Lansing, MI 48824, USA
| | - Yee Lu
- Division of Nephrology, Department of Internal Medicine, University of Michigan Medicine, Ann Arbor, MI 48109, USA
| | - Erica L. Campagnaro
- Division of Hematology and Oncology, Department of Internal Medicine, University of Michigan Medicine, Ann Arbor, MI 48109, USA
| | - Kenneth J. Woodside
- Division of Nephrology, Department of Internal Medicine, University of Michigan Medicine, Ann Arbor, MI 48109, USA
| | - Matthew F. Cusick
- Department of Pathology, University of Michigan Medicine, Ann Arbor, MI 48109, USA
- Correspondence: (C.-S.H.); (M.F.C.)
| |
Collapse
|
10
|
Cornaby C, Montgomery MC, Liu C, Weimer ET. Unique Molecular Identifier-Based High-Resolution HLA Typing and Transcript Quantitation Using Long-Read Sequencing. Front Genet 2022; 13:901377. [PMID: 35879986 PMCID: PMC9308011 DOI: 10.3389/fgene.2022.901377] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 05/05/2022] [Indexed: 01/03/2023] Open
Abstract
HLA typing provides essential results for stem cell and solid organ transplants, as well as providing diagnostic benefits for various rheumatology, gastroenterology, neurology, and infectious diseases. It is becoming increasingly clear that understanding the expression of patient HLA transcripts can provide additional benefits for many of these same patient groups. Our study cohort was evaluated using a long-read RNA sequencing methodology to provide rapid HLA genotyping results and normalized HLA transcript expression. Our assay used NGSEngine to determine the HLA genotyping result and normalized mRNA transcript expression using Athlon2. The assay demonstrated an excellent concordance rate of 99.7%. Similar to previous studies, for the class I loci, patients demonstrated significantly lower expression of HLA-C than HLA-A and -B (Mann-Whitney U, p value = 0.0065 and p value = 0.0154, respectively). In general, the expression of class II transcripts was lower than that of class I transcripts. This study demonstrates a rapid high-resolution HLA typing assay using RNA-Seq that can provide accurate HLA genotyping and HLA allele-specific transcript expression in 7-8 h, a timeline short enough to perform the assay for deceased donors.
Collapse
Affiliation(s)
- Caleb Cornaby
- Molecular Immunology Laboratory, McLendon Clinical Laboratories, UNC Health, Chapel Hill, NC, United States
| | - Maureen C Montgomery
- Molecular Immunology Laboratory, McLendon Clinical Laboratories, UNC Health, Chapel Hill, NC, United States
| | - Chang Liu
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Eric T Weimer
- Molecular Immunology Laboratory, McLendon Clinical Laboratories, UNC Health, Chapel Hill, NC, United States.,Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, United States
| |
Collapse
|
11
|
Aspectos técnicos y clínicos de la prueba cruzada de histocompatibilidad en el trasplante de órganos sólidos. BIOMÉDICA 2022; 42:391-413. [PMID: 35867930 PMCID: PMC9467682 DOI: 10.7705/biomedica.6255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Indexed: 11/21/2022]
Abstract
La presencia de anticuerpos dirigidos contra los antígenos leucocitarios humanos (Human Leukocyte Antigens, HLA) que se expresan en las células del donante, es uno de los factores de riesgo más importantes asociados con las complicaciones clínicas después del trasplante. La prueba cruzada es una de las pruebas de histocompatibilidad más eficaces para la detección de anticuerpos específicos contra el donante en los receptores de injertos. En los primeros métodos de la prueba cruzada, se utilizaba la citotoxicidad dependiente del complemento, que es útil para detectar dichos anticuerpos responsables del rechazo hiperagudo del injerto, pero carece de la sensibilidad adecuada. Por ello, se desarrollaron métodos de pruebas cruzadas más sensibles, entre ellas, la prueba cruzada por citometría de flujo que hoy se considera el método preferido. En este artículo se revisa la evolución de la prueba cruzada y los factores más importantes que deben tenerse en cuenta al realizarla y al interpretar los resultados de esta prueba fundamental para la supervivencia a largo plazo del injerto.
