Xenotransplantation (Xenotransplantation)

Publisher: International Xenotransplantation Association, Wiley

Journal description

Xenotransplantation which is published quarterly will provide its readership with rapid communication of new findings in the field of organ and tissue transplantation across species barriers. Unsolicited contributions of full length and brief communications dealing with both basic and applied studies in this field will be considered for publication pending scientific review to assure high quality. In addition review articles of timely subjects will be solicited by the editors.

Current impact factor: 2.84

Impact Factor Rankings

2015 Impact Factor Available summer 2016
2014 Impact Factor 2.84
2013 Impact Factor 1.779
2012 Impact Factor 2.565
2011 Impact Factor 2.326
2010 Impact Factor 2.067
2009 Impact Factor 2.711
2008 Impact Factor 2.288
2007 Impact Factor 2.588
2006 Impact Factor 1.777
2005 Impact Factor 2.114
2004 Impact Factor 2.876
2003 Impact Factor 2.437
2002 Impact Factor 2.581
2001 Impact Factor 2.079
2000 Impact Factor 3.268
1999 Impact Factor 2.904
1998 Impact Factor 3.671

Impact factor over time

Impact factor

Additional details

5-year impact 2.61
Cited half-life 6.10
Immediacy index 0.79
Eigenfactor 0.00
Article influence 0.53
Website Xenotransplantation website
Other titles Xenotransplantation (Online)
ISSN 1399-3089
OCLC 44974358
Material type Document, Periodical, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details


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    • On author's personal website, institutional repositories, arXiv, AgEcon, PhilPapers, PubMed Central, RePEc or Social Science Research Network
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    • Non-Commercial
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    • Must link to publisher version with set statement (see policy)
    • If OnlineOpen is available, BBSRC, EPSRC, MRC, NERC and STFC authors, may self-archive after 12 months
    • If OnlineOpen is available, AHRC and ESRC authors, may self-archive after 24 months
    • Publisher last contacted on 07/08/2014
    • This policy is an exception to the default policies of 'Wiley'
  • Classification

