Posttransplant metabolic syndrome in children and adolescents after liver transplantation: a systematic review

Preservation of fat mass at the expense of lean mass in children with end-stage chronic liver disease

BACKGROUND

Sarcopenia predicts morbidity and mortality in end-stage chronic liver disease (ESCLD). Here, we describe changes in body composition in children with ESCLD before and after liver transplantation (LT).

METHODS

Retrospective analysis of whole body DXA scans performed before and after LT over 4 years. Appendicular and whole-body fat mass and lean mass were expressed as fat mass (FMI) and lean mass (LMI) index z-scores. Sarcopenia was defined as leg LMI z-score <-1.96.

RESULTS

Eighty-three DXA scans of children before or after LT were studied. Sarcopenia had a positive correlation with weight (0.8, p < .01), height (0.48, p < .05), and BMI z-score (0.77, p < .01), as well as arm, trunk, and total mean mass indices. It correlated negatively with indices of hypersplenism: PLTs (-0.57, p < .01), Neu (-0.50, p < .05), WCC (-0.44, p < .05), and days to discharge (-0.46, p < .05). At baseline: 13/25 (52%) children were sarcopenic and stayed in the hospital after LT for longer. Eight were stunted with a higher WCC and Ne/Ly ratio. All had normal FM indices. One year after LT, 12/26 children remained sarcopenic. Seven were stunted. Two years after LT, 5/15 were sarcopenic, and 5 were stunted. Three years after LT, 1/10 was sarcopenic, and 2 were stunted. By 4 years after LT, 1/7 was sarcopenic, and the same one was stunted. FM indices remained normal.

CONCLUSIONS

Sarcopenic patients stayed longer in the hospital after LT. Lean mass indices were mostly within the normal range by 4 years after LT. 32% of children were stunted, and markers of inflammation were correlated with stunting. Fat mass was preserved at the cost of lean mass.

Changes in nutritional status and the development of obesity and metabolic syndrome following pediatric heart transplantation

BACKGROUND

Nutritional status in pediatric patients undergoing heart transplantation (HT) is frequently a focus of clinical management and requires high resource utilization. Pre-operative nutrition status has been shown to affect post-operative mortality but no studies have been performed to assess how nutritional status may change and the risk of developing nutritional comorbidities long-term in the post-transplant period.

METHODS

A single-center retrospective chart review of patients ≥2 years of age who underwent heart transplantation between 1/1/2005 and 4/30/2020 was performed. Patient data were collected at listing, time of transplant, 1-year, and 3-year follow-up post-transplant. Nutrition status was classified based on body mass index (BMI) percentile in the primary analysis. Alternative nutritional indices, namely the nutrition risk index (NRI), prognostic nutrition index (PNI), and BMI z-score, were utilized in secondary analyses.

RESULTS

Of the 63 patients included, the proportion of patients with overweight/obese status increased from 21% at listing to 41% at 3-year follow-up. No underweight patients at listing became overweight/obese at follow-up. Of patients who were overweight/obese at listing, 88% maintained that status at 3-year follow-up. Overweight/obese status at listing, 1-year, and 3-year post-transplantation were significantly associated with developing metabolic syndrome. In comparison to the alternative nutritional indices, BMI percentile best predicted post-transplant metabolic syndrome.

CONCLUSIONS

The results suggest that pediatric patients who undergo heart transplantation are at risk of developing overweight/obesity and related nutritional sequelae (ie, metabolic syndrome). Improved surveillance and interventions targeted toward overweight/obese HT patients should be investigated to reduce the burden of associated comorbidities.

Cognitive function of children with biliary atresia after primary living donor liver transplantation

BACKGROUND

The survival rate of children with biliary atresia (BA) after liver transplantation (LT) is significantly improved, and their quality of life has attracted much attention.This study aimed to investigate the cognition and its influencing factors in children with BA after primary living donor LT (BA-pLDLT) during infancy.

METHODS

Children with BA were recruited 6 months after pLDLT at Children's Hospital of Chongqing Medical University (2018-2022). Demographic and clinical data were collected from the health information system. Cognition was assessed using the Chinese version of the Griffiths Mental Development scale (GMDS-C). Multivariate linear regression were used to analyze the influencing factors of their cognitive function.

