The IPTA Nashville consensus conference on post-transplant lymphoproliferative disorders after solid organ transplantation in children: IV-consensus guidelines for the management of post-transplant lymphoproliferative disorders in children and adolescents.

The International Pediatric Transplant Association convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorders (PTLD) after pediatric solid organ transplantation. This report addresses the outcomes of deliberations by the PTLD Management Working Group. A strong recommendation was made for reduction in immunosuppression as the first step in management. Similarly, strong recommendations were made for the use of the anti-CD20 monoclonal antibody (rituximab) as was the case for chemotherapy in selected scenarios. In some scenarios, there is uncoupling of the strength of the recommendations from the available evidence in situations where such evidence is lacking but collective clinical experiences drive decision-making. Of note, there are no large, randomized phase III trials of any treatment for PTLD in the pediatric age group. Current gaps and future research priorities are highlighted.

Point-of-Care Ultrasound training in undergraduate education in the European Union: current situation and perspectives.

BACKGROUND: Given the widespread use of Point-of-Care UltraSound (PoCUS) in clinical practice, with ultrasound machines becoming more portable and affordable, recommendations and position statements from ultrasound societies now promote teaching PoCUS in the undergraduate curriculum. Nevertheless, surveys about PoCUS teaching in European medical schools are lacking. This survey aims to overview the current and future undergraduate PoCUS courses in the European Union (EU). RESULTS: A questionnaire was sent to medical schools in 26 of the 27 countries of the EU; Luxembourg is the only country without a medical school. The survey was completed by the dean or a member of the medical school with knowledge of the medical curriculum. Of the 58 medical schools from 19 countries that responded to the survey, 18 (31.0%) from 13 (68.4%) EU countries reported the existence of an undergraduate PoCUS curriculum and a further 16 (27.6%) from 12 (41.4%) EU countries intended to offer it in the future. No significant difference was observed between the current and future PoCUS curricula regarding its content and purpose. Less than 40 h of theoretical teaching is provided in all the medical schools and less than 40 h of practical training is provided in 12 (75%) of the 16 medical schools which answered this specific question. Of the 40 (69%) surveyed medical schools that do not currently teach PoCUS, 20 (50%) intend to offer PoCUS courses in the future. CONCLUSION: Although the lack of teaching hours in curricula suggests that most PoCUS courses are introductory in nature and that medical students are possibly not trained to become autonomous in clinical practice, evaluating the feasibility and impact of PoCUS teaching on clinical practice should be promoted. The medical schools that intend to develop this curriculum should be encouraged to implement validated tools to objectively assess their programs and students' performances.

The IPTA Nashville Consensus Conference on Post-Transplant lymphoproliferative disorders after solid organ transplantation in children: III - Consensus guidelines for Epstein-Barr virus load and other biomarker monitoring.

The International Pediatric Transplant Association convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorders after solid organ transplantation in children. In this report from the Viral Load and Biomarker Monitoring Working Group, we reviewed the existing literature regarding the role of Epstein-Barr viral load and other biomarkers in peripheral blood for predicting the development of PTLD, for PTLD diagnosis, and for monitoring of response to treatment. Key recommendations from the group highlighted the strong recommendation for use of the term EBV DNAemia instead of "viremia" to describe EBV DNA levels in peripheral blood as well as concerns with comparison of EBV DNAemia measurement results performed at different institutions even when tests are calibrated using the WHO international standard. The working group concluded that either whole blood or plasma could be used as matrices for EBV DNA measurement; optimal specimen type may be clinical context dependent. Whole blood testing has some advantages for surveillance to inform pre-emptive interventions while plasma testing may be preferred in the setting of clinical symptoms and treatment monitoring. However, EBV DNAemia testing alone was not recommended for PTLD diagnosis. Quantitative EBV DNAemia surveillance to identify patients at risk for PTLD and to inform pre-emptive interventions in patients who are EBV seronegative pre-transplant was recommended. In contrast, with the exception of intestinal transplant recipients or those with recent primary EBV infection prior to SOT, surveillance was not recommended in pediatric SOT recipients EBV seropositive pre-transplant. Implications of viral load kinetic parameters including peak load and viral set point on pre-emptive PTLD prevention monitoring algorithms were discussed. Use of additional markers, including measurements of EBV specific cell mediated immunity was discussed but not recommended though the importance of obtaining additional data from prospective multicenter studies was highlighted as a key research priority.