Collapse
|
12
|
Hiho SJ, Levvey B, Carroll R, Nicolson I, Mihaljcic M, Diviney MB, Snell GI, Sullivan LC, Westall GP. The clinical utility and thresholds of Virtual and Halifaster Flow crossmatches in lung transplantation. HLA 2022; 99:580-589. [PMID: 35340124 DOI: 10.1111/tan.14613] [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: 11/10/2021] [Revised: 03/20/2022] [Accepted: 03/21/2022] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Immune sensitization, defined as the presence of alloreactive donor-specific antibodies (DSA), is associated with increased wait-times and inferior transplant outcomes. Identifying pre-transplant DSA with a physical cell-based assay is critical in defining immunological risk. However, improved solid phase antibody detection has provided the potential to forgo this physical assay. Here, we evaluated the association between DSA mean fluorescence intensity (MFI) and the recently introduced Halifaster Flow cytometry crossmatch (FXM) to determine if MFI could predict the outcome of FXM and whether a virtual crossmatch (VXM) would provide an accurate risk assessment. METHODS Sera from 134 waitlisted lung patients was retrospectively assessed by Halifaster FXM against lymphocytes preparations from 32 donors, resulting in 265 FXMs. HLA typing was performed to 2-field allelic level and Luminex single antigen beads (SAB) used to identify DSA. The association between FXM and Luminex MFI was calculated using ROC analysis. MFI threshold accuracy was confirmed using a separate validation cohort (174 recipient sera and 34 donors), whereby both virtual crossmatch (VXM) and FXMs were compared. RESULTS From the 265 FXM performed, 48 (18%) T-cell (TFXM) and 56 (21%) B-cell (BFXM) were positive. In the evaluation cohort, MFI thresholds of 2000 for HLA-A, B, DRB1 and >4000 for DQB1, were predictive of a positive FXM. The validation cohort of 233 paired FXM and VXM confirmed these MFI thresholds for both TFXM and BFXM with an accuracy of 91.4% and 89.3% respectively. CONCLUSION A positive VXM, defined with HLA-specific MFI thresholds predicts Halifaster FXM reactivity, and can potentially expedite organ allocation, by minimising the need for the more time-consuming flow cytometry crossmatch. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Steven J Hiho
- Lung Transplant Service, Department of Respiratory Medicine, Alfred Hospital and Monash University, Melbourne, Australia.,Australian Red Cross LifeBlood, Victorian Transplantation and Immunogenetics, Melbourne, Australia
| | - Bronwyn Levvey
- Lung Transplant Service, Department of Respiratory Medicine, Alfred Hospital and Monash University, Melbourne, Australia
| | - Robert Carroll
- Australian Red Cross LifeBlood, Victorian Transplantation and Immunogenetics, Melbourne, Australia.,Medical Sciences University of South Australia, Australia
| | - Ian Nicolson
- Australian Red Cross LifeBlood, Victorian Transplantation and Immunogenetics, Melbourne, Australia
| | - Masa Mihaljcic
- Australian Red Cross LifeBlood, Victorian Transplantation and Immunogenetics, Melbourne, Australia
| | - Mary B Diviney
- Australian Red Cross LifeBlood, Victorian Transplantation and Immunogenetics, Melbourne, Australia
| | - Gregory I Snell
- Lung Transplant Service, Department of Respiratory Medicine, Alfred Hospital and Monash University, Melbourne, Australia
| | - Lucy C Sullivan
- Lung Transplant Service, Department of Respiratory Medicine, Alfred Hospital and Monash University, Melbourne, Australia.,Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Australia.,Australian Red Cross LifeBlood, South Australian Transplantation and Immunogenetics, Adelaide, Australia
| | - Glen P Westall
- Lung Transplant Service, Department of Respiratory Medicine, Alfred Hospital and Monash University, Melbourne, Australia
| |
Collapse
|
13
|
Putheti P, Liwski RS, Jindra PT. Reducing number of laboratories performing complement dependent cytotoxicity crossmatching: Reasons and conclusions. Hum Immunol 2022; 83:467-475. [DOI: 10.1016/j.humimm.2022.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 01/24/2022] [Accepted: 02/03/2022] [Indexed: 11/15/2022]
|
14
|
Rosser C, Sage D. Approaches for the characterization of clinically relevant pre-transplant human leucocyte antigen (HLA) antibodies in solid organ transplant patients. Int J Immunogenet 2021; 48:385-402. [PMID: 34346180 DOI: 10.1111/iji.12552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/30/2021] [Accepted: 07/22/2021] [Indexed: 11/27/2022]
Abstract
The avoidance of antibody-mediated rejection (AMR) attributed to human leucocyte antigen (HLA) antibody incompatibility remains an essential function of clinical Histocompatibility and Immunogenetics (H&I) laboratories who are supporting solid organ transplantation. Developments in HLA antibody identification assays over the past thirty years have greatly reduced unexpected positive cellular crossmatches and improved solid organ transplant outcomes. For sensitized patients, the decision to register unacceptable HLA antigen mismatches is often heavily influenced by results from solid phase antibody assays, particularly the Luminex® Single Antigen Bead (SAB) assays, although the clinical relevance of antibodies identified solely by these assays remains unclear. As such, the identification of non-clinically relevant antibodies may proportionally increase the number of unacceptable transplant mismatches registered, with an associated increase in waiting time for a compatible organ. We reflect on the clinical relevance of antibodies identified solely by the Luminex SAB® assays and consider whether the application of additional assays and/or tools could further develop our ability to define the clinical relevance of antibodies identified in patient sera. Improvements in this area would assist equity of access to a compatible transplant for highly sensitized patients awaiting a solid organ transplant.
