Optimizing pediatric liver transplantation: Evaluating the impact of donor age and graft type on patient survival outcome

BACKGROUND

We examined the combined effects of donor age and graft type on pediatric liver transplantation outcomes with an aim to offer insights into the strategic utilization of these donor and graft options.

METHODS

A retrospective analysis was conducted using a national database on 0-2-year-old (N = 2714) and 3-17-year-old (N = 2263) pediatric recipients. These recipients were categorized based on donor age (≥40 vs <40 years) and graft type. Survival outcomes were analyzed using the Kaplan-Meier and Cox proportional hazards models, followed by an intention-to-treat (ITT) analysis to examine overall patient survival.

RESULTS

Living and younger donors generally resulted in better outcomes compared to deceased and older donors, respectively. This difference was more significant among younger recipients (0-2 years compared to 3-17 years). Despite this finding, ITT survival analysis showed that donor age and graft type did not impact survival with the exception of 0-2-year-old recipients who had an improved survival with a younger living donor graft.

CONCLUSIONS

Timely transplantation has the largest impact on survival in pediatric recipients. Improving waitlist mortality requires uniform surgical expertise at many transplant centers to provide technical variant graft (TVG) options and shed the conservative mindset of seeking only the "best" graft for pediatric recipients.

Small-for-size syndrome in a 9.7 kg pediatric recipient with a whole liver graft

BACKGROUND

Small-for-size syndrome (SFSS) in pediatric liver transplant recipients, particularly those weighing less than 10 kg, is rare. This report describes a case of a 15-month-old whole liver transplant recipient who suffered SFSS, and systematic literature review was performed to identify outcomes of such cases and potential risk factors for SFSS.

CASE PRESENTATION

A 15-month-old toddler with a history of biliary atresia underwent a deceased donor whole liver transplant. The graft weighed 160 g, resulting in a graft-to-recipient weight ratio (GRWR) of 1.6%. The post-operative course was complicated by SFSS, characterized by massive ascites causing hemodynamic instability and compromised hepatic artery flow. Pharmacological intervention with octreotide was initiated, and the patient eventually recovered.

CONCLUSION

In small pediatric recipients, especially those weighing less than 10 kg, the native liver body weight ratio (LBWR) is significantly higher. When selecting an appropriately sized graft for these recipients, this higher ratio should be taken into consideration. The literature review suggests that a GRWR of less than 2% is associated with a higher incidence of small-for-size syndrome in small pediatric recipients weighing less than 10 kg.

Food Insecurity and Pediatric Nonalcoholic Fatty Liver Disease Severity

OBJECTIVE

To determine the association between food insecurity and pediatric nonalcoholic fatty liver disease (NAFLD).

METHODS

Cross-sectional study of patients < 21 years of age with histologically confirmed NAFLD. The Household Food Security Survey Module was administered to determine food insecurity status. Skin lipidomics were performed to explore pathophysiologic mechanisms.

RESULTS

Seventy-three patients with histologically confirmed NAFLD completed the Household Food Security Survey Module. Of these, the majority were male (81%) and non-Hispanic (53%), with a mean age at biopsy of 13 ± 3 years. Food insecurity was seen in 42% (n = 31). Comparison of features between food insecure and food secure subgroups revealed no differences in sex, ethnicity, BMI z-score, aminotransferases, or histologic severity. However, children experiencing food insecurity presented on average 2 years before their food secure counterparts (12.3 ± 3.0 vs 14.4 ± 3.6 years, P = .015). A subset of 31 patients provided skin samples. Skin lipidomics revealed that food insecurity was associated with down-regulated features from the lipoamino acid class of lipids, previously linked to inflammation and adipocyte differentiation.

CONCLUSIONS

Food insecurity is highly prevalent in children with NAFLD and is associated with earlier presentation. Lipidomic analyses suggest a possible pathophysiologic link that warrants further exploration.

Protein biomarkers GDF15 and FGF21 to differentiate mitochondrial hepatopathies from other pediatric liver diseases

BACKGROUND

Mitochondrial hepatopathies (MHs) are primary mitochondrial genetic disorders that can present as childhood liver disease. No recognized biomarkers discriminate MH from other childhood liver diseases. The protein biomarkers growth differentiation factor 15 (GDF15) and fibroblast growth factor 21 (FGF21) differentiate mitochondrial myopathies from other myopathies. We evaluated these biomarkers to determine if they discriminate MH from other liver diseases in children.

METHODS

Serum biomarkers were measured in 36 children with MH (17 had a genetic diagnosis); 38 each with biliary atresia, α1-antitrypsin deficiency, and Alagille syndrome; 20 with NASH; and 186 controls.

RESULTS

GDF15 levels compared to controls were mildly elevated in patients with α1-antitrypsin deficiency, Alagille syndrome, and biliary atresia-young subgroup, but markedly elevated in MH (p<0.001). FGF21 levels were mildly elevated in NASH and markedly elevated in MH (p<0.001). Both biomarkers were higher in patients with MH with a known genetic cause but were similar in acute and chronic presentations. Both markers had a strong performance to identify MH with a molecular diagnosis with the AUC for GDF15 0.93±0.04 and for FGF21 0.90±0.06. Simultaneous elevation of both markers >98th percentile of controls identified genetically confirmed MH with a sensitivity of 88% and specificity of 96%. In MH, independent predictors of survival without requiring liver transplantation were international normalized ratio and either GDF15 or FGF21 levels, with levels <2000 ng/L predicting survival without liver transplantation (p<0.01).

CONCLUSIONS

GDF15 and FGF21 are significantly higher in children with MH compared to other childhood liver diseases and controls and, when combined, were predictive of MH and had prognostic implications.

