Successful Organ Transplantation Research Articles

Artificial neural network and bioavailability of the immunosuppression drug.

The success of organ transplant is determined by number of demographic, clinical, immunological and genetic variables. Artificial intelligence tools, such as artificial neural networks (ANNs) or classification and regression trees (CART) can handle multiple independent variables and predict the dependent variables by deducing the complex nonlinear relationships between variables. In the last two decades, several researchers employed these tools to identify donor-recipient matching pairs, to optimize immunosuppressant doses, to predict allograft survival and to minimize adverse drug reactions. These models showed better performance characteristics than the empirical dosing strategies in terms of sensitivity, specificity, overall accuracy, or area under the curve of receiver-operating characteristic curves. The performance of the models was dependent directly on the input variables. Recent studies identified protein biomarkers and pharmacogenetic determinants of immunosuppressants as additional variables that increase the precision in prediction. Accessibility of medical records, proper follow-up of transplant cases, deep understanding of pharmacokinetic and pharmacodynamic pathways of immunosuppressant drugs coupled with genomic and proteomic markers are essential in developing an effective artificial intelligence platform for transplantation. Artificial intelligence has a greater clinical utility both in pretransplantation and posttransplantation periods to get favourable clinical outcomes, thus ensuring successful graft survival.

TRANSPLANTATION IN UKRAINE: INTERNATIONAL EXPERIENCE AND DEVELOPMENT TRENDS

The relevance of the article is that transplantation and donation of human organs could not appear in science and clinical practice at the same time. Thus, in contrast to surgery, which has developed and improved gradually, for the successful transplantation of human organs and tissues, it is necessary in the first place a significant baggage of scientific knowledge, starting with how the human body works. it takes place by completing the advanced skill of vascular suturing, knowledge of immunology and much more. Thus, it was not until the end of the 19th century that scientists came close to the idea that not only damaged tissues on the human body could heal - by closing a surgical incision or a wound on a bruised knee, but also the ability to isolate the tissue completely or completely. organism. The purpose of the article is to analyze foreign experience in the use of transplantation opportunities for organ transplantation, as well as opportunities for the implementation of positive experience in the Ukrainian realities. In the articles highlighted the risk of involvement with the opening of the market for the provision of trade management services of donor organizations. It was found that during the implementation of such activities an important point is to ensure the safety of nuclear transparency of the process, selection with the help of donors (obtaining voluntary consent from the individual, which allowed the use of its organs), providing a licensed challenge to human response. with the medical practice with the applied training, and ending the possible prosecution of persons who provide compliance with the relevant medical operations. It is emphasized that the Spanish system has created such a reliable legal and sanitary base that only in these conditions the advanced world figures on transplantation became possible. Today in Spain there is a presumption of positive permission - if a Spaniard has not said the opposite about life, he is automatically transferred to the scale of potential donors. Naturally, it became possible to pass such a law only when the society was ready for it, and when the system guaranteed you full reliability of all procedures provided by the legislation of the country.

Tacrolimus Trough Variability- Predictors and Outcomes in Pediatric Heart Transplantation

Tacrolimus is a narrow therapeutic index drug, requiring consistent levels to maximize solid organ transplant success while reducing adverse effects. High tacrolimus trough level variability (TTLV) is a significant predictor of late rejection in both kidney and liver transplant. We sought to describe the prevalence of high TTLV in our pediatric heart transplant (HT) population, and identify whether this variability is associated with patient specific factors and poor outcomes. Single center, retrospective study of HT patients from 1/2002 - 12/2018. Multi-organ recipients and retransplants were excluded. Records were reviewed for demographics, tacrolimus trough levels (TTLs) and outcomes (rejection, coronary vasculopathy, need for re-transplantation, death). Variability was calculated as the TTL standard deviation (SD) using each patient's TTLs from 1 year post-HT to last follow-up. High TTLV was defined as SD ≥3. Statistical analysis included Kruskal-Wallis, Chi-squared, and Wilcoxon rank sum testing. A total of 119 patients were included (male, 57%) with pre-HT diagnoses of congenital heart disease (57%) and cardiomyopathy (42%). The median age at HT was 2.7 yrs (IQR 0.8, 12.2) with a follow-up time post HT of 5.7 yrs (IQR 3.3, 9.9). A total of 6,344 TTLs were included, with a median of 33 TTLs/pt (IQR 14, 76). The median SD for the entire cohort was 3.1 (IQR 2.3, 4.0) with 55% of the population having a SD ≥3. Levels obtained from 1-5 yrs of age were found to have significantly greater variability (median SD 3.1 [IQR 2.4, 4.1]; p-value< 0.01) than 6-12 yrs (SD 2.5) and 12+ yrs (SD 2.5). After dichotomizing patients for higher variability (SD ≥ 3), there were no significant associations with patient specific factors including: sex, pre-HT diagnosis, pre-HT clinical course (acute vs chronic), age at HT, time with HT and Hollingshead Socioeconomic Score. High TTLV was associated with increased rejection treatment (74% vs 44%, p<0.01), higher frequency of coronary vasculopathy (23% vs 7%, p=0.02), and death (20% vs 6%, p=0.02). TTLV is high in pediatric HT recipients, especially in those < 5 yrs. Patients with a SD ≥3 experienced a higher frequency of poor outcomes including rejection, coronary vasculopathy and death.