Collapse
Affiliation(s)
- Carla Rosser
- NHS Blood and Transplant (Tooting), Histocompatibility and Immunogenetics, London, UK
| | - Deborah Sage
- NHS Blood and Transplant (Tooting), Histocompatibility and Immunogenetics, London, UK
| |
Collapse
|
15
|
Patel JK, Coutance G, Loupy A, Dilibero D, Hamilton M, Kittleson M, Kransdorf E, Azarbal B, Seguchi O, Zhang X, Chang D, Geft D, Czer L, Varnous S, Kobashigawa JA. Complement inhibition for prevention of antibody-mediated rejection in immunologically high-risk heart allograft recipients. Am J Transplant 2021; 21:2479-2488. [PMID: 33251691 DOI: 10.1111/ajt.16420] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 11/18/2020] [Accepted: 11/18/2020] [Indexed: 02/02/2023]
Abstract
Allosensitization represents a major barrier to heart transplantation (HTx). We assessed the efficacy and safety of complement inhibition at transplant in highly sensitized heart transplant recipients. We performed a single-center, single-arm, open-label trial (NCT02013037). Patients with panel reactive antibodies (PRA) ≥70% and pre-formed donor-specific antibodies (DSA) were eligible. In addition to standard of care, patients received nine infusions of eculizumab during the first 2 months posttransplant. The primary composite endpoint was antibody-mediated rejection (AMR) ≥pAMR2 and/or left ventricular dysfunction during the first year. Secondary endpoints included hemodynamic compromise, allograft rejection, and patient survival. Twenty patients were included. Median cPRA and mean fluorescence intensity of immunodominant DSA were 95% (90%-97%) and 6250 (5000-10 000), respectively. Retrospective B cell and T cell flow crossmatches were positive in 14 and 11 patients, respectively. The primary endpoint occurred in four patients (20%). Survival at 1 year was 90% with no deaths resulting from AMR. In a prespecified analysis comparing treated patients to matched control patients, we observed a dramatic reduction in the risk of biopsy-proven AMR in patients treated with eculizumab (HR = 0.36, 95% CI = 0.14-0.95, p = .032). Our findings support the prophylactic use of complement inhibition for heart transplantation at high immunological risk. ClinincalTrials.gov, NCT02013037.
Collapse
Affiliation(s)
- Jignesh K Patel
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Guillaume Coutance
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA.,Department of Cardiac and Thoracic Surgery, Cardiology Institute, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), Sorbonne University Medical School, Paris, France.,Paris Translational Research Centre for Organ Transplantation, Université de Paris, INSERM, Paris, France
| | - Alexandre Loupy
- Paris Translational Research Centre for Organ Transplantation, Université de Paris, INSERM, Paris, France.,Kidney Transplant Department, Necker Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Deanna Dilibero
- Department of Pharmacy, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Michele Hamilton
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Michelle Kittleson
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Evan Kransdorf
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Babak Azarbal
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Osamu Seguchi
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA.,Department of Transplant Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Xiaohai Zhang
- HLA Laboratory, Comprehensive Transplant Center, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - David Chang
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Dael Geft
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Lawrence Czer
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| | - Shaida Varnous
- Department of Cardiac and Thoracic Surgery, Cardiology Institute, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), Sorbonne University Medical School, Paris, France
| | - Jon A Kobashigawa
- Department of Cardiology, Cedars-Sinai Medical Center, Smidt Heart Institute, Los Angeles, California, USA
| |
Collapse
|
16
|
Franz BJ, Petraroia R, Faust CD, Crawford T, Smalls S, Vongsavanh C, Gibson K, Schmitz JL. Abrogating biologics interference in flow cytometric crossmatching. Hum Immunol 2021; 82:574-580. [PMID: 33934934 DOI: 10.1016/j.humimm.2021.01.016] [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: 10/01/2020] [Revised: 01/04/2021] [Accepted: 01/27/2021] [Indexed: 10/21/2022]
Abstract
The flow cytometric crossmatch is currently the gold standard for evaluating donor and recipient histocompatibility. The assay however does have limitations and is sensitive to false positive reactions resulting from the presence of non-HLA antibodies or therapy related immune biologics. Such false positive reactions can lead to the inappropriate decline of an acceptable donor organ or unnecessary therapeutic intervention. Here we describe the successful validation of anti-idiotype blocking antibodies in prevention of false positive flow crossmatch results caused by biologic therapy. Blocking antibodies specific for the Fab portion of Rituximab and/or Alemtuzumab were incubated with biologic containing patient serum prior to use in flow cytometric crossmatching. Biologic blocking successfully negated false positive crossmatch results with Rituximab (B cell ave. % change = -97%) or Alemtuzumab (T cell ave. % change = -99%, B cell ave. % change = -95%) infused sera respectively. Simultaneous blocking of these biologics was also successful. A complex case is presented to demonstrate the application of this procedure.
