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Goerlich CE, Singh AK, Griffith BP, Mohiuddin MM. The immunobiology and clinical use of genetically engineered porcine hearts for cardiac xenotransplantation. NATURE CARDIOVASCULAR RESEARCH 2022; 1:715-726. [PMID: 36895262 PMCID: PMC9994617 DOI: 10.1038/s44161-022-00112-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A summary of the scientific rationale of the advancements that led to the first genetically modified pig-to-human cardiac xenotransplantation is lacking in a complex and rapidly evolving field. Here, we aim to aid the general readership in the understanding of the gradual progression of cardiac (xeno)transplantation research, the immunobiology of cardiac xenotransplantation (including the latest immunosuppression, cardiac preservation and genetic engineering required for successful transplantation) and the regulatory landscape related to the clinical application of cardiac xenotransplantation for people with end-stage heart failure. Finally, we provide an overview of the outcomes and lessons learned from the first genetically modified pig-to-human cardiac heart xenotransplantation.
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Affiliation(s)
- Corbin E Goerlich
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Avneesh K Singh
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Bartley P Griffith
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Muhammad M Mohiuddin
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
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Singh AK, Goerlich CE, Shah AM, Zhang T, Tatarov I, Ayares D, Horvath KA, Mohiuddin MM. Cardiac Xenotransplantation: Progress in Preclinical Models and Prospects for Clinical Translation. Transpl Int 2022; 35:10171. [PMID: 35401039 PMCID: PMC8985160 DOI: 10.3389/ti.2022.10171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/11/2022] [Indexed: 12/02/2022]
Abstract
Survival of pig cardiac xenografts in a non-human primate (NHP) model has improved significantly over the last 4 years with the introduction of costimulation blockade based immunosuppression (IS) and genetically engineered (GE) pig donors. The longest survival of a cardiac xenograft in the heterotopic (HHTx) position was almost 3 years and only rejected when IS was stopped. Recent reports of cardiac xenograft survival in a life-sustaining orthotopic (OHTx) position for 6 months is a significant step forward. Despite these achievements, there are still several barriers to the clinical success of xenotransplantation (XTx). This includes the possible transmission of porcine pathogens with pig donors and continued xenograft growth after XTx. Both these concerns, and issues with additional incompatibilities, have been addressed recently with the genetic modification of pigs. This review discusses the spectrum of issues related to cardiac xenotransplantation, recent progress in preclinical models, and its feasibility for clinical translation.
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Affiliation(s)
- Avneesh K. Singh
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Corbin E. Goerlich
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Aakash M. Shah
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Tianshu Zhang
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Ivan Tatarov
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
| | | | - Keith A. Horvath
- National Heart, Lung, and Blood Institute, National Institute of Health, Bethesda, MD, United States
| | - Muhammad M. Mohiuddin
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
- *Correspondence: Muhammad M. Mohiuddin,
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Reichart B, Längin M. On the way (my way) to clinical xenogeneic heart transplantation. Presented at the 15th biannual IXA meeting, Munich, October 11, 2019. Xenotransplantation 2020; 27:e12637. [DOI: 10.1111/xen.12637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 07/30/2020] [Indexed: 01/04/2023]
Affiliation(s)
- Bruno Reichart
- Transregional Collaborative Research Center 127 Walter Brendel Centre of Experimental Medicine LMU Munich Munich Germany
| | - Matthias Längin
- Department of Anaesthesiology University Hospital LMU Munich Munich Germany
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Wang L, Cooper DKC, Burdorf L, Wang Y, Iwase H. Overcoming Coagulation Dysregulation in Pig Solid Organ Transplantation in Nonhuman Primates: Recent Progress. Transplantation 2018; 102:1050-1058. [PMID: 29538262 PMCID: PMC7228622 DOI: 10.1097/tp.0000000000002171] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/22/2018] [Accepted: 01/26/2018] [Indexed: 01/17/2023]
Abstract
There has recently been considerable progress in the results of pig organ transplantation in nonhuman primates, largely associated with the availability of (i) pigs genetically engineered to overcome coagulation dysregulation, and (ii) novel immunosuppressive agents. The barriers of thrombotic microangiopathy and/or consumptive coagulation were believed to be associated with (i) activation of the graft vascular endothelial cells by a low level of antipig antibody binding and/or complement deposition and/or innate immune cell activity, and (ii) molecular incompatibilities between the nonhuman primate and pig coagulation-anticoagulation systems. The introduction of a human coagulation-regulatory transgene, for example, thrombomodulin, endothelial protein C receptor, into the pig vascular endothelial cells has contributed to preventing a procoagulant state from developing, resulting in a considerable increase in graft survival. In the heterotopic (non-life-supporting) heart transplant model, graft survival has increased from a maximum of 179 days in 2005 to 945 days. After life-supporting kidney transplantation, survival has been extended from 90 days in 2004 to 499 days. In view of the more complex coagulation dysfunction seen after pig liver and, particularly, lung transplantation, progress has been less dramatic, but the maximum survival of a pig liver has been increased from 7 days in 2010 to 29 days, and of a pig lung from 4 days in 2007 to 9 days. There is a realistic prospect that the transplantation of a kidney or heart, in combination with a conventional immunosuppressive regimen, will enable long-term recipient survival.