Event-free survival of maralixibat-treated patients with Alagille syndrome compared to a real-world cohort from GALA

BACKGROUND AND AIMS

Alagille syndrome (ALGS) is characterized by chronic cholestasis with associated pruritus and extrahepatic anomalies. Maralixibat, an ileal bile acid transporter inhibitor, is an approved pharmacologic therapy for cholestatic pruritus in ALGS. Since long-term placebo-controlled studies are not feasible or ethical in children with rare diseases, a novel approach was taken comparing 6-year outcomes from maralixibat trials with an aligned and harmonized natural history cohort from the G lobal AL agille A lliance (GALA) study.

APPROACH AND RESULTS

Maralixibat trials comprise 84 patients with ALGS with up to 6 years of treatment. GALA contains retrospective data from 1438 participants. GALA was filtered to align with key maralixibat eligibility criteria, yielding 469 participants. Serum bile acids could not be included in the GALA filtering criteria as these are not routinely performed in clinical practice. Index time was determined through maximum likelihood estimation in an effort to align the disease severity between the two cohorts with the initiation of maralixibat. Event-free survival, defined as the time to first event of manifestations of portal hypertension (variceal bleeding, ascites requiring therapy), surgical biliary diversion, liver transplant, or death, was analyzed by Cox proportional hazards methods. Sensitivity analyses and adjustments for covariates were applied. Age, total bilirubin, gamma-glutamyl transferase, and alanine aminotransferase were balanced between groups with no statistical differences. Event-free survival in the maralixibat cohort was significantly better than the GALA cohort (HR, 0.305; 95% CI, 0.189-0.491; p <0.0001). Multiple sensitivity and subgroup analyses (including serum bile acid availability) showed similar findings.

CONCLUSIONS

This study demonstrates a novel application of a robust statistical method to evaluate outcomes in long-term intervention studies where placebo comparisons are not feasible, providing wide application for rare diseases. This comparison with real-world natural history data suggests that maralixibat improves event-free survival in patients with ALGS.

Sarcopenia is associated with osteopenia and impaired quality of life in children with genetic intrahepatic cholestatic liver disease

BACKGROUND

Sarcopenia occurs in pediatric chronic liver disease, although the prevalence and contributing factors in genetic intrahepatic cholestasis are not well-described. The objective of this study was to measure muscle mass in school-aged children with genetic intrahepatic cholestasis and assess relationships between sarcopenia, clinical variables, and outcomes.

METHODS

Estimated skeletal muscle mass (eSMM) was calculated on dual-energy x-ray absorptiometry obtained in a Childhood Liver Disease Research Network study of children with bile acid synthesis disorders(BASD) alpha-1 antitrypsin deficiency (a1ATd), chronic intrahepatic cholestasis (CIC), and Alagille syndrome (ALGS). Relationships between eSMM, liver disease, and transplant-free survival were assessed.

RESULTS

eSMM was calculated in 127 participants (5-18 y): 12 BASD, 41 a1ATd, 33 CIC, and 41 ALGS. eSMM z-score was lower in CIC (-1.6 ± 1.3) and ALGS (-2.1 ± 1.0) than BASD (-0.1 ± 1.1) and a1ATd (-0.5 ± 0.8, p < 0.001). Sarcopenia (defined as eSMM z-score ≤- 2) was present in 33.3% of CIC and 41.5% of ALGS participants. eSMM correlated with bone mineral density in the 4 disease groups (r=0.52-0.55, p < 0.001-0.07), but not serum bile acids, bilirubin, aspartate aminotransferase/platelet ratio index, or clinically evident portal hypertension. Of the 2 patients who died (1 with sarcopenia) and 18 who underwent liver transplant (LT, 4 with sarcopenia), eSMM z-score did not predict transplant-free survival. eSMM z-score correlated with the Physical Pediatric Quality of Life Inventory score (r=0.38-0.53, p = 0.007-0.04) in CIC and a1ATd.

CONCLUSION

Severe sarcopenia occurs in some children with ALGS and CIC. The lack of correlation between eSMM and biochemical cholestasis suggests mechanisms beyond cholestasis contribute to sarcopenia. While sarcopenia did not predict transplant-free survival, LT and death were infrequent events. Future studies may define mechanisms of sarcopenia in genetic intrahepatic cholestasis.

An appraisal of technical variant grafts compared to whole liver grafts in pediatric liver transplant recipients: Multicenter analysis from the SPLIT registry

BACKGROUND

Shortages of liver allografts for children awaiting transplantation have led to high LT waitlist mortality. Prior studies have shown that usage of TVG can reduce waiting time and waitlist mortality, but their use is not universal. We sought to compare patient and graft survival between WLG and TVG and to identify potential associated risk factors in a contemporary pediatric LT cohort.

METHODS

We performed a retrospective analysis of patient survival, graft survival, and biliary and vascular complications for LT recipients <18 years old entered into the Society of Pediatric Liver Transplantation prospective multicenter database.

RESULTS

Of 1839 LT recipients, 1029 received a WLG and 810 received a TVG from either a LD or a DD. There was no difference in patient survival or graft survival by graft type. Three-year patient survival and graft survival were 96%, 93%, and 96%, and 95%, 89%, and 92% for TVG-LD, TVG-DD, and WLG, respectively. Biliary complications were more frequent in TVG. Hepatic artery thrombosis was more frequent in WLG. Multivariate analysis revealed primary diagnosis was the only significant predictor of patient survival. Predictors for graft survival included time-dependent development of biliary and vascular complications.

CONCLUSIONS

There were no significant differences in patient and graft survival based on graft types in this North American multi-center pediatric cohort. Widespread routine use of TVG should be strongly encouraged to decrease mortality on the waitlist for pediatric LT candidates.

Natural history of liver disease in a large international cohort of children with Alagille syndrome: Results from the GALA study

BACKGROUND AND AIMS

Alagille syndrome (ALGS) is a multisystem disorder, characterized by cholestasis. Existing outcome data are largely derived from tertiary centers, and real-world data are lacking. This study aimed to elucidate the natural history of liver disease in a contemporary, international cohort of children with ALGS.

