Calreticulin regulates hepatic stellate cell activation through modulating TGF-beta-induced Smad signaling

Liver fibrosis is characterized by excessive deposition of extracellular matrix (ECM) as a wound healing process. Activated hepatic stellate cells (HpSCs) are the major producer of the ECM and play a central role in liver fibrogenesis. It has been widely accepted that elimination of activated HpSCs or reversion to a quiescent state can be a feasible strategy for resolving the disease, further highlighting the urgent need for novel therapeutic targets. Calreticulin (CRT) is a molecular chaperone that normally resides in the endoplasmic reticulum (ER), important in protein folding and trafficking through the secretory pathway. CRT also plays a critical role in calcium (Ca2+) homeostasis, with its Ca2+ storage capacity. In the current study, we aimed to demonstrate its function in directing HpSC activation. In a mouse liver injury model, CRT was up-regulated in HpSCs. In cellular experiments, we further showed that this activation was through modulating the canonical TGF-β signaling. As down-regulation of CRT in HpSCs elevated intracellular Ca2+ levels through a form of Ca2+ influx, named store-operated Ca2+ entry (SOCE), we examined whether moderating SOCE affected TGF-β signaling. Interestingly, blocking SOCE had little effect on TGF-β-induced gene expression. In contrast, inhibition of ER Ca2+ release using the inositol trisphosphate receptor inhibitor 2-APB increased TGF-β signaling. Treatment with 2-APB did not alter SOCE but decreased intracellular Ca2+ at the basal level. Indeed, adjusting Ca2+ concentrations by EGTA or BAPTA-AM chelation further enhanced TGF-β-induced signaling. Our results suggest a crucial role of CRT in the liver fibrogenic process through modulating Ca2+ concentrations and TGF-β signaling in HpSCs, which may provide new information and help advance the current discoveries for liver fibrosis.

Long-term outcomes of active vaccination against de novo hepatitis B among pediatric recipients of living donor liver transplantations with anti-HBc (+) grafts: a retrospective case-control study

BACKGROUND

Active vaccination has been utilized to prevent de novo hepatitis B virus infection (DNHB) in anti-HBc (+) grafts after liver transplantation (LT). However, the long-term efficacy of active vaccination and graft/patient outcomes of anti-HBc (+) grafts have yet to be comprehensively investigated.

MATERIALS AND METHODS

Among 204 pediatric patients enrolled in the study, 82 recipients received anti-HBc (+) grafts. For DNHB prevention, active vaccination was repeatedly administered prior to transplant. Anti-viral therapy was given to patients with pre-transplant anti-HBs<1000 IU/ ml (non-robust response) for 2 years and discontinued when post-transplant patients achieved anti-HBs>1000 IU/mL, while anti-viral therapy was not given in patients with an anti-HBs titer over 1000 IU/mL. The primary outcome was to investigate the long-term efficacy of active vaccination, while the secondary outcomes included the graft and patient survival rates.

RESULTS

Among the 82 anti-HBc (+) transplant patients, 68% of recipients achieved a robust immune response, thus not requiring antiviral therapy. Two patients (2.4%) developed DNHB infection, one of which was due to an escape mutant. With a median follow-up of 150 months, the overall 10-year patient and graft survival rates were significantly worse in recipients of anti-HBc (+) grafts than those of anti-HBc (-) grafts (85.2% vs 93.4%, P=0.026; 85.1% vs 93.4%, P=0.034, respectively). Additionally, the 10-year patient and graft outcomes of the anti-HBc (+) graft recipients were significantly worse than those of the anti-HBc (-) graft recipients after excluding early mortality and non-graft mortality values (90.8% vs 96.6%, P=0.036; 93.0% vs 98.3%, P=0.011, respectively).

CONCLUSION

Our long-term follow-up study demonstrates that active vaccination is a simple, cost-effective strategy against DNHB infection in anti-HBc (+) graft patients, whereby the need for life-long antiviral therapy is removed. Notably, both the anti-HBc (+) grafts and patients exhibited inferior long-term survival rates, although the exact mechanisms remain unclear.

