Are we ready for pig-to-human clinical xenotransplantation trials? / Estamos prontos para ensaios clínicos de xenotransplante porco-para-humanos? / ¿Estamos listos para ensayos clínicos de xenotrasplante del cerdo al humano?

Abstract: The invention and widely use of organ allotransplantation provides effective treatment of some originally fetal diseases such as liver/kidney failure and has saved million of lives around the globe. However, the scarcity of human organs has caused many patients, who could have been treated, to die while waiting for suitable organs around the world. Pig-to human xenotransplantation provides a potential solution to solve this tough problem. Pig organs have been considered as major sources of xenotransplantation because of the sufficient number of donors, the sizes of organs, and physiologically structural similarities. However, xenotransplantation also has some problems, such as the possibility of spreading animal diseases to human, the interspecies immunological barrier, organs of animal origin challenging human nature, and potential informed consent issues. This article will discuss these potential issues and to see whether it is the suitable time to conduct clinical xenotransplantation trials in humans.

Resumen: La invención y el amplio uso de trasplantes alógenos proporciona tratamiento efectivo de algunas enfermedades de origen fetal, como la insuficiencia renal y hepática, y ha salvado a millones de pacientes en el mundo. Sin embargo, la escasez de órganos humanos ha causado que muchos pacientes en el mundo, que podrían haber sido tratados, murieran por esperar un órgano adecuado. El xenotrasplante del cerdo al humano proporciona una solución potencial para resolver este difícil problema. Los órganos de cerdo han sido considerados como fuentes mayores para xenotrasplantes debido al suficiente número de donantes, el tamaño de los órganos y estructuras fisiológicas similares. No obstante, el xenotrasplante también tiene algunos problemas, como la posibilidad de expandir enfermedades animales a humanos, la barrera inmunológica entre especies, el desafío para la naturaleza humana de tener órganos de origen animal y problemas potenciales de consentimiento informado. Este artículo discute estos temas potenciales y plantea si estamos en un momento apropiado para realizar ensayos clínicos de xenotrasplantes en humanos.

Resumo: A invenção e amplo uso de alotransplante de órgãos propicia tratamento efetivo para algumas doenças originalmente fetais tais como falência hepática/renal e tem salvo milhões de vidas em todo o globo. Entretanto, a escassez de órgãos humanos tem causado a morte de muitos pacientes que poderiam ter sido tratados - aguardando por órgãos apropriados em todo o globo. Xenotransplante porco-para-humanos propicia uma solução potencial para resolver este difícil problema. Órgãos de porco tem sido considerados como as principais fontes de xenotransplante por causa do número suficiente de doadores, do tamanho dos órgãos e de similaridades estruturais fisiológicas. Entretanto, xenotransplante também tem alguns problemas, tais como a possibilidade de disseminar doenças animais aos humanos, a barreira imunológica entre espécies, órgão de origem animal desafiando a natureza humana e aspectos potenciais de consentimento informado. Esse artigo discutirá esses aspectos potenciais e verificará se é o momento adequado para conduzir ensaios clínicos de xenotransplante em humanos.

Is the Population of Santiago de Cuba Sensitized to Xenotransplantation? A Multivariate Analysis.

INTRODUCTION: New transplant-related therapies such as xenotransplantation of solid cells, tissues, and organs are still poorly understood, especially in countries without preclinical xenotransplantation programs. OBJECTIVE: Analyze the attitude toward xenotransplantation among the population of Santiago de Cuba. METHOD: Type of study. Cross-sectional observational study. SAMPLE: Random sampling of 455 individuals residing in Santiago de Cuba. Assessment instrument. Validated questionnaire of attitude toward the xenotransplant, "PCID-XenoTx-Ríos." Field work. Random selection based on stratification. Anonymous and self-administered completion. RESULTS: A total of 49.9% would accept a solid organ xenotransplant if they needed it and the results were similar to those currently obtained with human organs, 27.5% have doubts, and the remaining 22.6% would not accept it. They are presented as statistically significant variables (P < .05): level of studies; comment with the family about the donation; opinion of a partner; religion; opinion of religion; performing prosocial activities; attitude toward donation; previous relationship with the organ donation and transplant; favorable attitude toward live kidney donation. In the multivariate analysis, the following persist: 1. level of university studies: odds ratio (OR) = 5.076; 2. not having a partner: OR = 5.154; 3. belonging to another religion: OR = 2.061; 4. favorable attitude toward organ donation: OR = 5; and 5. favorable attitude toward living donation: OR = 3.759. CONCLUSIONS: The population of Santiago de Cuba is less sensitized toward xenotransplantation, possibly due to ignorance of the issue due to lack of preclinical trials in their countries.