RESULTS

In total, 57 children with BA-pLDLT, aged 5.00(3.90-9.30) months at transplantation and 25.00(14.00-60.80) months at evaluation were included. The general developmental quotient (89.02 ± 12.07) and motor, language, eye-hand coordination, performance, and practical reasoning quotients of these children were significantly lower than the normative mean values of GMDS-C(P < 0.05). Of the 57 children, 16 (28.07%) had borderline developmental delay (DQ between 70 and 84), 3 (5.26%) had developmental delay (DQ < 70), and 11(19.29%) had language delay. Reoperation for biliary or vascular complications after pLDLT was a risk factor for decreased general development quotient and motor quotient and lower ZW at assessment was associated with decline motor quotient.

CONCLUSION

Children with BA-pLDLT have varying degrees of developmental delays in early life. Reoperation and nutritional deficiencies had adverse effects on cognitive development.

Liver Transplant Outcomes in Young Adults with Cirrhosis Related to Nonalcoholic Fatty Liver Disease

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NASH) and cryptogenic cirrhosis (CC) is constantly increasing in adolescents and young adults (AYAs).

METHODS

In a retrospective UNOS database evaluation, we analyzed postoperative outcomes of AYAs with nonalcoholic NASH/CC undergoing LT between January 1st, 2003 and March 5th, 2021. After exclusions, 85,970 LT recipients, 393 (47.1%) AYAs with NASH/CC and 441 (52.9%) AYAs with other metabolic conditions, were analyzed.

RESULTS

During the study period, the number of LTs performed for AYAs with NASH/CC increased from 4%-7% but decreased from 6.6%-5.3% compared to LTs performed for NASH/CC in all ages. In comparison to AYAs with other metabolic conditions, AYA LT recipients with NASH/CC had a higher prevalence of metabolic syndrome (MetS) components, including diabetes and increased body mass index (P < .0001 for both). Patient and graft survival in AYAs with NASH/CC were significantly lower in comparison to AYAs transplanted for other metabolic conditions (P < .0001) (Hazard Ratio = 1.93, P < .001). Patient survival in AYAs with NASH/CC was significantly better in comparison to older (40-65-year-old) patients with the same diagnosis (P = .01).

CONCLUSIONS

Our study found that the overall number of LTs in AYAs with NASH increased significantly, but to a lesser degree compared to the older population with the same diagnosis. Outcomes after LT in AYAs with NASH/CC were worse compared to LT for other metabolic conditions, but significantly better in comparison to older patients. The prevalence of LT for NASH/CC in AYAs is growing. MetS may contribute to worse outcomes in AYAs.

Long-term mortality in pediatric solid organ recipients-A nationwide study

BACKGROUND

The present study aimed at investigating long-term mortality of patients who underwent solid organ transplantation during childhood and at identifying their causes of death.

METHODS

A cohort of 233 pediatric solid organ transplant recipients who had a kidney, liver, or heart transplantation between 1982 and 2015 in Finland were studied. Year of birth-, sex-, and hometown-matched controls (n = 1157) were identified using the Population Register Center registry. The Causes of Death Registry was utilized to identify the causes of death.

RESULTS

Among the transplant recipients, there were 60 (25.8%) deaths (median follow-up 18.0 years, interquartile range of 11.0-23.0 years). Transplant recipients' risk of death was nearly 130-fold higher than that of the controls (95% CI 51.9-1784.6). The 20-year survival rates for kidney, liver, and heart recipients were 86.1% (95% CI 79.9%-92.3%), 58.5% (95% CI 46.2%-74.1%), and 61.4% (95% CI 48.1%-78.4%), respectively. The most common causes of death were cardiovascular diseases (23%), infections (22%), and malignancies (17%). There were no significant differences in survival based on sex or transplantation era.

CONCLUSION

The late mortality is still significantly higher among pediatric solid organ recipients in comparison with controls. Cardiovascular complications, infections, and cancers are the main causes of late mortality for all studied transplant groups. These findings emphasize the cruciality of careful monitoring of pediatric transplant recipients in order to reduce long-term mortality.

