Long-term Follow-up of a Randomized Trial of Tacrolimus or Cyclosporine A Microemulsion in Children Post Liver Transplantation.

The aim of this study was to determine the long-term efficacy and safety of tacrolimus (Tac) and cyclosporine immunosuppression in pediatric liver transplantation (LTx). METHODS: One hundred fifty-six patients who had taken part in a multicenter, randomized, open, parallel study of Tac and corticosteroids versus cyclosporine A microemulsion (CyA-ME), corticosteroids, and azathioprine. Patients were assessed at regular intervals up to 14 y after LTx. Analysis was conducted descriptively. RESULTS: In a long-term follow-up, there was a similar incidence of acute rejection (Tac versus CyA-ME, 5 versus 8) and graft loss (5 versus 10). There were 11 deaths in the cohort, which were from infectious complications/malignancy in the Tac group (n = 2/5) and from chronic rejection/liver failure in the CyA-ME group (n = 3/6). A similar incidence of Epstein-Barr virus and posttransplant lymphoproliferative disease was observed (8 versus 8, 3 versus 3). However, there was a greater incidence of cosmetic adverse events in the CyA-ME cohort, with higher incidences of hypertrichosis (8 versus 27) and gum hyperplasia (20 versus 6). Growth improved equally in both groups. Overall, 81% of patients randomized to Tac remained on Tac therapy at study end, compared with 31% of patients randomized to CyA-ME. Common reasons for switching from CyA-ME included steroid-resistant/acute rejection (n = 12/8) and cosmetic changes (n = 8). CONCLUSIONS: This study is the first prospective, observational follow-up study of pediatric patients randomized to Tac and CyA-ME to evaluate long-term outcomes. Our analysis was limited by the degree of switchover between the cohorts; however, there were fewer deaths from chronic rejection/liver failure and reduced adverse events with Tac. Long-term use of Tac and Tac combination therapy appears to be safe and effective immunosuppression for pediatric LTx recipients.

Effects of Delta-Like Noncanonical Notch Ligand 1 Expression of Human Fetal Liver Hepatoblasts on Hematopoietic Progenitors.

Although the hepatic and hematopoietic progenitors of the liver are well characterized, the interactions between these two lineages remain mostly elusive. Hepatoblasts express delta-like noncanonical Notch ligand 1 (Dlk1), whose cleaved extracellular domain can become a soluble protein. We assessed the effects of DLK1 gene expression knockdown in cultures of total fetal liver cells. Furthermore, we separated Dlk1+ hepatoblasts from the total liver cell fraction and investigated effects of direct cell contact. Dlk1- cells were cultured either without Dlk1+ hepatoblasts, in direct contact with hepatoblasts, or separated from hepatoblasts by a porous membrane in inserts to inhibit cell contact but allow free exchange of molecules. Expression of the hepatic and hematopoietic genes, colony forming unit potential of various hematopoietic progenitors, and cell numbers and types were investigated. We found that DLK1 knockdown in total fetal liver cell cultures decreased total cell numbers. The expression of hepatic progenitor genes and mature hematopoietic genes was affected. Hematopoietic BFU-E and CFU-GM colony numbers were reduced significantly. The depletion of Dlk1+ hepatoblasts in culture decreased the potential of all hematopoietic progenitors to form colonies of all types and reduced the percentage of mature hematopoietic cells. The addition of hepatoblasts in inserts to Dlk1- cells further decreased the potential to form the CFU-GM and CFU-GEMM colonies and the percentage of mature hematopoietic cells but increased total cell numbers. Conclusively, direct contact of Dlk1 supports hematopoietic progenitor expansion and functionality that cannot be reconstituted in coculture without direct cell contact.

Digital liver biopsy: Bio-imaging of fatty liver for translational and clinical research.