Melatonin and organ transplantation: what is the relationship?

Melatonin has anti-inflammatory and antioxidant properties that can influence tissue growth and apoptosis. This aspect may influence the success of organ transplantation. To evaluate the relationship between melatonin and organ transplantation. A systematic review was performed in PubMed databases using the search terms: "melatonin physiology" or "melatonin therapy" and "transplant pharmacology" or "transplant physiology" or "transplant therapy" or "Transplant therapy". Experiments on the organs of the reproductive system were not included. After analysis, five articles were selected after reading the title and abstract of 50 manuscripts. The works were divided into two aspects: a) analysis of the influence of the organ transplantation procedure on melatonin production; b) action of melatonin on organ transplantation. The cardiac transplantation surgical procedure, immunosuppression, and graft did not influence melatonin secretion in rodents, but there was a significant reduction of melatonin in the renal transplantation procedure in patients with renal insufficiency. Melatonin administration in experimental models decreased rejection and improved transplant success. Studies show that melatonin can reduce organ and species dependence, and the use of melatonin decreases graft rejection.

Max and Keira’s law: an overview on the advantages, disadvantages and alternatives to an opt-out organ donation system in the UK

Summary: Despite definite implementation of the law, there have been concerns over the presumed consent given for retrieving organs from the deceased; ignorance and lethargy from certain members of the public may mean that true informed consent can never be obtained when collecting organs. To combat this, expensive national campaigns would need to be launched to make the public aware of the new process, as well as educating them on how to opt out of the process if necessary. Regardless of these challenges, there are many advantages to the new law. Advantages include an increase in successful organ donations and transplant, as well as potentially an increased availability of organs for use in medical research, drug development and university teaching. Relevance: To increase the number of organ donors in England, the government will implement Max and Keira’s Law: all adults over the age of 18 living in the United Kingdom become potential organ donors after their death, unless they choose to opt out. The law will be employed by spring 2020. Despite there being presumed consent for the retrieval of organs, families of the deceased will still be contacted to recheck consent, and ensure that family wishes are upheld. Take Home Messages: Based on the advantages, the move to the opt-out system appears to be a sensible method to increase the number of organs available for use in medicine. Proposed alternatives such as xenotransplantation and 3D bioprinting have the obvious benefit of providing an almost infinite supply of organs. However, these alternatives remain in the preclinical stages, with ethical challenges and infection risks that need to be overcome before they can be used in hospitals.

At the heart of organ donation. Case reports of organ donation after cardiac death in two patients with successfully repaired AAST grade V cardiac injuries

BackgroundTrauma victims could be an important source of organs. This article presents two cases of successful organ donation and transplant, after Maastricht category III cardiac death in patients with successfully repaired AAST grade V traumatic cardiac injuries.Case presentationThe first donor was an adult patient with self-inflicted heart stab wound and non-survivable burn injury. The second one was an adult patient with blunt cardiac and abdominal trauma and an anoxic brain injury due to a car accident. The cardiac injury was promptly repaired in both patients. In the first case, adequate organ perfusion ante-mortem was achieved thanks to venoarterial extracorporeal membrane oxygenation and intensive care unit support. The above procedure allowed successful organ donation and transplantation even after Maastricht category III cardiac death. This is the first case reported where, for organ donation purposes, it was made necessary first thing to avoid the immediate death of the patient, due to a rare and frequently not survivable cardiac injury. The challenge of preserving organ perfusion, due to major burn injury effects, was faced afterwards.ConclusionsThe outcomes of these two cases suggest that a repaired heart injury should not be considered as an absolute contraindication to organ donation, even if it is associated with non-survivable major burns. Therefore, cardiac death could provide an opportunity for these kinds of patients to contribute to the pool of potential organ donors.