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Affiliation(s)
- Liaoran Wang
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham AL
- Second Affiliated Hospital, University of South China, Hengyang City, Hunan, China
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham AL
| | - Lars Burdorf
- Division of Cardiac Surgery, Department of Surgery, University of Maryland, Baltimore VAMC, Baltimore, MD
| | - Yi Wang
- Second Affiliated Hospital, University of South China, Hengyang City, Hunan, China
| | - Hayato Iwase
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham AL
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Abicht JM, Kourtzelis I, Reichart B, Koutsogiannaki S, Primikyri A, Lambris JD, Chavakis T, Holdt L, Kind A, Guethoff S, Mayr T. Complement C3 inhibitor Cp40 attenuates xenoreactions in pig hearts perfused with human blood. Xenotransplantation 2017; 24:10.1111/xen.12262. [PMID: 27677785 PMCID: PMC5358808 DOI: 10.1111/xen.12262] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 07/11/2016] [Accepted: 08/12/2016] [Indexed: 01/26/2023]
Abstract
BACKGROUND The complement system plays a crucial role in acute xenogeneic reactions after cardiac transplantation. We used an ex vivo perfusion model to investigate the effect of Cp40, a compstatin analog and potent inhibitor of complement at the level of C3. METHODS Fifteen wild-type pig hearts were explanted, cardiopleged, and reperfused ex vivo after 150 minutes of cold ischemia. Hearts were challenged in a biventricular working heart mode to evaluate cardiac perfusion and function. In the treatment group (n=5), the complement cascade was blocked at the level of C3 using Cp40, using diluted human blood. Untreated human and porcine blood was used for controls. RESULTS Throughout the perfusion, C3 activation was inhibited when Cp40 was used (mean of all time points: 1.11 ± 0.34% vs 3.12 ± 0.48% control activation; P<.01). Compared to xenoperfused controls, the cardiac index improved significantly in the treated group (6.5 ± 4.2 vs 3.5 ± 4.8 mL/min/g; P=.03, 180 minutes perfusion), while the concentration of lactate dehydrogenase as a maker for cell degradation was reduced in the perfusate (583 ± 187 U/mL vs 2108 ± 1145 U/mL, P=.02). Histological examination revealed less hemorrhage and edema, and immunohistochemistry confirmed less complement fragment deposition than in untreated xenoperfused controls. CONCLUSIONS Cp40 efficiently prevents C3 activation of the complement system, resulting in reduced cell damage and preserved function in wild-type porcine hearts xenoperfused ex vivo. We suggest that this compstatin analog, which blocks all main pathways of complement activation, could be a beneficial perioperative treatment in preclinical and in future clinical xenotransplantation.
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Affiliation(s)
- Jan-Michael Abicht
- Department of Anaesthesiology, Ludwig Maximilian University, Munich, Germany
| | - Ioannis Kourtzelis
- Department of Clinical Pathobiochemistry, Medical Faculty, Technische Universität Dresden, Germany
| | - Bruno Reichart
- Walter-Brendel-Centre, Ludwig Maximilian University Munich, Germany
| | - Sophia Koutsogiannaki
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
| | - Alexandra Primikyri
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
| | - John D. Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
| | - Triantafyllos Chavakis
- Department of Clinical Pathobiochemistry, Medical Faculty, Technische Universität Dresden, Germany
| | - Lesca Holdt
- Institute of Laboratory Medicine of Ludwig Maximilian University, Munich, Germany
| | - Alexander Kind
- Chair of Livestock Biotechnology, School of Life Sciences Weihenstephan, Technical University of Munich, Germany
| | - Sonja Guethoff
- Department of Cardiovascular Surgery, Ludwig Maximilian University, Munich, Germany
| | - Tanja Mayr
- Department of Anaesthesiology, Ludwig Maximilian University, Munich, Germany
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Abicht J, Mayr T, Reichart B, Buchholz S, Werner F, Lutzmann I, Schmoeckel M, Bauer A, Thormann M, Langenmayer M, Herbach N, Pohla H, Herzog R, McGregor CGA, Ayares D, Wolf E, Klymiuk N, Baehr A, Kind A, Hagl C, Ganswindt U, Belka C, Guethoff S, Brenner P. Pre‐clinical heterotopic intrathoracic heart xenotransplantation: a possibly useful clinical technique. Xenotransplantation 2015; 22:427-42. [DOI: 10.1111/xen.12213] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/19/2015] [Indexed: 01/24/2023]
Affiliation(s)
- Jan‐Michael Abicht
- Department of Anaesthesiology Ludwig‐Maximilian University Munich Germany
- Transregio Collaborative Research Center 127 Walter Brendel Centre of Experimental Medicine Ludwig Maximilian University Munich Germany
| | - Tanja Mayr
- Department of Anaesthesiology Ludwig‐Maximilian University Munich Germany
- Transregio Collaborative Research Center 127 Walter Brendel Centre of Experimental Medicine Ludwig Maximilian University Munich Germany
| | - Bruno Reichart
- Transregio Collaborative Research Center 127 Walter Brendel Centre of Experimental Medicine Ludwig Maximilian University Munich Germany
| | - Stefan Buchholz
- Department of Cardiovascular Surgery Ludwig Maximilian University Munich Germany
| | - Fabian Werner
- Department of Cardiovascular Surgery Ludwig Maximilian University Munich Germany
| | - Isabelle Lutzmann
- Department of Cardiovascular Surgery Ludwig Maximilian University Munich Germany
| | - Michael Schmoeckel
- Department of Cardiovascular Surgery Ludwig Maximilian University Munich Germany
- Department of Cardiac Surgery Asklepios Klinik St Georg Hamburg Germany
| | - Andreas Bauer
- Department of Anaesthesiology Ludwig‐Maximilian University Munich Germany
| | - Michael Thormann
- Department of Cardiovascular Surgery Ludwig Maximilian University Munich Germany
| | - Martin Langenmayer
- Institute of Veterinary Pathology Ludwig Maximilian University Munich Germany
| | - Nadja Herbach
- Institute of Veterinary Pathology Ludwig Maximilian University Munich Germany
| | - Heike Pohla
- Tumor Immunology Laboratory LIFE Center Ludwig Maximilian University Munich Germany
| | - Rudolf Herzog
- Transregio Collaborative Research Center 127 Walter Brendel Centre of Experimental Medicine Ludwig Maximilian University Munich Germany
| | | | | | - Eckhard Wolf
- Department of Molecular Animal Breeding and Biotechnology Ludwig Maximilian University Munich Germany
| | - Nikolai Klymiuk
- Department of Molecular Animal Breeding and Biotechnology Ludwig Maximilian University Munich Germany
| | - Andrea Baehr
- Department of Molecular Animal Breeding and Biotechnology Ludwig Maximilian University Munich Germany
| | - Alexander Kind
- Chair of Livestock Biotechnology School of Life Sciences Weihenstephan Technical University of Munich Germany
| | - Christian Hagl
- Department of Cardiovascular Surgery Ludwig Maximilian University Munich Germany
| | - Ute Ganswindt