The rapidly growing field of functional, molecular and structural bio-imaging is providing an extraordinary new opportunity to overcome the limits of invasive liver biopsy and introduce a "digital biopsy" for in vivo study of liver pathophysiology. To foster the application of bio-imaging in clinical and translational research, there is a need to standardize the methods of both acquisition and the storage of the bio-images of the liver. It can be hoped that the combination of digital, liquid and histologic liver biopsies will provide an innovative synergistic tri-dimensional approach to identifying new aetiologies, diagnostic and prognostic biomarkers and therapeutic targets for the optimization of personalized therapy of liver diseases and liver cancer. A group of experts of different disciplines (Special Interest Group for Personalized Hepatology of the Italian Association for the Study of the Liver, Institute for Biostructures and Bio-imaging of the National Research Council and Bio-banking and Biomolecular Resources Research Infrastructure) discussed criteria, methods and guidelines for facilitating the requisite application of data collection. This manuscript provides a multi-Author review of the issue with special focus on fatty liver.

Response of Human Fetal Liver Progenitor Cell Types to Temperature and pH Stresses In Vitro.

Prolonged physiological stresses, including abnormal pH and temperature, are deleterious. However, human hepatic progenitors have been shown to be quite tolerant of temporary temperature stress such as in cold ischemia. We aimed at identifying how various stresses affect liver progenitors, and at determining whether distinct effects exist on different progenitor cells of the human liver. Total fetal liver cells were exposed to low (25°C), normal (37°C), or high (40°C) temperatures, or low (6.76), normal (7.35), or high (7.88) pH in vitro. Culture at 25°C increased cell numbers and percentages of proliferation marker Ki67+ total cells. In total cell cultures, percentages of CD326+ hepatic progenitors co-expressing DLK1 (delta-like 1 homolog), SSEA4, or CD90 increased, as well as proliferation of SSEA4+ and CD235a+ progenitors. Analyses of presorted hepatic progenitors revealed that culture at 25°C increased cell numbers of CD326+ hepatic stem/progenitor cells but not DLK+ hepatoblasts. The expression of several mesenchymal genes was reduced, and distinct hepatic stem/progenitor cell colonies emerged. At 40°C, numbers of adherent hepatic cells decreased but those of hematopoietic nonadherent cells increased. High pH did not cause major effects. Acidic pH resulted in decreased total cell numbers and affected hematopoietic cells. Percentages of DLK1+ hepatoblasts were increased, but those of hematopoietic mature CD45+ cells were decreased. In particular, proliferation of adherent hepatic CD326+, SSEA4+ progenitors, and hematopoietic CD45+ cells and CD235a+ erythroblasts was reduced. Conclusively, our data indicate that low-temperature stress stimulates hepatic progenitor and erythroblast proliferation, whereas acidic pH promotes hepatic maturation and reduces hematopoietic cells.

Epithelial cell adhesion molecule fragments and signaling in primary human liver cells.

Epithelial Cell Adhesion Molecule (EpCAM), or CD326, is a trans-membrane glycoprotein expressed by multiple normal epithelia as well as carcinoma. Human hepatic stem cells and bile duct epithelium of the liver are EpCAM positive. In tumor cell lines, its intracellular domain can be released after cleavage of the extracellular domain. Within the cell nucleus, it induces cell proliferation, but cleavage depends on cell contact. Fragments of various lengths have been described in tumor cells. Despite its described important role in proliferation in tumor cells, there is not much known about the expression and role of EpCAM fragments in primary human liver cells. Here, we demonstrate that EpCAM protein fragments and function are considerable different between tumor cells, normal fetal and adult liver cells. Contrary to previously reported findings in tumor cells, gene knockdown or treatment with an inhibitor of the cleavage enzyme ADAM17 (TACE) rather increased cell numbers in primary human fetal liver-derived EpCAM-positive cells. EpCAM fragment sizes were not affected by treatment with inhibitor. Knockdown of EPCAM gene expression by siRNA in sorted cells did not significantly affect proliferation-associated genes or cell numbers. The intracellular domain could not be detected within cell nuclei of fetal and adult liver cells. In conclusion, signaling through the intracellular domain of EpCAM appears to be a mechanism that induces proliferation specifically in tumorigenic cells but not in normal primary EpCAM-positive liver cells.

