Detection of inflammasome activation in liver tissue during the donation process as potential biomarker for liver transplantation.

Deceased donor liver transplantation (LT) is a crucial lifesaving option for patients with end-stage liver diseases. Although donation after brain death (DBD) remains the main source of donated organs, exploration of donation after circulatory death (DCD) addresses donor scarcity but introduces challenges due to warm ischemia. While technical advances have improved outcomes, challenges persist, with a 13% mortality rate within the first year. Delving into liver transplantation complexities reveals the profound impact of molecular signaling on organ fate. NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation play a pivotal role, influencing inflammatory responses. The NLRP3 inflammasome, found in hepatocytes, contributes to inflammation, fibrosis, and liver cell death. This study explores these dynamics, shedding light on potential biomarkers and therapeutic targets. Samples from 36 liver transplant patients were analyzed for ASC specks detection and inflammasome-related gene expression. Liver biopsies, obtained before and after cold ischemia storage, were processed for immunofluorescence, qRT-PCR, and Western blot. One year post-LT clinical follow-up included diagnostic procedures for complications, and global survival was assessed. Immunofluorescence detected activated inflammasome complexes in fixed liver tissues. ASC specks were identified in hepatocytes, showing a trend toward more specks in DCD livers. Likewise, inflammasome-related gene expression analysis indicated higher expression in DCD livers, decreasing after cold ischemia. Similar results were found at protein level. Patients with increased ASC specks staining exhibited lower overall survival rates, correlating with IL1B expression after cold ischemia. Although preliminary, these findings offer novel insights into utilizing direct detection of inflammasome activation in liver tissue as a biomarker. They suggest its potential impact on post-transplant outcomes, potentially paving the way for improved diagnostic approaches and personalized treatment strategies in LT.

Cell-specific Extracellular Vesicles and Their miRNA Cargo Released Into the Organ Preservation Solution During Cold Ischemia Storage as Biomarkers for Liver Transplant Outcomes.

BACKGROUND: Liver transplantation (LT) is crucial for end-stage liver disease patients, but organ shortages persist. Donation after circulatory death (DCD) aims to broaden the donor pool but presents challenges. Complications like acute rejection, hepatic artery thrombosis, and biliary issues still impact posttransplant prognosis. Biomarkers, including extracellular vesicles (EVs) and microRNAs (miRNAs), show promise in understanding and monitoring posttransplant events. This study explores the role of EVs and their miRNA cargo in LT, including their potential as diagnostic tools. METHODS: EVs from intrahepatic end-ischemic organ preservation solution (eiOPS) in 79 donated livers were detected using different techniques (nanosight tracking analysis, transmission electron microscopy, and flow cytometry). EV-derived miRNAs were identified by quantitative real time-polymerase chain reaction. Bioinformatics analysis was performed using the R platform. RESULTS: Different-sized and origin-specific EVs were found in eiOPS, with significantly higher concentrations in DCD compared with donation after brain death organs. Additionally, several EV-associated miRNAs, including let-7d-5p, miR-28-5p, miR-200a-3p, miR-200b-3p, miR-200c-3p, and miR-429, were overexpressed in DCD-derived eiOPS. These miRNAs also exhibited differential expression patterns in liver tissue biopsies. Pathway analysis revealed enrichment in signaling pathways involved in extracellular matrix organization and various cellular processes. Moreover, specific EVs and miRNAs correlated with clinical outcomes, including survival and early allograft dysfunction. A predictive model combining biomarkers and clinical variables showed promise in acute rejection detection after LT. CONCLUSIONS: These findings provide new insights into the use of EVs and miRNAs as biomarkers and their possible influence on posttransplantation outcomes, potentially contributing to improved diagnostic approaches and personalized treatment strategies in LT.

Endothelial cell activation mediated by cold ischemia-released mitochondria is partially inhibited by defibrotide and impacts on early allograft function following liver transplantation.

DAMPs (danger-associated molecular patterns) are self-molecules of the organism that appear after damage. The endothelium plays several roles in organ rejection, such as presenting alloantigens to T cells and contributing to the development of inflammation and thrombosis. This study aimed to assess whether DAMPs present in the organ preservation solution (OPS) after cold ischemic storage (CIS) contribute to exacerbating the endothelial response to an inflammatory challenge and whether defibrotide treatment could counteract this effect. The activation of cultured human umbilical vein endothelial cells (HUVECs) was analyzed after challenging with end-ischemic OPS (eiOPS) obtained after CIS. Additionally, transwell assays were performed to study the ability of eiOPS to attract lymphocytes across the endothelium. The study revealed that eiOPS upregulated the expression of MCP-1 and IL-6 in HUVECs. Moreover, eiOPS increased the membrane expression of ICAM-1and HLA-DR, which facilitated leukocyte migration toward a chemokine gradient. Furthermore, eiOPS demonstrated its chemoattractant ability. This activation was mediated by free mitochondria. Defibrotide was found to partially inhibit the eiOPS-mediated activation. Moreover, the eiOPS-mediated activation of endothelial cells (ECs) correlated with early allograft dysfunction in liver transplant patients. Our finding provide support for the hypothesis that mitochondria released during cold ischemia could trigger EC activation, leading to complications in graft outcomes. Therefore, the analysis and quantification of free mitochondria in the eiOPS samples obtained after CIS could provide a predictive value for monitoring the progression of transplantation. Moreover, defibrotide emerges as a promising therapeutic agent to mitigate the damage induced by ischemia in donated organs.