- Department of Radiation Oncology Ludwig Maximilian University Munich Germany
| | - Claus Belka
- Department of Radiation Oncology Ludwig Maximilian University Munich Germany
| | - Sonja Guethoff
- Transregio Collaborative Research Center 127 Walter Brendel Centre of Experimental Medicine Ludwig Maximilian University Munich Germany
- Department of Cardiovascular Surgery Ludwig Maximilian University Munich Germany
| | - Paolo Brenner
- Transregio Collaborative Research Center 127 Walter Brendel Centre of Experimental Medicine Ludwig Maximilian University Munich Germany
- Department of Cardiovascular Surgery Ludwig Maximilian University Munich Germany
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Mohiuddin MM, Reichart B, Byrne GW, McGregor CGA. Current status of pig heart xenotransplantation. Int J Surg 2015; 23:234-239. [PMID: 26318967 PMCID: PMC4684783 DOI: 10.1016/j.ijsu.2015.08.038] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/06/2015] [Accepted: 08/12/2015] [Indexed: 02/03/2023]
Abstract
Significant progress in understanding and overcoming cardiac xenograft rejection using a clinically relevant large animal pig-to-baboon model has accelerated in recent years. This advancement is based on improved immune suppression, which attained more effective regulation of B lymphocytes and possibly newer donor genetics. These improvements have enhanced heterotopic cardiac xenograft survival from a few weeks to over 2 years, achieved intrathoracic heterotopic cardiac xenograft survival of 50 days and orthotopic survival of 57 days. This encouraging progress has rekindled interest in xenotransplantation research and refocused efforts on preclinical orthotopic cardiac xenotransplantation.
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Affiliation(s)
| | - Bruno Reichart
- Walter-Brendel-Centre for Experimental Medicine, Ludwig-Maximilians-University, Munich, Germany
| | - Guerard W Byrne
- Institute of Cardiovascular Science, University College London, London, UK; Department of Surgery, Mayo Clinic Rochester, MN, USA
| | - Christopher G A McGregor
- Institute of Cardiovascular Science, University College London, London, UK; Department of Surgery, Mayo Clinic Rochester, MN, USA
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Cooper DKC, Satyananda V, Ekser B, van der Windt DJ, Hara H, Ezzelarab MB, Schuurman HJ. Progress in pig-to-non-human primate transplantation models (1998-2013): a comprehensive review of the literature. Xenotransplantation 2014; 21:397-419. [PMID: 25176336 DOI: 10.1111/xen.12127] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 06/03/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND The pig-to-non-human primate model is the standard choice for in vivo studies of organ and cell xenotransplantation. In 1998, Lambrigts and his colleagues surveyed the entire world literature and reported all experimental studies in this model. With the increasing number of genetically engineered pigs that have become available during the past few years, this model is being utilized ever more frequently. METHODS We have now reviewed the literature again and have compiled the data we have been able to find for the period January 1, 1998 to December 31, 2013, a period of 16 yr. RESULTS The data are presented for transplants of the heart (heterotopic and orthotopic), kidney, liver, lung, islets, neuronal cells, hepatocytes, corneas, artery patches, and skin. Heart, kidney, and, particularly, islet xenograft survival have increased significantly since 1998. DISCUSSION The reasons for this are briefly discussed. A comment on the limitations of the model has been made, particularly with regard to those that will affect progression of xenotransplantation toward the clinic.
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Affiliation(s)
- David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
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Byrne GW, Azimzadeh AM, Ezzelarab M, Tazelaar HD, Ekser B, Pierson RN, Robson SC, Cooper DKC, McGregor CGA. Histopathologic insights into the mechanism of anti-non-Gal antibody-mediated pig cardiac xenograft rejection. Xenotransplantation 2013; 20:292-307. [PMID: 25098626 PMCID: PMC4126170 DOI: 10.1111/xen.12050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/31/2013] [Indexed: 01/13/2023]
Abstract
The histopathology of cardiac xenograft rejection has evolved over the last 20 yr with the development of new modalities for limiting antibody-mediated injury, advancing regimens for immune suppression, and an ever-widening variety of new donor genetics. These new technologies have helped us progress from what was once an overwhelming anti-Gal-mediated hyperacute rejection to a more protracted anti-Gal-mediated vascular rejection to what is now a more complex manifestation of non-Gal humoral rejection and coagulation dysregulation. This review summarizes the changing histopathology of Gal- and non-Gal-mediated cardiac xenograft rejection and discusses the contributions of immune-mediated injury, species-specific immune-independent factors, transplant and therapeutic procedures, and donor genetics to the overall mechanism(s) of cardiac xenograft rejection.
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Affiliation(s)
- Guerard W Byrne
- Institute of Cardiovascular Science, University College London, London, UK; Department of Surgery, Mayo Clinic, Rochester, MN, USA
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Abstract
PURPOSE OF REVIEW Cardiac xenotransplantation (CXTx) remains a promising approach to alleviate the chronic shortage of donor hearts. This review summarizes recent results of heterotopic and orthotopic CXTx, highlights the role of non-Gal antibody in xenograft rejection, and discusses challenges to clinical orthotopic CXTx. RECENT FINDINGS Pigs mutated in the α 1,3 galactosyltransferase gene (GTKO pigs) are devoid of the galactose α1,3 galactose (αGal) carbohydrate antigen. This situation effectively eliminates any role for anti-Gal antibody in GTKO cardiac xenograft rejection. Survival of heterotopic GTKO cardiac xenografts in nonhuman primates continues to increase. GTKO graft rejection commonly involves vascular antibody deposition and variable complement deposition. Non-Gal antibody responses to porcine antigens associated with inflammation, complement, and hemostatic regulation and to new carbohydrate antigens have been identified. Their contribution to rejection remains under investigation. Orthotopic CXTx is limited by early perioperative cardiac xenograft dysfunction (PCXD). However, hearts affected by PCXD recover full cardiac function and orthotopic survival up to 2 months without rejection has been reported. SUMMARY CXTx remains a promising technology for treating end-stage cardiac failure. Genetic modification of the donor and refinement of immunosuppressive regimens have extended heterotopic cardiac xenograft survival from minutes to in excess of 8 months.