HCV replication in gastrointestinal mucosa: Potential extra-hepatic viral reservoir and possible role in HCV infection recurrence after liver transplantation.

PURPOSE: Hepatitis C virus (HCV) predominantly infects hepatocytes, although it is known that receptors for viral entry are distributed on a wide array of target cells. Chronic HCV infection is indeed characterized by multiple non-liver manifestations, suggesting a more complex HCV tropism extended to extrahepatic tissues and remains to be fully elucidated. In this study, we investigated the gastrointestinal mucosa (GIM) as a potential extrahepatic viral replication site and its contribution to HCV recurrence. METHODS: We analyzed GIM biopsies from a cohort of 76 patients, 11 of which were HCV-negative and 65 HCV-positive. Of these, 54 biopsies were from liver-transplanted patients. In 29 cases, we were able to investigate gastrointestinal biopsies from the same patient before and after transplant. To evaluate the presence of HCV, we looked for viral antigens and genome RNA, whilst to assess viral replicative activity, we searched for the replicative intermediate minus-strand RNA. We studied the genetic diversity and the phylogenetic relationship of HCV quasispecies from plasma, liver and gastrointestinal mucosa of HCV-liver-transplanted patients in order to assess HCV compartmentalization and possible contribution of gastrointestinal variants to liver re-infection after transplantation. RESULTS: Here we show that HCV infects and replicates in the cells of the GIM and that the favorite hosts were mostly enteroendocrine cells. Interestingly, we observed compartmentalization of the HCV quasispecies present in the gastrointestinal mucosa compared to other tissues of the same patient. Moreover, the phylogenetic analysis revealed a high similarity between HCV variants detected in gastrointestinal mucosa and those present in the re-infected graft. CONCLUSIONS: Our results demonstrated that the gastrointestinal mucosa might be considered as an extrahepatic reservoir of HCV and that could contribute to viral recurrence. Moreover, the finding that HCV infects and replicates in neuroendocrine cells opens new perspectives on the role of these cells in the natural history of HCV infection.

A matched pair analysis of multicenter longterm follow-up after split-liver transplantation with extended right grafts.

Split-liver transplantation has been proposed as an alternative to whole liver (WL) transplantation to expand the donor pool, but studies comparing adult longterm outcomes between the 2 methods are conflicting and limited. This is the first Italian multicenter study that retrospectively analyzed 119 matched-pair recipients of whole and extended right grafts (ERGs) for longterm survival outcomes. In the overall population, WL recipients showed higher patient survival at 1 (93% versus 73%), 5 (87% versus 65%), and 10 years (83% versus 60%) after transplantation compared with split-liver recipients (P < 0.001); graft survivals of WL recipients were also superior at 1 (90% versus 76%), 5 (84% versus 57%), and 10 years (81% versus 52%) posttransplant (P < 0.001). However, among the 81 matched pairs that survived the first posttransplant year, 5- and 10-year patient survivals were 90% and 81% for split recipients and 99% and 96% for whole recipients, respectively (P = 0.34). The 5- and 10-year graft survivals were also comparable: 87% and 77% for split recipients, and 86% and 82% for whole recipients (P = 0.86). Cox regression analysis identified donor age >50, donor-to-recipient weight ratio < 1, retransplantation status, and United Network for Organ Sharing I-IIA status as risk factors for partial graft use. There were no significant differences in 5-year outcomes based on center volume. In conclusion, we demonstrate that adult liver transplantation with ERGs can achieve longterm success comparable with that of whole grafts in appropriate patients but should be selectively used in patients with risk factors. Liver Transplantation 23 1384-1395 2017 AASLD.

Donor safety in living donor liver donation: An Italian multicenter survey.