Sarcopenia and Fat Mass in Children With Chronic Liver Disease and Its Impact on Liver Transplantation

In adults, weight loss and sarcopenia are prognostic indicators of poor outcomes for patients awaiting liver transplant (LT). We tested the hypothesis that sarcopenia in children awaiting LT was related to poor outcomes.

Methods

Children with end-stage chronic liver disease undergoing assessment for LT were recruited into an observational longitudinal study. Anthropometry and body composition (BC; whole-body dual-energy x-ray absorptiometry scan) were assessed before and, on average, 1 year after LT.

Results

Eleven children (6 females:5 males) were assessed (4.7 to 17.2 years; median, 9.9) at baseline. Nine children went on to have an LT. The aspartate aminotransferase-to-platelet ratio index had a significant positive correlation with trunk lean mass and trunk lean mass index (LMI) SD score (SDS). At baseline, 4 patients were sarcopenic with appendicular LMI SDS less than -1.96. All fat mass and fat mass index (FMI) SDSs were within the normal range (above -1.96). There was a strong negative correlation between FMI SDS and height SDS. After transplant, there was a significant reduction in trunk LMI from 1.20 to -0.51 (95% CI, 1.03-2.4; P < 0.01). Body mass index SDS had a negative correlation with days to discharge after transplant. The majority of patients discharged after 16 days were sarcopenic. One year after transplantation, all patients were alive with normal graft function regardless of BC before LT.

Conclusion

FMIs were normal regardless of LMIs and correlated negatively with height. BC was related to days to discharge after LT but not to outcomes a year after LT.

Kidney disease in children with heart or liver transplant

Over the past few decades, there has been increasing recognition of kidney disease in children with non-kidney solid organ transplantation. The risk of kidney disease in children undergoing heart or liver transplantation is higher than the general population as the underlying disease and its associated management may directly impair kidney function. Both heart and liver failures contribute to hypoperfusion and kidney ischemia before patients reach the point of transplant. The transplant surgery itself can often be complicated by acute kidney injury (AKI), which may be further exacerbated by a complicated postoperative course. In the short- and long-term post-transplant period, these children are at risk of acute illness, exposed to nephrotoxic medications, and susceptible to rare but severe infections and immunologic insults that may contribute to AKI and chronic kidney disease (CKD). In some, CKD can progress to kidney failure with replacement therapy (KFRT). CKD and KFRT are associated with increased morbidity and mortality in this patient population. Therefore, it is critical to monitor for and recognize the risk factors for kidney injury in this population and mitigate these risks. In this paper, the authors provide an overview of kidney disease pertaining to heart and liver transplantation in children with guidance on monitoring, diagnosis, prevention, and management.

Care of Pediatric Solid Organ Transplant Recipients: An Overview for Primary Care Providers

As the number of living pediatric solid organ transplant (SOT) recipients continues to grow, there is an increased likelihood that primary care providers (PCPs) will encounter pediatric SOT recipients in their practices. In addition, as end-stage organ failure is replaced with chronic medical conditions in transplant recipients, there is a need for a comprehensive approach to their management. PCPs can significantly enhance the care of immunosuppressed hosts by advising parents of safety considerations and avoiding adverse drug interactions. Together with subspecialty providers, PCPs are responsible for ensuring that appropriate vaccinations are given and can play an important role in the diagnosis of infections. Through early recognition of rejection and posttransplant complications, PCPs can minimize morbidity. Growth and development can be optimized through frequent assessments and timely referrals. Adherence to immunosuppressive regimens can be greatly improved through reinforcement at every encounter, particularly among adolescents. PCPs can also improve long-term outcomes by easing the transition of pediatric SOT recipients to adult providers. Although guidelines exist for the primary care management of adult SOT recipients, comprehensive guidance is lacking for pediatric providers. In this evidence-based overview, we outline the main issues affecting pediatric SOT recipients and provide guidance for PCPs regarding their management from the first encounter after the transplant to the main challenges that arise in childhood and adolescence. Overall, PCPs can and should use their expertise and serve as an additional layer of support in conjunction with the transplant center for families that are caring for a pediatric SOT recipient.