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: As a step towards clinical cardiac xenotransplantation, our experimental heterotopic intrathoracic xenotransplantation model offers a beating and ejecting donor heart while retaining the recipient's native organ as a backup in case of graft failure. Clinically applicable immunosuppressive regimens (IS) were investigated first, then treatments known to be effective in hypersensitized patients or those with recalcitrant rejection reactions. Methods: Consecutive experiments were carried out between 2009 and 2013. Twenty-one genetically modified pigs (GGTA1-knockout/hCD46/± thrombomodulin, in one case HLA-E instead) were used as donors. In all experiments, two cycles of immunoabsorption reduced preformed antibodies. Recipient baboons were divided into two groups according to IS regimen: In group one (n = 10), pre-treatment started either one (anti-CD20) or four weeks (anti-CD20 plus the proteasome inhibitor bortezomib) prior to transplantation. The extended conventional (as for allotransplantation) immunosuppressive maintenance regimen included anti-thymocyte globuline, tacrolimus, mycophenolate mofetil, methylprednisolone and weekly anti-CD20. In group two (n = 11), myeloablative pre-treatment as in multiple myeloma patients (long and short regimens) was added to extended conventional IS; postoperative total thoracic and abdominal lymphoid irradiation (TLI; single dose of 600 cGY) was used to further reduce antibody-producing cells. Results: In the perioperative course, the surgical technique was safely applied: 19 baboons were weaned off extracorporeal circulation and 17 extubated. Nine animals were lost in the early postoperative course due to causes unrelated to surgical technique or IS regimen. Excluding these early failures, median graft survival times of group 1 and 2 were 18.5 (12-50) days and 16 (7-35) days. Necropsy examination of group 1 donor organs revealed hypertrophy of the left ventricular wall in the six longer-lasting grafts; myocardial histology confirmed pre-clinical suspicion of humoral rejection, which was not inhibited by the extended conventional IS including intensified treatments, and signs of thrombotic microangiopathy. Grafts of group 2 presented with only mild-to-moderate features of humoral rejection and thrombotic microangiopathy, except in one case of delayed rejection on day 17. The other experiments in this group were terminated because of untreatable pulmonary oedema, recurring ventricular fibrillation, Aspergillus sepsis, as well as a combination of a large donor organ and late toxic side effects due to TLI. Conclusions: Longer-term results were difficult to achieve in this model due to the IS regimens used. However, we conclude that heterotopic intrathoracic heart transplantation may be an option for clinical xenotransplantation.
    Xenotransplantation 11/2015; DOI:10.1111/xen.12213
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    ABSTRACT: Introduction: Research into the transplantation of solid organs from animals (xenotransplantation) is generating interest and curiosity given that this could be a way of resolving the shortage in transplant organs. However, the fact is that currently xenotransplantation is far from becoming a clinical practice. Objective: To analyse the attitude of medical students from Spanish universities towards the donation of organs from animals and to determine the factors affecting their attitudes. Material and methods: Type of study: A sociological, interdisciplinary, observational and multicentre study in Spain. Study population: Students enrolled on the medical degree in Spain (n = 34 000). Sample size: A sample of 9598 students (a confidence level of 99% and precision of ± 1%) stratified by geographical area and academic year. Instrument of measurement: A validated questionnaire of attitude towards organ xenotransplantation (PCID-XenoTx RIOS) which was self-administered and completed anonymously. Results: A completion rate of 95.7% (n = 9275) was obtained. If the results of xenotransplantation were as good as in human donation, 81% (n = 7491) would be in favour, 3% (n = 308) against and 16% (n = 1476) undecided. The following variables affected this attitude: sex (P < 0.001); academic year (P < 0.001); discussion of transplantation with one's family (P < 0.001) and friends (P < 0.001); the opinion of one's partner (P < 0.001); the respondent's attitude towards organ donation (P < 0.001); religion (P < 0.001); and participation in altruistic activities (P < 0.001). The following variables persisted in the multivariate analysis: (1) being a female (OR = 1.794; P < 0.001); (2) academic year (OR = 2.487; P < 0.001); (3) having spoken about the issue with one's family (OR = 1.200; P = 0.019); (4) the favourable opinion of one's partner (OR = 1.526; P = 0.028); (5) an attitude in favour of donation (OR = 2.087; P < 0.001); (6) being an atheist/agnostic, (OR = 2.5; P < 0.001); and (7) a belief that one's religion is in favour of transplantation (OR = 1.317; P = 0.005). Conclusions: Spanish medical students have a favourable attitude towards xenotransplantation. This willingness and interest could be a decisive platform for the development and strengthening of research, both for centres with a pre-clinical xenotransplantation programme and new healthcare centres.
    Xenotransplantation 11/2015; DOI:10.1111/xen.12208

  • Xenotransplantation 11/2015; DOI:10.1111/xen.12210

  • Xenotransplantation 11/2015; 22(S1).

