1
|
Abstract
PURPOSE OF REVIEW Although numerous experimental models to induce allograft tolerance have been reported, it has been difficult to translate these basic studies to clinical transplantation. However, successful induction of tolerance in HLA-mismatched kidney transplantation has recently been reported. In this review, recent progress in tolerance induction in preclinical (nonhuman primates) and clinical transplantation is summarized. RECENT FINDINGS Among many clinical trials to induce renal allograft tolerance, success has so far been achieved only by combining donor bone marrow with organ transplantation. Induction of renal allograft tolerance by transient or durable mixed chimerism has been reported in HLA-matched or mismatched kidney transplant recipients. More recently, renal allograft tolerance by induction of full donor chimerism has also been reported using a more intensified preparative conditioning regimen. SUMMARY Durable allograft tolerance has been achieved by induction of hematopoietic chimerism in clinical kidney transplantation, with outstanding long-term results in successful cases. However, these approaches have been associated with higher early complications than are seen following transplantation with conventional immunosuppression. Improvements in the consistency and safety of tolerance induction and extension of successful protocols to other organs will be the next steps in bringing tolerance to a wider range of clinical applications.
Collapse
|
2
|
Kawai T, Benedict Cosimi A. Induction of tolerance in clinical kidney transplantation. Clin Transplant 2010; 24 Suppl 22:2-5. [PMID: 20590685 DOI: 10.1111/j.1399-0012.2010.01268.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Induction of donor-specific tolerance has been an ultimate goal in organ transplantation. Although numerous regimens for the induction of allograft tolerance have been developed in rodents, their application to primates has been limited. The approaches that have been successfully applied in primates can be divided into (i) use of total lymphoid irradiation, (ii) costimulatory blockade, (iii) profound depletion of recipient T cells, (iv) infusion of regulatory cells and (v) donor bone marrow (DBM) infusion/transplantation. Among these approaches, successful allograft tolerance has been achieved in clinical kidney transplantation using DBM transplantation.
Collapse
Affiliation(s)
- Tatsuo Kawai
- Massachusetts General Hospital, Transplant Center, Harvard Medical School, Boston, MA, USA.
| | | |
Collapse
|
3
|
Donor bone marrow transplantation as an approach to tolerance induction for clinical kidney transplantation. Curr Opin Organ Transplant 2007. [DOI: 10.1097/mot.0b013e3282f1fc01] [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]
|
4
|
Hale DA, Dhanireddy K, Bruno D, Kirk AD. Induction of transplantation tolerance in non-human primate preclinical models. Philos Trans R Soc Lond B Biol Sci 2006; 360:1723-37. [PMID: 16147537 PMCID: PMC1569541 DOI: 10.1098/rstb.2005.1703] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Short-term outcomes following organ transplantation have improved considerably since the availability of cyclosporine ushered in the modern era of immunosuppression. In spite of this, many of the current limitations to progress in the field are directly related to the existing practice of relatively non-specific immunosuppression. These include increased risks of opportunistic infection and cancer, and toxicity associated with long-term immunosuppressive drug exposure. In addition, long-term graft loss continues to result in part from a failure to adequately control the anti-donor immune response. The development of a safe and reliable means of inducing tolerance would ameliorate these issues and improve the lives of transplant recipients, yet given the improving clinical standard of care, the translation of new therapies has become appropriately more cautious and dependent on increasingly predictive preclinical models. While convenient and easy to use, rodent tolerance models have not to date been reliably capable of predicting a therapy's potential efficacy in humans. Non-human primates possess an immune system that more closely approximates that found in humans, and have served as a more rigorous preclinical testing ground for novel therapies. Prior to clinical adaptation therefore, tolerance regimens should be vetted in non-human primates to ensure that there is sufficient potential for efficacy to justify the risk of its application.
Collapse
Affiliation(s)
- Douglas A Hale
- Digestive and Kidney Diseases, National Institute of Diabetes, NIH, Transplantation Branch, Bethesda, MD 20892, USA.
| | | | | | | |
Collapse
|
5
|
Quatra F, Lowenberg DW, Buncke HJ, Romeo OM, Brooks D, Buntic RF, Baxter-Lowe LA. Induction of tolerance to composite tissue allograft in a rat model. Microsurgery 2006; 26:573-8. [PMID: 17091475 DOI: 10.1002/micr.20297] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The goal of this study was to establish a rat model that can be used to determine the variables in influencing induction of tolerance to composite tissue allografts. An anti T-cell depleting agent (R73) and 15-deoxyspergualin were given in different doses and schedule to four groups of Lewis rats receiving a limb transplant from Brown-Norway donors. Graft survival prolongation was maximal combining a single dose of R73 and a 20-day administration of 15-deoxyspergualin. Long-term survivors accepted a skin graft from Brown-Norway donors at 80 days, but rejected grafts from an unrelated donor. Skin grafting did not influence survival of the transplanted limb. Mixed allogeneic chimerism was not detectable in peripheral blood by flow cytometry, but immunohistochemistry identified donor-derived cells in the thymus of tolerant recipients at 100 days. These results suggest a state of donor-specific, dynamic tolerance, with potential for future application in human composite tissue allotransplantation.