Effectiveness and efficiency of teleimaging in the transplantation process: a mixed method protocol

BackgroundThe transplantation process usually takes place without transplant teams being able to use imaging data to assess graft quality. The decision of whether to go get the graft or not is therefore limited and suboptimal. “Cristal images” is a teleimaging project allowing real-time visualization of images of the organs of the donor. The objective of our study is to assess whether the use of a secure teleimaging can improve the effectiveness and efficiency of the procurement and transplantation processes.MethodsWe will use the exhaustive national registry of organ allocation and transplantation, and compare outcomes before the deployment of “Cristal images” (years 2015–2016) and after it becomes operational (years 2018–2019) for heart, lung, liver and kidney transplant in a before-after study, combined with a preference elicitation study. The primary endpoint will be the number of successful organ transplantations. Secondary endpoints will be related to the efficiency of the transplant process (decision making, transportation, cost) and a preference elicitation study will determine the relative preferences of transplant teams towards few “Cristal images”’ components or potential developments, which are yet to be determined through a qualitative analysis based on interviews with professionals.DiscussionThis study will provide stakeholders data on the efficiency of real-time visualization for transplant teams and identify the levers likely to influence the technology use among these teams.Trial registrationclinicaltrials.gov: NCT03201224, 13 June 2017, retrospectively registered.

Nanodelivery of Mycophenolate Mofetil to the Organ Improves Transplant Vasculopathy.

Inflammation occurring within the transplanted organ from the time of harvest is an important stimulus of early alloimmune reactivity and promotes chronic allograft rejection. Chronic immune-mediated injury remains the primary obstacle to the long-term success of organ transplantation. However, organ transplantation represents a rare clinical setting in which the organ is accessible ex vivo, providing an opportunity to use nanotechnology to deliver therapeutics directly to the graft. This approach facilitates the directed delivery of immunosuppressive agents (ISA) to target local pathogenic immune responses prior to the transplantation. Here, we have developed a system of direct delivery and sustained release of mycophenolate mofetil (MMF) to treat the donor organ prior to transplantation. Perfusion of a donor mouse heart with MMF-loaded PEG-PLGA nanoparticles (MMF-NPs) prior to transplantation abrogated cardiac transplant vasculopathy by suppressing intragraft pro-inflammatory cytokines and chemokines. Our findings demonstrate that ex vivo delivery of an ISA to donor organs using a nanocarrier can serve as a clinically feasible approach to reduce transplant immunity.

Multidrug-resistant Gram-negative bacterial infections in solid organ transplant recipients-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice.

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of infections due to multidrug-resistant (MDR) Gram-negative bacilli in the pre- and post-transplant period. MDR Gram-negative bacilli, including carbapenem-resistant Enterobacteriaceae, MDR Pseudomonas aeruginosa, and carbapenem-resistant Acinetobacter baumannii, remain a threat to successful organ transplantation. Clinicians now have access to at least five novel agents with activity against some of these organisms, with others in the advanced stages of clinical development. No agent, however, provides universal and predictable activity against any of these pathogens, and very little is available to treat infections with MDR nonfermenting Gram-negative bacilli including Abaumannii. Despite advances, empiric antibiotics should be tailored to local microbiology and targeted regimens should be tailored to susceptibilities. Source control remains an important part of the therapeutic armamentarium. Morbidity and mortality associated with infections due to MDR Gram-negative organisms remain unacceptably high. Heightened infection control and antimicrobial stewardship initiatives are needed to prevent these infections, curtail their transmission, and limit the evolution of MDR Gram-negative pathogens, especially in the setting of organ transplantation.

Bone disease following solid organ transplantation: A narrative review and recommendations for management from The European Calcified Tissue Society.