Combined Hounsfield units of hepatocellular carcinoma on computed tomography and PET as a noninvasive predictor of early recurrence after living donor liver transplantation: Time-to-recurrence survival analysis

BACKGROUND

Liver transplantation is an effective treatment for preventing hepatocellular carcinoma (HCC) recurrence. This retrospective study aimed to quantitatively evaluate the attenuation in Hounsfield units (HU) on contrast-enhanced computed tomography (CECT) as a prognostic factor for hepatocellular carcinoma (HCC) following liver transplantation as a treatment. Our goal is to optimize its predictive ability for early tumor recurrence and compare it with the other imaging modality-positron emission tomography (PET).

METHODS

In 618 cases of LDLT for HCC, only 131 patients with measurable viable HCC on preoperative CECT and preoperative positron emission tomography (PET) evaluations were included, with a minimum follow-up period of 6 years. Cox regression models were developed to identify predictors of postoperative recurrence. Performance metrics for both CT and PET were assessed. The correlation between these two imaging modalities was also evaluated. Survival analyses were conducted using time-dependent receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) to assess accuracy and determine optimized cut-off points.

RESULTS

Univariate and multivariate analyses revealed that both arterial-phase preoperative tumor attenuation (HU) and PET were independent prognostic factors for recurrence-free survival. Both lower arterial tumor enhancement (Cut-off value = 59.2, AUC 0.88) on CT and PET positive (AUC 0.89) increased risk of early tumor recurrence 0.5-year time-dependent ROC. Composites with HU < 59.2 and a positive PET result exhibited significantly higher diagnostic accuracy in detecting early tumor recurrence (AUC = 0.96).

CONCLUSION

Relatively low arterial tumor enhancement values on CECT effectively predict early HCC recurrence after LDLT. The integration of CT and PET imaging may serve as imaging markers of early tumor recurrence in HCC patients after LDLT.

TEMPORARY REMOVAL: A novel scoring system to predict short-term mortality after living donor liver transplantation for acute liver failure

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Usefulness of Diffusion-Weighted Imaging in Evaluating Acute Cellular Rejection and Monitoring Treatment Response in Liver Transplant Recipients

Acute cellular rejection (ACR) is a significant immune issue among recipients following liver transplantation. Although diffusion-weighted magnetic resonance imaging (DWI) is widely used for diagnosing liver disease, it has not yet been utilized for monitoring ACR in patients after liver transplantation. Therefore, the aim of this study was to evaluate the efficacy of DWI in monitoring treatment response among recipients with ACR. This study enrolled 25 recipients with highly suspected ACR rejection, and all subjects underwent both biochemistry and DWI scans before and after treatment. A pathological biopsy was performed 4 to 24 h after the first MRI examination to confirm ACR and degree of rejection. All patients were followed up and underwent a repeated MRI scan when their liver function returned to the normal range. After data acquisition, the DWI data were post-processed to obtain the apparent diffusion coefficient (ADC) map on a voxel-by-voxel basis. Five regions of interest were identified on the liver parenchyma to measure the mean ADC values from each patient. Finally, the mean ADC values and biochemical markers were statistically compared between ACR and non-ACR groups. A receiver operating characteristic (ROC) curve was constructed to evaluate the performance of the ADC and biochemical data in detecting ACR, and correlation analysis was used to understand the relationship between the ADC values, biochemical markers, and the degree of rejection. The histopathologic results revealed that 20 recipients had ACR, including 10 mild, 9 moderate, and 1 severe rejection. The results demonstrated that the ACR patients had significantly lower hepatic ADC values than those in patients without ACR. After treatment, the hepatic ADC values in ACR patients significantly increased to levels similar to those in non-ACR patients with treatment. The ROC analysis showed that the sensitivity and specificity for detecting ACR were 80% and 95%, respectively. Furthermore, the correlation analysis revealed that the mean ADC value and alanine aminotransferase level had strong and moderate negative correlation with the degree of rejection, respectively (r = -0.72 and -0.47). The ADC values were useful for detecting hepatic ACR and monitoring treatment response after immunosuppressive therapy.

Drug-Eluting Bead Transarterial Chemoembolization for Hepatocellular Carcinoma: The Effectiveness of Different Particle Sizes in Downstaging and Bridging in Living Donor Liver Transplantation

AIM

To compare the effectiveness of drug-eluting bead transarterial chemoembolization (DEB-TACE) with different particle sizes in bridging and downstaging in pretransplant hepatocellular carcinoma patients. Assess the recurrent and survival rates after living donor liver transplantation (LDLT).