  • Xenotransplantation 11/2015; 22(S1). DOI:10.1111/xen.12205
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Survival of vascularized xenografts is dependent on pre-emptive inhibition of the xenoantibody response against galactosyltransferase knockout (GTKO) porcine organs. Our analysis in multiple GTKO pig-to-primate models of xenotransplantation has demonstrated that the anti-non-gal-α-1,3-gal (anti-non-Gal) xenoantibody response displays limited structural diversity. This allowed our group to identify an experimental compound which selectively inhibited induced anti-non-Gal IgM xenoantibodies. However, because this compound had an unknown safety profile, we extended this line of research to include screening small molecules with known safety profiles allowing rapid advancement to large animal models. Methods: The NIH clinical collections of small molecules were screened by ELISA for their ability to inhibit xenoantibody binding to GTKO pig endothelial cells. Serum collected from non-immunosuppressed rhesus monkeys at day 14 post-injection with GTKO pig endothelial cells was utilized as a source of elicited xenoantibody for initial screening. Virtual small molecule screening based on xenoantibody structure was used to assess the likelihood that the identified small molecules bound xenoantibody directly. As a proxy for selectivity, ELISAs against tetanus toxoid and the natural antigens laminin, thyroglobulin, and single-stranded DNA (ssDNA) were utilized to assess the ability of the identified reagents to inhibit additional antibody responses. The identified inhibitory small molecules were further tested for their ability to inhibit xenoantibody elicited in multiple settings, including rhesus monkeys pre-treated with an anti-non-Gal selective anti-idiotypic antibody, non-immunosuppressed rhesus monkeys immunized with wild-type fetal pig isletlike cell clusters, and non-immunosuppressed baboons transplanted with GTKO multiple transgenic pig kidneys. Results: Four clinically relevant small molecules inhibited anti-non-Gal IgM binding to GTKO pig endothelial cells in vitro. Three of these drugs displayed a limited region of structural similarity suggesting they may inhibit xenoantibody by a similar mechanism. One of these, the anti-hypertensive agent clonidine, displayed only minimal inhibition of antibodies elicited by vaccination against tetanus toxoid or pre-existing natural antibodies against laminin, thyroglobulin, or ssDNA. Furthermore, clonidine inhibited elicited anti-non-Gal IgM from all animals that demonstrated a xenoantibody response in each experimental setting. Conclusions: Clinically relevant small molecule drugs with known safety profiles can inhibit xenoantibody elicited against non-Gal antigens in diverse experimental xenotransplantation settings. These molecules are ready to be tested in large animal models. However, it will first be necessary to optimize the timing and dosing required to inhibit xenoantibodies in vivo.
    Xenotransplantation 10/2015; DOI:10.1111/xen.12199
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    ABSTRACT: Background: Rejection of Gal-free (GTKO) donor pig cardiac xenografts is strongly associated with vascular non-Gal antibody binding, endothelial cell (EC) injury, and activation and microvascular thrombosis. We adopted a pig-to-SCID/beige small animal transplant model to compare the pathogenicity of baboon and human anti-pig antibody. Methods: Wild-type (GT(+) ) or GTKO porcine coronary arteries (PCAs) were transplanted into the infrarenal aorta of SCID/beige mice. Three days after transplant, recipients were infused with anti-pig antibody (anti-SLA class I, an isotype control, naive or sensitized baboon serum, or naive human serum). PCAs were recovered 24 h after antibody infusion and examined using histology, immunohistochemistry, and in situ hybridization. Results: Dose-dependent intragraft thrombosis occurred after infusion of anti-SLA I antibody (but not isotype control) in GT(+) and GTKO PCA recipients. Naive baboon serum induced thrombosis in GT(+) grafts. Thrombosis was significantly reduced by pre-treating naive baboon serum with Gal polymer and not observed when this serum was infused to GTKO PCA recipients. Naive human serum caused dose-dependent intragraft thrombosis of GTKO PCAs. In all cases, thrombosis involved graft-specific vascular antibody and complement deposition, macrophage adherence, EC delamination, and subendothelial thrombus formation. Conclusions: This study provides the first direct in vivo comparison of the pathogenicity of naive human and baboon serum. The results suggest that human preformed non-Gal antibody may have increased pathogenicity compared to baboon. This model, which showed a rejected graft histopathology similar to antibody-mediated rejection in cardiac xenotransplantation, may be useful to assess the pathogenicity of individual protein or carbohydrate specific non-Gal reactive antibodies.
    Xenotransplantation 10/2015; DOI:10.1111/xen.12198
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    ABSTRACT: Background: Intraportal infusion is currently the method of choice for clinical islet cell transplantation but suffers from poor efficacy. As the liver may not represent an optimal transplantation site for Langerhans islets, we examined the potential of neonatal porcine islet-like clusters (NPICCs) to engraft in skeletal muscle as an alternative transplantation site. Methods: Neonatal porcine islet-like clusters were isolated from 2- to 5-day-old piglets and either transplanted under the kidney capsule (s.k.) or injected into the lower hindlimb muscle (i.m.) of streptozotocin-diabetic NOD-SCID IL2rγ(-/-) (NSG) mice. Survival, vascularization, maturation, and functional activity were analyzed by intraperitoneal glucose tolerance testing and immunohistochemical analyses. Results: Intramuscular transplantation of NPICCs resulted in development of normoglycemia and restored glucose homeostasis. Time to reversal of diabetes and glucose tolerance (AUC glucose and AUC insulin) did not significantly differ as compared to s.k. transplantation. Intramuscular grafts exhibited rapid neovascularization and graft composition with cytokeratin-positive ductal cells and beta cells at post-transplant weeks 2 and 8 and after establishment of normoglycemia was comparable in both groups. Conclusions: Intramuscular injection represents a minimally invasive but efficient alternative for transplantation of NPICCs and, thus, offers an attractive alternative site for xenotransplantation approaches. These findings may have important implications for improving the outcome and the monitoring of pig islet xenotransplantation.
    Xenotransplantation 10/2015; DOI:10.1111/xen.12201