Collapse
Affiliation(s)
- Brian J Franz
- Histocompatibility Laboratory, McLendon Clinical Laboratories, UNC Hospitals, Chapel Hill, NC, USA
| | - Rosanne Petraroia
- Histocompatibility Laboratory, McLendon Clinical Laboratories, UNC Hospitals, Chapel Hill, NC, USA
| | - Cynthia D Faust
- Histocompatibility Laboratory, McLendon Clinical Laboratories, UNC Hospitals, Chapel Hill, NC, USA
| | - Tricia Crawford
- Histocompatibility Laboratory, McLendon Clinical Laboratories, UNC Hospitals, Chapel Hill, NC, USA
| | - Shari Smalls
- Histocompatibility Laboratory, McLendon Clinical Laboratories, UNC Hospitals, Chapel Hill, NC, USA
| | - Candy Vongsavanh
- Histocompatibility Laboratory, McLendon Clinical Laboratories, UNC Hospitals, Chapel Hill, NC, USA
| | - Keisha Gibson
- Division Pediatric Nephrology, Department of Pediatrics, UNC School of Medicine, Chapel Hill, NC, USA
| | - John L Schmitz
- Histocompatibility Laboratory, McLendon Clinical Laboratories, UNC Hospitals, Chapel Hill, NC, USA; Department of Pathology & Laboratory Medicine, UNC School of Medicine, Chapel Hill, NC, USA.
| |
Collapse
|
17
|
New challenges, new opportunities: Next generation sequencing and its place in the advancement of HLA typing. Hum Immunol 2021; 82:478-487. [PMID: 33551127 DOI: 10.1016/j.humimm.2021.01.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 12/29/2020] [Accepted: 01/18/2021] [Indexed: 02/07/2023]
Abstract
The Human Leukocyte Antigen (HLA) system has a critical role in immunorecognition, transplantation, and disease association. Early typing techniques provided the foundation for genotyping methods that revealed HLA as one of the most complex, polymorphic regions of the human genome. Next Generation Sequencing (NGS), the latest molecular technology introduced in clinical tissue typing laboratories, has demonstrated advantages over other established methods. NGS offers high-resolution sequencing of entire genes in time frames and price points considered unthinkable just a few years ago, contributing a wealth of data informing histocompatibility assessment and standards of clinical care. Although the NGS platforms share a high-throughput massively parallel processing model, differing chemistries provide specific strengths and weaknesses. Research-oriented Third Generation Sequencing and related advances in bioengineering continue to broaden the future of NGS in clinical settings. These diverse applications have demanded equally innovative strategies for data management and computational bioinformatics to support and analyze the unprecedented volume and complexity of data generated by NGS. We discuss some of the challenges and opportunities associated with NGS technologies, providing a comprehensive picture of the historical developments that paved the way for the NGS revolution, its current state and future possibilities for HLA typing.