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Affiliation(s)
- Guerard W Byrne
- University College London, Institute for Cardiovascular Sciences, London, UK.
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Postrach J, Bauer A, Schmoeckel M, Reichart B, Brenner P. Heart xenotransplantation in primate models. Methods Mol Biol 2012; 885:155-68. [PMID: 22565995 DOI: 10.1007/978-1-61779-845-0_10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Xenotransplantation is a potential solution for the worldwide persisting donor organ shortage. However, immunological and physiological barriers need to be overcome before the first clinical trials can be started. Nonhuman primates are considered the most suitable recipients in preclinical xenotransplantation models. Heterotopic abdominal cardiac xenotransplantation is a well-established nonworking heart model for immunological and biological studies on acute and delayed xenograft rejection and xenograft survival. Nevertheless, orthotopic life-supporting pig-to-baboon heart transplantation is the only accepted model for future cardiac xenotransplantation in humans so far. Survival times of 3 months in at least 60% of consecutive experiments have to be achieved and a minimum number of ten nonhuman primates have to survive for this period of time before clinical transplantation may be started. We recently introduced the heterotopic thoracic technique of pig-to-baboon heart transplantation. We believe that this technique combines the advantages of a working heart model with the safety of heterotopic transplantation. We describe the technical procedure of the three different pig-to-baboon models and give detailed information on perioperative care of the recipients.
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Affiliation(s)
- Johannes Postrach
- Department of Cardiac Surgery, Ludwig-Maximilians University Munich, Munich, Germany.
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Kim JS, Lee HM, Oh BC, Lim HG, Lee JR. Effect of hyperkalemia and hemolysis caused by hyperacute rejection on cardiac function in pig to human ex vivo xenogeneic cardiac perfusion model. Korean Circ J 2011; 41:130-6. [PMID: 21519511 PMCID: PMC3079132 DOI: 10.4070/kcj.2011.41.3.130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 05/11/2010] [Accepted: 05/31/2010] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Hyperacute rejection (HAR) is a major obstacle to successful xenotransplantation of vascularized organs. This study was conducted to observe the effect of hemolysis of perfused human whole blood on pig heart function, and determine the major risk factors for preservation of xenoperfused cardiac function using ex-vivo pig to human xenogeneic cardiac perfusion model. MATERIALS AND METHODS Harvested pig hearts were perfused with normal human whole blood (group 1), two different types of pre-treated human whole blood (group 2: immunoglobulins were depleted by plasmapheresis, group 3: pre-treated with plasmapheresis, GAS914, cobra venom factor (CVF) and steroid), and normal porcine whole blood as control (group 4) for 3 hours. RESULTS Duration of heart beat was significantly prolonged in group 2 and group 3. Histological examination showed widespread HAR features but was gradually delayed in groups 2 and 3 compared to group 1. The absolute levels of serum creatine kinase-MB and Troponin I increased gradually, and was lower in group 3. Serum hemoglobin levels were rapidly increased in groups 3 and 4, compared to group 1. Extracellular potassium level increased sharply from the beginning of blood perfusion in groups 1, 2 and 3, compared to group 4. CONCLUSION Pretreatment of human whole blood, including immunoglobulin depletion, CVF and steroid reduced and delayed the destruction of pig myocardium by HAR. However, the increased extracellular potassium levels in groups 1, 2 and 3 reflected that these treatments could not prohibit myocardial injury by HAR.
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Affiliation(s)
- Jun Seok Kim
- Department of Thoracic and Cardiovascular Surgery, School of Medicine, Konkuk University, Seoul, Korea
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Schmoeckel M. Xenotransplantation: die ewige Zukunft der Herztransplantation? ZEITSCHRIFT FUR HERZ THORAX UND GEFASSCHIRURGIE 2010. [DOI: 10.1007/s00398-009-0765-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Pierson RN. Antibody-mediated xenograft injury: mechanisms and protective strategies. Transpl Immunol 2009; 21:65-9. [PMID: 19376229 PMCID: PMC2695451 DOI: 10.1016/j.trim.2009.03.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Revised: 12/09/2008] [Accepted: 03/25/2009] [Indexed: 11/28/2022]
Abstract
The use of porcine organs for clinical transplantation is a promising potential solution to the shortage of human organs. Preformed anti-pig antibody is the primary cause of hyperacute rejection, while elicited antibody can contribute to subsequent "delayed" xenograft rejection. This article will review recent progress to overcome antibody mediated xenograft rejection, through modification of the host immunity and use of genetically engineered pig organs.
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Affiliation(s)
- Richard N Pierson
- Department of Surgery, University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD 21201, USA.