APPROACH AND RESULTS

This was a multicenter retrospective study of children with a clinically and/or genetically confirmed ALGS diagnosis, born between January 1997 and August 2019. Native liver survival (NLS) and event-free survival rates were assessed. Cox models were constructed to identify early biochemical predictors of clinically evident portal hypertension (CEPH) and NLS. In total, 1433 children (57% male) from 67 centers in 29 countries were included. The 10 and 18-year NLS rates were 54.4% and 40.3%. By 10 and 18 years, 51.5% and 66.0% of children with ALGS experienced ≥1 adverse liver-related event (CEPH, transplant, or death). Children (>6 and ≤12 months) with median total bilirubin (TB) levels between ≥5.0 and <10.0 mg/dl had a 4.1-fold (95% confidence interval [CI], 1.6-10.8), and those ≥10.0 mg/dl had an 8.0-fold (95% CI, 3.4-18.4) increased risk of developing CEPH compared with those <5.0 mg/dl. Median TB levels between ≥5.0 and <10.0 mg/dl and >10.0 mg/dl were associated with a 4.8 (95% CI, 2.4-9.7) and 15.6 (95% CI, 8.7-28.2) increased risk of transplantation relative to <5.0 mg/dl. Median TB <5.0 mg/dl were associated with higher NLS rates relative to ≥5.0 mg/dl, with 79% reaching adulthood with native liver ( p < 0.001).

CONCLUSIONS

In this large international cohort of ALGS, only 40.3% of children reach adulthood with their native liver. A TB <5.0 mg/dl between 6 and 12 months of age is associated with better hepatic outcomes. These thresholds provide clinicians with an objective tool to assist with clinical decision-making and in the evaluation of therapies.

Epidemiology and outcomes of surgical site infections among pediatric liver transplant recipients

INTRODUCTION

Surgical site infections (SSI) are a significant cause of morbidity in liver transplant recipients, and the current data in the pediatric population are limited. The goal of this study was to identify the incidence, classification, risk factors, and outcomes of SSIs among children undergoing liver transplantation (LT).

METHODS

A single-center, retrospective descriptive analysis was performed of patients age ≤18 years undergoing LT between September 2007 and April 2017. SSI identified within the first 30 days were analyzed. Primary endpoints included incidence, classification, risk factors, and outcomes associated with SSIs.

RESULTS

We included 86 patients, eight patients (9.3%) developed SSIs. Among segmental grafts (SG) recipients, 7/61 (11.4%) developed SSI. Among whole grafts recipients, 1/25 (4%) developed SSI. SSIs were associated with the presence of biliary complications (35% vs. 3%, p < .01; odds ratios 24, 95% CI: 3.41-487.37, p<.01). There were no differences in long term graft or patient survival associated with SSI. Patients who developed SSI were more likely to undergo reoperation (50% vs. 16.7%, p = .045) and had an increased total number of hospital days in the first 60 days post-transplant (30.5 vs. 12.5 days, p = .001).

CONCLUSIONS

SSIs after pediatric LT was less frequent than what has been previously reported in literature. SSIs were associated with the presence of biliary complications without an increase in mortality. SG had an increased rate of biliary complications without an association to SSIs but, considering its positive impact on organ shortage barriers, should not be a deterrent to the utilization of SGs.

North American Biliary Stricture Management Strategies in Children After Liver Transplantation: A Multicenter Analysis From the Society of Pediatric Liver Transplantation (SPLIT) Registry

Biliary strictures affect 4%-12% of pediatric liver transplantations. Biliary strictures can contribute to graft loss if left untreated; however, there remains no consensus on the best course of treatment. Study objectives included analyses of outcomes associated with biliary stricture management strategies via percutaneous transhepatic cholangiography (PTC), endoscopic retrograde cholangiopancreatography (ERCP), or surgery. We identified pediatric liver transplantation recipients (2011-2016) with biliary strictures from the Society of Pediatric Liver Transplantation (SPLIT) registry and retrieved imaging, procedural, and operative reports from individual centers. Subanalyses were performed to specifically evaluate PTC and ERCP for "optimal biliary outcome" (OBO), defined as graft survival with stricture resolution and without recurrence or surgery. A total of 113 children with a median follow-up of 3.9 years had strictures diagnosed 100 days (interquartile range, 30-290) after liver transplantation; 81% were isolated anastomotic strictures. Stricture resolution was achieved in 92% within 101 days, more frequently with isolated anastomotic strictures (96%). 20% of strictures recurred, more commonly in association with hepatic artery thrombosis (32%). Patient and graft survival at 1 and 3 years were 99% and 98% and 94% and 92%, respectively. In a subgroup analysis of 79 patients with extrahepatic strictures managed by PTC/ERCP, 59% achieved OBO following a median of 4 PTC, and 75% following a median of 3 ERCP (P < 0.001). Among patients with OBO, those with ERCP had longer time intervals between successive procedures (41, 47, 54, 62, 71 days) than for PTC (27, 31, 36, 41, 48 days; P < 0.001). Allograft salvage was successful across all interventions. Stricture resolution was achieved in 92%, with 20% risk of recurrence. Resolution without recurrence was highest in patients with isolated anastomotic strictures and without hepatic artery thrombosis.

Severe Acute Respiratory Syndrome Coronavirus-2 Infection in Children With Liver Transplant and Native Liver Disease: An International Observational Registry Study

OBJECTIVE

Increased mortality risk because of severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) infection in adults with native liver disease (LD) and liver transplant (LT) is associated with advanced age and comorbid conditions. We aim to report outcomes for children with LD and LT enrolled in the NASPGHAN/SPLIT SARS-CoV2 registry.

METHODS

In this multicenter observational cohort study, we collected data from 91 patients <21 years (LD 44, LT 47) with laboratory-confirmed SARS-CoV2 infection between April 21 and September 17, 2020.