Major concerns about donor morbidity and mortality still limit the use of living donor liver transplantation (LDLT) to overcome the organ shortage. The present study assessed donor safety in LDLT in Italy reporting donor postoperative outcomes in 246 living donation procedures performed by 7 transplant centers. Outcomes were evaluated over 2 time periods using the validated Clavien 5-tier grading system, and several clinical variables were analyzed to determine the risk factors for donor morbidity. Different grafts were obtained from the 246 donor procedures (220 right lobe, 10 left lobe, and 16 left lateral segments). The median follow-up after donation was 112 months. There was no donor mortality. One or more complications occurred in 82 (33.3%) donors, and 3 of them had intraoperative complications (1.2%). Regardless of graft type, the rate of major complications (grade ≥ 3) was 12.6% (31/246). The overall donor morbidity and the rate of major complications did not differ significantly over time: 26 (10.6%) donors required hospital readmission throughout the follow-up period, whereas 5 (2.0%) donors required reoperation. Prolonged operative time (>400 minutes), intraoperative hypotension (systolic < 100 mm Hg), vascular abnormalities, and intraoperative blood loss (>300 mL) were multivariate risk factors for postoperative donor complications. In conclusion, from the standpoint of living donor surgery, a meticulous and well-standardized technique that reduces operative time and prevents blood loss and intraoperative hypotension may reduce the incidence of donor complications. Transparency in reporting results after LDLT is mandatory, and we should continue to strive for zero donor mortality. Liver Transplantation 23 184-193 2017 AASLD.

Complications and Near-Miss Events After Hepatectomy for Living-Related Liver Donation: An Italian Single Center Report of One Hundred Cases.

BACKGROUND In healthy individuals, such as liver living donors, potential complications may occur during surgery. Reporting such complications and near-miss events is mandatory to improve living donor management and safety. MATERIAL AND METHODS This retrospective study was performed on a prospective database with the aim of providing a brief analysis of the perioperative, medium-term, and long-term complications, and the near-miss events in a single center series of 100 consecutive liver resections for adult-to-adult living-donor liver transplantation. RESULTS Only 23.3% of potential living donors underwent surgery. No living donor mortality was reported; 29 patients (29%) experienced at least one complication. Five patients developed mild long-term dysfunction; two aborted hepatectomies, and there were two near-miss events reported. CONCLUSIONS A strategy for an accurate assessment of living donor complications and strict selection criterion cannot be overemphasized, as well as the need to continuously update center patient outcome reports.

Response of Primary Human Bone Marrow Mesenchymal Stromal Cells and Dermal Keratinocytes to Thermal Printer Materials In Vitro.

Advancement in thermal three-dimensional printing techniques has greatly increased the possible applications of various materials in medical applications and tissue engineering. Yet, potential toxic effects on primary human cells have been rarely investigated. Therefore, we compared four materials commonly used in thermal printing for bioengineering, namely thermally printed acrylonitrile butadiene styrene, MED610, polycarbonate, and polylactic acid, and investigated their effects on primary human adult skin epidermal keratinocytes and bone marrow mesenchymal stromal cells (BM-MSCs) in vitro. We investigated indirect effects on both cell types caused by potential liberation of soluble substances from the materials, and also analyzed BM-MSCs in direct contact with the materials. We found that even in culture without direct contact with the materials, the culture with MED610 (and to a lesser extent acrylonitrile butadiene styrene) significantly affected keratinocytes, reducing cell numbers and proliferation marker Ki67 expression, and increasing glucose consumption, lactate secretion, and expression of differentiation-associated genes. BM-MSCs had decreased metabolic activity, and exhibited increased cell death in direct culture on the materials. MED610 and acrylonitrile butadiene styrene induced the strongest expression of genes associated to differentiation and estrogen receptor activation. In conclusion, we found strong cell-type-specific effects of the materials, suggesting that materials for applications in regenerative medicine should be carefully selected not only based on their mechanical properties but also based on their cell-type-specific biological effects.

Mini-Invasive Approach Contributes to Expand the Indication for Liver Resection for Hepatocellular Carcinoma Without Increasing the Incidence of Posthepatectomy Liver Failure and Other Perioperative Complications: A Single-Center Analysis.

