Background & Aims: Reports of complications among adult right hepatic lobe donors have been limited to single centers. The rate and severity of complications in living donors were investigated in the ...9-center Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). Methods: A retrospective observational study design was used. Participants included all potential living donors evaluated between 1998 and 2003. Complication severity was graded using the Clavien scoring system. Results: Of 405 donors accepted for donation, 393 underwent donation, and 12 procedures were aborted. There were 245 donors (62%) who did not experience complications; 82 (21%) had 1 complication, and 66 (17%) had 2 or more. Complications were scored as grade 1 (minor; n = 106, 27%), grade 2 (potentially life threatening; n = 103, 26%), grade 3 (life threatening; n = 8, 2%), and grade 4 (leading to death; n = 3, 0.8%). Common complications included biliary leaks beyond postoperative day 7 (n = 36, 9%), bacterial infections (n = 49, 12%), incisional hernia (n = 22, 6%), pleural effusion requiring intervention (n = 21, 5%), neuropraxia (n = 16, 4%), reexploration (n = 12, 3%), wound infections (n = 12, 3%), and intraabdominal abscess (n = 9, 2%). Two donors developed portal vein thrombosis, and 1 had inferior vena caval thrombosis. Fifty-one (13%) donors required hospital readmission, and 14 (4%) required 2 to 5 readmissions. Conclusions: Adult living liver donation was associated with significant donor complications. Although most complications were of low-grade severity, a significant proportion were severe or life threatening. Quantification of complication risk may improve the informed consent process, perioperative planning, and donor care.
Stem cell transplantation to the liver is a promising therapeutic strategy for a variety of disorders. Hepatocyte transplantation has short-term efficacy but can be problematic due to portal ...hypertension, inflammation, and sinusoidal thrombosis. We have previously transplanted small mouse endoderm progenitor (EP) cells to successfully reverse a murine model of hemophilia B, and labeling these cells with iron nanoparticles renders them responsive to magnetic fields, which can be used to enhance engraftment. The mechanisms mediating progenitor cell migration from the sinusoidal space to the hepatocyte compartment are unknown. Here we find human EP and hepatic progenitor (HP) cells can be produced from human embryonic stem cells with high efficiency, and they also readily uptake iron nanoparticles. This provides a simple manner through which one can readily identify transplanted cells in vivo using electron microscopy, shortly after delivery. High resolution imaging shows progenitor cell morphologies consistent with epithelial-to-mesenchymal transition (EMT) mediating invasion into the hepatic parenchyma. This occurs in as little as 3 h, which is considerably faster than observed when hepatocytes are transplanted. We confirmed activated EMT in transplanted cells in vitro, as well as in vivo 24 h after transplantation. We conclude that EMT naturally occurs concurrent with EP and HP cell engraftment, which may mediate the rate, safety, and efficacy of early cell engraftment in the undamaged quiescent liver.
Alternative splicing is critical for development; however, its role in the specification of the three embryonic germ layers is poorly understood. By performing RNA-Seq on human embryonic stem cells ...(hESCs) and derived definitive endoderm, cardiac mesoderm, and ectoderm cell lineages, we detect distinct alternative splicing programs associated with each lineage. The most prominent splicing program differences are observed between definitive endoderm and cardiac mesoderm. Integrative multi-omics analyses link each program with lineage-enriched RNA binding protein regulators, and further suggest a widespread role for Quaking (QKI) in the specification of cardiac mesoderm. Remarkably, knockout of QKI disrupts the cardiac mesoderm-associated alternative splicing program and formation of myocytes. These changes arise in part through reduced expression of BIN1 splice variants linked to cardiac development. Mechanistically, we find that QKI represses inclusion of exon 7 in BIN1 pre-mRNA via an exonic ACUAA motif, and this is concomitant with intron removal and cleavage from chromatin. Collectively, our results uncover alternative splicing programs associated with the three germ lineages and demonstrate an important role for QKI in the formation of cardiac mesoderm.
Myofibroblast activation is a cellular response elicited by a variety of physiological or pathological insults whereby cells initiate a coordinated response intended to eradicate the insult and then ...revert back to a basal state. However, an underlying theme in various disease states is persistent myofibroblast activation that fails to resolve. Based on multiple observations, we hypothesized that the secreted factors harvested from co-culturing amniotic stem cells might mimic the anti-inflammatory state that cell-free amniotic fluid (AF) elicits. We optimized an amnion epithelial and amniotic fluid cell co-culture system, and tested this hypothesis in the context of myofibroblast activation. However, we discovered that co-cultured amniotic cell conditioned media (coACCM) and AF have opposing effects on myofibroblast activation: coACCM activates the epithelial–mesenchymal transition (EMT) and stimulates gene expression patterns associated with myofibroblast activation, while AF does the opposite. Intriguingly, extracellular vesicles (EVs) purified from AF are necessary and sufficient to activate EMT and inflammatory gene expression patterns, while the EV-depleted AF potently represses these responses. In summary, these data indicate that coACCM stimulates myofibroblast activation, while AF represses it. We interpret these findings to suggest that coACCM, AF, and fractionated AF represent unique biologics that elicit different cellular responses that are correlated with a wide variety of pathological states, and therefore could have broad utility in the clinic and the lab.