Long-term Outcome of Asymptomatic Patients With Graft Fibrosis in Protocol Biopsies After Pediatric Liver Transplantation.

BACKGROUND: The histological prevalence of allograft fibrosis in asymptomatic children after liver transplantation (LT) is well documented. However, long-term graft and patient survival remain unclear. This retrospective multicenter study aims to determine the prevalence of allograft fibrosis and analyze the long-term outcome for patients transplanted in childhood. METHODS: We reviewed clinical data of children who had undergone 10-y protocol liver biopsies. We excluded patients with autoimmune hepatitis, primary sclerosing cholangitis, hepatitis B or C, and retransplantation. In total, 494 patients transplanted in childhood across 12 international transplant centers were included. We evaluated the development of fibrosis by comparing the results with biopsies obtained 5 and 15 y post-LT. Histological findings were correlated with graft and patient survival up to 20 y post-LT. RESULTS: In the 10-y biopsies, periportal or pericentral fibrosis was observed in 253 patients (51%), 87 (18%) had bridging fibrosis, 30 (6%) had cirrhosis, and 124 (25%) had no fibrosis. The prevalence and stage of graft fibrosis significantly progressed from 5 to 10 y. At 10 y, the severity of fibrosis correlated significantly with inflammation. Patients with graft cirrhosis in the 10-y biopsy were more likely to die or require retransplantation subsequently ( P = 0.027). CONCLUSIONS: At 10 y post-LT, most patients transplanted in childhood developed fibrosis, based on the protocol liver biopsies. Although mild-to-moderate graft fibrosis did not largely affect patient or graft survival up to 20 y post-LT, this progressive fibrosis finding has substantial implications for developing cirrhosis and portal hypertension in adult care.

The IPTA Nashville consensus conference on Post-Transplant lymphoproliferative disorders after solid organ transplantation in children: II-consensus guidelines for prevention.

The International Pediatric Transplant Association (IPTA) convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorder after solid organ transplantation in children. In this report from the Prevention Working Group, we reviewed the existing literature regarding immunoprophylaxis and chemoprophylaxis, and pre-emptive strategies. While the group made a strong recommendation for pre-emptive reduction of immunosuppression at the time of EBV DNAemia (low to moderate evidence), no recommendations for use could be made for any prophylactic strategy or alternate pre-emptive strategy, largely due to insufficient or conflicting evidence. Current gaps and future research priorities are highlighted.

Proceedings of ESPGHAN Monothematic Conference 2020: "Acute Liver Failure in Children": Diagnosis and Initial Management.

OBJECTIVES: The Hepatology Committee of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) aims to educate pediatric gastroenterologists, members of ESPGHAN and professionals from other specialties promoting an exchange of clinical expertise in the field of pediatric hepatology. Herewith we have concentrated on detailing the recent advances in acute liver failure in infants and children. METHODS: The 2020 ESPGHAN monothematic three-day conference on pediatric hepatology disease, entitled "acute liver failure" (ALF), was organized in Athens, Greece. ALF is a devastating disease with high mortality and most cases remain undiagnosed. As knowledge in diagnosis and treatment of ALF in infants and children has increased in the past decades, the objective was to update physicians in the field with the latest research and developments in early recognition, curative therapies and intensive care management, imaging techniques and treatment paradigms in these age groups. RESULTS: In the first session, the definition, epidemiology, various causes of ALF, in neonates and older children and recurrent ALF (RALF) were discussed. The second session was dedicated to new aspects of ALF management including hepatic encephalopathy (HE), coagulopathy, intensive care interventions, acute on chronic liver failure, and the role of imaging in treatment and prognosis. Oral presentations by experts in various fields are summarized highlighting key learning points. CONCLUSIONS: The current report summarizes the major learning points from this meeting. It also identifies areas where there is gap of knowledge, thereby identifying the research agenda for the near future.

Proceedings of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition Monothematic Conference, 2020: "Acute Liver Failure in Children": Treatment and Directions for Future Research.