METHODS

Retrospective review of 580 patients who underwent TACE using DEB from August 2012 to June 2020 at Taiwan Kaohsiung Chang Gung Memorial Hospital. Pre- and post-TACE computed tomography scan images of the liver were reviewed, and treatment responses were assessed using modified Response Evaluation Criteria in Solid Tumors criteria. Patients were divided by who met the criteria (n = 342) or beyond (n = 238) the University of California San Francisco criteria for successful bridging and downstaging rate evaluation. Each group was divided into subgroups according to DEB particle sizes (group A: <100μm, group B: 100-300 μm, group C: 300-500 μm, and group D: 500-700 μm) to compare objective response rate and post-LDLT survival rate.

RESULTS

Overall successful bridging and downstaging rate is 97.1% and 58.4%, respectively, in the group of patients who meet the criteria (n = 332) and are beyond (n = 139) the University of California San Francisco criteria. Group B (100-300 μm) had a higher successful bridging rate (99.5%, P = .003) and downstaging rate (63.8%, P = .443). This subgroup also demonstrated a higher objective response rate in single (93.2%, P = .038) tumors, multiple (83.3%, P = .001) tumors, and tumors with size less than 5 cm (93.9%, P = .005). There are no significant differences in post-LDLT overall survival rate between different particle sizes.

CONCLUSION

TACE with 100 to 300 μm DEB particles is associated with a better chance of bridging and downstaging hepatocellular carcinoma patients to LDLT.

Sarcopenia Affects Liver Regeneration and Long-Term Survival Rate After Living-Donor Liver Transplantation in Patients With Hepatocellular Carcinoma

PURPOSE

Despite technological and immunologic innovations, some living-donor liver transplant (LDLT) recipients still face poor liver regeneration. Sarcopenia is often recognized as a biomarker for poor outcomes in surgical patients. This study aimed to evaluate associations between sarcopenia and liver regeneration in LDLT recipients.

MATERIALS AND METHODS

This retrospective review included consecutive patients who had received LDLT at Chang Gung Memorial Hospital between 2005 and 2017. Sarcopenia was assessed using the psoas muscle index (PMI) in cross-sectional images. Receiver operating characteristic curve analysis was used to determine the ability of PMI to predict relatively poor survival rates. Correlations between liver regeneration and sarcopenia were evaluated using regression analysis.

RESULTS

A total of 109 LDLT recipients were included. The 1-, 3-, 5, 10-, and 15-year survival rates were 93.7%, 84.8%, 79.7%, 74.7%, and 73.3% in males and 93.3%, 83.3%, 83.3%, 71.4%, and 71.4% in females. PMIs were significantly different based on 10- and 15-year overall survival rates (P = .001 and P = .000) in male patients. Receiver operating characteristic curve analysis revealed the PMI cutoff point at 6.7 cm2/m2 (sensitivity = 48.3%, specificity = 81%, AUC (area under the ROC curve) = 0.685) based on 10-year survival. Linear regression analysis revealed that PMI was significantly associated with liver regeneration in males (P = .013).

CONCLUSIONS

Sarcopenia and low PMI are associated with poor liver regeneration and long-term survival after LDLT in male patients. Further studies, including sarcopenia with conventional scores, may help to more reliably predict liver regeneration and mortality among LDLT patients with hepatocellular carcinoma.

Epidemiology and Risk Factors of Early Bacterial Infections After Pediatric Living Donor Liver Transplantation

BACKGROUND

Advancements in surgical techniques, immunosuppression regimens, and peri-operative and postoperative care have resulted in marked improvement in outcomes after pediatric living donor liver transplantation (PLDLT). Despite these developments, infectious complications remain a major cause of morbidity and mortality.

METHODS

This is a retrospective cohort analysis of pediatric recipients from January 2004 to December 2018. Patients were classified into infected and non-infected groups based on the occurrence of bacterial infection during the first 3 months after transplant. Perioperative risk factors for early post-transplant bacterial infections and postoperative outcomes were investigated.

RESULTS

Seventy-two out of 221 children developed early bacterial infection (32.6%). The first episodes of bacterial infection most frequently occurred in the second week after LDLT (37.5%). In multivariate analysis, active infection before transplant and complications with Clavien-Dindo grading >3 were the only independent risk factors. Early bacterial infections were independently associated with longer intensive care unit stays, longer hospital stays, and a higher incidence of readmission for bacterial infection during the first year after transplant. Additionally, the overall patient survival rate was significantly higher in the non-infected group (P = .001). Risk factors for infection, such as age, weight, disease severity, ABO-incompatible, and other operative factors, were not identified as independent risk factors.