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Ekser B, Rigotti P, Gridelli B, Cooper DKC. Xenotransplantation of solid organs in the pig-to-primate model. Transpl Immunol 2008; 21:87-92. [PMID: 18955143 DOI: 10.1016/j.trim.2008.10.005] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2008] [Accepted: 10/09/2008] [Indexed: 12/12/2022]
Abstract
Xenotransplantation using pig organs could solve the significant increasing shortage of donor organs for allotransplantation. In the last two decades, major progress has been made in understanding the xenoimmunobiology of pig-to-nonhuman primate transplantation, and today we are close to clinical trials. The ability to genetically engineer pigs, such as human decay-accelerating factor (hDAF), CD46 (membrane cofactor protein), or alpha1,3-galactosyltransferase gene-knockout (GT-KO), has been a significant step toward the clinical application of xenotransplantation. Using GT-KO pigs and novel immunosuppressant agents, 2 to 6 months' survival of heterotopic heart xenotransplants has been achieved. In life-supporting kidney xenotransplantation, promising survival of close to 3 months has been achieved. However, liver and lung xenotransplantations do not have such encouraging survival as kidney and heart xenotransplantation. Although the introduction of hDAF and GT-KO pigs largely overcame hyperacute rejection, acute humoral xenograft rejection (AHXR) remains a challenge to be overcome if survival is to be increased. In several studies, when classical AHXR was prevented, thrombotic microangiopathy and coagulation dysregulation became more obvious, which make them another hurdle to be overcome. The initiating cause of failure of pig cardiac and renal xenografts may be antibody-mediated injury to the endothelium, leading to the development of microvascular thrombosis. Potential contributing factors toward the development of the thrombotic microangiopathy include: 1) the presence of preformed anti-non-Gal antibodies, 2) the development of very low levels of elicited antibodies to non-Gal antigens, 3) natural killer cell or macrophage activity, and 4) inherent coagulation dysregulation between pigs and primates. The breeding of pigs transgenic for an 'anticoagulant' or 'anti-thrombotic' gene, such as human tissue factor pathway inhibitor, hirudin, or CD39, or lacking the gene for the prothrombinase, fibrinogen-like protein-2, is anticipated to inhibit the change in the endothelium to a procoagulant state that takes place in the pig organ after transplantation. A further limitation for organ xenotransplantation is the potential for cross-species infection. As far as exogenous viruses are concerned, porcine cytomegalovirus has been detected in the tissues of recipient non-human primates, although no invasive disease was reported. Until today, no formal evidence has been presented from in vivo studies in non-human primates or from humans exposed to pig organs, tissues, or cells that porcine endogenous retroviruses infect primate cells. Xenotransplantation is a potential answer to the current organ shortage. Its future depends on; 1) further genetic modification of pigs, 2) the introduction of novel immunosuppressive agents that target the innate immune system and plasma cells, and 3) the development of clinically-applicable methods to induce donor-specific tolerance.
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Affiliation(s)
- Burcin Ekser
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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Affiliation(s)
- Amit Joshi
- The Howard P Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, NY 12180, USA
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17
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Reduced Fibrin Deposition and Intravascular Thrombosis in hDAF Transgenic Pig Hearts Perfused With Tirofiban. Transplantation 2007; 84:1667-76. [DOI: 10.1097/01.tp.0000295742.45413.dc] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Brandl U, Erhardt M, Michel S, Jöckle H, Burdorf L, Bittmann I, Rössle M, Mordstein V, Brenner P, Hammer C, Reichart B, Schmoeckel M. Soluble Galalpha(1,3)Gal conjugate combined with hDAF preserves morphology and improves function of cardiac xenografts. Xenotransplantation 2007; 14:323-32. [PMID: 17669174 DOI: 10.1111/j.1399-3089.2007.00410.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Cytotoxic anti-Galalpha(1,3)Gal antibodies play a key role in the rejection of pig organs transplanted into primates. Regimens reducing anti-Galalpha(1,3)Gal antibodies were associated with severe side effects unable to prevent antibody rebound until soluble synthetic oligosaccharides with terminal Galalpha(1,3)Gal inhibiting antigen binding became available. We displayed kinetics of anti-pig and anti-Galalpha(1,3)Gal IgM and IgG antibody levels using GAS914, a Galalpha(1,3)Gal trisaccharide conjugated to poly-l-lysine, and investigated corresponding changes of parameters of heart function. METHODS Using a working heart model, hDAF pig hearts were perfused with human blood containing GAS914 (group 1). As controls hDAF pig hearts (group 2) and landrace pig hearts (group 3) were perfused with human blood only. Levels of anti-Galalpha(1,3)Gal (IgM, IgG) and anti-pig antibodies were assessed to prove the effectiveness of GAS914. As parameters of heart function, cardiac output (CO), stroke work index (SWI), coronary blood flow (CBF) and coronary resistance were measured. Creatine phosphokinases, lactate dehydrogenase and aspartate aminotransferase were evaluated as markers of myocardial damage. Histological and immunohistochemical investigations were performed at the end of perfusion. RESULTS In group 1 an immediate and extensive reduction in both IgM and IgG anti-Galalpha(1,3)Gal was found. Anti-pig antibodies were eliminated accordingly. Antibody binding to GAS914 was complete before the start of organ perfusion. Corresponding to rapid antibody elimination in group 1 GAS914 not only was able to significantly prolong the beating time of the heart in hDAF pigs, but also to clearly improve functional parameters. When switching to the working heart mode hDAF pig hearts perfused with human blood containing GAS914 (group 1) revealed a CO starting at a significantly higher level than hDAF (group 2) and non-transgenic pig hearts (group 3) perfused with human blood only. Similarly, in group 1 SWI was significantly increased at the beginning of perfusion compared to that of group 2 and group 3. The increase in CBF during perfusion and the corresponding fall of coronary resistance occurred without significant differences between the groups revealing the independence of hDAF and GAS914. CONCLUSIONS Due to an immediate and profound reduction in Galalpha(1,3)Gal-specific antibodies, soluble Galalpha(1,3)Gal conjugates not only prolong survival, but also improve the hemodynamic performance of the heart in DAF pigs.
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Affiliation(s)
- Ulrike Brandl
- Department of Cardiac Surgery, Ludwig-Maximilians-University Munich, Munich, Germany.
