Organización Nacional de Trasplantes

Ongoing shortages of organs for transplantation have prompted the critical question of which countries have the highest organ donation rates and how each can increase those rates. The existing metric of donors per million population is flawed because it does not sufficiently account for important differences in the underlying population, including age distributions of deaths in the population. We sought to develop a better approach to analyze country-specific data on organ donation, including deaths stratified by age, to allow assessment of performance across the world. We used death data from the World Health Organization and donation data from 17 countries across 3 continents. We calculated age group-stratified organ donation rates as donors per 1000 deaths and estimated each country's potential to increase donation if the age group-specific donation rate mirrored that of the highest-performing country in each age group. There was a 4-fold difference in overall donation rates, with far greater variability within age strata, including a 10-fold difference in donation rates for the oldest age group (70 y and older). The United States showed the greatest potential to increase donations in absolute terms (>8000 increased donors per year), whereas Argentina, Germany, and Hungary had the greatest potential in relative terms. Although countries may have similar overall donation rates, the breakdown within specific age groups varies widely. Examining age-specific donation rates is a necessary step for accurate international comparisons of transplant systems and can enable targeted interventions to augment donation.

Organoids derived from human pluripotent stem (hPS) cells hold promise for therapeutic purposes. However, technological advances to overcome their massive production while ensuring differentiation fidelity are still lacking. Here we report a procedure sustaining the derivation of kidney organoids from hPS cells (hPSC-kidney organoids) using a scalable, reproducible and affordable approach that allows hPSC-kidney organoid differentiation into different renal cell types. Using single-cell RNA sequencing, confocal image analysis, metabolic assays and CRISPR-Cas9 engineering for generation of fluorescent reporters, we show that hPSC-kidney organoids exhibit transcriptional variety and cellular composition following cell-to-cell contact. We infuse human kidney organoids into ex vivo porcine kidneys using normothermic machine perfusion, and demonstrate in vivo engraftment of hPSC-kidney organoids. We further evaluate the immune response, confirming the feasibility and viability of the procedure. We identify cells of human origin after normothermic machine perfusion and in vivo transplantation by means of in situ hybridization, immunohistochemistry, confocal microscopy, image analysis and quantification, in vivo imaging, and flow cytometry. This work provides a foundation for using hPSC-kidney organoids for ex vivo cell-based therapies in clinical trials.

Uncontrolled donation after circulatory death (uDCD) represents a promising yet underutilized approach to expanding the lung donor pool amid persistent organ shortages. Since the first successful lung transplantation from a uDCD donor in 2001, increasing clinical experience and advancements in organ preservation have demonstrated its feasibility. This review critically explores historical evolution, physiological basis, preservation techniques, ethical and legal considerations, and clinical outcomes of uDCD lung transplantation. The lung's unique ability to maintain viability through passive oxygen diffusion in the absence of perfusion supports its potential in the uDCD context. Compared to donors after brain death (DBD), uDCD donors may avoid systemic inflammatory response, potentially preserving graft quality. However, concerns persist regarding ischemia-reperfusion injury and mitochondrial dysfunction, highlighting the need for mitigation strategies such as ex vivo lung perfusion and normothermic ventilation. Ethical and legal challenges—particularly those related to the determination of death and consent—remain key obstacles. Organizational demands, including rapid coordination between prehospital, hospital teams and transplant teams, further limit broader implementation. Despite these barriers, reported outcomes are encouraging: to date, over 70 transplants from uDCD donors have been documented, with 1-year survival rates ranging from 71% to 87.5% and long-term outcomes comparable to DBD transplants. Integration of uDCD into routine clinical practice will require standardized protocols, robust public engagement, and institutional commitment. When appropriately implemented, uDCD lung transplantation offers a viable opportunity to increase donor availability and improve access to life-saving treatment.