Danger signals released during cold ischemia storage activate NLRP3 inflammasome in myeloid cells and influence early allograft function in liver transplantation.

BACKGROUND: Innate immunity plays a fundamental role in solid organ transplantation. Myeloid cells can sense danger signals or DAMPs released after tissue or cell damage, such as during ischemia processes. This study aimed to identify DAMPs released during cold ischemia storage of human liver and analyze their ability to activate the inflammasome in myeloid cells and the possible implications in terms of short-term outcomes of liver transplantation. METHODS: 79 samples of organ preservation solution (OPS) from 79 deceased donors were collected after cold static storage. We used different analytical methods to measure DAMPs in these end-ischemic OPS (eiOPS) samples. We also used eiOPS in the human macrophage THP-1 cell line and primary monocyte cultures to study inflammasome activation. FINDINGS: Different DAMPs were identified in eiOPS, several of which induced both priming and activation of the NLRP3 inflammasome in human myeloid cells. Cold ischemia time and donation after circulatory death negatively influenced the DAMP signature. Moreover, the presence of oligomeric inflammasomes and interleukin-18 in eiOPS correlated with early allograft dysfunction in liver transplant patients. INTERPRETATION: DAMPs released during cold ischemia storage prime and activate the NLRP3 inflammasome in liver macrophages after transplantation, inducing a pro-inflammatory environment that will complicate the outcome of the graft. The use of pharmacological blockers targeting DAMPs or the NLRP3 inflammasome in liver ischemia during static cold storage or through extracorporeal organ support could be a suitable strategy to increase the success of liver transplantation. FUNDING: Fundación Mutua Madrileña and Instituto de Salud Carlos III, Madrid, Spain.

Results of treatment of papillary thyroid microcarcinoma adapted to risk of recurrence.

BACKGROUND: The incidence of papillary thyroid microcarcinoma (PTMC) is increasing. OBJECTIVE: To analyze the long-term prognosis of PTMC. METHOD: Study population: patients with a histopathological diagnosis of PTMC (size ≤ 1 cm) treated according to the risk of recurrence of the Latin American Thyroid Society. Inclusion criteria: minimum follow-up of 2 years, availability of histopathological samples, and treatment compliance. Exclusion criteria: previous thyroid surgery, other synchronous malignancies or ectopic location of the PTMC. Study variables: persistences, recurrences and mortality. RESULTS: Based on the risk of recurrence, PTMC has very low risk in 65.2% (n = 105), low risk in 17.4% (n = 28) and high risk in 17.4% (n = 28). In high risk patients, total thyroidectomy was performed in all cases, cervical lymphadenectomy in 57,1% (n = 16) and metabolic therapy with I131 in all cases. During a mean follow-up of 119,8 ± 65 months, 0.6% (n = 1) of recurrences took place. Risk factors associated to recurrence were not identified. No patient died due to MCPT. CONCLUSIONS: PTMC treated based on its risk of recurrence has a good long-term prognosis, without persistences, with a low number of recurrences and absence of disease-associated mortality.

ANTECEDENTES: La incidencia del microcarcinoma papilar de tiroides (MCPT) está aumentado. OBJETIVO: Analizar el pronóstico a largo plazo del MCPT. MÉTODO: Población a estudio: pacientes con diagnóstico histopatológico de MCPT (tamaño ≤ 1 cm) tratados según el riesgo de recurrencia de la Sociedad Latinoamericana de Tiroides. Criterios de inclusión: seguimiento mínimo de 2 años, disponibilidad de las muestras histopatológicas y cumplimiento del tratamiento. Criterios de exclusión: cirugía tiroidea previa, otras patologías malignas sincrónicas o localización ectópica del MCPT. Variables a estudio: persistencias, recidivas y mortalidad. RESULTADOS: Según el riesgo de recurrencia, el 65.2% (n = 105) tuvo muy bajo riesgo, el 17.4% (n = 28) bajo riesgo y el 17,4% (n = 28) alto riesgo. En los pacientes de alto riesgo se realizó tiroidectomía total en todos los casos, linfadenectomía cervical en el 57,1% (n = 16) y terapia metabólica con I131 en todos los casos. Durante un seguimiento medio de 119,8 ± 65 meses hubo un 0,6% (n = 1) de recurrencias. No se evidenciaron factores de riesgo asociados a recidiva de la enfermedad. Ningún paciente falleció debido al MCPT. CONCLUSIONES: El MCPT tratado en función del riesgo de recurrencia tiene un buen pronóstico a largo plazo, sin persistencias, con una baja cifra de recurrencias y ausencia de mortalidad debida a la enfermedad.