RESULTS

Patients with LD were more likely to require admission (70% vs 43% LT, P = 0.007) and pediatric intensive care unit (PICU) management (32% vs 4% LT, P = 0.001). Seven LD patients required mechanical ventilation (MV) and 2 patients died; no patients in the LT cohort died or required MV. Four LD patients presented in pediatric acute liver failure (PALF), 2 with concurrent multisystem inflammatory syndrome in children (MIS-C); all recovered without LT. Two LD patients had MIS-C alone and 1 patient died. Bivariable logistic-regression analysis found that patients with nonalcoholic fatty LD (NAFLD) (odds ratio [OR] 5.6, P = 0.02) and LD (OR 6.1, P = 0.01, vs LT) had higher odds of severe disease (PICU, vasopressor support, MV, renal replacement therapy or death).

CONCLUSIONS

Although not directly comparable, LT recipients had lower odds of severe SARS-CoV2 infection (vs LD), despite immunosuppression burden. NAFLD patients reported to the registry had higher odds of severe SARS-CoV2 disease. Future controlled studies are needed to evaluate effective treatments and further stratify LD and LT patients with SARS-CoV2 infection.

Alternative Etiologies of Liver Disease in Children With Suspected NAFLD

OBJECTIVES

To determine the prevalence of alternative causes of liver disease in a cohort of youth with overweight and obesity undergoing evaluation for suspected nonalcoholic fatty liver disease (NAFLD).

METHODS

Multicenter, retrospective cohort study of patients aged ≤18 years with overweight and obesity and evidence of elevated serum aminotransferases and/or hepatic steatosis on imaging, referred for suspected NAFLD to Cincinnati Children's Hospital Medical Center (2009-2017) or Yale New Haven Children's Hospital (2012-2017). Testing was performed to exclude the following: autoimmune hepatitis (AIH), Wilson disease, viral hepatitis (B and C), thyroid dysfunction, celiac disease, α-1 antitrypsin deficiency, and hemochromatosis.

RESULTS

A total of 900 children with overweight and obesity (63% boys, 26% Hispanic ethnicity) were referred, with a median age of 13 years (range: 2-18). Most had severe obesity (n = 666; 76%) with a median BMI z score of 2.45 (interquartile range [IQR]: 2.2-2.7). Median alanine aminotransferase level at presentation was 64 U/L (IQR: 42-95). A clinically indicated liver biopsy was performed in 358 children (40%) at a median of 6 months (IQR: 1-14) post initial visit; of those, 46% had confirmed nonalcoholic steatohepatitis. Positive autoantibodies were observed in 13% of the cohort, but none met criteria for AIH. Only 19 (2%) were found to have other causes of liver disease, with no cases of viral hepatitis or Wilson disease detected.

CONCLUSIONS

In a large, multicenter cohort, the vast majority of children with overweight and obesity with presumed or confirmed NAFLD tested negative for other causes of liver disease. In contrast to a previous pediatric report, no patient was diagnosed with AIH.

The Sclerosing Cholangitis Outcomes in Pediatrics (SCOPE) Index: A Prognostic Tool for Children

BACKGROUND AND AIMS

Disease progression in children with primary sclerosing cholangitis (PSC) is variable. Prognostic and risk-stratification tools exist for adult-onset PSC, but not for children. We aimed to create a tool that accounts for the biochemical and phenotypic features and early disease stage of pediatric PSC.

APPROACH AND RESULTS

We used retrospective data from the Pediatric PSC Consortium. The training cohort contained 1,012 patients from 40 centers. We generated a multivariate risk index (Sclerosing Cholangitis Outcomes in Pediatrics [SCOPE] index) that contained total bilirubin, albumin, platelet count, gamma glutamyltransferase, and cholangiography to predict a primary outcome of liver transplantation or death (TD) and a broader secondary outcome that included portal hypertensive, biliary, and cancer complications termed hepatobiliary complications (HBCs). The model stratified patients as low, medium, or high risk based on progression to TD at rates of <1%, 3%, and 9% annually and to HBCs at rates of 2%, 6%, and 13% annually, respectively (P < 0.001). C-statistics to discriminate outcomes at 1 and 5 years were 0.95 and 0.82 for TD and 0.80 and 0.76 for HBCs, respectively. Baseline hepatic fibrosis stage was worse with increasing risk score, with extensive fibrosis in 8% of the lowest versus 100% with the highest risk index (P < 0.001). The model was validated in 240 children from 11 additional centers and performed well.

CONCLUSIONS

The SCOPE index is a pediatric-specific prognostic tool for PSC. It uses routinely obtained, objective data to predict a complicated clinical course. It correlates strongly with biopsy-proven liver fibrosis. SCOPE can be used with families for shared decision making on clinical care based on a patient's individual risk, and to account for variable disease progression when designing future clinical trials.

Oral Vancomycin, Ursodeoxycholic Acid, or No Therapy for Pediatric Primary Sclerosing Cholangitis: A Matched Analysis

BACKGROUND AND AIMS

Many children with primary sclerosing cholangitis (PSC) receive oral vancomycin therapy (OVT) or ursodeoxycholic acid (UDCA). There is a paucity of data on whether these medications improve outcomes.

APPROACH AND RESULTS

We analyzed retrospective data from the Pediatric PSC Consortium. Children treated with OVT were matched 1:1:1 to those treated with UDCA or managed with observation (no treatment) based on the closest propensity score, ensuring similar baseline characteristics. Two hundred sixty-four patients (88 each with OVT, UDCA, or observation) had matching propensity scores and were similar in demographics, phenotype, immunosuppression, baseline biochemistry, and hepatic fibrosis. After 1 year in an intention-to-treat analysis, all outcome metrics were similar regardless of treatment group. In OVT, UDCA, and untreated groups, respectively: Gamma-glutamyltransferase normalized in 53%, 49%, and 52% (P = not significant [NS]), liver fibrosis stage was improved in 20%, 13%, and 18% and worsened in 11%, 29%, and 18% (P = NS), and the 5-year probability of liver transplant listing was 21%, 10%, and 12% (P = NS). Favorable outcome was associated with having a mild phenotype of PSC and minimal hepatic fibrosis.