Collapse
Affiliation(s)
- Fabio Quatra
- The Buncke Clinic and the H.J. Buncke Microsurgical Laboratory, Department of Orthopaedic Surgery, California Pacific Medical Center, University of California, San Francisco, CA, USA
| | | | | | | | | | | | | |
Collapse
|
6
|
Abstract
Significant advances have been made in the understanding of allograft rejection. There is growing awareness that allograft acceptance, or tolerance, is also an active process rather than a passive absence of rejection. Mechanistic awareness of this process has spawned many preclinical strategies for the prevention of allograft rejection without the need for chronic immunosuppression. These therapies are currently entering clinical trials. This article reviews the prevailing therapies that hold promise for future clinical application. In particular, their application in children is discussed, as are biologic aspects of childhood immunity that may play a role in the success or failure of these strategies.
Collapse
Affiliation(s)
- Jonathan P Pearl
- Department of Surgery, National Naval Medical Center, 8901 Wisconsin Avenue, Bethesda, MD 20889-5600, USA
| | | | | |
Collapse
|
7
|
Yamada K, Vagefi PA, Utsugi R, Kitamura H, Barth RN, LaMattina JC, Sachs DH. Thymic transplantation in miniature swine: III. Induction of tolerance by transplantation of composite thymokidneys across fully major histocompatibility complex-mismatched barriers. Transplantation 2003; 76:530-6. [PMID: 12923439 DOI: 10.1097/01.tp.0000080608.42480.e8] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND This study determines whether composite thymokidney (TK) grafts, created by implantation of autologous thymic tissue beneath the donor's renal capsule before transplantation, could induce allogeneic transplantation tolerance across two-haplotype fully major histocompatibility complex (MHC)- mismatched barriers in juvenile MGH-miniature swine. METHODS TK grafts were prepared by implanting autologous thymic tissue under the renal capsule of donor animals 2 to 3 months before transplantation. Four recipients were treated with a T-cell-depleting immunotoxin and received fully MHC-mismatched TK grafts plus a 12-day course of cyclosporine A (CsA). Control animals were treated with CsA alone or both CsA and immunotoxin, but with a normal kidney or a kidney implanted with autologous lymph node rather than thymus. Renal graft function was assessed by plasma creatinine levels and histologic analyses. Immunologic status was monitored by cell-mediated lympholysis assays. RESULTS All four recipients of fully MHC-mismatched TK transplants treated with immunotoxin and a 12-day course of CsA accepted their composite renal allografts long-term. All control recipients receiving a TK and CsA alone, a normal kidney or a composite kidney containing lymph node tissue acutely rejected their grafts. CONCLUSIONS To our knowledge, this is the first demonstration that functional vascularized thymic grafts can induce transplantation tolerance across fully MHC-mismatched barriers in a large animal model.
Collapse
Affiliation(s)
- Kazuhiko Yamada
- Transplantation Biology Research Center, Massachusetts General Hospital, Boston, Massachusetts 02129, USA
| | | | | | | | | | | | | |
Collapse
|
8
|
Abstract
The decision to perform a human hand transplant was justified perhaps on less than an ideal scientific basis-only approximately 60 rat limb transplants and 2 primate limb transplants have survived for longer than 200 days and only 8 of 19 pig limb osteomyocutaneous transplants showed no signs of rejection at 90 days. It seems unlikely that the survival of a human hand transplant will be any better than the survival of a kidney transplant, which has a half-life of approximately 7.5 to 9.5 years. Fourteen hand transplants, however, have now been performed in 11 humans with the skin component of 1 remaining viable up to 3 years after surgery. Intermittent episodes of acute rejection seem to have been relatively simple to reverse by temporarily increasing the dose of immunosuppressive agents and steroids. Chronic rejection has occurred in 1 patient, necessitating re-amputation of the transplanted hand. Active range of motion of the digits has been surprisingly better than would have been expected based on previous results of replantation, but return of sensibility has been less than optimal. The immunosuppression has been well tolerated without any major medical problems or life-threatening episodes, but some patients have developed chronic viral and fungal infections and several have developed posttransplant diabetes. Extrapolating from the previous experience of solid-organ transplants, chronic immunosuppression may predispose a hand transplant patient to an 80% chance of developing an infection, a 20% potential risk of developing posttransplant diabetes, and a 4% to 18% potential risk of developing a malignancy. Even though there is universal agreement that composite tissue allograft transplantation will become the ultimate reconstructive option, no one can predict the eventual role of hand transplantation in the future, but perhaps an international database of these hand transplant patients should be established so that independent reviewers can more objectively evaluate their functional outcome, the incidence of chronic rejection, and the risks of long-term immunosuppression.