HLA-E and -G class Ib molecules were considered unrelated to viral antigen presentation. HLA-E binds nonamers from the leader sequences of other HLA-I molecules and the human cytomegalovirus (HCMV) UL40 protein, interacting with CD94/NKG2 NK cell receptors. Yet, evidence that HLA-E may present some pathogen-derived peptides to CD8+ T lymphocytes has been reported. By contrast, HLA-G binds a broad spectrum of endogenous sequences but its role in antigen presentation is unknown. An experimental approach was set up to search for HCMV antigens displayed by HLA-G in infected cells. Among the analysed peptidome, 22 sequences corresponding to 16 HCMV molecules were identified; 17 peptides were confirmed to interact invitro with HLA-G of which 10 displayed characteristic anchor residues. As compared to the response in short-term (6 h) assays to immunodominant IE-1 and pp65 antigens, none of the HLA-G-binding peptides stimulated cytokine production by CD8+ T cells from HCMV-seropositive blood donors (n = 15). Following a 14-day peptide stimulation of PBMC and expansion with IL-2, CD8+ T cells specifically responding to a subset of these viral antigens were detected in some individuals, yet were not restricted by HLA-G in functional assays. A subset of viral peptides did bind to both HLA-G and -E but were not recognised by CD94/NKG2 NK cell receptors. Our results provide the first evidence that HLA-G may display potentially immunogenic viral peptides in HCMV-infected cells, yet do not support their ability to promote HLA-G-restricted CD8+ T cell responses nor to modulate NK cell functions.

Introducción. La readmisión hospitalaria dentro de los primeros 30 días después del egreso es un desafío global. En pacientes trasplantados renales, la tasa de readmisión es cercana al 30 % y aumenta la mortalidad entre un 50 y un 75 %. El objetivo de este estudio fue determinar la tasa de readmisión hospitalaria en los primeros 30 días en pacientes trasplantados renales en una institución colombiana e identificar sus principales factores de riesgo. Métodos. Estudio de cohorte retrospectiva con receptores de trasplante renal de Colombiana de Trasplantes, entre julio de 2008 y mayo de 2024. Se realizó un análisis de regresión logística para identificar factores de riesgo para la readmisión hospitalaria dentro de los 30 días postrasplante. Resultados. Se incluyeron 1612 pacientes. La tasa de readmisión a 30 días fue del 16,3 %. Los factores de riesgo con diferencias estadísticamente significativas fueron edad del receptor, diabetes mellitus, tipo de inducción, transfusión, hemoglobina, función retardada del injerto, duración de la hospitalización, estancia en Unidad de Cuidados Intensivos, reintervención quirúrgica, edad del donante y criterios expandidos del donante. Luego del ajuste con modelos de regresión, los principales factores fueron transfusión sanguínea (OR=13,31), niveles de hemoglobina (OR=0,80), función retardada del injerto (OR=2,83) y reintervención quirúrgica (OR=3,11). Conclusión. La identificación de estos factores de riesgo asociados a readmisión hospitalaria en pacientes con trasplante renal es crucial para tomar decisiones clínicas informadas y mejorar los desenlaces en Colombia.

Therapies derived from substances of human origin (SoHOs) such as organs, cells, and tissues provide life-saving or life-changing treatment for millions of people worldwide each year. However, many people lack timely access to SoHO-based therapies because of insufficient supplies of these exceptional health resources and/or broader barriers in access to healthcare. Despite well-established governmental commitments to promote health equity in general and equity of access to SoHOs in particular, information about inequities in access to most SoHO-based therapies is scarce. Furthermore, the issue of equitable allocation of SoHO-based therapies has received little attention from policymakers and ethicists, except in the context of organ allocation for transplantation. Consequently, the extent and nature of potential inequities within and between countries are largely unknown, and few sources of guidance are available to support progress toward equity in global access to SoHO-based therapies. We present here the findings of an international ethics working group convened in preparation for the 2023 Global Summit on Convergence in Transplantation, organized in Santander, Spain. The group sought to assess potential gaps in knowledge about inequities involving SoHO-based therapies, to elucidate systemic factors that may influence access to these therapies, and to consider how policies and frameworks governing access to and allocation of SoHO-based therapies may promote equity when it is necessary to define boundaries in access because of insufficiency of supply. In discussing these challenges, we also outline several recommendations for action by governments and health authorities.