Are Dominicans in Favor of Xenotransplantation? A Study of the Attitude of Dominican Immigrants Residing in Spain and the United States.

Xenotransplantation carries many social and cultural implications. The immigrant population in countries with xenotransplantation programs, such as Spain and the United States, will play an important role in accepting such therapy. The objective of the study is to analyze the attitude toward xenotransplantation among the Dominican population residing in the United States and Spain. METHODS: The study population was born in the Dominican Republic and resides in the southeastern United States and Spain. A sample population older than 15 years was obtained randomly and stratified by age and sex. Attitude was assessed using a validated questionnaire on psychosocial aspects toward xenotransplantation (PCID-XENOTx-Ríos). A random selection of people to be surveyed was carried out. Assistance from immigration support associations was needed to advise on the location of potential respondents. RESULTS: A total of 123 respondents were included in the study: A sample was taken of residents of the population from the Dominican Republic residing in Florida, United States (n = 66), and in Spain (n = 57). If it was assumed that xenotransplanted organs functioned as well as human ones, 30% would be in favor. If the results were worse, only 7% would be in favor. This favorable attitude was related to the following variables (P < .05): level of education, an attitude in favor of deceased and living organ donation, and having spoken about donation and transplantation within the family. CONCLUSIONS: The attitude toward xenotransplantation among the population from the Dominican Republic who are residing in the southeastern United States and Spain is unfavorable.

Level of Acceptance of Solid Organ and Tissue Xenotransplantation Among the Bolivian Population Residing in Spain.

The Bolivian population is growing in Spain. Xenotransplantation of organs and/or tissues carries many social and cultural implications. It is important to find out the level of acceptance of xenotransplantation in immigrant populations, especially in populations where there are preclinical trials. The objective of the study is to analyze the attitude toward xenotransplantation of organs and tissues in the Bolivian population residing in Spain and the variables that influence their attitude. METHODS: We selected a sample of the Bolivian population living in Spain. A sample of the population older than 15 years was obtained randomly and stratified by age and sex. Attitude was assessed using a validated questionnaire on psychosocial aspects toward xenotransplantation (PCID-XENOTX-Ríos). RESULTS: Of the 206 respondents, 26% of respondents are in favor of xenotransplantation of organs if it was assumed that xenotransplanted organs functioned as well as human ones. If the results were worse, only 6% would be in favor. The following factors were associated with this attitude: (1) level of education (P = .008), (2) a favorable attitude toward human donation (P = .004), (3) a partner's favorable attitude toward transplantation (P < .001), and (4) a belief that one might need a transplant in the future (P = .01). The following were associated with attitude in the multivariate analysis: (1) having secondary education (odds ratio, 3.690; P = .004) and (2) a partner's favorable attitude toward transplantation (odds ratio, 6.024; P = .003). CONCLUSIONS: The attitude of Bolivian residents in Spain toward xenotransplantation is negative and is determined by educational and family factors.

Pig islet xenotransplantation acceptance in a Latin-American diabetic population.

