Advancing kidney xenotransplantation with anesthesia and surgery - bridging preclinical and clinical frontiers challenges and prospects.

Xenotransplantation is emerging as a vital solution to the critical shortage of organs available for transplantation, significantly propelled by advancements in genetic engineering and the development of sophisticated immunosuppressive treatments. Specifically, the transplantation of kidneys from genetically engineered pigs into human patients has made significant progress, offering a potential clinical solution to the shortage of human kidney supply. Recent trials involving the transplantation of these modified porcine kidneys into deceased human bodies have underscored the practicality of this approach, advancing the field towards potential clinical applications. However, numerous challenges remain, especially in the domains of identifying suitable donor-recipient matches and formulating effective immunosuppressive protocols crucial for transplant success. Critical to advancing xenotransplantation into clinical settings are the nuanced considerations of anesthesia and surgical practices required for these complex procedures. The precise genetic modification of porcine kidneys marks a significant leap in addressing the biological and immunological hurdles that have traditionally challenged xenotransplantation. Yet, the success of these transplants hinges on the process of meticulously matching these organs with human recipients, which demands thorough understanding of immunological compatibility, the risk of organ rejection, and the prevention of zoonotic disease transmission. In parallel, the development and optimization of immunosuppressive protocols are imperative to mitigate rejection risks while minimizing side effects, necessitating innovative approaches in both pharmacology and clinical practices. Furthermore, the post-operative care of recipients, encompassing vigilant monitoring for signs of organ rejection, infectious disease surveillance, and psychological support, is crucial for ensuring post-transplant life quality. This comprehensive care highlights the importance of a multidisciplinary approach involving transplant surgeons, anesthesiologists, immunologists, infectiologists and psychiatrists. The integration of anesthesia and surgical expertise is particularly vital, ensuring the best possible outcomes of those patients undergoing these novel transplants, through safe procedural practices. As xenotransplantation moving closer to clinical reality, establishing consensus guidelines on various aspects, including donor-recipient selection, immunosuppression, as well as surgical and anesthetic management of these transplants, is essential. Addressing these challenges through rigorous research and collective collaboration will be the key, not only to navigate the ethical, medical, and logistical complexities of introducing kidney xenotransplantation into mainstream clinical practice, but also itself marks a new era in organ transplantation.

An Immunologic Compatibility Testing Was Not Useful for Donor Selection in Fecal Microbiota Transplantation for Ulcerative Colitis.

Fecal microbiota transplantation (FMT) is an effective procedure against Clostridioides difficile infection (CDI), with promising but still suboptimal performance in other diseases, such as ulcerative colitis (UC). The recipient's mucosal immune response against the donor's microbiota could be relevant factor in the effectiveness of FMT. Our aim was to design and validate an individualized immune-based test to optimize the fecal donor selection for FMT. First, we performed an in vitro validation of the test by co-culturing lymphocytes obtained from the small intestine mucosa of organ donor cadavers (n=7) and microbe-associated molecular patterns (MAMPs) obtained from the feces of 19 healthy donors. The inflammatory response was determined by interleukin supernatant quantification using the Cytometric Bead Array kit (B&D). We then conducted a clinical pilot study with 4 patients with UC using immunocompetent cells extracted from rectal biopsies and MAMPs from 3 donor candidates. We employed the test results to guide donor selection for FMT, which was performed by colonoscopy followed by 4 booster instillations by enema in the following month. The microbiome engraftment was assessed by 16S rDNA massive sequencing in feces, and the patients were clinically followed-up for 16 weeks. The results demonstrated that IL-6, IL-8, and IL-1ß were the most variable markers, although we observed a general tolerance to the microbial insults. Clinical and colonoscopy remission of the patients with UC was not achieved after 16 weeks, although FMT provoked enrichment of the Bacteroidota phylum and Prevotella genus, with a decrease in the Actinobacteriota phylum and Agathobacter genus. The most relevant result was the lack of Akkermansia engraftment in UC. In summary, the clinical success of FMT in patients with UC appears not to be influenced by donor selection based on the explored recipient's local immunological response to FMT, suggesting that this approach would not be valid for FMT fecal donor optimization in such patients.

A semen-based stimulation method to analyze cytokine production by uterine CD56bright natural killer cells in women with recurrent pregnancy loss.