Collapse
|
18
|
Daniëls L, Claas FHJ, Kramer CSM, Senev A, Vanden Driessche M, Emonds MP, Van Laecke S, Hellemans R, Abramowicz D, Naesens M. The role of HLA-DP mismatches and donor specific HLA-DP antibodies in kidney transplantation: a case series. Transpl Immunol 2020; 65:101287. [PMID: 32194154 DOI: 10.1016/j.trim.2020.101287] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 03/14/2020] [Accepted: 03/14/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND The impact of HLA-DP mismatches on renal allograft outcome is still poorly understood and is suggested to be less than that of the other HLA loci. The common association of HLA-DP donor-specific antibodies (DSA) with other DSA obviates the evaluation of the actual effect of HLA-DP DSA. METHODS From a large multicenter data collection, we retrospectively evaluated the significance of HLA-DP DSA on transplant outcome and the immunogenicity of HLA-DP eplet mismatches with respect to the induction of HLA-DP DSA. Furthermore, we evaluated the association between the MFI of HLA-DP antibodies detected in Luminex assays and the outcome of flowcytometric/complement-dependent cytotoxicity (CDC) crossmatches. RESULTS In patients with isolated pretransplant HLA-DP antibodies (N = 13), 6 experienced antibody-mediated rejection (AMR) and 3 patients lost their graft. In HLAMatchmaker analysis of HLA-DP mismatches (N = 72), HLA-DP DSA developed after cessation of immunosuppression in all cases with 84DEAV (N = 14), in 86% of cases with 85GPM (N = 6/7), in 50% of cases with 56E (N = 6/12) and in 40% of cases with 56A mismatch (N = 2/5). Correlation analysis between isolated HLA-DP DSA MFI and crossmatches (N = 90) showed negative crossmatch results with HLA-DP DSA MFI <2000 (N = 14). Below an MFI of 10,000 CDC crossmatches were also negative (N = 33). Above these MFI values both positive (N = 35) and negative (N = 16) crossmatch results were generated. CONCLUSIONS Isolated HLA-DP DSA are rare, yet constitute a significant risk for AMR. We identified high-risk eplet mismatches that can lead to HLA-DP DSA formation. We therefore recommend HLA-DP typing to perform HLA-DP DSA analysis before transplantation. HLA-DP DSA with high MFI were not always correlated with positive crossmatch results.
Collapse
Affiliation(s)
- Liesbeth Daniëls
- Histocompatibility and Immunogenetics Laboratory (HILA), Red Cross-Flanders, Mechelen, Belgium.
| | - Frans H J Claas
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
| | - Cynthia S M Kramer
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
| | - Aleksandar Senev
- Histocompatibility and Immunogenetics Laboratory (HILA), Red Cross-Flanders, Mechelen, Belgium
| | | | - Marie-Paule Emonds
- Histocompatibility and Immunogenetics Laboratory (HILA), Red Cross-Flanders, Mechelen, Belgium; Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | | | - Rachel Hellemans
- Department of Nephrology, Antwerp University Hospital and Antwerp University, Edegem, Belgium
| | - Daniel Abramowicz
- Department of Nephrology, Antwerp University Hospital and Antwerp University, Edegem, Belgium
| | - Maarten Naesens
- Department of Nephrology and Renal Transplantation, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| |
Collapse
|
19
|
Using Nanopore Whole-Transcriptome Sequencing for Human Leukocyte Antigen Genotyping and Correlating Donor Human Leukocyte Antigen Expression with Flow Cytometric Crossmatch Results. J Mol Diagn 2020; 22:101-110. [DOI: 10.1016/j.jmoldx.2019.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 08/27/2019] [Accepted: 09/11/2019] [Indexed: 01/07/2023] Open
|
20
|
Morris AB, Sullivan HC, Krummey SM, Gebel HM, Bray RA. Out with the old, in with the new: Virtual versus physical crossmatching in the modern era. HLA 2019; 94:471-481. [PMID: 31515937 DOI: 10.1111/tan.13693] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/26/2019] [Accepted: 09/10/2019] [Indexed: 12/15/2022]
Abstract
The virtual crossmatch (VXM) is gaining acceptance as an alternative approach to assess donor:recipient compatibility prior to transplantation. In contrast to a physical crossmatch, the virtual crossmatch does not require viable donor cells but rather relies on complete HLA typing of the donor and current antibody assessment of the recipient. Thus, the VXM can be performed in minutes which allows for faster transplant decisions thereby increasing the likelihood that organs can be shipped across significant distances yet safely transplanted. Here, we present a brief review of the past 50 years of histocompatibility testing; from the original complement-dependent cytotoxicity crossmatch in 1969 to the new era of molecular HLA typing, solid-phase antibody testing and virtual crossmatching. These advancements have shaped a paradigm shift in our approach to transplantation. That is, foregoing a prospective physical crossmatch in favor of a VXM. In this review, we undertake an in-depth analysis of the pros- and cons- of physical and virtual crossmatching.Finally, we provide objective data on the selected use of the VXM which demonstrate the value of a VXM in lieu of the traditional physical crossmatch for safe and efficient organ transplantation.