Multicentric Study to Evaluate Mexican Medical Students' Knowledge of Transplants and Organ Donation.

INTRODUCTION: Transplants and organ donation are greatly aided by future medical professionals having adequate knowledge of this topic. This study aimed to elucidate the level of Mexican medical students' knowledge in the field of transplants and organ donation. MATERIALS AND METHODS: The evaluation instrument was designed and validated. The design used simple sampling with replacement, selecting a random sample of 5 universities from among the institutional members of the Mexican Association of Departments and Schools of Medicine (Asociación Mexicana de Facultades y Escuelas de Medicina [AMFEM]). The sample was composed of 3214 medical students. Measures of central tendency were determined, and the mean scores obtained across the different universities were compared using a Kruskal-Wallis test. The odds ratio was calculated for the students whose school or department included instruction on transplants and donation within their curriculum. Kendall correlation was used for the students' academic grade level and score. All analyses considered a threshold of P < .05. RESULTS: A questionnaire was administered to a sample of 2563 students to evaluate their knowledge of transplants and organ donation. The average score was 4.02 on a scale of 0 to 10 (standard deviation 0.03), with a 95% confidence interval (3.96-4.08). Students whose school or department taught the subject of transplants and donations within their curriculum obtained an odds ratio of 1.44 (P = .0000822). CONCLUSIONS: The findings of this study suggest that medical students in Mexico do not have sufficient knowledge of transplants and organ donation.

Attitudes of Latin American Immigrants Resident in Florida (United States) Toward Related Living Kidney Donation.

INTRODUCTION: Latin American immigrants comprise an important population group in the United States. The purpose of this study was to analyze the attitude toward living kidney donation found among Latin American citizens who are residents in Florida and to identify the psychosocial variables affecting their attitude. MATERIAL AND METHODS: A sample of Latin American residents in the state of Florida was randomly obtained and stratified by nationality, age, and sex (n = 1524). Attitude was assessed through a validated questionnaire that was self-administered and completed anonymously. Descriptive, Student t test and the χ2 test were used to analyze findings. RESULTS: The questionnaire completion rate was 94% (N = 1433), with 59% (n = 845) in favor of related living donation, 40% (n = 571) were opposed to donation, with the remaining 1% (n = 17) undecided. The following variables were related to attitude toward living donation: country of origin (P < .001), marital status (P < .001), having descendants (P = .004), educational background (P < 0.001), having had previous experience of donation and transplantation (P < .001), attitude toward deceased donation (P < .001), considering the possibility of needing a transplant (P < .001), the respondent's partner's opinion (P < .001), having considered the subject with one's family (P < .001), having carried out prosocial type activities (P < .001), the respondent's religion (P < .001), knowing that one's religion is in favor of this therapy (P < .001), concern about mutilation after donation (P < .001), and considerations of the risks of living donation (P < .001). CONCLUSIONS: The attitude toward related living kidney donation of Latin American residents in Florida is not very favorable (only 59%).

International collaborative donor project. / Proyecto colaborativo internacional donante.

The International Donor Collaborative Project (PCID) research group was created in 1996 in Spain with the aim of promoting research in the field of organ donation and transplantation, led by Spanish surgeons. During this period they have developed the questionnaires of the PCID, both the attitude towards cadaver and live donation, which are the most used questionnaires in publications in indexed journals. They have been the driving group of stratified studies representative of the populations under study, and of the performance of multivariate statistical analyzes in the field of psycho-social research in organ donation and transplantation. The main contributions of the group focus on the analysis of health center professionals and emerging migrant groups. In recent years, studies have been extended to the United States, Latin America (mainly Mexico) and Europe.

Knowledge and attitude towards organ donation of medicine students of a Northwestern Mexico public university / Actitud y conocimiento sobre donación de órganos de estudiantes de medicina de una universidad pública del noreste de México

Objective: To evaluate the knowledge and attitude towards organ donation of medicine students of a Northwestern Mexico public university. Materials and Methods: A prolective, descriptive, observational, and cross-sectional study. A 34 items cross-sectional survey evaluating knowledge and attitude towards organ donation in 3,056 medicine students during 2013-2015. Descriptive statistics were used as absolute frequencies, percentages, mean and standard deviation, as well as the Chi-square test. A p < 0.05 was considered significant. Results: 74% of students would donate their own organs, mainly due to reciprocity (41%). 26% of students would not donate, 48% of them because of fear that their organs could be taken before death. 86% would donate organs from a relative. 64% have spoken about organ donation and transplantation with their family and 67% with friends. 50% said they had received no information about it. 68% understand the concept of brain death. Conclusion: Students received little information about organ donation during college. Despite that, most of them showed a positive attitude and are willing to donate.