  • Xenotransplantation 10/2015; 22(S1).
  • [Show abstract] [Hide abstract]
    ABSTRACT: The development of the Edmonton Protocol encouraged a great deal of optimism that a cell-based cure for type I diabetes could be achieved. However, donor organ shortages prevent islet transplantation from being a widespread solution as the supply cannot possibly equal the demand. Porcine islet xenotransplantation has the potential to address these shortages, and recent preclinical and clinical trials show promising scientific support. Consequently, it is important to consider whether the current science meets the ethical requirements for moving toward clinical trials. Despite the potential risks and the scientific unknowns that remain to be investigated, there is optimism regarding the xenotransplantation of some types of tissue, and enough evidence has been gathered to ethically justify clinical trials for the most safe and advanced area of research, porcine islet transplantation. Researchers must make a concerted effort to maintain a positive image for xenotransplantation, as a few well-publicized failed trials could irrevocably damage public perception of xenotransplantation. Because all of society carries the burden of risk, it is important that the public be involved in the decision to proceed. As new information from preclinical and clinical trials develops, policy decisions should be frequently updated. If at any point evidence shows that islet xenotransplantation is unsafe, then clinical trials will no longer be justified and they should be halted. However, as of now, the expected benefit of an unlimited supply of islets, combined with adequate informed consent, justifies clinical trials for islet xenotransplantation.
    Xenotransplantation 09/2015; 22(5). DOI:10.1111/xen.12196
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    ABSTRACT: Background Nitric oxide (NO) can reduce platelet adhesion and vascular resistance. Tempol can scavenge the reactive oxygen species (ROS) that induce tissue injury. As xenograft rejection attenuates endogenous NO production and generates ROS, we evaluated the potential effect of an NO donor (SIN-1, 3-morpholinosydnonimine) and tempol on hyperacute xenograft dysfunction using an ex vivo porcine lung perfusion model.Methods For the evaluation of von Willebrand factor (vWF) secretion, human endothelial cells were stimulated with thrombin. Porcine lungs were perfused with either fresh human whole blood (unmodified control group [n = 4]), SIN-1 (n = 4), or SIN and tempol (n = 4).ResultsSIN-1 and tempol significantly inhibited vWF secretion from endothelial cells in vitro. However, they did not suppress xenogeneic complement activation. In an ex vivo pulmonary perfusion model, SIN-1 improved pulmonary xenograft function by reducing pulmonary vascular resistance (PVR), inhibiting complement activation, and inhibiting thrombin generation. Combined treatment with tempol and SIN-1 potentiated PVR reduction, but slightly enhanced complement activation.Conclusions An NO donor is expected to improve pulmonary xenograft function through inhibition of vWF secretion, vasoconstriction, thrombin generation, and indirectly through inhibition of complement activation. The additional effects of tempol on an NO donor were not considered significant in an ex vivo xenograft system.
    Xenotransplantation 09/2015; 22(5). DOI:10.1111/xen.12195
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    ABSTRACT: The objective of this study was to investigate the humoral immune response to xenogeneic antigens administered during the fetal state utilizing a baboon-to-pig model. Nine fetuses from an alpha-1,3-galactosyltransferase gene knockout (GalT-KO) MGH-miniature swine sow underwent transuterine ultrasound-guided intraportal injection of T-cell depleted baboon bone marrow (B-BM) at mid-gestation. Two juvenile GalT-KO swine undergoing direct B-BM intraportal injection were used as controls. Postnatal humoral tolerance was induced in the long-term surviving piglets as demonstrated by the absence of any antibody response to baboon donor cells. In addition, a second intraportal B-BM administration at 2.5 months post-birth led to no antibody formation despite re-exposure to xenogeneic antigens. This B-cell unresponsiveness was abrogated only when the animal was exposed subcutaneously to third-party xenogeneic and allogeneic antigens, suggesting that the previously achieved humoral non-responsiveness was donor specific. In comparison, the two juvenile GalT-KO control swine demonstrated increasing anti-baboon IgM and IgG levels following intraportal injection. In summary, xenogeneic B-cell tolerance was induced through in utero intraportal exposure to donor cells and this tolerance persisted following postnatal rechallenge with donor B-BM, but was lost on exposure to third-party antigen, possibly as a result of cross-reactive antibody formation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
    Xenotransplantation 08/2015; 22(5). DOI:10.1111/xen.12186