Collapse
Affiliation(s)
- Anna B Morris
- Department of Surgery, Emory University, Atlanta, Georgia
| | - H C Sullivan
- Department of Pathology, Emory University, Atlanta, Georgia
| | | | - Howard M Gebel
- Department of Pathology, Emory University, Atlanta, Georgia
| | - Robert A Bray
- Department of Pathology, Emory University, Atlanta, Georgia
| |
Collapse
|
21
|
Development of data-driven models for the flow cytometric crossmatch. Hum Immunol 2019; 80:983-989. [PMID: 31530432 DOI: 10.1016/j.humimm.2019.09.004] [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: 06/28/2019] [Revised: 08/13/2019] [Accepted: 09/05/2019] [Indexed: 01/08/2023]
Abstract
HLA laboratories use virtual crossmatching (VXM) to predict recipient and donor compatibility using HLA antibody data and donor HLA type. Increasingly, transplant centers are utilizing VXM as the final compatibility determination prior to transplant. However, the VXM interpretation is based on HLA experience of individual transplant centers. This study developed data-driven algorithms that predicted flow cytometric crossmatch (FCXM) outcomes using HLA antibody mean fluorescent intensity (MFI) data and donor HLA typing without the need for human interpretation.Two algorithms were evaluated; an MFI Optimal-Threshold model and a Least-Squares-Fitting model. The Optimal-Threshold model correctly determined between 81.5% and 85.5% of T or B-cell responses. A class I antibody MFI threshold of 4670 was optimal for predicting T-cell response while an antibody MFI threshold of 6180 was optimal for predicting B-cell responses. HLA class I antibodies had a 1.47-fold greater influence on FCXM outcomes than class II antibodies. HLA-B antibodies influenced T and B-cell responses more than HLA-A or -C (-B > -A > -C). The Least-Squares-Fitting model increased accuracy to 94.1% and 88.8% for T and B-cell responses, respectively. The algorithms described here provide enhanced FCXM prediction and novel insights into the influence of specific HLA antibodies on the crossmatch outcome.
Collapse
|
22
|
Carey BS, Poulton KV, Poles A. Factors affecting HLA expression: A review. Int J Immunogenet 2019; 46:307-320. [PMID: 31183978 DOI: 10.1111/iji.12443] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/26/2019] [Accepted: 05/03/2019] [Indexed: 12/22/2022]
Abstract
The detection and semiquantitative measurement of circulating human leucocyte antigen (HLA)-specific antibodies is essential for the management of patients before and after transplantation. In addition, the pretransplant cross-match to assess the reactivity of recipient HLA antibody against donor lymphocytes has long been the gold standard to prevent hyperacute rejection. Whilst both of these tests assume that recipient HLA-specific antibody is the only variable in the assessment of transplant risk, this is not the case. Transplant immunologists recognize that some HLA antigens are expressed at levels a magnitude lower than others (e.g., HLA-C, HLA-DQ), but within loci, and between different cell types there are many factors that influence HLA expression in both resting and activated cells. HLA is not usually expressed without the specific promoter proteins NLRC5, for HLA class I, and CIITA, for class II. The quantity of HLA protein production is then affected by factors including promoter region polymorphisms, alternative exon splice sites, methylation and microRNA-directed degradation. Different loci are influenced by multiple combinations of these control mechanisms making prediction of HLA regulation difficult, but an ability to measure the cellular expression of each HLA antigen, in conjunction with knowledge of circulating HLA-specific antibody, would lead to a more informed algorithm to assess transplant risk.
Collapse
Affiliation(s)
- B Sean Carey
- Histocompatibility and Immunogenetics, Combined Laboratory, University Hospitals Plymouth, Plymouth, UK
| | | | - Anthony Poles
- Histocompatibility and Immunogenetics, Combined Laboratory, University Hospitals Plymouth, Plymouth, UK
| |
Collapse
|
23
|
|
24
|
|
25
|
Sullivan HC, Dean CL, Liwski RS, Biswas S, Goodman AL, Krummey S, Gebel HM, Bray RA. (F)Utility of the physical crossmatch for living donor evaluations in the age of the virtual crossmatch. Hum Immunol 2018; 79:711-715. [PMID: 30081064 DOI: 10.1016/j.humimm.2018.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 07/23/2018] [Accepted: 08/02/2018] [Indexed: 12/12/2022]
Abstract
Flow cytometric crossmatches (FCXM) are routinely performed to support living-donor renal transplantation. While long a laboratory mainstay, a physical crossmatch is costly, time consuming, and frequently poses interpretative conundrums with both false-positive and false- negative results. Given the increased utilization of the virtual crossmatch (vXM) in the deceased donor setting, our aim was to assess its utility in living donor evaluations. We reviewed 100 living donor FCXMs and retrospectively performed a vXM for each pair. Seventy-five (75) cases were concordant, (i.e., FCXM-/vXM- or FCXM+/vXM+) while 25 cases were discordant; Five were vXM+/FCXM- and 20 were FCXM+/vXM-. Since donor-specific antibodies (DSA) were not detected in the 20 FCXM+/vXM- cases, these were interpreted as false-positive, i.e., due to non-HLA antibodies. Importantly, none of these patients, when transplanted across a positive FCXM, experienced early antibody mediated rejection or subsequently developed HLA DSA. These data reveal that, for the vast majority of living donor evaluations, a vXM is an acceptable vetting procedure.