CONCLUSIONS

We presented the largest-ever description of outcomes on OVT in PSC and compared them to carefully matched patients on UDCA or no therapy. Neither OVT nor UDCA showed improvement in outcomes compared to a strategy of observation. Patients progressed to end-stage liver disease at similar rates. Spontaneous normalization of biochemistry is common in children receiving no therapy, particularly in the majority of children with a mild phenotype and an early stage of disease. Placebo-controlled treatment trials are needed to identify effective treatments for pediatric PSC.

Significance of autoantibody seropositivity in children with obesity and non-alcoholic fatty liver disease

BACKGROUND

Autoantibodies are frequently positive in adults with nonalcoholic fatty liver disease (NAFLD) without concurrent autoimmune hepatitis (AIH). The clinical significance of this is unknown in children.

OBJECTIVE

To determine the prevalence of autoantibody positivity in pediatric NAFLD and to evaluate its association with disease severity.

METHODS

Multicenter, retrospective study of patients ≤18 years of age with biopsy-confirmed NAFLD. Descriptive statistics were used and groups were compared using Wilcoxon-Mann Whitney or χ² testing, and multivariable logistic regression was used for binary or ordinal outcomes.

RESULTS

One hundred and thirty six patients with a median age of 14 years were included. The median body mass index Z-score was 2.5 (interquartile range 2.2, 2.6). Positive antinuclear antibody (ANA), anti-smooth muscle antibody (ASMA), anti-liver-kidney microsomal antibody, or any combination of autoantibodies were observed in 22%, 14%, 0%, and 33% of patients, respectively. The proportion of patients with a steatosis score ≥2 was significantly higher in those with positive ANA (P = .045). In the multivariable regression analysis, positive ANA was associated with increased odds of steatosis score ≥2 (odds ratio, 5.91; 95% confidential interval, 1.50-23.26), after controlling for potential confounders. No other significant histology differences were seen between the groups.

CONCLUSIONS

Positive ANA and ASMA are common in children with NAFLD; however, anti-LKM positivity is not. ANA positivity is associated with more severe steatosis.

Fontan-Associated Liver Disease: Screening, Management, and Transplant Considerations

Surgical innovation and multidisciplinary management have allowed children born with univentricular physiology congenital heart disease to survive into adulthood. An estimated global population of 70 000 patients have undergone the Fontan procedure and are alive today, most of whom are <25 years of age. Several unexpected consequences of the Fontan circulation include Fontan-associated liver disease. Surveillance biopsies have demonstrated that virtually 100% of these patients develop clinically silent fibrosis by adolescence. As they mature, there are increasing reports of combined heart-liver transplantation resulting from advanced liver disease, including bridging fibrosis, cirrhosis, and hepatocellular carcinoma, in this population. In the absence of a transplantation option, these young patients face a poor quality of life and overall survival. Acknowledging that there are no consensus guidelines for diagnosing and monitoring Fontan-associated liver disease or when to consider heart transplantation versus combined heart-liver transplantation in these patients, a multidisciplinary working group reviewed the literature surrounding Fontan-associated liver disease, with a specific focus on considerations for transplantation.

Impact of Acuity Circles on Outcomes for Pediatric Liver Transplant Candidates

BACKGROUND

In December 2018, United Network for Organ Sharing approved an allocation scheme based on recipients' geographic distance from a deceased donor (acuity circles [ACs]). Previous analyses suggested that ACs would reduce waitlist mortality overall, but their impact on pediatric subgroups was not considered.

METHODS

We applied Scientific Registry of Transplant Recipients data from 2011 to 2016 toward the Liver Simulated Allocation Model to compare outcomes by age and illness severity for the United Network for Organ Sharing-approved AC and the existing donor service area-/region-based allocation schemes. Means from each allocation scheme were compared using matched-pairs t tests.

RESULTS

During a 3-year period, AC allocation is projected to decrease waitlist deaths in infants (39 versus 55; P < 0.001), children (32 versus 50; P < 0.001), and teenagers (15 versus 25; P < 0.001). AC allocation would increase the number of transplants in infants (707 versus 560; P < 0.001), children (677 versus 547; P < 0.001), and teenagers (404 versus 248; P < 0.001). AC allocation led to decreased median pediatric end-stage liver disease/model for end-stage liver disease at transplant for infants (29 versus 30; P = 0.01), children (26 versus 29; P < 0.001), and teenagers (26 versus 31; P < 0.001). Additionally, AC allocation would lead to fewer transplants in status 1B in children (97 versus 103; P = 0.006) but not infants or teenagers. With AC allocation, 77% of pediatric donor organs would be allocated to pediatric candidates, compared to only 46% in donor service area-/region-based allocation (P < 0.001).

CONCLUSIONS

AC allocation will likely address disparities for pediatric liver transplant candidates and recipients by increasing transplants and decreasing waitlist mortality. It is more consistent with federally mandated requirements for organ allocation.

A Low ω-6 to ω-3 PUFA Ratio (n-6:n-3 PUFA) Diet to Treat Fatty Liver Disease in Obese Youth

BACKGROUND

Recent literature suggests that the Western diet's imbalance between high ω-6 (n-6) and low ω-3 (n-3) PUFA intake contributes to fatty liver disease in obese youth.

OBJECTIVES

We tested whether 12 wk of a low n-6:n-3 PUFA ratio (4:1) normocaloric diet mitigates fatty liver and whether the patatin-like containing domain phospholipase 3 (PNPLA3) rs738409 variant affects the response.