OBJECTIVES: The Hepatology Committee of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) aims to educate pediatric gastroenterologists, members of ESPGHAN and professionals from other specialties promoting an exchange of clinical expertise in the field of pediatric hepatology. METHODS: The 2020 single topic ESPGHAN monothematic 3-day conference on pediatric liver disease, was organized in Athens, Greece and was entitled " Acute Liver Failure" (ALF). ALF is a devastating disease with high mortality and in a considerable fraction of patients, the cause remains unresolved. As knowledge in diagnosis and treatment of ALF in infants and children has increased in the past decades, the objective was to update physicians in the field with developments in medical therapy and indications for liver transplantation (LT) and to identify areas for future research in clinical and neurocognitive outcomes in ALF. RESULTS: We recently reported the epidemiology, diagnosis, and initial intensive care management issues in separate manuscript. Herewith we report on the medical treatment, clinical lessons arising from pediatric studies, nutritional and renal replacement therapy (RRT), indications and contraindications for LT, neurocognitive outcomes, new techniques used as bridging to LT, and areas for future research. Oral presentations by experts in various fields are summarized highlighting key learning points. CONCLUSIONS: The current report summarizes the current insights in medical treatment of pediatric ALF and the directions for future research.

Everolimus is Safe as a Second-/Third-Line Therapy in Pediatric Autoimmune Hepatitis.

Autoimmune hepatitis (AIH) can lead to progressive fibrosis in patients refractory to conventional therapy with prednisolone and azathioprine. The use of mammalian target of rapamycin (mTOR) inhibitors has recently emerged in refractory AIH, but no data have been published about everolimus in pediatric AIH to date. Our aim was to share our experience about everolimus as a second-/third-line therapy in pediatric AIH. Methods: Pretransplant AIH patients aged 0-18 years who received everolimus therapy from 2014 to 2021 were retrospectively identified. All patients underwent regular plasma monitoring of everolimus trough levels to avoid toxicity and assess adherence. Special attention was paid to the clinical and biochemical occurrence of everolimus-related adverse events. Results: We report six difficult-to-treat AIH patients who received everolimus therapy for 8-46 months (median 28 months). No side effects were reported when everolimus plasma trough levels were in the therapeutic range. Liver transaminases improved in 5 of 6 patients at everolimus introduction and significantly decreased at the last follow-up (FU) in our cohort (P < 0.05). None of our patients achieved complete biochemical remission at the last FU and 3 of 6 admitted to have suboptimal adherence to therapy. Conclusions: Our data bring preliminary safety for the use of everolimus as a second-/third-line therapy in pediatric AIH. Although liver transaminases improved in our cohort, prospective studies are needed to determine if everolimus can induce long-term remission.

Sequential Treatment of Biliary Atresia With Kasai Hepatoportoenterostomy and Liver Transplantation: Benefits, Risks, and Outcome in 393 Children.

Introduction: Surgical treatment of biliary atresia (BA) is still based on sequential strategy with Kasai hepatoportoenterostomy (KP) followed by liver transplantation (LT), in case of complicated secondary biliary cirrhosis. Concerns have been expressed regarding the risks of LT related to previous KP, suggesting primary LT as an exclusive treatment of BA. Methods: Single-center retrospective analysis including 393 pediatric patients who underwent LT for BA from 1993 to 2018, categorized into two groups: with (KP) or without (NoKP) previous KP. Pre-LT clinical condition was estimated considering age at LT, time on waiting list, pediatric end-stage liver disease score (PELD), and presence of portal vein hypoplasia. Post-LT outcome was evaluated considering patient and graft survival rates, and need for early reoperation due to abdominal or graft-related complications (<45 days after LT). Results: Two-hundred ninety-six patients (75.3%) were categorized in the KP group, and 97 (24.7%) in the NoKP group. Median age at LT was 1.14 years in the KP group and 0.85 years in the NoKP group (p < 0.0001). PELD score was significantly less severe in KP patients (p < 0.05). One-year patient survival rates were 96.9 and 96.8% in the KP and NoKP groups, respectively (p = 0.43), and the corresponding graft survival was 92.5 and 94.8% (p = 0.97). The need for early reoperation was more frequent in the KP group (29.8%) vs. NoKP group (12.4%, p = 0.01). The rate of bowel perforation was non-significantly higher in the KP group (8.1%) vs. NoKP group (3.1%, p = 0.11). Conclusions: The sequential strategy including KP and LT allowed performing LT in patients with significant older age and better clinical conditions, when compared to those transplanted without previous KP. Patient and graft survivals were not impacted by previous KP. Although previous KP was associated with an increased rate of post-LT surgical complications, bowel perforation and bleeding did not occur significantly more frequently. Such results support the current strategy based on sequential treatment.