CONCLUSION

We have demonstrated that there are similarities and disparities in the epidemiology and risk factors for early bacterial infection after transplant between centers. Identification and better characterization of these predisposing factors are essential in the modification of current preventive strategies and treatment protocols to improve outcomes for this highly vulnerable group.

Biliary complications after adult-to-adult living-donor liver transplantation: An international multicenter study of 3633 cases

In living-donor liver transplantation, biliary complications including bile leaks and biliary anastomotic strictures remain significant challenges, with incidences varying across different centers. This multicentric retrospective study (2016-2020) included 3633 adult patients from 18 centers and aimed to identify risk factors for these biliary complications and their impact on patient survival. Incidences of bile leaks and biliary strictures were 11.4% and 20.6%, respectively. Key risk factors for bile leaks included multiple bile duct anastomoses (odds ratio, [OR] 1.8), Roux-en-Y hepaticojejunostomy (OR, 1.4), and a history of major abdominal surgery (OR, 1.4). For biliary anastomotic strictures, risk factors were ABO incompatibility (OR, 1.4), blood loss >1 L (OR, 1.4), and previous abdominal surgery (OR, 1.7). Patients experiencing biliary complications had extended hospital stays, increased incidence of major complications, and higher comprehensive complication index scores. The impact on graft survival became evident after accounting for immortal time bias using time-dependent covariate survival analysis. Bile leaks and biliary anastomotic strictures were associated with adjusted hazard ratios of 1.7 and 1.8 for graft survival, respectively. The study underscores the importance of minimizing these risks through careful donor selection and preoperative planning, as biliary complications significantly affect graft survival, despite the availability of effective treatments.

Risk factors for pre-transplantation bacteremia in adults with end-stage liver disease: Effects on outcomes of liver transplantation

BACKGROUND AND AIM

Limited data are available regarding pre-liver transplantation (LT) bacteremia in adults with end-stage liver disease. In this study, we investigated the risk factors independently associated with pre-LT bacteremia and their effects on clinical outcomes of LT.

METHODS

This retrospective study performed between 2010 and 2021 included 1287 LT recipients. The study population was categorized into patients with pre-LT bacteremia and those without pre-LT infection. Pre-LT bacteremia was defined as bacteremia detected within 90 days before LT.

RESULTS

Among 1287 LT recipients, 92 (7.1%) developed pre-LT bacteremia. The mean interval between bacteremia and LT was 28.3 ± 19.5 days. Of these 92 patients, seven (7.6%) patients died after LT. Of the 99 microorganisms isolated in this study, gram-negative bacteria were the most common microbes (72.7%). Bacteremia was mainly attributed to spontaneous bacterial peritonitis. The most common pathogen isolated was Escherichia coli (25.2%), followed by Klebsiella pneumoniae (18.2%), and Staphylococcus aureus (15.1%). Multivariate analysis showed that massive ascites (adjusted odds ratio [OR] 1.67, 95% confidence Interval [CI] 1.048-2.687) and a prolonged international normalized ratio for prothrombin time (adjusted OR 1.13, 95% CI 1.074-1.257) were independent risk factors for pre-LT bacteremia in patients with end-stage liver disease. Intensive care unit and in-hospital stay were significantly longer, and in-hospital mortality was significantly higher among LT recipients with pre-LT bacteremia than among those without pre-LT infection.

CONCLUSIONS

This study highlights predictors of pre-LT bacteremia in patients with end-stage liver disease. Pre-LT bacteremia increases the post-transplantation mortality risk.

Peri-operative extracorporeal membrane oxygenation in adult and pediatric living donor liver transplantation: a single-center experience

Background

Extracorporeal membrane oxygenation (ECMO) is a potential rescue therapy for patients with acute cardiopulmonary dysfunction refractory to conventional treatment. In this study, we described the clinical profiles and outcomes of adult and pediatric living donor liver transplantation (LDLT) patients who received ECMO support during the peri-operative period.

Methods

From June 1994 to December 2020, eleven out of the 1,812 LDLTs performed at Kaohsiung Chang Gung Memorial Hospital required ECMO support: six for respiratory failure, three for cardiogenic shock, and two for refractory septic shock. Comparison between the survivor and non-survivor groups was made.

