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.

Resilience Related to Quality of Life Perceived in Elderly Patients With Orthotopic Liver Transplant for More Than 10 Years.

INTRODUCTION: Resilience is the ability to recover or adequately face adverse situations. It acts as a protective factor against negative events and/or complex stages of life, such as a chronic and complex disease requiring liver transplant. Age can also have an effect on a patient's ability to deal with liver transplant, resilience here being a predictor of well-being. OBJECTIVE: To analyze the level of resilience and its relationship with health-related quality of life (HRQoL) in patients over 60 years of age who underwent an orthotopic liver transplant (OLT) more than 10 years ago. MATERIALS AND METHODS: We conducted a cross-sectional descriptive study at the Hospital Clínico Virgen Arrixaca. INSTRUMENT: 1. To analyze resilience we used the Connor-Davidson Resilience Scale (CD-RISC 17) which measures 3 dimensions (tenacity/self-efficacy, personal control, and social competence). 2. To evaluate HRQoL, we used the Short Form-36 Health Survey (SF-36) questionnaire which covers 8 dimensions and produces 2 summary scores. Variables included age, sex, and post-OLT survival. Non-parametric statistical analysis was performed (P < .05). RESULTS: We analyzed 47 patients, 68% men (n = 32). The average age was 70.85 ± 0.98 years and average post-OLT survival was 15.79 ± 0.78 years. In terms of resilience, men had higher scores in tenacity/self-efficacy (90.82 ± 2.71 vs 84.79 ± 3.49; P = .029) and personal control (82.5 ± 3.79 vs 69.33 ± 5.23; P = .023). The longer the post-OLT period, the less personal control (R = -0.298; P = .042). Regarding HRQoL, the dimension of personal control is positively related: physical function (R = 0.388; P = .007); general health (R = 0.429; P = .003); vitality (R = 0.560; P = .000); social function (R = 0.402; P = .005); mental health (R = 0.311; P = .034); and physical summary (R = 0.381; P = .008). Like social competence, it is related to mental health (R = 0.360; P = .013) and mental summary (R = 0.384; P = .008). CONCLUSION: These patients showed adequate levels of resilience. A greater resilience is related to greater general health, vitality, social functioning, and mental health.

Self-Esteem Related to Quality of Life in Patients Over 60 Years Old Who Received an Orthotopic Liver Transplantation More Than 10 Years Ago.

BACKGROUND: Orthotopic liver transplantation (OLT) represents an improvement in the quality of life (QoL) in the short to medium term. However, there is little information about QoL in the long-term post-transplant and its relation with psychological variables such as self-esteem. OBJECTIVE: To analyze the perceived QoL in relation to the level of self-esteem in patients over 60 years of age who received an OLT more than 10 years ago. MATERIALS AND METHODS: Cross-sectional descriptive study. Including patients from the Hospital Clínico Universitario Virgen de la Arrixaca (HCUVA). INSTRUMENT: to evaluate the QoL: EuroQol-5D questionnaire; to evaluate health status: 1. social transfer index and 2. visual analog scale (VAS); to measure self-esteem level: Rosenberg scale. Sociodemographic and clinical variables. Nonparametric analysis (P < .05). RESULTS: Analyzed 46 patients, 70% men (n = 32) and 30% women (n = 14); mean age of 70.85 ± 6.7 years and mean years of post-OLT survival of 15.91 ± 5.3 years. Average score in QoL: 0.8 ± 0.17 in the social transfer index and 77.07 ± 16.82 in the VAS. Average level of self-esteem: 34 ± 3.55 point. When analyzing the variables, there are no differences in age or post-OLT years. There are significant differences according to sex (P = .001). However, the diagnosis influences the patient's perception of QoL (P < .001). The post-OLT survival correlates negatively with social transfer index (P = .017) and self-esteem level (P = .045). In addition, those patients living in the city presented a higher level of self-esteem (P = .03). CONCLUSION: Sex, diagnosis, post-OLT years, social environment, and place of residence have an influence on the QoL and self-esteem of patients.