Objetivo: Averiguar la actitud y el conocimiento que tienen los estudiantes de medicina de una universidad pública del noreste de México sobre la donación de órganos y tejidos. Material y métodos: Estudio prolectivo, descriptivo, observacional y trans- versal. Se incluyeron 3056 encuestas de 34 reactivos realizadas a estudiantes de medicina durante el periodo 2013-2015 y se eliminaron aquellas con menos del 80% de los reactivos contestados. Análisis estadístico: frecuencias absolutas, porcentajes, medias, desviación estándar y prueba de ji al cuadrado. Se consideró significativo un valor de p < 0.05. Resultados: El 74% de los estudiantes donaría sus órganos y el 41% lo haría por reciprocidad; del 26% que no donaría sus órganos, el 48% no lo haría por temor a que tomen sus órganos antes de estar muerto. Un 86% estaría dispuesto a donar los órganos de algún familiar. El 64% ha comentado el tema de la donación con su familia y el 67% con amigos. El 50% no ha recibido información alguna sobre el tema. El 68% entiende el concepto de muerte encefálica. Conclusión: Pocos estudiantes reciben información sobre donación de órganos al llegar a la universidad; pese a ello, la mayoría tiene una actitud positiva y estarían dispuestos a donar.

Level of awareness of personnel in hospital services related to the donation process: A Spanish and Latin American multicenter study.

BACKGROUND: Services related to the donation and transplantation process are fundamental for developing solid organ transplantation and procuring organs from deceased donors. This study was conducted to analyze the attitude toward deceased organ donation among hospital personnel working in donation- and transplantation-related services in hospitals in Spain and Latin America. METHODS: Nine hospital centers within the "International Donor Collaborative Project" were selected (Spain, Mexico, Cuba, and Costa Rica). A random employee sample was taken and stratified according to the type of service and job category in transplant-related hospital services. RESULTS: Of the 925 employees surveyed, 78% were in favor of donation. By job category, attitude was more favorable among physicians (89%; p < 0.001). By type of service, attitude was more positive among personnel in transplant patient follow-up units (87%; p = 0.018). By country, the Cubans were most in favor (91%), followed by the Mexicans (81%), the Costa Ricans (77%), and the Spanish (70%; p < 0.001). Other factors were age (p < 0.001), sex (p = 0.005), considering the possibility of needing a transplant (p = 0.002), understanding the concept of brain death (p < 0.001), being in favor of living donation (p < 0.001), having discussed the subject of donation and transplantation within the family and the partner (p < 0.001), carrying out pro-social activities (p = 0.002), and concern about mutilation after donation (p = 0.002). CONCLUSIONS: Transplant-related personnel had a favorable attitude toward deceased donation, although it was not as positive as we would expect, especially among non-physicians. This attitude needs to be improved because of the negative effect that can result in organ donation. There were pronounced differences between countries, and the discordance between attitude and actual deceased donation rates in each country is notable.

[Severe lower gastrointestinal tract bleeding due to diverticulosis]. / Hemorragia digestiva baja grave de origen diverticular.

INTRODUCTION: Diverticulosis is the most frequent cause of lower gastrointestinal (GI) bleeding in adults in western countries. The aims of the present study were to analyze: 1) the diagnostic and therapeutic management of patients with severe lower GI bleeding due to diverticulosis; 2) associated morbidity and mortality; 3) the need for surgery, and 4) bleeding recurrence rates after hospital discharge. MATERIAL AND METHODS: Were retrospectively reviewed 42 patients with severe lower GI bleeding due to diverticulosis. Patients with rectorrhagia requiring transfusion of at least three packed red blood cell units and those with a decrease in hematocrit of 10 points or more were included. As a control group, we used 133 patients with severe lower GI hemorrhage due to causes other than colonic diverticular disease. RESULTS: All patients were stabilized with conservative measures except one who required emergency surgery. Colonoscopy was performed in 39 patients and the most frequent finding consisted of recent signs of bleeding independently of whether colonoscopy was performed early or was delayed. Endoscopic treatment with Argon laser electrocoagulation was performed in one patient. Bleeding recurrence after hospital discharge occurred in 13 patients (31%); of these, seven (16%) required hospital readmission. CONCLUSION: Severe lower GI bleeding due to diverticulosis can usually be resolved with conservative treatment although the percentage of bleeding recurrence is high. Early endoscopy is not as important as in the remaining causes of severe lower GI bleeding.