  • Xenotransplantation 08/2015; 22(5). DOI:10.1111/xen.12187
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    ABSTRACT: In pig-to-baboon heart/artery patch transplantation models, adequate costimulation blockade prevents a T-cell response. After heart transplantation, coagulation dysfunction (thrombocytopenia, reduced fibrinogen, increased D-dimer) and inflammation (increased C-reactive protein [CRP]) develop. We evaluated whether coagulation dysfunction and/or inflammation can be detected following pig artery patch transplantation. Baboons received heart (n = 8) or artery patch (n = 16) transplants from genetically engineered pigs and a costimulation blockade-based regimen. Heart grafts functioned for 15-130 days. Artery recipients were euthanized after 28-84 days. Platelet counts, fibrinogen, D-dimer, and CRP were measured. Thrombocytopenia and reduced fibrinogen developed only in recipients of hearts not expressing a coagulation-regulatory protein (n = 4), but not in other heart or patch recipients. However, in heart recipients (n = 8), there were sustained increases in D-dimer (<0.5 to 1.9 ug/ml [P < 0.01]) and CRP (0.26-2.2 mg/dl [P < 0.01]). In recipients of artery patches, there were also sustained increases in D-dimer (<0.5 to 1.4 ug/ml [P < 0.01]) and CRP (0.26 to 1.5 mg/dl [P < 0.001]). An IL-6R antagonist suppressed the increase in CRP, but not D-dimer. The pig artery patch model has proved valuable for determining immunosuppressive regimens that prevent sensitization to pig antigens. This model also provides information on the sustained systemic inflammation in xenograft recipients (SIXR). An IL-6R antagonist may help suppress this response. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
    Xenotransplantation 08/2015; 22(5). DOI:10.1111/xen.12182
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    ABSTRACT: Porcine microorganisms may be transmitted to the human recipient when xenotransplantation with pig cells, tissues, and organs will be performed. Most of such microorganisms can be eliminated from the donor pig by specified or designated pathogen-free production of the animals. As human cytomegalovirus causes severe transplant rejection in allotransplantation, considerable concern is warranted on the potential pathogenicity of porcine cytomegalovirus (PCMV) in the setting of xenotransplantation. On the other hand, despite having a similar name, PCMV is different from HCMV. The impact of PCMV infection on pigs is known; however, the influence of PCMV on the human transplant recipient is unclear. However, first transplantations of pig organs infected with PCMV into non-human primates were associated with a significant reduction of the survival time of the transplants. Sensitive detection methods and strategies for elimination of PCMV from donor herds are required.
    Xenotransplantation 08/2015; 22(5). DOI:10.1111/xen.12180
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    ABSTRACT: Background During the process of islet isolation, pancreatic enzymes are activated and released, adversely affecting islet survival and function. We hypothesize that the exocrine component of pancreases harvested from pre-weaned juvenile pigs is immature and hence pancreatic tissue from these donors is protected from injury during isolation and prolonged tissue culture.Methods Biopsy specimens taken from pancreases harvested from neonatal (5–10 days), pre-weaned juvenile (18–22 days), weaned juvenile (45–60 days), and young adult pigs (>90 days) were fixed and stained with hematoxylin and eosin. Sections were examined under a fluorescent microscope to evaluate exocrine zymogen fluorescence intensity (ZFI) and under an electron microscope to evaluate exocrine zymogen granule density (ZGD).ResultsExocrine content estimation showed significantly lower ZFI and ZGD in juvenile pig pancreases (1.5 ± 0.04 U/μm2, ZFI; 1.03 ± 0.07 × 103/100 μm2, ZGD) compared to young adult pigs (2.4 ± 0.05U/μm2, ZFI; 1.53 ± 0.08 × 103/100 μm2 ZGD). Islets in juvenile pig pancreases were on average smaller (105.2 ± 11.2 μm) than islets in young adult pigs (192 ± 7.7 μm), but their insulin content was comparable (80.9 ± 2.2% juvenile; 84.2 ± 0.3% young adult, P > 0.05). All data expressed as mean ± SEM.Conclusion Porcine islet xenotransplantation continues to make strides toward utilization in clinical trials of type 1 diabetes. Porcine donor age and weaning status influence the extent of exocrine maturation of the pancreas. Juvenile porcine pancreases may represent an alternative donor source for islet xenotransplantation as their exocrine component is relatively immature; this preserves islet viability during extended tissue culture following isolation.
    Xenotransplantation 08/2015; 22(5). DOI:10.1111/xen.12184