Cytokine secretion by NK cells is abnormal in some women with recurrent pregnancy loss (RPL). Cytokine production is usually evaluated after stimulation with PMA and ionomycin. However, stimulation of uterine NK cells with semen corresponds more closely to physiological conditions at the time of conception. As seminal plasma has immunomodulatory properties, we aimed to elucidate compatibility between uterine NK cells and semen. Endometrial samples were stimulated with PMA/ionomycin, semen, seminal plasma, or spermatozoa. Thereafter, cytokine production by NK (CD56bright) cells was evaluated using flow cytometry and compared between women with and without a history of RPL associated with abnormal NK cell distribution in the endometrium or unexplained RPL. The ratios (%) of NK cells producing IFN-γ and TNF-α (NK1 phenotype), IL-4 (NK1/NK2 phenotype), and IL-10 (NK1/NKr1 phenotype) were significantly lower after stimulation with semen than with PMA/ionomycin (P < 0.01). After exposure to semen, ratios (%) of NK cells producing IL-4 and IL-10 in patients with unexplained RPL were significantly lower (P < 0.05), whereas those of NK1/NK2 and NK1/NKr1 were significantly higher (P < 0.01) than those in controls. The shift of endometrial NK cells to the NK2 phenotype was more pronounced when stimulated by semen than by PMA/ionomycin. However, a semen-induced shift to NK1 in women with unexplained RPL could induce miscarriage. Couple-specific immunological compatibility tests through semen stimulation in vitro might provide important information to avoid RPL.

Immunological compatibility status of placenta-derived stem cells is mediated by scaffold 3D structure.

Placenta-derived amniotic epithelial cells (AECs), a great cell source for tissue engineering and stem cell therapy, are immunologically inert in their native state; however, immunological changes in these cells after culture and differentiation have challenged their applications. The aim of this study was to investigate the effect of 2D and 3D scaffolds on human lymphocyte antigens (HLA) expression by AECs. The effect of different preparation parameters including pre-freezing time and temperature was evaluated on 3D chitosan-gelatine scaffolds properties. Evaluation of MHC class I, HLA-DR and HLA-G expression in AECs after 7 d culture on 2D bed and 3D scaffold of chitosan-gelatine showed that culture of AECs on the 2D substrate up-regulated MHC class I and HLA-DR protein markers on AECs surface and down-regulated HLA-G protein. In contrast, 3D scaffold did not increase protein expression of MHC class I and HLA-DR. Moreover, HLA-G protein expression remained unchanged in 3D culture. These results confirm that 3D scaffold can remain AECs in their native immunological state and modification of physical properties of the scaffold is a key regulator of immunological markers at the gene and protein expression levels; a strategy which circumvents rejection challenge of amniotic stem cells to be translated into the clinic.

Supervivencia de pacientes trasplantados en relación con la compatibilidad inmunológica / Survival of transplant patients in relation to immunological compatibility

Introducción: El trasplante renal es uno de los métodos de sustitución de la función renal y tiene como factor de mayor influencia en su supervivencia, la compatibilidad inmunológica del sistema mayor. Objetivos: Definir la supervivencia del trasplante y su relación con el grado de compatibilidad. Métodos: Se realizó un estudio retrospectivo sobre el tiempo de supervivencia con base hospitalaria de los 512 trasplantes en el período comprendido entre los años 1993 y 2010, ambos incluidos con seguimiento y corte al concluir el año 2019. Se empleó el Kaplan Meier para calcular las supervivencias, se utilizó el paquete estadístico Statiscal Package Social Science (Spss) versión 22.0. Resultados: 397 pacientes recibieron riñones cadavéricos al momento del corte, 11,3 por ciento de los injertos estaban funcionando, mientras que para los 115 que recibieron de vivo, el 45,2 por ciento, p=0,000. La mediana de supervivencia para el cadavérico fue de 3,1 años (SD 2,4-3,8) y dentro de ellos los que compartieron tres o más antígenos lograron el doble de sobrevida, p=0,033. Para el de donante vivo, la mediana fue de 16,0 años (SD 9,1-22,9) y dentro de este grupo 104 pacientes que compartían un haplotipo lograron 44,2 por ciento de función, los hermanos que eran idénticos un 66,0 por ciento. Por parentesco los que recibieron riñones de hermanos tienen mejor supervivencias que de padres a hijos, p=0,001. Conclusiones: Se definió que la compatibilidad inmunológica del sistema mayor entre donante y receptor propicia diferencias en la función de los injertos(AU)