Results

The survival rate for liver transplantation (LT) patients on ECMO support is 36.4%-40% in adults and 33.3% in pediatrics, while the survival rate per indication is as follows: acute respiratory distress syndrome (ARDS) (50%), cardiogenic shock (33.3%), and sepsis (0%). Shorter durations of LT-to-ECMO and pre-ECMO mechanical ventilation were observed in the survivor group. On the other hand, we observed persistently elevated total bilirubin levels in non-survivors, while none of the survivors had aspartate aminotransferase (AST)/alanine aminotransferase (ALT) levels >1,000 U/L. A higher proportion of non-survivors were on concurrent continuous renal replacement therapy (CRRT).

Conclusions

Our experience has proven ECMO's utility during the peri-operative period for both adult and pediatric LDLT patients, more specifically for indications other than septic shock. Further studies are needed to better understand the factors leading to poor outcomes in order to identify patients who will more likely benefit from ECMO.

Novel Benchmark for Adult-to-Adult Living-donor Liver Transplantation: Integrating Eastern and Western Experiences

OBJECTIVE

To define benchmark values for adult-to-adult living-donor liver transplantation (LDLT).

BACKGROUND

LDLT utilizes living-donor hemiliver grafts to expand the donor pool and reduce waitlist mortality. Although references have been established for donor hepatectomy, no such information exists for recipients to enable conclusive quality and comparative assessments.

METHODS

Patients undergoing LDLT were analyzed in 15 high-volume centers (≥10 cases/year) from 3 continents over 5 years (2016-2020), with a minimum follow-up of 1 year. Benchmark criteria included a Model for End-stage Liver Disease ≤20, no portal vein thrombosis, no previous major abdominal surgery, no renal replacement therapy, no acute liver failure, and no intensive care unit admission. Benchmark cutoffs were derived from the 75th percentile of all centers' medians.

RESULTS

Of 3636 patients, 1864 (51%) qualified as benchmark cases. Benchmark cutoffs, including posttransplant dialysis (≤4%), primary nonfunction (≤0.9%), nonanastomotic strictures (≤0.2%), graft loss (≤7.7%), and redo-liver transplantation (LT) (≤3.6%), at 1-year were below the deceased donor LT benchmarks. Bile leak (≤12.4%), hepatic artery thrombosis (≤5.1%), and Comprehensive Complication Index (CCI ® ) (≤56) were above the deceased donor LT benchmarks, whereas mortality (≤9.1%) was comparable. The right hemiliver graft, compared with the left, was associated with a lower CCI ® score (34 vs 21, P < 0.001). Preservation of the middle hepatic vein with the right hemiliver graft had no impact neither on the recipient nor on the donor outcome. Asian centers outperformed other centers with CCI ® score (21 vs 47, P < 0.001), graft loss (3.0% vs 6.5%, P = 0.002), and redo-LT rates (1.0% vs 2.5%, P = 0.029). In contrast, non-benchmark low-volume centers displayed inferior outcomes, such as bile leak (15.2%), hepatic artery thrombosis (15.2%), or redo-LT (6.5%).

CONCLUSIONS

Benchmark LDLT offers a valuable alternative to reduce waitlist mortality. Exchange of expertise, public awareness, and centralization policy are, however, mandatory to achieve benchmark outcomes worldwide.

Uranyl Polyoxotungstate Cluster for Visible-Light-Driven Heterogeneous C-H Selective Fluorination

The selective fluorination of C-H bonds at room temperature using heterogeneous visible-light catalysts is both interesting and challenging. Herein, we present the heterogeneous sandwich-type structure uranyl-polyoxotungstate cluster Na17{Na@[(SbW9O33)2(UO2)6(PO3OH)6]}·46H2O (denoted as U6P6) to regulate the selective fluorination of the C-H bond under visible light and room temperature. This is the first report in which uranyl participates in the fluorination reaction in the form of an insoluble substance. U6P6 is capable of the effective selective fluorination of cycloalkanes and the recyclability of the photocatalyst due to the synergistic effect of multiple uranyl (UO2)2+ and the insolubility of organic reagents of polyoxotungstate. In situ electron paramagnetic resonance spectroscopy captured the generation of cycloalkane radicals during the photoreaction, confirming the mechanism of direct hydrogen atom transfer.