Solid organ transplantation is an established therapy for end-stage organ failure. Both pre-transplantation bone disease and immunosuppressive regimens result in rapid bone loss and increased fracture rates. The European Calcified Tissue Society (ECTS) formed a working group to perform a systematic review of existing literature on the consequences of end-stage kidney, liver, heart, and lung disease on bone health. Moreover, we assessed the characteristics of post-transplant bone disease and the skeletal effects of immunosuppressive agents and aimed to provide recommendations for the prevention and treatment of transplantation-related osteoporosis. Characteristics of bone disease may differ depending on the organ that fails, but patients awaiting solid organ transplantation frequently depict a wide spectrum of bone and mineral abnormalities. Common features are a decreased bone mass and impaired bone strength with consequent high fracture risk, all of which are aggravated in the early post-transplantation period. Both the underlying disease leading to end-stage organ failure and the immunosuppression regimens implemented after successful organ transplantation have detrimental effects on bone mass, quality and strength. Given existing ample data confirming the high frequency of bone disease in patients awaiting solid organ transplantation, we recommend that all transplant candidates should be assessed for osteoporosis and fracture risk and, if indicated, treated before and after transplantation. Since bone loss in the early post-transplantation period occurs in virtually all solid organ recipients and is associated with glucocorticoid administration, the goal should be to use the lowest possible dose and to taper and withdraw glucocorticoids as early as possible.

Stable Regulation of Senescence-Related Genes in Galactose-alpha1,3-galactose Epitope Knockout and Human Membrane Cofactor Protein hCD46 Pig

BackgroundPigs are considered suitable animal donor models for xenotransplantation. For successful organ transplantation, immune rejection must be overcome. Xenotransplantation has recently been successfully performed using galactose-alpha1,3-galactose epitopes knockout (GalTKO) and a human membrane cofactor protein (hCD46) in a pig model. However, the growth and lifespan of the grafted organ have not been evaluated. Therefore, in the present study we evaluated aging and 84 senescence-related genes using the RT2 Profiler PCR array and whole blood samples from GalTKO/hCD46 Massachusetts General Hospital (MGH) pigs. MethodsExperimental groups were double GalTKO/hCD46 (5-month-old), single GalTKO/hCD46 (2-year-old), and non-genetically modified (>3.5-year-old; control group within the same strain). Age-matched white hairless Yucatan (WHY) miniature pig groups were used as controls. ResultsAmong the 19 senescence-related genes selected from the 84 genes for further evaluation, 13 were upregulated in the double GalTKO/hCD46 MGH pigs compared to control MGH pigs; however, in WHY pigs, only 4 genes were up- or down-regulated among the 19 genes. Moreover, in double GalTKO/hCD46 MGH and WHY pigs, the expression of the 19 genes changed only 1- to 2-fold, suggesting that there were no significant differences in senescence signals between the 2 pig lines. ConclusionsThe present results indicate that the double GalTKO/hCD46 MGH pig might be a suitable model for human xenotransplantation studies. However, we used a limited number of experimental individuals, so further studies using larger experimental groups should be conducted to verify the present results.

Genetic Variants Associated With Immunosuppressant Pharmacokinetics and Adverse Effects in the DeKAF Genomics Genome-wide Association Studies.

The immunosuppressants tacrolimus and mycophenolate are important components to the success of organ transplantation, but are also associated with adverse effects, such as nephrotoxicity, anemia, leukopenia, and new-onset diabetes after transplantation. In this report, we attempted to identify genetic variants which are associated with these adverse outcomes. We performed a genome-wide association study, using a genotyping array tailored specifically for transplantation outcomes containing 722 147 single nucleotide polymorphisms, and 2 cohorts of kidney allograft recipients-a discovery cohort and a confirmation cohort-to identify and then confirm genetic variants associated with immunosuppressant pharmacokinetics and adverse outcomes. Several genetic variants were found to be associated with tacrolimus trough concentrations. We did not confirm variants associated with the other phenotypes tested although several suggestive variants were identified. These results show that adverse effects associated with tacrolimus and mycophenolate are complex, and recipient risk is not determined by a few genetic variants with large effects with but most likely are due to many variants, each with small effect sizes, and clinical factors.

First Russian experience of liver and kidneys transplantation obtained from the donor with out-of-hospital irreversible cardiac arrest

Organs’ shortage remains the main limiting problem for accessibility of organ transplantation. There is the growing interest among transplant society for use organs obtained from «uncontrolled» donors after cardiac death (uDCDs), or, asystolic donors. But the warm ischemic time is critical factor for wide accepting of practice of transplantation such kind of organs. The article presents the first case of successful clinical organ transplants from the donor with out-of-hospital irreversible cardiac arrest obtained with help of life support devices.