Management and outcome of hepatic artery thrombosis after pediatric liver transplantation.

BACKGROUND: Pediatric LT are at particular risk of HAT, and its management still constitutes a matter of debate. Our purpose was to study predisposing factors and outcome of HAT post-LT, including the impact of surgical revisions on survival and biliary complications. METHODS: Among 882 primary pediatric LT performed between 1993 and 2015, 36 HAT were encountered (4.1%, 35 fully documented). Each HAT case was retrospectively paired with a LT recipient without HAT, according to diagnosis, age at LT, type of graft, and era. RESULTS: Five-year patient survivals were 77.0% versus 83.9% in HAT and non-HAT paired groups, respectively (P = .321). Corresponding graft survivals were 20.0% versus 80.5% (P < .001), and retransplantation rates 77.7% versus 10.7%, respectively (P < .001). One-year biliary complication-free survivals were 16.6% versus 83.8% in the HAT and non-HAT groups, respectively (P < .001). Regarding chronology of surgical re-exploration, only HAT cases that occurred within 14 days post-LT were re-operated, fourteen of them being explored within 7 days post-LT (revascularization rate: 6/14), versus two beyond 7 days (no revascularization). When revascularization was achieved, graft and biliary complication-free survival rates at 1 year were 33.3% and 22.2%, respectively, both rates being 0.0% in case of failure. CONCLUSIONS: The pejorative prognosis associated with HAT in terms of graft survival is confirmed, whereas patient survival could be preserved through retransplantation. Results suggest that HAT should be re-operated if occurring within 7 days post-LT, but not beyond.

Intracranial Hypertension and Papilledema in a Large Cohort of Pediatric Patients With Alagille Syndrome.

AIMS AND BACKGROUND: Ophthalmic abnormalities are amongst the 5 major criteria required for a diagnosis of Alagille syndrome (ALGS), of which embryotoxon, pseudopapilledema, and hypopigmented retinopathy are the most common. Papilledema with or without intracranial hypertension (ICHT) is rarely described. We report 9 pediatric cases of ALGS with bilateral papilledema, 5 of which were diagnosed with ICHT. METHODS: The ophthalmic data from 85 patients with clinically and/or genetically (n = 37) proven ALGS were reviewed. The study inclusion criteria were a positive diagnosis of ALGS and availability of ophthalmic follow-up data. Ophthalmic data from 40 patients after liver transplantation (LT) for other indications were also analyzed. RESULTS: Nine (13.0%) of the 69 patients meeting the inclusion criteria had papilledema. The neurological and neuroimaging results in all 9 patients were normal. These 9 patients were categorized into 4 groups: a nontransplant group (n = 1), a group with pretransplant papilledema persistent after LT (n = 2), a group with papilledema occurring after LT with spontaneous resolution (n = 1), and a group with papilledema and signs of ICHT after LT (n = 5). The patients with ICHT were treated with steroids alone (n = 1) or with acetazolamide (n = 4). A ventriculoperitoneal shunt was placed in 2 of the 5 cases because of progressive visual loss. Pseudopapilledema was present in 10 additional patients (14.5%, 10/69). One (2.5%) of the 40 patients without ALGS developed papilledema after LT. CONCLUSIONS: True ICHT may be underdiagnosed in patients with ALGS. Our findings underscore the need for close ophthalmic follow-up before and after LT in these patients.

Outcomes Following Pouch Formation in Paediatric Ulcerative Colitis: A Study From the Porto Group of ESPGHAN.