Post Living Donor Liver Transplantation Small-for-size Syndrome: Definitions, Timelines, Biochemical, and Clinical Factors for Diagnosis: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

BACKGROUND

When a partial liver graft is unable to meet the demands of the recipient, a clinical phenomenon, small-for-size syndrome (SFSS), may ensue. Clear definition, diagnosis, and management are needed to optimize transplant outcomes.

METHODS

A Consensus Scientific committee (106 members from 21 countries) performed an extensive literature review on specific aspects of SFSS, recommendations underwent blinded review by an independent panel, and discussion/voting on the recommendations occurred at the Consensus Conference.

RESULTS

The ideal graft-to-recipient weight ratio of ≥0.8% (or graft volume standard liver volume ratio of ≥40%) is recommended. It is also recommended to measure portal pressure or portal blood flow during living donor liver transplantation and maintain a postreperfusion portal pressure of <15 mm Hg and/or portal blood flow of <250 mL/min/100 g graft weight to optimize outcomes. The typical time point to diagnose SFSS is the postoperative day 7 to facilitate treatment and intervention. An objective 3-grade stratification of severity for protocolized management of SFSS is proposed.

CONCLUSIONS

The proposed grading system based on clinical and biochemical factors will help clinicians in the early identification of patients at risk of developing SFSS and institute timely therapeutic measures. The validity of this newly created grading system should be evaluated in future prospective studies.

Management of Established Small-for-size Syndrome in Post Living Donor Liver Transplantation: Medical, Radiological, and Surgical Interventions: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) following living donor liver transplantation is a complication that can lead to devastating outcomes such as prolonged poor graft function and possibly graft loss. Because of the concern about the syndrome, some transplants of mismatched grafts may not be performed. Portal hyperperfusion of a small graft and hyperdynamic splanchnic circulation are recognized as main pathogenic factors for the syndrome. Management of established SFSS is guided by the severity of the presentation with the initial focus on pharmacological therapy to modulate portal flow and provide supportive care to the patient with the goal of facilitating graft regeneration and recovery. When medical management fails or condition progresses with impending dysfunction or even liver failure, interventional radiology (IR) and/or surgical interventions to reduce portal overperfusion should be considered. Although most patients have good outcomes with medical, IR, and/or surgical management that allow graft regeneration, the risk of graft loss increases dramatically in the setting of bilirubin >10 mg/dL and INR>1.6 on postoperative day 7 or isolated bilirubin >20 mg/dL on postoperative day 14. Retransplantation should be considered based on the overall clinical situation and the above postoperative laboratory parameters. The following recommendations focus on medical and IR/surgical management of SFSS as well as considerations and timing of retransplantation when other therapies fail.

Preventing Small-for-size Syndrome in Living Donor Liver Transplantation: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) is a well-recognized complication following liver transplantation (LT), with up to 20% developing this following living donor LT (LDLT). Preventing SFSS involves consideration of factors before the surgical procedure, including donor and recipient selection, and factors during the surgical procedure, including adequate outflow reconstruction, graft portal inflow modulation, and management of portosystemic shunts. International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplant Society of India Consensus Conference was convened in January 2023 to develop recommendations for the prediction and management of SFSS in LDLT. The format of the conference was based on the Grading of Recommendations, Assessment, Development, and Evaluation system. International experts in this field were allocated to 4 working groups (diagnosis, prevention, anesthesia, and critical care considerations, and management of established SFSS). The working groups prepared evidence-based recommendations to answer-specific questions considering the currently available literature. The working group members, independent panel, and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and evidence-based recommendations provided by working group 2 that can be implemented to prevent SFSS in LDLT patients.

Anesthesia and Critical Care for the Prediction and Prevention for Small-for-size Syndrome: Guidelines from the ILTS-iLDLT-LTSI Consensus Conference

BACKGROUND

During the perioperative period of living donor liver transplantation, anesthesiologists and intensivists may encounter patients in receipt of small grafts that puts them at risk of developing small for size syndrome (SFSS).

METHODS

A scientific committee (106 members from 21 countries) performed an extensive literature review on aspects of SFSS with proposed recommendations. Recommendations underwent a blinded review by an independent expert panel and discussion/voting on the recommendations occurred at a consensus conference organized by the International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplantation Society of India.