BACKGROUND: Liver resection (LR) for hepatocellular carcinoma (HCC) is the best alternative option for increasing the survival of many patients with intermediate or advanced stages of the Barcelona Clinic Liver Cancer staging classification. Mini-invasive approach may play a positive role in treating a tumor rising almost exclusively in a diseased liver. METHODS: A prospectively collected database was retrospectively reviewed for 167 consecutive patients who underwent LR between 1999 and 2015. RESULTS: A total of 38 LRs were performed from 1999 to 2009 (Period I), and 129 between 2010 and 2015 (Period II). Laparoscopic procedures increased from 5.3% to 38.1%. Not undergoing laparoscopic LR increased length of stay, and Clavien Grade II or worse complications. Ninety-day mortality decreased from 5.2% to 0%, and morbidity did not differ significantly, despite the fact that the most complex patients were in Period II. CONCLUSIONS: Mini-invasive approaches allow to safely expand limits of LR for HCC; in particular, laparoscopic approach favors surgical option even in more complex patients without increase the risk of posthepatic liver failure or other postsurgical complications.

Liver Volume Restoration and Hepatic Microarchitecture in Small-for-Size Syndrome.

BACKGROUND: We investigated preoperative parameters that could work as markers of liver regeneration (LR), and tried to create an algorithm for therapeutic decision-making, looking at the clinical setting of post-hepatectomy liver failure (PHLF) after major liver resection for malignancies (LRM) and of the small-for-size syndrome (SFSS) after adult-to-adult living related liver transplantation (LRLT), considering PHLF and SFSS a single clinical entity. MATERIAL AND METHODS: The clinical data of 2 series of 10 consecutive patients who experienced liver-specific complications after LRLT or LRM between 2008 and 2013 were analyzed. LR was evaluated by multidetector computed tomography (MDCT) and hepatic parenchymal findings with specific re-examinations of liver biopsies. The analysis was done according to demographics, tumor characteristics, and postoperative complications occurring within 90 days of surgery and codified within the Clavien classification. RESULTS: A total of 13 cases of SFSS occurred in 8 LRLT recipients (61.5%) and in 5 patients after LRM (38.5%). The incidence of SFSS was significantly associated with a greater spleen volume/future remnant liver volume ratio (1.08±0.5; P=0.02) and a reduced number of hepatic tumors (0.58±0.6; P=0.04). A greater degree of LR was not associated with a lesser likelihood of developing SFSS (P=0.31). SFSS incidence and re-examination of post-operative liver biopsies differed according to the evidence of focal endothelial denudation in the portal vein and centrilobular hepatocanalicular cholestasis. We found an association between SFSS incidence and the immunohistochemical overexpression of cytological proliferation marker Ki-67 (29.3±29.8%; P=0.007), which was a significant predictor of poor post-operative survival (OR=1.12, C.I.: 1.013; 1.242). CONCLUSIONS: SFSS is a rare but dangerous clinical entity characterized by anarchic hepatic regeneration. We suggest focusing on early diagnosis in order to establish non-surgical modulation of the portal inflow, in conjunction with optimization of medical management.

Role of transcription factor CCAAT/enhancer-binding protein alpha in human fetal liver cell types in vitro.