Immune privilege in corneal transplantation.

Corneal transplantation is the most successful solid organ transplantation performed in humans. The extraordinary success of orthotopic corneal allografts, in both humans and experimental animals, is related to the phenomenon of "immune privilege". Inflammation is self-regulated to preserve ocular functions because the eye has immune privilege. At present, three major mechanisms are considered to provide immune privilege in corneal transplantation: 1) anatomical, cellular, and molecular barriers in the cornea; 2) tolerance related to anterior chamber-associated immune deviation and regulatory T cells; and 3) an immunosuppressive intraocular microenvironment. This review describes the mechanisms of immune privilege that have been elucidated from animal models of ocular inflammation, especially those involving corneal transplantation, and its relevance for the clinic. An update on molecular, cellular, and neural interactions in local and systemic immune regulation is provided. Therapeutic strategies for restoring immune privilege are also discussed.

Investigation of single nucleotide polymorphisms in porcine candidate genes for blood component traits in pigs

This study used 209 public single nucleotide polymorphism (SNP) arrays for 151 candidate genes of pigs to analyse their association with nine blood component traits (insulin-like growth factor-I, insulin, immuno globulin, lymphocyte, monocyte, eosinophil, basophil, neutrophil and atypical lymph) in 209 Korean native pigs and Yorkshire F 2 hybrids. Of these, 52 SNPs in 49 candidate genes showed significant association with one or more blood component traits. Nineteen of these SNPs were found to be present in blood component QTL regions. The 49 candidate genes corresponding to 52 SNPs with significant effects were detected and used for gene ontology analysis to understand the function of the candidate genes at molecular level. Based on functional classification (biological process, cellular components, and molecular function) of annotated candidates, 34 candidate genes (11 genes of IGF-1, 9 of IS, 9 of IG, 6 of NP, and 3 of EP) were detected. Additionally, eight genes ( PSMB4 , PSME3 , MAPKAPK3 , CTLA4 , CUL7 , GGT1 , IDH3B , and RXRB ) interacting with four immune pathways (immune system, adaptive immune system, Class I MHC-mediated antigen processing and presentation, and antigen processing: ubiquitination and proteasome degradation) were found through pathway and network analyses. The eight candidate genes identified in this study are included in class I MHC-mediated antigen pathway, which is an important factor that determines the success of organ transplantation in addition to the improvement of diseases and immunity of pigs. Therefore, these genes can potentially be used in heterogeneous organ research in future research. Keywords: Association analysis, gene network, pathway, SNP, swine

Detecting donor-specific antibodies: the importance of sorting the wheat from the chaff.

Human leukocyte antigen (HLA) compatibility is very important for successful transplantation of solid organs. In this paper, we focused on the humoral arm of immunity in the clinical setting of organ transplantation: how HLA antibodies develop, how they can be detected, and what they can do to injure organ transplants. Specifically, we explore the technical perspectives of detecting donor-specific antibodies (DSA) in HLA laboratories, and use real-life clinical cases to explain the principles. Currently there are many tools in our HLA antibody detection toolbox: conventional cytotoxicity cross match, flow cross match, and solid phase assays using beads conjugated with single or multiple HLA antigens. Single antigen bead (SAB) assay is the most sensitive tool available for detecting HLA antibodies and assessing the immunological risk for organ transplant. However, there are intrinsic limitations to solid-phase assays and they are prone to both false negativity and importantly, false positivity. Denatured antigens on single antigen beads might be the most prominent source of false positive reactivity, and may have been underestimated by many HLA experts. No single assay is perfect and therefore multiple methods, including the less sensitive assays, should be employed to determine the clinical relevance of detected HLA antibodies. Thoughtful process, including knowledge of HLA systems, cross reactivity, epitopes, and the patient's clinical history should be employed to correctly interpret data. The clinical team should work closely with HLA laboratories to ensure accurate interpretation of information and optimal management of patients before and after organ transplantation.