Healthy Body Weights With Corticosteroid-free Immunosuppression Is the Best Predictor of Cardiovascular Health in Children After Liver Transplantation

INTRODUCTION

Cardiometabolic dysregulation (CMD) influences morbidity and mortality risk in adults post-liver transplantation (LTx). CMD is reported in 10% to 25% of pediatric LTx recipients, but no information regarding the longitudinal expression of CMD is available. The study objective was to examine the longitudinal expression of CMD and associations with body composition and growth in children post-LTx.

METHODS

A retrospective review was conducted in youth (34 F/30 M) who underwent LTx between 1994 and 2015 at the Stollery Children's Hospital. Primary outcomes included serum markers of CMD (insulin, glucose, hemoglobin A1C [A1C], homeostasis model assessment for insulin resistance [abnormal >3], lipid panel triglycerides, total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol) and systolic/diastolic blood pressure (BP: absolute/z scores).

RESULTS

Mean (±SD) age, weight z, height z, body mass index z was 9.7 ± 3.4 years (3.5-17.9), 0.26 ± 1.03, 0.017 ± 1.2, and 0.41 ± 1.05, respectively. The majority of children had percentage fat mass, percentage fat-free mass within normal reference ranges. Systolic/diastolic BP was within healthy references ranges in 83.1% and 93.5% of children, respectively. Serum insulin (83.4%) and high-density lipoprotein-cholesterol (43.9%) concentrations were low, with abnormal findings of other laboratory markers found in <5% of participants. Abnormal findings for metabolic parameters were independent of weight z, body mass index z, fat mass, and corticosteroids but were positively related to child's age (>9.7 years) and fat-free mass (total, arms). Insulin levels decreased significantly in the first 4 years post-LTx, but no changes in lipid panel, A1C and glucose were noted over 10 years.

CONCLUSIONS

Pediatric LTx recipients with healthy body weights and corticosteroid-free immunosuppression have a low expression of CMD over 10 years.

Cardiovascular Risk Assessment in Pediatric Liver Transplant Patients

OBJECTIVES

Cardiovascular (CV) diseases play a leading role in the mortality of adult liver transplant (LT) recipients. However, data regarding CV risk factors in children after LT remain sparse. The present study assessed the presence of CV risk factors and signs of CV impairment in LT children.

METHODS

A total of 42 LT recipients (21 men, age 9.93 ± 3.57 years) were studied. Body composition [body mass index standard deviation score, percentage of body fat (by bioimpedance analysis)], lipid profiles, glycemic control, blood pressure, and arterial stiffness [assessed by aortic pulse wave velocity (PWV)] were evaluated. The effect of different treatment modalities [tacrolimus (TAC) (n = 30) or cyclosporine (CyA) (n = 11)] was also analyzed.

RESULTS

Almost 18% of children were overweight or obese. Patients on TAC had a significantly higher body fat mass and percentage of body fat compared with the CyA group (P < 0.02). Borderline to high lipid values were present in 40% of patients. Children on CyA had higher serum cholesterol levels compared to TAC (P < 0.004). Nineteen percent of patients had hypertension. Half of the patients had glomerular filtration rate values <90 mL/min/1.73 m, whereas PWV values were above the 95th percentile in 12%.

CONCLUSIONS

Increased body fat, chronic kidney disease, high lipid content, hypertension, and increased arterial stiffness are already present and are in part related to the type of immunosuppression regimen in LT children >5 years following transplantation. Long-term follow-up is needed to evaluate their impact on CV health and survival.

Hepatic Steatosis Is Prevalent Following Orthotopic Liver Transplantation in Children With Cystic Fibrosis

OBJECTIVES

Systematic study of allograft liver histology in children undergoing orthotopic liver transplantation (LT) for cystic fibrosis-related liver disease (CFLD).

METHODS

Retrospective clinicopathologic review of explants and allograft liver biopsies from 13 children and adolescents with CFLD.