Background & Aims: More than 2000 adult-to-adult living donor liver transplantations (LDLT) have been performed in the United States, yet the potential benefit to liver transplant candidates of ...undergoing LDLT compared with waiting for deceased donor liver transplantation (DDLT) is unknown. The aim of this study was to determine whether there is a survival benefit of adult LDLT. Methods: Adults with chronic liver disease who had a potential living donor evaluated from January 1998 to February 2003 at 9 university-based hospitals were analyzed. Starting at the time of a potential donor’s evaluation, we compared mortality after LDLT to mortality among those who remained on the waiting list or received DDLT. Median follow-up was 4.4 years. Comparisons were made by hazard ratios (HR) adjusted for LDLT candidate characteristics at the time of donor evaluation. Results: Among 807 potential living donor recipients, 389 underwent LDLT, 249 underwent DDLT, 99 died without transplantation, and 70 were awaiting transplantation at last follow-up. Receipt of LDLT was associated with an adjusted mortality HR of 0.56 (95% confidence interval CI: 0.42–0.74; P < .001) relative to candidates who did not undergo LDLT. As centers gained greater experience (>20 LDLT), LDLT benefit was magnified, with a mortality HR of 0.35 (95% CI: 0.23–0.53; P < .001). Conclusions: Adult LDLT was associated with lower mortality than the alternative of waiting for DDLT. This reduction in mortality was magnified as centers gained experience with LDLT. This reduction in transplant candidate mortality must be balanced against the risks undertaken by the living donors themselves.
The objective of this study was to characterize the patient population with respect to patient selection, assess surgical morbidity and graft failures, and analyze the contribution of perioperative ...clinical factors to recipient outcome in adult living donor liver transplantation (ALDLT).
Previous reports have been center-specific or from large databases lacking detailed variables. The Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL) represents the first detailed North American multicenter report of recipient risk and outcome aiming to characterize variables predictive of graft failure.
Three hundred eighty-five ALDLT recipients transplanted at 9 centers were studied with analysis of over 35 donor, recipient, intraoperative, and postoperative variables. Cox regression models were used to examine the relationship of variables to the risk of graft failure.
Ninety-day and 1-year graft survival were 87% and 81%, respectively. Fifty-one (13.2%) grafts failed in the first 90 days. The most common causes of graft failure were vascular thrombosis, primary nonfunction, and sepsis. Biliary complications were common (30% early, 11% late). Older recipient age and length of cold ischemia were significant predictors of graft failure. Center experience greater than 20 ALDLT was associated with a significantly lower risk of graft failure. Recipient Model for End-stage Liver Disease score and graft size were not significant predictors.
This multicenter A2ALL experience provides evidence that ALDLT is a viable option for liver replacement. Older recipient age and prolonged cold ischemia time increase the risk of graft failure. Outcomes improve with increasing center experience.
The purpose of donor evaluation for adult‐to‐adult living donor liver transplantation (LDLT) is to discover medical conditions that could increase the donor postoperative risk of complications and to ...determine whether the donor can yield a suitable graft for the recipient. We report the outcomes of LDLT donor candidates evaluated in a large multicenter study of LDLT. The records of all donor candidates and their respective recipients between 1998 and 2003 were reviewed as part of the Adult‐to‐Adult Living Donor Liver Transplantation Cohort Study (A2ALL). The outcomes of the evaluation were recorded along with demographic data on the donors and recipients. Of the 1011 donor candidates evaluated, 405 (40%) were accepted for donation. The donor characteristics associated with acceptance (P < 0.05) were younger age, lower body mass index, and biological or spousal relationship to the recipient. Recipient characteristics associated with donor acceptance were younger age, lower Model for End‐stage Liver Disease score, and shorter time from listing to first donor evaluation. Other predictors of donor acceptance included earlier year of evaluation and transplant center. Conclusion: Both donor and recipient features appear to affect acceptance for LDLT. These findings may aid the donor evaluation process and allow an objective assessment of the likelihood of donor candidate acceptance. (HEPATOLOGY 2007.)
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