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Bauer A, Baschnegger H, Renz V, Brandl U, Brenner P, Thein E, Reichart B, Schmoeckel M, Christ F. Comparison of propofol and isoflurane anesthesia in orthotopic pig-to-baboon cardiac xenotransplantation. Xenotransplantation 2007; 14:249-54. [PMID: 17489866 DOI: 10.1111/j.1399-3089.2007.00383.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Orthotopic pig-to-baboon xenogeneic heart transplantation (oXHTx) is the only accepted preclinical animal model for cardiac xenotransplantation. We compared the hemodynamic stability of a propofol- and isoflurane-based anesthetic regimen during oXHTx. METHODS Hearts from 12 hDAF or hCD46 transgenic pigs (Sus scrofa; body weight 7 to 32 kg) were transplanted into baboons (Papio anubis and Papio hamadryas; body weight 9 to 26 kg) in the orthotopic life-supporting position. Animals received a propofol-based intravenous regimen or inhalation anesthesia with isoflurane. Analgesia was achieved with fentanyl in both groups. Systemic hemodynamic variables were measured before, during and after cardiopulmonary bypass (CPB) and the need for inotropic or vasoactive pharmacological support was compared before and after CPB. RESULTS Global hemodynamic variables [i.e. heart rate, mean arterial pressure (MAP) and cardiac output] were not significantly different in propofol-anesthetized baboons compared to baboons anesthetized with isoflurane. Baboons anesthetized with isoflurane showed a trend towards less pharmacological support required to achieve an adequate MAP of >60 mmHg after CPB (propofol: epinephrine 0.13 [0.05; 0.16] and norepinephrine 0.15 [0.02; 0.16] microg/kg/min vs. isoflurane: epinephrine 0.05 [0.02; 0.08] and norepinephrine 0.06 [0.02; 0.19] microg/kg/min; no significant difference). CONCLUSIONS Propofol and isoflurane appear to provide equal hemodynamic stability in orthotopic cardiac pig-to-baboon xenotransplantation prior to the start of CPB. The trend of a reduced catecholamine support needed after CPB, however, suggests that isoflurane may be the preferred drug for maintenance of anesthesia in this primate model.
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Affiliation(s)
- Andreas Bauer
- Clinic for Anaesthesiology, Ludwig Maximilian University Munich, Munich, Germany.
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Brandl U, Michel S, Erhardt M, Brenner P, Burdorf L, Jöckle H, Bittmann I, Rössle M, Mordstein V, Baschnegger H, Bauer A, Hammer C, Reichart B, Schmoeckel M. Transgenic animals in experimental xenotransplantation models: orthotopic heart transplantation in the pig-to-baboon model. Transplant Proc 2007; 39:577-8. [PMID: 17362786 DOI: 10.1016/j.transproceed.2006.12.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Pig organs are at risk for hyperacute and acute vascular rejection mediated by anti-pig antibodies, mainly binding to the Galalpha(1,3)Gal epitope. Acute cellular rejection is characterized by progressive infiltration of mononuclear cells. There is an ongoing search for immunosuppressive regimens that provide adequate protection against all patterns of xenograft rejection, but have no severe impact on the condition of xenograft recipients. Herein orthotopic heart transplantations were performed from hDAF or hCD46 piglets to nonsplenectomized baboons. Basic immunosuppression consisted of tacrolimus, sirolimus, GAS914, steroids, and ATG. Group 1 received basic immunosuppression. Group 2 was additionally treated with rituximab and group 3 with half-dose cyclophosphamide. Group 4 received cyclophosphamide and an anti-HLA-DR antibody. Three baboons received GAS914 and TPC. Monitoring included the regular assessment of anti-porcine antibodies, blood counts, therapeutic drug monitoring, and graft histology. Two grafts failed due to technical mistakes. In group 1, baboons died after 1 and 9 days. In group 2, maximum survival was 30 hours. In group 3, baboons lived 20 hours, 25 days, and 14 days. Group 4 survival times were 9.5 hours, 5.5 hours, 4 days, 34 hours, and 3 days. An increase of non-Galalpha(1,3)Gal antibodies was observed. Depositions of immunoglobulins and complement revealed a humoral rejection process. No cellular infiltration could be observed. In conclusion, suppressing cellular rejection with half-dose cyclophosphamide together with tacrolimus and sirolimus produced longer graft survival with a good general condition. Prevention of acute xenograft rejection further needs inhibition of non-Galalpha(1,3)Gal cytotoxicity by sufficient depression of B-cell activation.
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Affiliation(s)
- U Brandl
- Department of Cardiac Surgery, Institute for Surgical Research, Clinic for Anaesthesiology, and the Institute for Pathology, Ludwig-Maximilians-University of Munich, Munich, Germany.
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Xenotransplantation of thoracic organs. Curr Opin Organ Transplant 2007. [DOI: 10.1097/mot.0b013e32809876fc] [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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Baumann BC, Stussi G, Huggel K, Rieben R, Seebach JD. Reactivity of human natural antibodies to endothelial cells from Galalpha(1,3)Gal-deficient pigs. Transplantation 2007; 83:193-201. [PMID: 17264816 DOI: 10.1097/01.tp.0000250478.00567.e5] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Xenoreactive human natural antibodies (NAb) are predominantly directed against galactose-alpha(1,3)galactose (Gal). Binding of immunoglobulin (Ig) G and IgM NAb activates porcine endothelial cells (pEC) and triggers complement lysis responsible for hyperacute xenograft rejection. In vitro, IgG NAb induce human natural killer (NK) cell-mediated lysis of pEC by antibody-dependent cell-mediated cytotoxicity (ADCC). The present study examined the levels of anti-porcine NAb in a large number of individuals and addressed the functional role of non-Gal anti-porcine NAb. METHODS Sera from 120 healthy human blood donors were analyzed for the presence of anti-porcine NAb by flow cytometry using porcine red blood cells (pRBC), lymphoblastoid cells (pLCL), and pEC derived from control or Gal-deficient pigs. Xenogeneic complement lysis was measured by flow cytometry using human serum and rabbit complement. ADCC was analyzed by chromium-release assays using human serum and freshly isolated NK cells. RESULTS Human IgM binding to pRBC was found in 93% and IgG binding in 86% of all samples. Non-Gal NAb comprised 13% of total IgM and 36% of total IgG binding to pEC. NAb/complement-induced lysis and ADCC of Gal-deficient compared to Gal-positive pEC were 21% and 29%, respectively. The majority of anti-Gal and non-Gal IgG NAb were of the IgG2 subclass. CONCLUSIONS The generation of Gal-deficient pigs has overcome hyperacute anti-Gal-mediated xenograft rejection in nonhuman primates. Non-Gal anti-porcine NAb represent a potentially relevant immunological hurdle in a subgroup of individuals by inducing endothelial damage in xenografts.