AIM: The transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα) has been shown to play an important role in liver development, cell proliferation and differentiation. It is, however, largely unknown if C/EBPα regulates cell differentiation and proliferation differently in the diverse cell types of the human liver. We investigated the role of C/EBPα in primary human fetal liver cells and liver cell subpopulations in vitro using a 3-D perfusion bioreactor as an advanced in vivo-like human organ culture model. METHODS: Human fetal liver cells were investigated in vitro. C/EBPα gene expression was knocked down using siRNA or overexpressed by plasmid transfection. Cell type-specific gene expression was studied, cell populations and their proliferation were investigated, and metabolic parameters were analyzed. RESULTS: When C/EBPα gene expression was knocked down, we observed a significantly reduced expression of typical endothelial, hematopoietic and mesenchymal genes such as CD31, vWF, CD90, CD45 and α-smooth muscle actin in fetal cells. The intracellular expression of hepatic proteins and genes for liver-specific serum proteins α-fetoprotein and albumin were reduced, their protein secretion was increased. Fetal endothelial cell numbers were reduced and hepatoblast numbers were increased. C/EBPα overexpression in fetal cells resulted in increased endothelial numbers, but did not affect mesenchymal cell types or hepatoblasts. CONCLUSION: We demonstrated that the effects of C/EBPα are specific for the different human fetal liver cell types, using an advanced 3-D perfusion bioreactor as a human in vivo-like model.

Phases I-II Matched Case-Control Study of Human Fetal Liver Cell Transplantation for Treatment of Chronic Liver Disease.

Fetal hepatocytes have a high regenerative capacity. The aim of the study was to assess treatment safety and clinical efficacy of human fetal liver cell transplantation through splenic artery infusion. Patients with end-stage chronic liver disease on the waiting list for liver transplantation were enrolled. A retrospectively selected contemporary matched-pair group served as control. Nonsorted raw fetal liver cell preparations were isolated from therapeutically aborted fetuses. The end points of the study were safety and improvement of the Model for End-Stage Liver Disease (MELD) and Child-Pugh scores. Nine patients received a total of 13 intrasplenic infusions and were compared with 16 patients on standard therapy. There were no side effects related to the infusion procedure. At the end of follow-up, the MELD score (mean ± SD) in the treatment group remained stable from baseline (16.0 ± 2.9) to the last observation (15.7 ± 3.8), while it increased in the control group from 15.3 ± 2.5 to 19 ± 5.7 (p = 0.0437). The Child-Pugh score (mean ± SD) dropped from 10.1 ± 1.5 to 9.1 ± 1.4 in the treatment group and increased from 10.0 ± 1.2 to 11.1 ± 1.6 in the control group (p = 0.0076). All treated patients with history of recurrent portosystemic encephalopathy (PSE) had no further episodes during 1-year follow-up. No improvement was observed in the control group patients with PSE at study inclusion. Treatment was considered a failure in six of the nine patients (three deaths not liver related, one liver transplant, two MELD score increases) compared with 14 of the 16 patients in the control group (six deaths, five of which were caused by liver failure, four liver transplants, and four MELD score increases). Intrasplenic fetal liver cell infusion is a safe and well-tolerated procedure in patients with end-stage chronic liver disease. A positive effect on clinical scores and on encephalopathy emerged from this preliminary study.

Liver regeneration after liver resection: clinical aspects and correlation with infective complications.

AIM: To investigate whether early liver regeneration after resection in patients with hepatic tumors might be influenced by post-operative infective complications. METHODS: A retrospective analysis of 27 liver resections for tumors performed in a single referral center from November 2004 to January 2010. Regeneration was evaluated by multidetector computed tomography at a mean follow-up of 43.85 d. The Clavien-Dindo classification was used to evaluate postoperative events in the first 6 mo after transplantation, and Centers for Disease Control and Prevention definitions were used for healthcare associated infections data. Generalized linear regression models with Gaussian family distribution and log link function were used to reveal the principal promoters of early liver regeneration. RESULTS: Ten of the 27 patients (37%) underwent chemotherapy prior to surgery, with a statistically significant prevalence of patients with metastasis (P = 0.007). Eight patients (30%) underwent embolization, 3 with primary tumors, and 5 with secondary tumors. Twenty patients (74%) experienced complications, with 12 (60%) experiencing Clavien-Dindo Grade 3a to 5 complications. Regeneration ≥ 100% occurred in 10 (37%) patients. The predictors were smaller future remnant liver volume (-0.002; P < 0.001), and a greater spleen volume/future remnant liver volume ratio (0.499; P = 0.01). Patients with a resection of ≥ 5 Couinaud segments experienced greater early regeneration (P = 0.04). Nine patients experienced surgical site infections, and in 7 cases Clavien-Dindo Grade 3a to 4 complications were detected (P = 0.016). There were no significant differences between patients with primary or secondary tumors, and either onset or infections or severity of surgical complications. CONCLUSION: Regardless of the onset of infective complications, future remnant liver and spleen volumes may be reliable predictors of early liver regeneration after hepatic resection on an otherwise healthy liver.