METHODS

In a single-arm unblinded study, obese youth 9-19 y of age with nonalcoholic fatty liver disease were treated with a normocaloric low n-6:n-3 PUFA ratio diet for 12 wk. The primary outcome was change in hepatic fat fraction (HFF%), measured by abdominal MRI. Metabolic parameters included alanine aminotransferase (ALT), lipids, measures of insulin sensitivity, and plasma oxidized linoleic acid metabolites (OXLAMs). Outcomes were also analyzed by PNPLA3 rs738409 genotype. Wilcoxon's signed rank test, the Mann-Whitney U test, and covariance pattern modeling were used.

RESULTS

Twenty obese adolescents (median age: 13.3 y; IQR: 10.5-16.4 y) were enrolled and 17 completed the study. After 12 wk of dietary intervention, HFF% decreased by 25.8% (P = 0.009) despite stable weight. We observed a 34.4% reduction in ALT (P = 0.001), 21.9% reduction in triglycerides (P = 0.046), 3.28% reduction in LDL cholesterol (P = 0.071), and a 26.3% improvement in whole body insulin sensitivity (P = 0.032). The OXLAMs 9-hydroxy-octadecandienoic acid (9-HODE) (P = 0.011), 13-HODE (P = 0.007), and 9-oxo-octadecadienoic acid (9-oxoODE) (P = 0.024) decreased after 12 wk. HFF% declined in both the not-at-risk (CC/CG) and at-risk (GG) PNPLA3 rs738409 genotype groups, with significant (P = 0.016) HFF% reduction in the GG group. Changes in 9-HODE (P = 0.023), 9-oxoODE (P = 0.009), and 13-oxoODE (P = 0.003) differed between the 2 genotype groups over time.

CONCLUSIONS

These data suggest that, independently of weight loss, a low n-6:n-3 PUFA diet ameliorates the metabolic phenotype of adolescents with fatty liver disease and that response to this diet is modulated by the PNPLA3 rs738409 genotype.This trial was registered at clinicaltrials.gov as NCT01556113.

Frequency of whole-organ in lieu of split-liver transplantation over the last decade: Children experienced increased wait time and death

Organ shortage is a barrier to liver transplantation (LT). Split LT (SLT) increases organ utilization, saving 2 recipients. A simulation of Organ Procurement and Transplantation Network/United Network for Organ Sharing data (2007-2017) was performed to identify whole-organ LT grafts (WLT) that met the criteria for being splittable to 2 recipients. Waitlist consequences presented. Deceased donor (DD) livers transplanted as whole organs were evaluated for suitability to split. Of these DD organs, we identified the adolescent and adult recipients of WLT who were suitable for SLT. Pediatric candidates suitable to share the SLT were ascertained from DD match-run lists, and 1342 splittable DD organs were identified; 438 WLT recipients met the criteria for accepting a SLT. Review of the 438 DD match-run lists identified 420 children next on the list suitable for SLT. Three hundred thirty-three children (79%) underwent LT, but had longer wait-times compared to 591 actual pediatric SLT recipients (median 147 days vs 44 days, P  < 0.001). Thirty-three of 420 children died on waitlist after a mean 206 days (standard deviation 317). Sharing organs suitable for splitting increases the number of LT, saving more lives. With careful patient selection, SLT will not be a disadvantage to the adult recipients. With a children-first allocation scheme, SLT will naturally increase the number of allografts because adult organs are too large for small children.

The Impact of Increased Allocation Priority for Children Awaiting Liver Transplant: A Liver Simulated Allocation Model (LSAM) Analysis

OBJECTIVE

The aim of the study was to investigate the impact of prioritizing infants, children, adolescents, and the sickest adults (Status 1) for deceased donor livers. We compared outcomes under two "SharePeds" allocation schema, which prioritize children and Status 1 adults for national sharing and enhanced access to pediatric donors or all donors younger than 35 years, to outcomes under the allocation plan approved by the Organ Procurement and Transplant Network in December 2017 (Organ Procurement and Transplantation Network [OPTN] 12-2017).

METHODS

The 2017 Liver Simulated Allocation Model and Scientific Registry of Transplant Recipients data on all US liver transplant candidates and liver offers 7/2013 to 6/2016 were used to predict waitlist deaths, transplants, and post-transplant deaths under the OPTN 12-2017 and SharePeds schema.

RESULTS

Prioritizing national sharing of pediatric donor livers with children (SharePeds 1) would decrease waitlist deaths for infants (<2 years, P = 0.0003) and children (2-11 years, P = 0.001), with no significant change for adults (P = 0.13). Prioritizing national sharing of all younger than 35-year-old deceased donor livers with children and Status 1A adults (SharePeds 2) would decrease waitlist deaths for infants, children, and all Status 1A/B patients (P < 0.0001 for each). SharePeds 1 and 2 would increase the number of liver transplants done in infants, children, and adolescents compared to the OPTN-2017 schema (P < 0.00005 for all age groups). Both SharePeds schema would increase the percentage of pediatric livers transplanted into pediatric recipients.

CONCLUSIONS

Waitlist deaths could be significantly decreased, and liver transplants increased, for children and the sickest adults, by prioritizing children for pediatric livers and with broader national sharing of deceased donor livers.