Collapse
Affiliation(s)
- Neil F Jones
- UCLA Hand Center, Department of Orthopaedic Surgery and Division of Plastic and Reconstructive Surgery, University of California, Los Angeles, CA 90095, USA
| |
Collapse
|
9
|
Myckatyn TM, Ellis RA, Grand AG, Sen SK, Lowe JB, Hunter DA, Mackinnon SE. The effects of rapamycin in murine peripheral nerve isografts and allografts. Plast Reconstr Surg 2002; 109:2405-17. [PMID: 12045568 DOI: 10.1097/00006534-200206000-00035] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The FKBP-12-binding ligand FK506 has been successfully used to stimulate nerve regeneration and prevent the rejection of peripheral nerve allografts. The immunosuppressant rapamycin, another FKBP-12-binding ligand, stimulates axonal regeneration in vitro, but its influence on nerve regeneration in peripheral nerve isografts or allografts has not been studied. Sixty female inbred BALB/cJ mice were randomized into six tibial nerve transplant groups, including three isograft and three allograft (C57BL/6J) groups. Grafts were left untreated (groups I and II), treated with FK506 (groups III and IV), or treated with rapamycin (groups V and VI). Nerve regeneration was quantified in terms of histomorphometry and functional recovery, and immunosuppression was confirmed with mixed lymphocyte reactivity assays. Animals treated with FK506 and rapamycin were immunosuppressed and demonstrated significantly less immune cell proliferation relative to untreated recipient animals. Although every animal demonstrated some functional recovery during the study, animals receiving an untreated peripheral nerve allograft were slowest to recover. Isografts treated with FK506 but not rapamycin demonstrated significantly increased nerve regeneration. Nerve allografts in animals treated with FK506, and to a lesser extent rapamycin, however, both demonstrated significantly more nerve regeneration and increased nerve fiber widths relative to untreated controls. The authors suggest that rapamycin can facilitate regeneration through peripheral nerve allografts, but it is not a neuroregenerative agent in this in vivo model. Nerve regeneration in FK506-treated peripheral nerve isografts and allografts was superior to that found in rapamycin-treated animals. Rapamycin may have a role in the treatment of peripheral nerve allografts when used in combination with other medications, or in the setting of renal failure that often precludes the use of calcineurin inhibitors such as FK506.
Collapse
Affiliation(s)
- Terence M Myckatyn
- Division of Plastic and Reconstructive Surgery, Washington University School of Medicine, One Barnes-Jewish Hospital Plaza, East Pavilion, St. Louis, MO 63110, USA
| | | | | | | | | | | | | |
Collapse
|
10
|
Pascual M, Theruvath T, Kawai T, Tolkoff-Rubin N, Cosimi AB. Strategies to improve long-term outcomes after renal transplantation. N Engl J Med 2002; 346:580-90. [PMID: 11856798 DOI: 10.1056/nejmra011295] [Citation(s) in RCA: 622] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Manuel Pascual
- Renal Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
| | | | | | | | | |
Collapse
|
11
|
Tolerance to Limb Tissue Allografts between Swine Matched for Major Histocompatibility Complex Antigens. Plast Reconstr Surg 2001. [DOI: 10.1097/00006534-200105000-00028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
12
|
|
13
|
Affiliation(s)
- R L Schmouder
- Department of Clinical Pharmacology, Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, USA
| |
Collapse
|
14
|
Abstract
Although studies of tolerance induction in large animals remain limited compared with murine studies, a number of encouraging observations have been recently reported - especially in nonhuman primate models. The development of antibodies or proteins binding to costimulatory molecules and of an immunotoxin that is active on T cells have been particularly important advances leading to expanded opportunities for extending strategies for tolerance induction to large animals.
Collapse
Affiliation(s)
- T Kawai
- Massachusetts General Hospital, Room White 510, Department of Surgery, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA.
| | | | | |
Collapse
|