A Bayesian methodology to improve prediction of early graft loss after liver transplantation derived from the liver match study.

BACKGROUND: To generate a robust predictive model of Early (3 months) Graft Loss after liver transplantation, we used a Bayesian approach to combine evidence from a prospective European cohort (Liver-Match) and the United Network for Organ Sharing registry. METHODS: Liver-Match included 1480 consecutive primary liver transplants performed from 2007 to 2009 and the United Network for Organ Sharing a time-matched series of 9740 transplants. There were 173 and 706 Early Graft Loss, respectively. Multivariate analysis identified as significant predictors of Early Graft Loss: donor age, donation after cardiac death, cold ischaemia time, donor body mass index and height, recipient creatinine, bilirubin, disease aetiology, prior upper abdominal surgery and portal thrombosis. RESULTS: A Bayesian Cox model was fitted to Liver-Match data using the United Network for Organ Sharing findings as prior information, allowing to generate an Early Graft Loss-Donor Risk Index and an Early Graft Loss-Recipient Risk Index. A Donor-Recipient Allocation Model, obtained by adding Early Graft Loss-Donor Risk Index to Early Graft Loss-Recipient Risk Index, was then validated in a distinct United Network for Organ Sharing (year 2010) cohort including 2964 transplants. Donor-Recipient Allocation Model updating using the independent Turin Transplant Centre dataset, allowed to predict Early Graft Loss with good accuracy (c-statistic: 0.76). CONCLUSION: Donor-Recipient Allocation Model allows a reliable donor and recipient-based Early Graft Loss prediction. The Bayesian approach permits to adapt the original Donor-Recipient Allocation Model by incorporating evidence from other cohorts, resulting in significantly improved predictive capability.

Isolation and characterization of multipotent cells from human fetal dermis.

We report that cells from human fetal dermis, termed here multipotent fetal dermal cells, can be isolated with high efficiency by using a nonenzymatic, cell outgrowth method. The resulting cell population was consistent with the definition of mesenchymal stromal cells by the International Society for Cellular Therapy. As multipotent fetal dermal cells proliferate extensively, with no loss of multilineage differentiation potential up to passage 25, they may be an ideal source for cell therapy to repair damaged tissues and organs. Multipotent fetal dermal cells were not recognized as targets by T lymphocytes in vitro, thus supporting their feasibility for allogenic transplantation. Moreover, the expansion protocol did not affect the normal phenotype and karyotype of cells. When compared with adult dermal cells, fetal cells displayed several advantages, including a greater cellular yield after isolation, the ability to proliferate longer, and the retention of differentiation potential. Interestingly, multipotent fetal dermal cells expressed the pluripotency marker SSEA4 (90.56 ± 3.15% fetal vs. 10.5 ± 8.5% adult) and coexpressed mesenchymal and epithelial markers (>80% CD90(+)/CK18(+) cells), coexpression lacking in the adult counterparts isolated under the same conditions. Multipotent fetal dermal cells were able to form capillary structures, as well as differentiate into a simple epithelium in vitro, indicating skin regeneration capabilities.

Right hepatic lobe living donation: a 12 years single Italian center experience.