RESULTS

It was determined that centers with experience in living donor liver transplantation should utilize potential small for size grafts. Higher risk recipients with sarcopenia, cardiopulmonary, and renal dysfunction should receive small for size grafts with caution. In the intraoperative phase, a restrictive fluid strategy should be considered along with routine use of cardiac output monitoring, as well as use of pharmacologic portal flow modulation when appropriate. Postoperatively, these patients can be considered for enhanced recovery and should receive proactive monitoring for SFSS, nutrition optimization, infection prevention, and consideration for early renal replacement therapy for avoidance of graft congestion.

CONCLUSIONS

Our recommendations provide a framework for the optimal anesthetic and critical care management in the perioperative period for patients with grafts that put them at risk of developing SFSS. There is a significant limitation in the level of evidence for most recommendations. This statement aims to provide guidance for future research in the perioperative management of SFSS.

Probing size-dependent defects in zinc oxide using synchrotron techniques: impact on photocatalytic efficiency

In the present study, synchrotron-based X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS) and X-ray excited optical luminescence (XEOL) have been used to investigate the induced defect states in metal oxide nanomaterials. Specifically, two synthesis approaches have been followed to develop unique nano-sized peanut-shaped (N-ZnO) nanostructures and micron-sized hexagonal rods (M-ZnO). XANES analysis at the Zn K-edge revealed the presence of defect states with a divalent oxidation state of zinc (Zn2+) in a tetrahedral structure. Furthermore, XAS measurements performed at the Zn L3,2-edge and O K-edge confirm higher oxygen-related defects in M-ZnO, while N-ZnO appeared to have a higher concentration of surface defects due to size confinement. Moreover, the in-line XEOL and time dependent-XEOL measurements exposed the radiative excitonic recombination phenomena occurring in the band-tailing region as a function of absorption length, X-ray energy excitation, and time. Based on the chronology developed in the defect state improvement, a possible energy band diagram is proposed to accurately locate the defect states in the two systems. Furthermore, the increased absorption intensity at the Zn L3,2-edge and the O K-edge under the UV lamp suggests delayed recombination of electrons and holes, highlighting their potential use as photo catalysts. The photocatalytic activity degrading the rhodamine B dye established M-ZnO as a superior catalyst with a rapid degradation rate and significant mineralization. Overall, this work provides valuable insights into ZnO defect states and provides a foundation for efficient advanced materials for environmental or other optoelectronic applications.

Portal Dynamics After Living Donor Liver Transplant in Pediatric Recipients: A 10-Year Follow-Up Retrospective Study

BACKGROUND

It may be difficult for pediatric patients to evaluate the impact of liver transplantation (LT) on splenomegaly due to the natural growth course. The long-term dynamics of portal vein (PV) size and PV flow after LT in pediatric patients are unclear. We aimed to evaluate the long-term transition of the splenic size, PV size, and PV flow velocity in pediatric patients who underwent successful living donor liver transplantation (LDLT) and survived >10 years.

METHODS

From October 2004 to December 2010, 39 pediatric patients (25 boys; 14 girls) underwent LDLT, received pre-LDLT and post-LDLT computed tomography scans and long-term ultrasound sonography follow-up, and survived >10 years without additional intervention at our institution. We analyzed the short- to mid-term and long-term impact of LDLT on splenic size, PV size, and PV flow velocity over time.

RESULTS

The PV diameter increased throughout the 10-year follow-up (P < .001). The PV flow velocity increased 1 day after LDLT (P< .001); proceeded to decrease 3 days after LDLT, reaching a low point 6 to 9 months after LDLT; and remained stable throughout the 10-year follow-up. Regression of the splenic volume at 6 to 9 months after LDLT (P < .001) was noted. However, the splenic size steadily increased on long-term follow-up.

CONCLUSIONS

Although LDLT has a significant short-term reduction effect on splenomegaly, the long-term transitional trend of the splenic size and PV diameter may increase along with children's growth. The PV flow reached a stable status 6 to 9 months after LDLT and remained so until 10 years after LDLT.

Conductive Lanthanide Metal-Organic Frameworks with Exceptionally High Stability

Electrically conductive metal-organic frameworks (MOFs) have been extensively studied for their potential uses in energy-related technologies and sensors. However, achieving that goal requires MOFs to be highly stable and maintain their conductivity under practical operating conditions with varying solution environments and temperatures. Herein, we have designed and synthesized a new series of {[Ln4(μ4-O)(μ3-OH)3(INA)3(GA)3](CF3SO3)(H2O)6}n (denoted as Ln4-MOFs, Ln = Gd, Tm, and Lu, INA = isonicotinic acid, GA = glycolic acid) single crystals, where electrons are found to transport along the π-π stacked aromatic carbon rings in the crystals. The Ln4-MOFs show remarkable stability, with minimal changes in conductivity under varying solution pH (1-12), temperature (373 K), and electric field as high as 800 000 V/m. This stability is achieved through the formation of strong coordination bonds between high-valent Ln(III) ions and rigid carboxylic linkers as well as hydrogen bonds that enhance the robustness of the electron transport path. The demonstrated lanthanide MOFs pave the way for the design of stable and conductive MOFs.