Introduction: Renal transplantation is one of the methods of renal function substitution and the main factor influencing survival is the immunological compatibility of the major system. Objectives: To define transplant survival and the relationship with the degree of compatibility. Methods: A retrospective study was carried out on the hospital-based survival time of 512 transplants from 1993 to 2010, including follow-up and the cut at the end of 2019. The Kaplan-Meier estimator was used to calculate the survivals, the statistical package Statistical Package Social Science (Spss) version 22.0 was used. Results: Three hundred ninety seven (397) patients received cadaveric kidneys at the cut, 11.3percent of the grafts were functioning, 115 received living grafts, 45.2percent p=0.000. The median survival for the cadaveric kidneys was 3.1 years (SD 2.4-3.8) and among them those who shared three or more antigens achieved twice the survival, p=0.033. For the living donor, the median was 16.0 years (SD 9.1-22.9) and within this group, 104 patients, sharing a haplotype, achieved 44.2percent function, siblings, who were identical, achieved 66 .0percent. By kinship, those who received kidneys from siblings have better survival than for those who received it from parents, p=0.001. Conclusions: Immunological compatibility of the major system between donor and recipient was defined to favor differences in the function of the grafts(AU)

Supervivencia del trasplante renal en relación con la compatibilidad inmunológica en Cuba / Kidney transplant survival in relation to immunological compatibility in Cuba

RESUMEN Introducción: El trasplante renal es uno de los métodos de sustitución de la función renal y tiene como factor de mayor influencia en su supervivencia, la compatibilidad inmunológica. Objetivo: Definir la supervivencia del trasplante y su relación con el grado de compatibilidad. Material y Métodos: Estudio retrospectivo, del tiempo de supervivencia con base hospitalaria, de los 827 pacientes trasplantados entre los nueve centros del país, en el quinquenio 2015-2019. Para estimar las curvas de supervivencias se empleó el Método de Kaplan Meier, por el SPSS 22.0. Resultados: Supervivencia del injerto al año 72,9 % y paciente 89,0 %, con media de sobrevida de los injertos de 3,6 años y del paciente de 4,6. Para los pacientes con dos y más compatibilidad, la supervivencia del injerto al año fue mayor, 77,0 % v/s 69,2 % y menos, para el resto. Posterior al año, también son diferentes las supervivencias por grado de compatibilidad. El rechazo agudo inmunológico, que es una de las principales causas de pérdidas de injertos, tiene mucho mayor incidencia en los trasplantados sin compatibilidad que en los compatibles (17,4 % v/s 9,9 %). Para las causas de muerte de los pacientes, la infección fue la predominante, y muy significativo para los que no comparten compatibilidad v/s los que sí (56,9 % v/s 31,9 %). Conclusiones: La compatibilidad inmunológica entre donante y receptor, propicia diferencia en las supervivencias de injertos y pacientes, siendo mejor mientras más compatibles sean el donante y el receptor.

ABSTRACT Introduction: Kidney transplant is one of the methods of kidney function replacement, and immunological compatibility is the most important factor influencing survival. Objective: To define transplant survival and its relationship with the degree of compatibility. Material and Methods: Hospital-based retrospective study of survival time of the 827 transplanted patients in the nine centers of the country during the five-year period (2015 - 2019). The Kaplan Meier method was used to estimate the survival curves, using SPSS version 22.0. Results: The graft survival was 72,9 % and the patient survival was 89,0 % in the first year; the mean graft survival was 3,6 years, and the patient survival was 4,6 years. For patients with two and more compatibilities, graft survival was significantly higher in the first year (77,0 % versus 69,2 %), but it was lower for the rest. One year after, the survival rates related to the degree of compatibility are also different. Acute immune rejection, which is one of the main causes of graft loss, has a much higher incidence among the transplanted patients without compatibility than in the compatible ones (17,4 % versus 9,9 %). Infection was the predominant cause of death in these patients, which was incredibly significant in those who do not share compatibility as opposed to those who do share it (56,9 % versus 31,9 %). Conclusions: Immunological compatibility between donor and recipient results in differences between graft and patient survival rates, so the more compatibility between the donor and the recipient, the higher the survival rate.