INTRODUCTION: Contemporary pediatric data on pouch outcomes are sparse, especially in the era of laparoscopic surgeries. We aimed to assess outcomes and predictors in children with ulcerative colitis/inflammatory bowel disease (IBD)-unclassified who underwent colectomy and ileal pouch-anal anastomosis. METHODS: This was a multicenter retrospective cohort study from 17 IBD centers affiliated with the pediatric IBD Porto group of ESPGHAN. An electronic REDcap system was used to collate baseline characteristics, demographic, clinical, management and surgical data, short- and long-term outcomes, and to identify potential predictors of pouch outcome. RESULTS: Of the 129 patients included, 86 (67%) developed pouchitis during follow-up of median 40 months (interquartile range 26-72), of whom 33 (26%) with chronic pouchitis. Patients operated on by surgeons performing <10 pouch surgeries/year had a higher rate of chronic pouchitis (11/27 [41%] vs 8/54 [15%], P = 0.013) on both univariable and multivariable analyses and also associated with time to pouchitis (P = 0.018) and chronic pouchitis (P = 0.020). At last follow-up, overall pouch performance was rated good/excellent in 86 (74%) patients. Time from colectomy to pouch formation was not associated with pouch outcomes. Despite higher rate of nonsevere surgical complications among children undergoing colectomy at <10 years of age (7/16 [44%] vs 10/92 [11%], P = 0.003), functional outcome and pouchitis rate did not differ. CONCLUSIONS: Pouchitis rate in children with ulcerative colitis/IBD unclassified is high. Surgeon experience is the major modifiable risk factor for pouch outcome. Our analyses suggest that pouch surgery can also be performed successfully in young children.

Nasobiliary drainage prior to surgical biliary diversion in progressive familial intrahepatic cholestasis type II.

Progressive familial intrahepatic cholestasis (PFIC) can cause intense pruritus that is refractory to medical therapy. Surgical biliary diversion techniques, including partial internal biliary diversion (PIBD), have been developed over the years to relieve pruritus without requiring liver transplantation. No clinical or genetic features can currently predict postoperative pruritus response. We present three PFIC type 2 (PIFC 2) patients who underwent transient endoscopic nasobiliary drainage (NBD) prior to PIBD surgery. Two patients repeatedly responded to NBD and presented with complete pruritus resolution after subsequent PIBD. NBD failed technically in the third patient, and PIBD was partially successful. Mild post-endoscopic biological pancreatitis occurred in 2/6 NBD procedures and resolved spontaneously. The only adverse effect observed within 7 years post-PIBD was very mild transient osmotic diarrhea.Conclusion: Our limited data suggest that NBD is a safe and effective way to predict pruritus response before performing permanent biliary diversion surgery in PFIC patients. What is Known: • Surgical biliary diversion techniques have been developed to relieve intractable pruritus in progressive familial intrahepatic cholestasis (PFIC). • No clinical or genetic features can currently predict pruritus response to surgery. What is New: • Our data suggest that nasobiliary drainage could be a safe and effective tool to predict pruritus response to biliary diversion and avoid unnecessary surgery in PFIC patients.

Infusion-related thrombogenesis by liver-derived mesenchymal stem cells controlled by anticoagulant drugs in 11 patients with liver-based metabolic disorders.

BACKGROUND: Mesenchymal stem cell (MSC) transplantation is a fast-developing therapy in regenerative medicine. However, some concerns have been raised regarding their safety and the infusion-related pro-coagulant activity. The aim of this study is to analyze the induced thrombogenic risk and the safety of adding anticoagulants during intraportal infusions of liver-derived MSCs (HepaStem), in patients with Crigler-Najjar (CN) and urea cycle disorders (UCD). METHODS: Eleven patients (6 CN and 5 UCD patients) were included in this partially randomized phase 1/2 study. Three cell doses of HepaStem were investigated: low (12.5 × 106 cells/kg), intermediate (50 × 106 cells/kg), and high doses (200 × 106 cells/kg). A combination of anticoagulants, heparin (10 I.U./5 × 106cells), and bivalirudin (1.75 mg/kg/h) were added during cell infusions. The infusion-related thrombogenic risk and anticoagulation were evaluated by clinical monitoring, blood sampling (platelet and D-dimer levels, activated clotting time, etc.) and liver Doppler ultrasound. Mixed effects linear regression models were used to assess statistically significant differences. RESULTS: One patient presented a thrombogenic event such as a partial portal vein thrombus after 6 infusions. Minor adverse effects such as petechiae, epistaxis, and cutaneous hemorrhage at the site of catheter placement were observed in four patients. A significant decrease in platelet and increase in D-dimer levels were observed at the end of the infusion cycle, normalizing spontaneously after 7 days. No significant and clinically relevant increase in portal vein pressure could be observed once the infusion cycle was completed. CONCLUSIONS: The safety- and the infusion-related pro-coagulant activity remains a concern in MSC transplantation. In our study, a combination of heparin and bivalirudin was added to prevent the thrombogenic risk induced by HepaStem infusions in 11 patients. A significant decrease in platelet and increase in D-dimer levels were observed, suggesting the activation of coagulation in these patients; however, this was spontaneously reversible in time. We can conclude that adding this combination of anticoagulants is safe and limits infusion-related thrombogenesis to subclinical signs in most of the patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01765283-January 10, 2013.