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Affiliation(s)
- Bettina C Baumann
- Department of Internal Medicine, Laboratory for Transplantation Immunology, University Hospital, Zurich, Switzerland
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Wu G, Pfeiffer S, Schröder C, Zhang T, Nguyen BN, Kelishadi S, Atkinson JB, Schuurman HJ, White DJG, Azimzadeh AM, Pierson RN. Coagulation cascade activation triggers early failure of pig hearts expressing human complement regulatory genes. Xenotransplantation 2007; 14:34-47. [PMID: 17214703 DOI: 10.1111/j.1399-3089.2006.00362.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Hyperacute rejection (HAR) and early graft failure (EGF) have been described in a minority of pig-to-baboon heart transplants using organs transgenic for human complement regulatory proteins (hCRP). Here we investigate the role of coagulation cascade activation in the pathogenesis of HAR and EGF in a consecutive series where a high incidence of these outcomes was observed. METHODS Twenty-eight naïve wild-caught Papio anubis baboons received heterotopic heart transplants from pigs transgenic for hDAF (n = 23) or hMCP (n = 5). Immunosuppression consisted of cyclosporine A, cyclophosphamide and MMF (n = 18) or anti-CD154 mAb (IDEC-131) and ATG (n = 10). Eleven received anti-Gal carbohydrates (GAS914, n = 8, or NEX1285, n = 3), of which four also underwent extracorporeal immunoadsorption (EIA), and 12 also received pharmacologic complement inhibitors (C1 INH, n = 9, or APT070, n = 3). RESULTS Excluding one technical failure, 14 of 27 transplants (11 hDAF, 3 hMCP) exhibited either HAR (n = 10) or EGF (n = 4). Surprisingly, neither complement inhibition (with C1 INH or APT070) nor anti-Gal antibody depletion with GAS914, NEX1285, or additional EIA consistently prevented HAR or EGF despite low or undetectable complement deposition. Strikingly, most grafts with HAR/EGF exhibited prominent fibrinogen and platelet deposition associated with systemic coagulation cascade activation, consistent with non-physiologic intravascular coagulation, in many instances despite little evidence for antibody-mediated complement activation. CONCLUSION We conclude that dysregulated coagulation correlates closely with and probably causes primary failure of pig hearts transgenic for hCRP. These data support efforts to define effective strategies to prevent dysregulated coagulation in pig organ xenografts.
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Affiliation(s)
- Guosheng Wu
- Baltimore VAMC, University of Maryland, Baltimore, MD, USA
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Wiebe K, Oezkur M, Pöling J, Haverich A. Potential of an Injectable Polymer to Prevent Hyperacute Rejection of Ex Vivo Perfused Porcine Lungs. Transplantation 2006; 82:681-8. [PMID: 16969293 DOI: 10.1097/01.tp.0000234819.18069.53] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Removal of xenoreactive antibodies in pig-to-human lung transplantation by columns or organ perfusions proofed to be unsatisfactory and associated with adverse effects. In an ex-vivo lung perfusion model, we evaluated the potential of a soluble trisaccharide polymer (GAS914) to bind alpha-Gal antibodies and to protect a pulmonary xenograft from hyperacute rejection (HAR) and pulmonary xenograft dysfunction. METHODS Porcine lungs were perfused with fresh human blood for 240 min. In the GAS914 treated group (n=6) the polymer was applied in three different concentrations. The control group (n=6) received no GAS914. Survival and function of perfused xenografts were monitored, and alpha-Gal antibodies as well as cytolytic anti-porcine antibodies analyzed. RESULTS In the GAS-treated group survival of lungs was significantly prolonged, pulmonary vascular resistance reduced, pulmonary edema prevented, and oxygenation improved. On histopathological evaluation application of GAS resulted in minimal graft injury and significantly less deposition of the terminal complement complex C5b-9. Following application of GAS914, up to 89.8% of IgG alpha-Gal, 79.5% of IgM and 73.6% of anti-porcine antibodies in the human blood were bound by the polymer. Subsequent perfusion of porcine lungs resulted in absorption of only 3% of the baseline IgG alpha-Gal antibodies in the GAS914 group, compared to 87% in the controls. CONCLUSIONS In this ex-vivo lung perfusion model, a trisaccharide polymer prevented immediate HAR, due to effective removal of alpha-Gal antibodies. In combination with additional strategies GAS914 may be a valuable tool in overcoming HAR and dysfunction of pulmonary xenografts.
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Affiliation(s)
- Karsten Wiebe
- Division of Thoracic and Cardiovascular Surgery, Hannover Medical School, Hannover, Germany.