RESULTS

In this study, the median age at LT for CFLD was 15.7 years. Notably, 10 of 13 (77%) CF explants had >5% steatosis and 8 of 13 (61.5%) demonstrated variable fibrosis. The median age, sex, type of transplant (liver vs liver-lung), pancreatic insufficiency status, body mass index (BMI) percentile, genotype, and prevalence of diabetes were comparable in those with and without explant steatosis. More than half of allograft biopsies showed significant steatosis (17/31, 54.8%) and lobular inflammation (16/31, 51.6%). Hepatocyte ballooning was less frequent (5/31, 16.1%). Overall, 6 patients (46.2%) had allograft steatosis that worsened over time in 2 patients (33%). None had advanced fibrosis (≥stage 3). Patients with allograft steatosis had significantly more biopsies, were more likely to be "liver only" recipients, had a shorter interval since transplant and higher body mass index percentile (although <85). Patients without explant steatosis never demonstrated allograft steatosis, whereas 60% of patients with explant steatosis (n = 6) developed varying degrees of allograft steatosis. The degree of explant steatosis did not predict its severity in allografts (P = 0.3).

CONCLUSION

This is the first study highlighting the development of allograft steatosis in CF patients. Our findings suggest that allograft steatosis in patients with CF may be related to pre-existing steatosis in native livers, regardless of other risk factors and may have implications on patient management and long-term graft/patient survival.

Risk markers for later cardiovascular diseases in liver-transplanted children and adolescents

BACKGROUND

Increased risk of cardiovascular diseases is well described after adult liver transplantation, whereas the risk in the pediatric population still is discussed. The aim of this study was to investigate the prevalence of metabolic syndrome in pediatric liver transplant recipients and whether measurements of carotid intima media thickness and pulse wave velocity were increased compared to healthy controls.

METHODS

We included 42 pediatric liver transplantation recipients and examined them for markers of metabolic syndrome, liver fibrosis measured by shear wave velocity, body fat measured by DXA scans and carotid intima-media thickness, and pulse wave velocity (n = 41 for the carotid scans). The ultrasound measurements of carotid intima-media thickness and pulse wave velocity were also conducted on 82 healthy children and adolescents matched on height and age, respectively.

RESULTS

Participants had a median age of 13.03 years, and median time since transplantation was 8.54 years. Compared to healthy controls, liver-transplanted patients had significantly increased intima-media thickness measurements in both control groups whereas there was no significant difference with regard to pulse wave velocity. Two patients (6.25%) were diagnosed with metabolic syndrome. Within the group of liver-transplanted pediatric patients, only elevated body mass index was associated with elevated carotid intima-media thickness measurement. Elevated pulse wave velocity was only associated with abdominal obesity. Factors not significantly correlated with either were age, sex, metabolic syndrome, hyperglycemia, triglycerides, years since transplantation, fibrosis of the liver, body fat content, smoking habits, HDL cholesterol levels, hypertension, and mono-drug versus multi-drug therapies.

CONCLUSION

Pediatric liver transplant recipients do have an increased risk of increased carotid intima-media thickness.

The Health Care Transition of Youth With Liver Disease Into the Adult Health System: Position Paper From ESPGHAN and EASL

BACKGROUND

Medical advances have dramatically improved the long-term prognosis of children and adolescents with once-fatal hepatobiliary diseases. However, there is no generally accepted optimal pathway of care for the transition from paediatric care to the adult health system.

AIM

The purpose of this position paper is to propose a transition process for young people with paediatric onset hepatobiliary diseases from child-centred to adult-centred healthcare services.

METHODS

Seventeen ESPGHAN/EASL physicians from 13 countries (Austria, Belgium, France, Germany, Hungary, Italy, the Netherlands, Norway, Poland, Spain, Sweden, Switzerland, and United Kingdom) formulated and answered questions after examining the currently published literature on transition from childhood to adulthood. PubMed and Google Scholar were systematically searched between 1980 and January 2018. Quality of evidence was assessed by the Grading of Recommendation Assessment, Development and Evaluation (GRADE) system. Expert opinions were used to support recommendations whenever the evidence was graded weak. All authors voted on each recommendation, using the nominal voting technique.