vWFpp/ADAMTS13 ratio is a useful marker of postliver transplantation thrombotic microangiopathy: A pediatric case report.

vWFpp/ADAMTS13 ratio should be further studied as a useful marker for diagnosis of thrombotic microangiopathy postliver transplantation. Immunosuppressive regimen modification and plasma supplementation can lead to recovery.

Management of Hepatitis B Virus Infection and Prevention of Hepatitis B Virus Reactivation in Children With Acquired Immunodeficiencies or Undergoing Immune Suppressive, Cytotoxic, or Biological Modifier Therapies.

Reactivation of hepatitis B virus (HBV) is a known complication of immune-suppressive, cytotoxic, and biological modifier therapies in patients currently infected with HBV or who have had past exposure to HBV. Nowadays, newer and emerging forms of targeted biologic therapies are available for the management of rheumatologic conditions, malignancies, inflammatory bowel disease, dermatologic conditions and solid-organ, bone marrow, or haematologic stem cell transplant but there is currently a lack of a systematic approach to the care of patients with or at risk of HBV reactivation. The Hepatology Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) together with a working group of ESPGHAN members with clinical and research expertise in viral hepatitis developed an evidence-based position paper on reactivation of HBV infection in children identifying pertinent issues addressing the diagnosis, prevention, and treatment of this condition. Relevant clinical questions were formulated and agreed upon by all the members of the working group. Questions were answered and positions were based on evidence resulting from a systematic literature search on PubMed and Embase from their inception to July 1, 2019. A document was produced and the working group and ESPGHAN Hepatology Committee members voted on each recommendation, using a formal voting technique. A recommendation was accepted provided upon agreement by at least 75% of the working group members. This position paper provides a comprehensive update on the diagnosis, prevention and treatment of HBV reactivation in children.

Detection of Human Microchimerism following Allogeneic Cell Transplantation Using Droplet Digital PCR.

BACKGROUND: Cell transplantation is in clinical development for the treatment of various ailments including acquired and inborn hepatic diseases. Detection and quantification of the donor cells after infusion remain difficult. Traditional methods (sex-based FISH, HLA mismatch, and Short Tandem Repeat PCR) can only achieve low levels of sensitivity (1%) and therefore are seldom used. The use of a droplet digital PCR (ddPCR) assay based on mismatch of null alleles is a promising alternative. METHODS: We selected genes with a high frequency of null genotype in the general population (SRY, RHD, TRY6, LEC3C, GSTM1, and GSTT1) and investigated their expression by liver progenitor cell donors and liver cell therapy recipients, in order to identify genes of interest for each donor/recipient couple. We first validated the detection of microchimerism by ddPCR and then used these assays to detect and quantify microchimerism in pre- and postinfusion liver biopsies. RESULTS: We validated the ddPCR detection of the selected genes based on linearity, precision, lack of inhibition, and accuracy, and we established limits of blank, limits of detection, and limits of quantification to ensure the reliability of the results. After genotyping donors and recipients, we were able to identify at least one gene of interest for each donor/recipient couple. We detected donor cells in the three patients posttransplantation. However, analysis of several biopsies taken at the same timepoint revealed a heterogeneous cell distribution. In addition, the values obtained remained below the limit of quantification. Therefore, the actual quantification of microchimerism may not be entirely accurate. CONCLUSIONS: Overall, our study demonstrates that the detection of microchimerism post-liver cell transplantation can be performed using ddPCR amplification of null allele genes expressed by the donor but absent from the recipient. However, this technique can be extended to other cell types and target organs in cell transplantation.

Novel insights into the assessment of risk of upper gastrointestinal bleeding in decompensated cirrhotic children.