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Brandl U, Erhardt M, Jöckle H, Michel S, Thein E, Bittmann I, Brenner P, Burdorf L, Hammer C, Schmoeckel M, Reichart B. Fluorescent microspheres reveal different regional blood flow in hyperacutely rejected nontransgenic and hDAF pig hearts. Transplant Proc 2006; 38:733-4. [PMID: 16647457 DOI: 10.1016/j.transproceed.2006.01.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Classic features of hyperacute rejection show differential severity in the inner compared to the outer myocardium. In the present study, regional blood flow (RBF) measured by fluorescent microspheres served as a marker of the extent of hyperacute rejection. Using a working heart model, hearts of nontransgenic and hDAF transgenic pigs were perfused with human blood. Additionally, hDAF transgenic pig hearts were perfused with human blood containing GAS914 or the GPIIb/IIIa inhibitor tirofiban. Injections of fluorescent microspheres into the donor heart were performed in situ and during perfusion. Reference arterial blood samples were collected from the inferior aorta and the afterload line. Perfusion was terminated before hyperacutely rejected hearts failed to pump against the afterload column. RBF was determined in tissue samples of standardized areas of the left atrium and ventricle. Each specimen was divided into subepicardial and subendocardial tissue samples. Fluorescence intensity was measured using an automated luminescence spectrometer. At the end of perfusion with human blood, hyperacutely rejected nontransgenic pig hearts showed a higher RBF in the subendocardium. In hDAF-transgenic pig hearts perfused with unmodified human blood the subendocardial/subepicardial blood flow ratio changed in favor of the subepicardium. This ratio was not further improved by GAS914. In contrast, tirofiban was able to assimilate subepicardial and subendocardial blood flow. In conclusion, RBF of hyperacutely rejected pig hearts was inhomogeneous. Inhibition of complement activation improved the reduced subepicardial RBF, but depletion of antibodies had no positive effect. The ability of tirofiban to further increase subepicardial RBF affirms thrombosis of subepicardial veins as the defining characteristic of hyperacute rejection.
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Affiliation(s)
- U Brandl
- Department of Cardiac Surgery, Institute for Surgical Research, and Institute for Pathology, Ludwig Maximilians University of Munich, Munich, Germany.
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Histopathology of discordant xenotransplantation. Curr Opin Organ Transplant 2006. [DOI: 10.1097/01.mot.0000218931.19773.f7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Rood PPM, Rood PPM, Hara H, Busch JL, Ezzelarab M, Zhu X, Ball S, Ayares D, Awwad M, Cooper DKC. Incidence and cytotoxicity of antibodies in cynomolgus monkeys directed to nonGal antigens, and their relevance for experimental models. Transpl Int 2006; 19:158-65. [PMID: 16441365 DOI: 10.1111/j.1432-2277.2005.00252.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The recent availability of pigs homozygous for alpha1,3-galactosyltransferase gene-knockout (GT-KO) has enabled the study of incidence and cytotoxicity of antibodies of cynomolgus monkeys directed to antigens other than Galalpha1,3Gal (Gal), termed nonGal antigens. To this aim, sera from 21 cynomolgus monkeys were tested by flow cytometry for binding of IgM and IgG to peripheral blood mononuclear cells (PBMC) from wild-type (WT) and GT-KO pigs. The sera were also tested for complement-dependent cytotoxicity to WT and GT-KO PBMC. Anti-WT IgM and IgG were found in 100% and 95%, respectively, and anti-GT-KO IgM and IgG in 76% and 66%, respectively, in the sera of the monkeys tested (P < 0.01). Whereas 100% of sera were cytotoxic to WT PBMC, only 76% were cytotoxic to GT-KO PBMC, and the level of cytotoxicity was significantly less (P < 0.01). Although the incidence and cytotoxicity of antibodies in monkey sera to GT-KO pig PBMC are significantly less than to WT PBMC, approximately three-quarters of the monkeys tested had cytotoxic antibodies to GT-KO PBMC. This incidence of cytotoxicity is significantly higher than that found in baboons and humans, suggesting the baboon may be an easier and possibly more suitable model to study antibody-mediated rejection of transplanted GT-KO pig organs and cells.
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Affiliation(s)
- Pleunie P M Rood
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA
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Bauer A, Baschnegger H, Abicht JM, Brandl U, Brenner P, Thein E, Hammer C, Reichart B, Peter K, Schmoeckel M, Christ F. hDAF porcine cardiac xenograft maintains cardiac output after orthotopic transplantation into baboon - a perioperative study. Xenotransplantation 2005; 12:444-9. [PMID: 16202067 DOI: 10.1111/j.1399-3089.2005.00242.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Only limited data are available on the physiological functional compatibility of cardiac xenografts after orthotopic pig to baboon transplantation (oXHTx). Thus we investigated hemodynamic parameters including cardiac output (CO) before and after oXHTx. METHODS Orthotopic xenogeneic heart transplantation from nine hDAF transgeneic piglets to baboons was performed. We used femoral arterial thermodilution for the invasive assessment of CO and stroke volume. RESULTS Baseline CO of the baboons after induction of anesthesia was 1.36 (1.0-1.9) l/min. 30 to 60 min after termination of the cardiopulmonary bypass, CO of the cardiac xenograft was significantly increased to 1.72 (1.3-2.1) l/min (P < 0.01). The stroke volumes of the baboon heart before transplantation and the cardiac xenograft was comparable [14.9 (11-26) vs. 11.8 (10-23) ml]. Thus the higher CO was achieved by an increase in heart rate after oXHTx [75.0 (69-110) vs. 140.0 (77-180)/min; P < 0.01]. Despite the increased CO, oxygen delivery was reduced [256 (251-354) vs. 227 (172-477) ml/min; P < 0.01] due to the inevitable hemodilution during the cardiopulmonary bypass and the blood loss caused by the surgical procedures. CONCLUSION Our results demonstrate that in the early phase after orthotopic transplantation of hDAF pig hearts to baboons, cardiac function of the donor heart is maintained and exceeds baseline CO. However, in the early intraoperative phase this was only possible by using inotropic substances and vasopressors due to the inevitable blood loss and dilution by the priming of the bypass circuit.
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Affiliation(s)
- Andreas Bauer
- Clinic for Anaesthesiology, Ludwig-Maximilians University Munich, Munich, Germany
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Baertschiger RM, Buhler LH. Xenotransplantation literature update March-April, 2005. Xenotransplantation 2005; 12:333-7. [PMID: 15943784 DOI: 10.1111/j.1399-3089.2005.00238.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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