Collapse
Affiliation(s)
- Harold C Sullivan
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA.
| | - Christina L Dean
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Robert S Liwski
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Shilpee Biswas
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Abigail L Goodman
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Scott Krummey
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Howard M Gebel
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Robert A Bray
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| |
Collapse
|
26
|
|
27
|
Donor-specific HLA antibodies in predicting crossmatch outcome: Comparison of three different laboratory techniques. Transpl Immunol 2017; 46:23-28. [PMID: 29157597 DOI: 10.1016/j.trim.2017.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/09/2017] [Accepted: 11/16/2017] [Indexed: 01/18/2023]
Abstract
The virtual crossmatch, which is based on single antigen bead technology, is used in the prediction of crossmatch results. However, this assay differs in sensitivity and specificity from crossmatch methods. In our study, the results of physical crossmatches, performed with three different methods, were assessed against virtual crossmatch results. The aim was to determine the potential cut-off values for donor specific antibodies (DSA) that would predict the crossmatch results obtained by different methods. The results of different crossmatch techniques were correlated with the virtual crossmatch. The receiver operating characteristic (ROC) analysis revealed the Flow cytometric crossmatch (FCXM) and Luminex crossmatch (LXM) to be the most accurate, with area under curve (AUC) values of 0.861 and 0.805, respectively. While we found that the virtual crossmatch correlated well with all the crossmatch results, FCXM produced the best results (83% of the DSA detected). LXM outperformed the other tests in terms of the accuracy in separating class II DSA.
Collapse
|
28
|
Paramesh AS, Neidlinger N, Salvatore M, Smith A, Friedman A, Payne W, Taber T, Wright C. OPO Strategies to Prevent Unintended Use of Kidneys Exported for High PRA (>98% cPRA) Recipients. Am J Transplant 2017; 17:2139-2143. [PMID: 28168823 DOI: 10.1111/ajt.14220] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 01/26/2017] [Accepted: 01/29/2017] [Indexed: 01/25/2023]
Abstract
Since the advent of the Kidney Allocation System (KAS), matched candidates with high (>98%) panel reactive antibody (hPRA) are given priority over local candidates with lower PRA. This often leads to exporting of kidneys. Data for these kidneys are not detailed on routine reports. Twenty-two organ procurement organizations prospectively submitted data from August 2015 to July 2016, describing allocation practices of kidneys to hPRA patients and outcomes of these kidneys. Five hundred twenty out of 6924 procured kidneys were exported for hPRA recipients. Of these, 402 (77.3%) were transplanted into the intended recipient (IR); 100 (19.2%) were transplanted into unintended recipients (UR), and 18 (3.5%) were discarded. The most common reason for use in an UR was a positive crossmatch (XM) (63%). The most common reasons for discard were donor quality (44%) and ischemic time (39%). Prior to kidney export, when tissue crossmatching was done, 96.2% of the kidneys went to the IR, versus 80.7% following virtual CM, versus 56.7% when no crossmatching was performed (p < 0.0001). A significant number of kidneys exported for hPRA patients are not being used in the IR or are being discarded. The most common reason for this is positive tissue XM. We report that unintended use of the kidney was minimized when tissue was shipped and XM results were known prior to exporting the kidney.