Gamma Glutamyltransferase Reduction Is Associated With Favorable Outcomes in Pediatric Primary Sclerosing Cholangitis

Adverse clinical events in primary sclerosing cholangitis (PSC) happen too slowly to capture during clinical trials. Surrogate endpoints are needed, but no such validated endpoints exist for children with PSC. We evaluated the association between gamma glutamyltransferase (GGT) reduction and long-term outcomes in pediatric PSC patients. We evaluated GGT normalization (< 50 IU/L) at 1 year among a multicenter cohort of children with PSC who did or did not receive treatment with ursodeoxycholic acid (UDCA). We compared rates of event-free survival (no portal hypertensive or biliary complications, cholangiocarcinoma, liver transplantation, or liver-related death) at 5 years. Of the 287 children, mean age of 11.4 years old, UDCA was used in 81% at a mean dose of 17 mg/kg/day. Treated and untreated groups had similar GGT at diagnosis (314 versus 300, P= not significant [NS]). The mean GGT was reduced at 1 year in both groups, with lower values seen in treated (versus untreated) patients (99 versus 175, P= 0.002), but 5-year event-free survival was similar (74% versus 77%, P= NS). In patients with GGT normalization (versus no normalization) by 1 year, regardless of UDCA treatment status, 5-year event-free survival was better (91% versus 67%, P< 0.001). Similarly, larger reduction in GGT over 1 year (> 75% versus < 25% reduction) was also associated with improved outcome (5-year event-free survival 88% versus 61%, P= 0.005). Conclusion:A GGT < 50 and/or GGT reduction of > 75% by 1 year after PSC diagnosis predicts favorable 5-year outcomes in children. GGT has promise as a potential surrogate endpoint in future clinical trials for pediatric PSC.

Biliary drainage as treatment for allograft steatosis following liver transplantation for PFIC-1 disease: A single-center experience

Development of macrovesicular steatosis post-LT in patients with PFIC-1 is increasingly being observed, with the etiology not fully understood. We highlight successful and effective EBD for reversal of allograft steatosis in 2 patients with PFIC-1 disease and discuss our experience with internal biliary diversion in this patient population.

The natural history of primary sclerosing cholangitis in 781 children: A multicenter, international collaboration

There are limited data on the natural history of primary sclerosing cholangitis (PSC) in children. We aimed to describe the disease characteristics and long-term outcomes of pediatric PSC. We retrospectively collected all pediatric PSC cases from 36 participating institutions and conducted a survival analysis from the date of PSC diagnosis to dates of diagnosis of portal hypertensive or biliary complications, cholangiocarcinoma, liver transplantation, or death. We analyzed patients grouped by disease phenotype and laboratory studies at diagnosis to identify objective predictors of long-term outcome. We identified 781 patients, median age 12 years, with 4,277 person-years of follow-up; 33% with autoimmune hepatitis, 76% with inflammatory bowel disease, and 13% with small duct PSC. Portal hypertensive and biliary complications developed in 38% and 25%, respectively, after 10 years of disease. Once these complications developed, median survival with native liver was 2.8 and 3.5 years, respectively. Cholangiocarcinoma occurred in 1%. Overall event-free survival was 70% at 5 years and 53% at 10 years. Patient groups with the most elevated total bilirubin, gamma-glutamyltransferase, and aspartate aminotransferase-to-platelet ratio index at diagnosis had the worst outcomes. In multivariate analysis PSC-inflammatory bowel disease and small duct phenotypes were associated with favorable prognosis (hazard ratios 0.6, 95% confidence interval 0.5-0.9, and 0.7, 95% confidence interval 0.5-0.96, respectively). Age, gender, and autoimmune hepatitis overlap did not impact long-term outcome.

CONCLUSION

PSC has a chronic, progressive course in children, and nearly half of patients develop an adverse liver outcome after 10 years of disease; elevations in bilirubin, gamma-glutamyltransferase, and aspartate aminotransferase-to-platelet ratio index at diagnosis can identify patients at highest risk; small duct PSC and PSC-inflammatory bowel disease are more favorable disease phenotypes. (Hepatology 2017;66:518-527).

Second-line Agents in Pediatric Patients With Autoimmune Hepatitis: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Ten percent to 20% of children with autoimmune hepatitis (AIH) require second-line therapy to achieve remission. Although current guidelines exist on first-line management, evidence for second-line therapy in treatment-refractory patients is lacking. Our aim was to perform a systematic review and meta-analysis of the efficacy and safety of second-line treatments used in this population.

METHODS

Electronic and manual searches were used to identify potential studies for inclusion. Studies were selected based on reported response rates to second-line therapies in children who failed response to prednisone and azathioprine. Data extraction and risk of bias assessment were performed independently by 2 reviewers. Meta-analysis using weighted estimate of response rates at 6 months was performed for each treatment option. Heterogeneity was assessed.

RESULTS

Fifteen studies of 76 pediatric patients with AIH were included in the review. Overall response rates at 6 months were estimated as 36% for mycophenolate mofetil (MMF) (N = 34, 95% confidence interval [CI] (16-57)), and 50% for tacrolimus (N = 4, 95% CI (0-100%)) and 83% for cyclosporine (N = 15, 95% CI (66%-100%)). Adverse effects were most frequent with cyclosporine (64% experiencing at least 1 adverse effect) followed by tacrolimus (54%) and MMF (48%). Pooled estimates of adverse events were 78% for cyclosporine (95% CI (54%-100%)), 42% for tacrolimus (95% CI (0%-85%)) and 45% for MMF (95% CI (25%-68%)). Sensitivity analyses were not performed due to small sample size.

CONCLUSIONS

Cyclosporine had the highest response rate at 6 months in children with standard-treatment-refractory AIH; however, it also had the highest rate of adverse events. MMF was the second most efficacious option with a low adverse effect rate.

Outcomes after discontinuation of routine use of transanastomotic biliary stents in pediatric liver transplantation at a single site

Routine use of transanastomotic biliary stents (RTBS) for biliary reconstruction in liver transplantation (LT) is controversial, with conflicting outcomes in adult randomized trials. Pediatric literature contains limited data. This study is a retrospective review of 99 patients who underwent first LT (2005-2014). In 2011, RTBS was discontinued at our center. This study describes biliary complications following LT with and without RTBS. 56 (56%) patients had RTBS. Median age at LT was 1.9 yr (IQR 0.7, 8.6); 55% were female. Most common indication for LT was biliary atresia (36%). Most common biliary reconstruction was Roux-en-Y choledochojejunostomy (75% with RTBS, 58% without RTBS, p = 0.09). Biliary complications (strictures, bile leaks, surgical revision) occurred in 23% without significant difference between groups (20% with RTBS, 28% without RTBS, p = 0.33). Patients with RTBS had routine cholangiography via the tube at 6-8 wk; thus, significantly more patients with RTBS had cholangiograms (91% vs. 19%, p < 0.0001). There was no difference in the number of patients who required therapeutic intervention via endoscopic or percutaneous transhepatic cholangiography (11% with RTBS, 19% no RTBS, p = 0.26). Routine use of RTBS for biliary reconstruction in pediatric LT may not be necessary, and possibly associated with need for costlier, invasive imaging without improvement in outcomes.