OBJECTIVES: Cirrhotic children wait-listed for liver transplant are prone to bleeding from gastrointestinal varices. Grade 2-3 esophageal varices, red signs, and gastric varices are well-known risk factors. However, the involvement of hemostatic factors remains controversial because of the rebalanced state of coagulation during cirrhosis. METHODS: Children suffering from decompensated cirrhosis were prospectively included while being on waitlist. Portal hypertension was assessed by ultrasound and endoscopy. Coagulopathy was evaluated through conventional tests, thromboelastometry, and platelet function testing. The included children were followed up until liver transplantation, and all bleeding episodes were recorded. Children with or without bleeding were compared according to clinical, radiological, endoscopic, and biological parameters. In addition, validation of a predictive model for risk of variceal bleeding comprising of grade 2-3 esophageal varices, red spots, and fibrinogen level <150 mg/dL was applied on this cohort. RESULTS: Of 20 enrolled children, 6 had upper gastrointestinal bleeding. Significant differences were observed in fibrinogen level, adenosine diphosphate, and thrombin-dependent platelet aggregation. The model used to compute the upper gastrointestinal bleeding risk had an estimated predictive performance of 81.0%. Platelet aggregation analysis addition improved the estimated predictive performance up to 89.0%. CONCLUSIONS: We demonstrated an association between hemostatic factors and the upper gastrointestinal bleeding risk. A low fibrinogen level and platelet aggregation dysfunction may predict the risk of bleeding in children with decompensated cirrhosis. A predictive model is available to assess the upper gastrointestinal bleeding risk but needs further investigations. Clinicaltrials.gov number: NCT03244332.

Phase I/II Trial of Liver-derived Mesenchymal Stem Cells in Pediatric Liver-based Metabolic Disorders: A Prospective, Open Label, Multicenter, Partially Randomized, Safety Study of One Cycle of Heterologous Human Adult Liver-derived Progenitor Cells (HepaStem) in Urea Cycle Disorders and Crigler-Najjar Syndrome Patients.

BACKGROUND: Regenerative medicine using stem cell technology is an emerging field that is currently tested for inborn and acquired liver diseases. OBJECTIVE: This phase I/II prospective, open label, multicenter, randomized trial aimed primarily at evaluating the safety of Heterologous Human Adult Liver-derived Progenitor Cells (HepaStem) in pediatric patients with urea cycle disorders (UCDs) or Crigler-Najjar (CN) syndrome 6 months posttransplantation. The secondary objective included the assessment of safety up to 12 months postinfusion and of preliminary efficacy. METHODS: Fourteen patients with UCDs and 6 with CN syndrome were divided into 3 cohorts by body weight and intraportally infused with 3 doses of HepaStem. Clinical status, portal vein hemodynamics, morphology of the liver, de novo detection of circulating anti-human leukocyte antigen antibodies, and clinically significant adverse events (AEs) and serious adverse events to infusion were evaluated by using an intent-to-treat analysis. RESULTS: The overall safety of HepaStem was confirmed. For the entire study period, patient-month incidence rate was 1.76 for the AEs and 0.21 for the serious adverse events, of which 38% occurred within 1 month postinfusion. There was a trend of higher events in UCD as compared with CN patients. Segmental left portal vein thrombosis occurred in 1 patient and intraluminal local transient thrombus in a second patient. The other AEs were in line with expectations for catheter placement, cell infusion, concomitant medications, age, and underlying diseases. CONCLUSIONS: This study led to European clinical trial authorization for a phase II study in a homogeneous patient cohort, with repeated infusions and intermediate doses.

Similarities and Differences in Allocation Policies for Pediatric Liver Transplantation Across the World.

OBJECTIVES: We aimed to investigate national allocation policies for pediatric liver transplantation (LT). METHOD: A survey was prepared by the European Society for Paediatric Gastroenterology Hepatology and Nutrition Hepatology Committee in collaboration with the North American Studies of Pediatric Liver Transplantation consortium. The survey was sent to pediatric hepatologists and transplant surgeons worldwide. National data were obtained from centrally based registries. RESULTS: Replies were obtained from 15 countries from 5 of the world continents. Overall donation rate varied between 9 and 35 per million inhabitants. The number of pediatric LTs was 4 to 9 per million inhabitants younger than 18 years for 13 of the 15 respondents. In children younger than 2 years mortality on the waiting list (WL) varied between 0 and 20%. In the same age group, there were large differences in the ratio of living donor LT to deceased donor LT and in the ratio of split liver segments to whole liver. These differences were associated with possible discrepancies in WL mortality. CONCLUSIONS: Similarities but also differences between countries were detected. The described data may be of importance when trying to reduce WL mortality in the youngest children.