Collapse
Affiliation(s)
- A S Paramesh
- Department of Surgery, Tulane University School of Medicine, New Orleans, LA.,Louisiana Organ Procurement Agency, Metairie, LA
| | | | | | - A Smith
- Department of Surgery, Tulane University School of Medicine, New Orleans, LA
| | | | - W Payne
- Department of Surgery, University of Minnesota, Minneapolis, MN
| | - T Taber
- Section of Nephrology, Indiana University School of Medicine, Indianapolis, IN
| | | |
Collapse
|
29
|
|
30
|
Reassessment of T Lymphocytes Crossmatches Results Prediction With Luminex Class I Single Antigen Flow Beads Assay. Transplantation 2017; 101:624-630. [DOI: 10.1097/tp.0000000000001239] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
31
|
Houp JA, Schillinger KP, Eckstein AJ, Vega RM, Desai NM, Lonze BE, Jackson AM. Casting a smaller net into a bigger donor pool: A single center's experience with the new kidney allocation system. Hum Immunol 2016; 78:49-53. [PMID: 27890719 DOI: 10.1016/j.humimm.2016.11.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 11/14/2016] [Accepted: 11/17/2016] [Indexed: 12/27/2022]
Abstract
The new kidney allocation system (KAS) provides additional allocation points for candidates with broad HLA sensitization in an effort to increase transplant rates for this underserved population. Following the implementation of KAS, our center lowered the HLA antibody threshold for listing unacceptable antigens from a cytotoxicity crossmatch level to a flow cytometric crossmatch level increasing Calculated Panel Reactive Antibody (CPRA) values and allocation points, yet restricting acceptable donor HLA phenotypes. As a result, many sensitized candidates were transitioned from 50% to 98% CPRA categories into the 99% CPRA regional share and 100% CPRA national share categories. Exposure to these larger donor pools significantly increased transplantation with compatible donors for 100% CPRA candidates, but regional sharing was not sufficient to increase transplantation rates for our 99% CPRA candidates. Competition within the 100% CPRA cohort identified inequities for 99.99-100.0% CPRA candidates and highlighted the continued need for desensitization therapies to reduce immunological barriers and provide transplant opportunities for the most highly sensitized candidates.
Collapse
Affiliation(s)
- Julie A Houp
- Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA
| | - Karl P Schillinger
- Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA
| | - Andrew J Eckstein
- Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA
| | - Renato M Vega
- Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA
| | - Niraj M Desai
- Department of Surgery, The Johns Hopkins University, Baltimore, MD, USA
| | - Bonnie E Lonze
- Department of Surgery, The Johns Hopkins University, Baltimore, MD, USA
| | - Annette M Jackson
- Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
32
|
Kamoun M, Phelan D, Noreen H, Marcus N, Klingman L, Gebel HM. HLA compatibility assessment and management of highly sensitized patients under the new kidney allocation system (KAS): A 2016 status report from twelve HLA laboratories across the U.S. Hum Immunol 2016; 78:19-23. [PMID: 27840088 DOI: 10.1016/j.humimm.2016.10.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 10/31/2016] [Accepted: 10/31/2016] [Indexed: 12/17/2022]
Abstract
Twelve HLA laboratories were surveyed to assess the methods and operational issues involved to define highly sensitized patients and to assess HLA compatibility under the new kidney allocation system (KAS) in the U.S. All laboratories used single antigen bead assays both pre- and post-KAS to define both broad and allele-specific HLA antibodies. The methods and threshold used to list HLA unacceptable antigens in UNet for virtual crossmatch (vXM) and the criteria used for determining HLA compatibility varied among laboratories. Laboratories reported several limitations of the current assays including the accuracy of quantifiable antibody fluorescence values, inadequate coverage of common alleles on the bead panels, and challenges in calibrating the vXM. The new KAS has resulted in a significant surge of deceased donor organ offers requiring vXM evaluation under tight time constraints. In the post-KAS period, eight of twelve laboratories (67%) indicated that their center did not proceed to transplant based on vXM without a prospective lymphocyte crossmatch. In conclusion, HLA laboratories play a critical role in deceased donor allocation for highly sensitized patients under the new KAS. Significant opportunities exist to improve the methods used in the assessment of HLA compatibility to safely transplant highly sensitized patients.
Collapse
Affiliation(s)
- M Kamoun
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States.
| | - D Phelan
- Department of Pathology & Immunology, Barnes-Jewish Hospital, Washington University of St. Louis, St. Louis, MO, United States
| | - H Noreen
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, United States
| | - N Marcus
- Department of Pathology & Laboratory Medicine, Emory University, Atlanta, GA, United States
| | - L Klingman
- Department of Pathology, Baylor University, Dallas, TX, United States
| | - H M Gebel
- Department of Pathology & Laboratory Medicine, Emory University, Atlanta, GA, United States
| |
Collapse
|
33
|
Picascia A, Grimaldi V, Napoli C. From HLA typing to anti-HLA antibody detection and beyond: The road ahead. Transplant Rev (Orlando) 2016; 30:187-94. [DOI: 10.1016/j.trre.2016.07.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 07/07/2016] [Accepted: 07/22/2016] [Indexed: 01/27/2023]
|