ORGAN DONATION AWARENESS

Organ transplantation is a medical procedure which a healthy organ is removed from the living or cadaver donor to be transplanted into the recipient whose related organ is no more functioning properly. There are two types of organ transplantation: living-donor and cadaver-donor transplantation. After the donation, related organs are taken from the patient following the brain death in the ICU and transplanted to the recipient. Organs can be used only when the brain death is confirmed and declared in the ICU. Brain death is the irreversible state of loss in the brain functions. According to the article 14 of the law No 2238, when a patient is officially brain-dead, the organs or tissues can be taken with the consent of their spouse, children of age, mother/father, siblings in order or an acquaintance of any of them if the rest is not present. Organ donation is when an individual gives their consent by documentation, with free will, and allow their tissues and organs to be donated for the treatment of other patients after the end of their life medically. According to the law no 2238, any citizen who is mentally healthy and above 18 years of age, can donate their organs and obtain an organ donation card. Organ transplantation is a very serious medical issue in Turkey as it is in other countries and the donation rates should be increased by informing the public and getting more participation. Success in organ transplantation can be obtained by a higher number of organ donations.&#x0D;

Corneal transplantation in the modern era.

Corneal blindness is one of the major causes of reversible blindness, which can be managed with transplantation of a healthy donor cornea. It is the most successful organ transplantation in the human body as cornea is devoid of vasculature, minimizing the risk of graft rejection. The first successful transplant was performed by Zirm, and since then, corneal transplantation has seen significant evolution. It has been possible because of the relentless efforts by researchers and the increase in knowledge about corneal anatomy, improvement in instruments and advancements in technology. Keratoplasty has come a long way since the initial surgeries wherein the whole cornea was replaced to the present day where only the selective diseased layer can be replaced. These newer procedures maintain structural integrity and avoid catastrophic complications associated with open globe surgery. Corneal transplantation procedures are broadly classified as full-thickness penetrating keratoplasty and partial lamellar corneal surgeries which include anterior lamellar keratoplasty [sperficial anterior lamellar keratoplasty (SALK), automated lamellar therapeutic keratoplasty (ALTK) and deep anterior lamellar keratoplasty (DALK)] and posterior lamellar keratoplasty [Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK)] broadly.

Severe atherosclerosis of donor hepatic arteries is a salvageable condition in liver transplantation to optimise the graft utilisation: A case series and review of the literature

IntroductionThe presence of atherosclerosis of the common hepatic artery (CHA) in donor livers potentially contributes to vascular complications after liver transplantation, thereby most of those organs are traditionally discarded. Herein, we describe the successful outcome of three patients transplanted with grafts that had severe atherosclerosis of the donor CHA up to the level of the gastroduodenal artery (GDA). Presentation of caseIn all three cases, endarterectomies were performed by dissection between the atheromatous core and the artery intima using a dissecting spatula, allowing to secure the lumen of the vessel. The native CHA/GDA patch was aligned with the corresponding CHA/GDA patch from the graft for the arterial reconstruction. No vascular complications were seen post-operatively. DiscussionEndarterectomy and anatomical reconstitution of the arterial tree, without any redundancy or kinking, allowed for the successful transplantation of organs that would be otherwise discarded. Further, the straight alignment of the arteries may enhance flow dynamics, preventing thrombosis. ConclusionThis report might guide future studies targeting means to increase the utility of donor livers discarded due to arterial atherosclerosis.

The degree of major histocompatibility complex matching between purebred Maltese and mongrel dogs using microsatellite markers.

Long-term maintenance of transplanted organs is one of the major factors that increases survival time of recipients. Although obtaining a major histocompatibility complex (MHC)-matched donor with the recipient is essential for successful organ transplantation, there have been limited reports on MHC matching between dogs. In this study, we analyzed the canine MHC matching rates using Maltese, one of the most popular purebred dogs, and mongrel dogs in Korea. Genomic DNA was extracted from blood leukocytes and DNA was amplified by polymerase chain reaction with primers specific to MHC microsatellite markers. The MHC matching degree was confirmed by the microsatellite markers using polyacrylamide gel electrophoresis. The MHC matching rates of each donor-recipient groups including Maltese-Maltese, mongrel-mongrel and Maltese-mongrel were 4.76%, 5.13% and 6.67%, respectively. There were no significant differences in the MHC matching degree between each group. These results demonstrate that MHC-matched donors could be selected from other breeds as much as from the same breed for transplantation. Knowledge of the MHC matching degree of purebred and mongrel dogs would offer valuable information not only for improving the success rate of organ transplantation surgery in canine patients but also for transplantation research using experimental canine models.