Abnormal Liver Biochemistry Is Common in Pediatric Inflammatory Bowel Disease: Prevalence and Associations

BACKGROUND

Liver enzymes (LEs) abnormalities associated with pediatric inflammatory bowel diseases (IBD) are understudied. We undertook to describe the development and associations of abnormal LEs in pediatric IBD.

METHODS

We ascertained a cohort of 300 children with IBD and collected retrospective data. A Kaplan-Meier analysis determined the time to development of different thresholds of abnormal LEs. Associations between clinical variables and the development of abnormal LEs were determined.

RESULTS

The probability of developing the first episode of abnormal LEs above the upper limit of normal (ULN) within 150 months was 58.1% (16.3% by 1 mo post-IBD diagnosis). There was a 6% prevalence of primary sclerosing cholangitis (PSC) or autoimmune sclerosing cholangitis (ASC) in this cohort. Of those diagnosed with PSC/ASC, 93% had persistent LE elevations at a threshold of >2× ULN, while those without PSC/ASC had a 4% probability of this abnormality. Elevated gamma glutamyltranspeptidase levels of 252 U/L had a 99% sensitivity and 71% specificity for PSC/ASC in IBD. After exclusion of patients with PSC/ASC, corticosteroids, antibiotics, and exclusive enteral nutrition demonstrated strongly positive associations with the first development of abnormal LEs >ULN (hazard ratio 2.1 [95% confidence interval, 1.3-3.3], hazard ratio 5.6 [95% confidence interval, 3.6-8.9], hazard ratio 4.2 [95% confidence interval, 1.6-11.3], respectively).

CONCLUSIONS

Abnormal LEs are common in pediatric IBD and occur early. PSC/ASC is associated with persistently high LEs and gamma glutamyltranspeptidase levels >252 U/L. Children with IBD are at risk of elevated LEs if they require medications other than 5-ASA to induce IBD remission.

The Academic Half-Day redesigned: Improving generalism, promoting CanMEDS and developing self-directed learners

BACKGROUND

The Montreal Children's Hospital Pediatric Residency Program redesigned its Academic Half-Day based on program concerns consistent with the published literature. These concerns included inadequate preparation for general paediatric practice, gaps in CanMEDS education and exclusive use of didactic lectures. Novel instructional methods included monthly simulation sessions to learn CanMEDS competencies, increased use of general paediatricians as instructors, implementation of a 'systems-based' curriculum and development of self-directed learning skills through activities such as 'Residents as Teachers'.

METHOD

A postimplementation online survey was sent to all 18 residents who had been exposed to both curricula. The survey was designed to determine the impact of the new curriculum on their perceived ability to retain information and acquire the competencies of a general paediatrician, and to assess the effect on their self-directed learning. Responses were recorded on a five-point Likert scale ranging from 'strongly disagree' to 'strongly agree'.

RESULTS

Fourteen of 18 (78%) residents completed the survey. All residents preferred the 'systems-based' educational program. Seventy-nine percent of all residents agreed that the simulation sessions were an effective method of learning the CanMEDS competencies. Importantly, 64% of residents voluntarily read more about the topics presented and 71% agreed that they retained the content better. Moreover, 79% believed that changes made to the teaching curriculum better prepared them for a general paediatric practice and 64% of residents believed that it better 'supplements' learning in the clinical setting.

CONCLUSION

The authors propose that the new curriculum is comprehensive, while developing the skills required for life-long learning as a general paediatrician.

The role of diagnostic imaging and liver biopsy in the diagnosis of focal nodular hyperplasia in children

BACKGROUND & AIMS

Focal nodular hyperplasia (FNH), a benign liver tumour, has a characteristic appearance on diagnostic imaging (DI) and histology. The role of liver biopsy in children for the diagnosis of FNH is unclear. This study investigates the diagnostic accuracy of DI for FNH in children without comorbidities, compared to liver biopsy.

METHODS

A total of 304 consecutive patients (age <18 years) with a biopsied liver mass were retrospectively ascertained (1990-2010). Individuals with a history of malignancy, liver disease or syndromes with increased malignancy risk were excluded. DI and biopsy data were reviewed.

RESULTS

After excluding 205 cases, 99 liver masses were studied. Based on histology, the most common diagnosis was hepatoblastoma (46/99, 44%) followed by FNH (23/99, 23%). The mean age at FNH diagnosis was 11.1 ± 5.2 years, with female preponderance (78%), and a median follow-up of 1.35 years (interquartile range 0.54, 4.20 years). 19/23 biopsy-proven FNH met standard criteria for FNH on DI. In 4/23 cases of biopsy-proven FNH, imaging did not suggest FNH. Two false positive cases included adenoma and fibrolamellar hepatocellular carcinoma. On review of original reports, DI had 82.6% sensitivity and 97.4% specificity for the diagnosis of FNH. On blind review, the sensitivity of DI for FNH diagnosis was 81.3% for MRI (13/16), and 53.3% for CT (8/15).

CONCLUSIONS

In this cohort of children with liver masses and no comorbidities, a diagnosis of FNH by imaging was highly specific, and MRI was the most sensitive study for its diagnosis. Liver biopsy may be deferred in selected children if the DI, particularly MRI, is indicative of FNH.