Mini invasive techniques are taking over conventional open liver resections in the setting of left lateral segmentectomy for living liver donation, and hydride procedure are being implemented for the living related right hepatectomy. Our center routinely performs laparoscopic left lateral segmentectomy for pediatric recipient and has been the first in the Europe performing an entirely robotic right hepatectomy. Great emphasis is posed on living donor safety which is the first priority during the entire operation, then the most majority of our procedures are still conventional open right hepatectomy (RHLD), defined as removal of a portion of liver corresponding to Couinaud segments 5-8, in order to obtain a graft for adult to adult living related liver transplant. During this 10 years period some changes, herein highlighted, have occurred to our surgical techniques. This study reports the largest Italian experience with RHLD, focused on surgical technique evolution over a 10 years period. Donor safety must be the first priority in right-lobe living-related donation: the categorization of complications of living donors, specially, after this "highly sensitive" procedure, reflects the need for prompt and detailed reports.

Phenotypical characterization of 6-21-week gestational age human dermis and epidermal cell isolation methods for in vitro studies on epidermal progenitors.

UNLABELLED: Cell banked epidermal skin progenitor cells have the potential to provide an "off-the-freezer" product. Such cells may provide a skin donor area-independent cell-spray grafting therapy for the treatment of burns. We first characterized fetal skin samples of gestational ages ranging from 6 to 21 weeks. As the results suggest that the phenotypic differentiation occurs after 10 weeks, which may complicate follow-up in vitro studies, we developed and compared different cell isolation techniques for human fetal skin-derived epithelial cells from tissue ages 6 to 9 weeks. We initially screened seven methods of characterization, concluding that two methods warranted further investigation: incubating the epidermal tissue in Petri-dishes with culture medium for spontaneous cell outgrowth, and wiping the epidermal tissue onto a dry Petri-dish culture surface followed by adding culture medium. Non-controllable culture contamination with dermal cells was the reason for excluding the other five methods. The results suggest that epidermal cells can be isolated from tissue exhibiting a single homogeneous layer of CK15(+) basal keratinocytes up to week 9. At later gestational ages, the ongoing skin differentiation results in a multi-layer basal structure and progenitors associated with the hair bulb would have to be considered. Spraying the resulting cells with a clinical spray device was successfully demonstrated in an in vitro model. CONCLUSION: Gestational age 6-9 weeks epidermal human fetal skin cells from the basal layer can be reproducibly isolated and transferred into culture for studies on the development of skin cell transplantation therapies.

Perivascular mesenchymal progenitors in human fetal and adult liver.

The presence of mesenchymal stem cells (MSCs) has been described in various organs. Pericytes possess a multilineage differentiation potential and have been suggested to be one of the developmental sources for MSCs. In human liver, pericytes have not been defined. Here, we describe the identification, purification, and characterization of pericytes in human adult and fetal liver. Flow cytometry sorting revealed that human adult and fetal liver contains 0.56%±0.81% and 0.45%±0.39% of CD146(+)CD45(-)CD56(-)CD34(-) pericytes, respectively. Of these, 41% (adult) and 30% (fetal) were alkaline phosphatase-positive (ALP(+)). In situ, pericytes were localized around periportal blood vessels and were positive for NG2 and vimentin. Purified pericytes could be cultured extensively and had low population doubling times. Immunofluorescence of cultures demonstrated that cells were positive for pericyte and mesenchymal cell markers CD146, NG2, CD90, CD140b, and vimentin, and negative for endothelial, hematopoietic, stellate, muscle, or liver epithelial cell markers von Willebrand factor, CD31, CD34, CD45, CD144, CD326, CK19, albumin, α-fetoprotein, CYP3A7, glial fibrillary acid protein, MYF5, and Pax7 by gene expression; myogenin and alpha-smooth muscle actin expression were variable. Fluorescence-activated cell sorting analysis of cultures confirmed surface expression of CD146, CD73, CD90, CD10, CD13, CD44, CD105, and ALP and absence of human leukocyte antigen-DR. In vitro differentiation assays demonstrated that cells possessed robust osteogenic and myogenic, but low adipogenic and low chondrogenic differentiation potentials. In functional in vitro assays, cells had typical mesenchymal strong migratory and invasive activity. In conclusion, human adult and fetal livers harbor pericytes that are similar to those found in other organs and are distinct from hepatic stellate cells.