Progress in porcine islet xenotransplantation has been accompanied by studies on acceptance of this new procedure by patients, health professionals or the general public. Such studies have not been done in the Latin-American population. We conducted a questionnaire in 108 diabetes patients (insulin-dependent, n = 53; insulin-independent, n = 55) in a public hospital in Argentina. The questions addressed the general perception of the xenotransplant procedure and specific items related to the outcome (achieving insulin independence, improvement in metabolic control, delay in emergence of diabetic complications, need for repeat procedures, potential of transfer of infectious viruses, association with psychological problems, and anticipated success in relation to achieving a cure). Eighty-six (79%) of the patients accepted islet xenotransplantation; this incidence was not different for insulin-dependent or insulin-independent patients, patients with or without complications, or patients with good or poor metabolic control. Also, over 75% of patients accepted the procedure if this is only associated with a reduction in insulin requirement, if the procedure just delays but not prevents the onset of complications, or if the procedure needs to be performed every 6 months. Fifty-seven percent of patients indicated acceptance even if the potential transmission of a virus infection cannot be completely ruled out: this outcome was not affected by the outbreak of the H1N1 flu epidemic during the conduct of this study. Forty percent of patients indicated that living with porcine cells in their body could give psychological problems. We conclude that this population of Latin-American diabetic patients shows a high acceptance rate of a porcine islet xenotransplantation product.

Level of acceptance of a clinical solid organ xenotransplantation program among personnel in organ transplant-related services in Spanish, Mexican, and Cuban hospital centers.

INTRODUCTION: Xenotransplantation is far from becoming a clinical reality. However, in vital organs it could be used as a bridge until a human organ becomes available, in an emergency situation. We analyzed the attitude toward xenotransplantation among personnel in transplant-related services in several hospitals in Spain and Latin America. METHODS: A random sample stratified by type of service and job category (n = 738), in transplant-related services (procurement units, transplant units, and transplant patient follow-up units) was examined in eight hospital centers from three different countries: Spain (n = 349), Mexico (n = 269), and Cuba (n = 120). A self-administered validated questionnaire was completed anonymously. RESULTS: Based on the assumption that all the results of xenotransplantation were similar to those achieved with human donors, most respondents [66% (n = 484)] would be in favor. The employees from Cuban centers had the most favorable attitudes (72% in favor), followed by the Spanish (64%) and the Mexicans (61%; P = .013). However, the differences were mainly determined by job category: Physicians showed the most favorable attitudes and auxiliary staff the least (67% vs 40%; P = .010). Attitudes were significantly related to beliefs about different types of human donation [deceased (P < .001) and living (P < .001)], the possibility of needing a transplant for oneself (P < .001), and a favorable attitude toward donating the organs of a deceased family member (P = .004). CONCLUSIONS: Currently, a third of health care employees working in transplant-related services are not in favor of xenotransplantation. More information should be provided about the subject, especially in centers with preclinical xenotransplantation programs.

Psychosocial aspects of xenotransplantation: survey in adolescent recipients of porcine islet cells.

INTRODUCTION: Transplantation is a process with several psychosocial challenges. Regarding the case of xenotransplantation, the perceived similarity between humans and pigs may be stressful. Adjustment disorders have been reported among transplantation recipients. We sought to assess the psychosocial aspects of xenotransplantation among porcine islet-cell recipients and their efforts to adapt themselves to this condition. MATERIAL AND METHODS: Ten insulin-dependent diabetes mellitus patients aged 14.58 +/- 7.93 who received porcine islet-cells were included. The bioartificial steel/fibrous tissue chamber method was used. All patients and their relatives were interviewed about their expectations, overall functioning, and experiences. The quality of life, enjoyment, and satisfaction scale and the hospital anxiety and depression scales were used. A 1-year follow-up was done. RESULTS: Their motivation was centered on autonomy; there were no troubles regarding the graft origin. Xenotransplantation was perceived with pragmatism, seeing pigs as an unlimited resource. The patients with best outcomes also had the greatest improvements in several quality of life areas (QOL) while the medium responders had fewer QOL improvements. The nonresponders experienced mainly frustration. Parents' concerns were not related to their children's health but to their recently gained autonomy. CONCLUSIONS: In addition to enthusiasm, the perception of animals as an unlimited source of organs may affect patient compliance; in this group, xenotransplantation was seen as using as a long-lasting drug, with chamber walls considered as a physical, immunologic, and, in certain manner, a psychological barrier.