Impact of Sirolimus versus Mycophenolate Mofetil on Kidney Function after Calcineurin Inhibitor Dose Reduction in Liver Transplant Recipients

Impaired kidney function is associated with increased morbidity and mortality in patients undergoing liver transplantation. Although immunosuppressants are essential in these patients, they impair kidney function. This study aimed to compare adverse kidney outcomes between patients treated with a reduced dose of tacrolimus (calcineurin inhibitor) plus sirolimus or mycophenolate mofetil (MMF) in the liver transplant center at Kaohsiung Chang Gung Memorial Hospital between April 2011 and December 2017. Propensity score matching was used to identify 232 patients. The risk of adverse kidney outcomes was estimated using Cox proportional hazards regression, and changes in kidney function over time were analyzed using linear mixed modeling. Acute kidney disease risks in this study cohort were not significantly different for the two immunosuppressants (aHR 1.04; 95% CI: 0.70-1.55, p = 0.8328). However, sirolimus use was significantly associated with a higher risk of estimated glomerular filtration rate decline > 30% than MMF (aHR, 2.09; 95% CI: 1.33-3.28; p = 0.0014). Our results demonstrate that sirolimus use may have worsened long-term kidney outcomes compared to MMF. Close monitoring of kidney function, dose adjustment, and timely transition to MMF is necessary for LT patients receiving sirolimus.

Changes in Serum Bone Metabolism Markers after Living Donor Liver Transplantation (LDLT) and Their Association with Fracture Occurrences

Living donor liver transplantation (LDLT) is lifesaving, but can lead to osteoporosis and fractures. In our 3-year study of 25 LDLT recipients, we observed significant reductions in lumbar spine and femoral neck T scores, along with bone resorption marker reductions and liver regeneration marker increases. Serum calcium levels increased, while osteoprotegerin (OPG) decreased and Dickkopf-related protein 1 (DKK-1) increased. Patients who suffered fractures within 3 years of LDLT had higher serum OPG, lower serum nuclear factor kappa B ligand (RANKL), a higher OPG/RANKL ratio and higher serum DKK-1 levels. OPG, RANKL, OPG/RANKL ratio and DKK-1 levels before LDLT predicted hip or spine fractures within three years after LDLT. Further research is necessary to determine the optimal level of osteoclastic activity for preventing fracture onset.

Overexpression of miR-4669 Enhances Tumor Aggressiveness and Generates an Immunosuppressive Tumor Microenvironment in Hepatocellular Carcinoma: Its Clinical Value as a Predictive Biomarker

Accumulating evidence suggests the involvement of tumor-derived exosomes in the development and recurrence of hepatocellular carcinoma (HCC). We previously identified miR-4669 as a highly expressed microRNA in circulating exosomes obtained from patients with post-transplant HCC recurrence. This study aimed to explore how overexpression of miR-4669 affects HCC development and recurrence. The impact of miR-4669 overexpression in Hep3B cells on tumor cell behavior and the tumor microenvironment was evaluated in vitro. In addition, the clinical value of exosomal miR-4669 for the prediction of treatment response to HCC downstaging therapies and following post-transplant HCC recurrence was explored. Overexpression of miR-4669 enhanced migration ability and led to acquired sorafenib resistance with an elevation of sirtuin 1 and long noncoding RNA associated with microvascular invasion. Active release of tumor-derived exosomes and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) contributed to generating an immunosuppressive tumor microenvironment through the induction of M2 macrophage polarization. The retrospective analysis demonstrated the clinical value of exosomal miR-4669 for predicting treatment response to HCC downstaging therapies and for risk assessment of post-transplant HCC recurrence. In summary, the present data demonstrate the impact of exosomal miR-4669 on HCC recurrence through the enhancement of tumor aggressiveness and generation of an immunosuppressive tumor microenvironment.