RESULTS

We reviewed the literature regarding the optimal timing for the initiation of the transition process and the transfer of the patient to adult services, principal documents, transition multi-professional team components, main barriers, and goals of the general transition process. A transition plan based on available evidence was agreed focusing on the individual young people's readiness and on coordinated teamwork, with transition monitoring continuing until the first year of adult services.We further agreed on selected features of transitioning processes inherent to the most frequent paediatric-onset hepatobiliary diseases. The discussion highlights specific clinical issues that will probably present to adult gastrointestinal specialists and that should be considered, according to published evidence, in the long-term tracking of patients.

CONCLUSIONS

Transfer of medical care of individuals with paediatric onset hepatobiliary chronic diseases to adult facilities is a complex task requiring multiple involvements of patients and both paediatric and adult care providers.

Hepatic steatosis after pediatric liver transplant

Hepatic steatosis develops after liver transplantation (LT) in 30% of adults, and nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in nontransplanted children. However, posttransplant steatosis has been minimally studied in pediatric LT recipients. We explored the prevalence, persistence, and association with chronic liver damage of hepatic steatosis in these children. In this single-center study of pediatric patients transplanted 1988-2015 (n = 318), 31% of those with any posttransplant biopsy (n = 271) had ≥ 1 biopsy with steatosis. Median time from transplant to first biopsy with steatosis was 0.8 months (interquartile range [IQR], 0.3-6.5 months) and to last biopsy with steatosis was 5.5 months (IQR, 1.0-24.5 months); 85% of patients with steatosis also had for-cause biopsies without steatosis. All available for-cause biopsies were re-evaluated (n = 104). Of 9 biopsies that could be interpreted as nonalcoholic steatohepatitis (NASH)/borderline NASH, with steatosis plus inflammation or ballooning, 8 also had features of cholestasis or rejection. Among 70 patients with surveillance biopsies 3.6-20.0 years after transplant, only 1 overweight adolescent had a biopsy with NAFLD (grade 1 steatosis, mild inflammation, no ballooning or fibrosis)-despite a 30% prevalence of overweight/obesity in the cohort and 27% with steatosis on previous for-cause biopsy. Steatosis on preceding for-cause biopsy was not associated with portal (P = 0.49) or perivenular fibrosis (P = 0.85) on surveillance biopsy. Hepatic steatosis commonly develops early after transplant in children and adolescents, but it rarely persists. Biopsies that did have steatosis with NASH characteristics were all for-cause, mostly in patients with NAFLD risk factors and/or confounding causes of liver damage. Prospective studies that follow children into adulthood will be needed to evaluate if and when hepatic steatosis presents a longterm risk for pediatric LT recipients. Liver Transplantation 23 957-967 2017 AASLD.

Prediabetes in Pediatric Recipients of Liver Transplant: Mechanism and Risk Factors

OBJECTIVE

To investigate the role of calcineurin inhibitor exposure and states of insulin resistance-obesity and adolescence-in prediabetes after pediatric liver transplant via oral glucose tolerance testing, which previously has not been done systematically in these at-risk youths.

STUDY DESIGN

This was a cross-sectional study of 81 pediatric recipients of liver transplant. Prediabetes was defined as impaired glucose tolerance (IGT; glucose ≥140 mg/dL at 2 hours) or impaired fasting glucose (IFG, ≥100 mg/dL). Corrected insulin response (CIR) was calculated as measure of insulin secretion, corrected for glucose (CIR₃₀, CIR₆₀, CIR₁₂₀).

RESULTS

Subjects were aged 8.1-30.0 years and 1.1-24.7 years post-transplant; 44% had prediabetes-27% IGT, 14% IFG, and 3% both. IGT was characterized by insulin hyposecretion, with lower CIR₆₀ and CIR₁₂₀ in IGT than subjects with normal glucose tolerance. Subjects with tacrolimus trough >6 µg/mL at study visit had lower CIR₁₂₀ than those with trough ≤6 µg/mL and those off calcineurin-inhibitors. Mean of tacrolimus troughs preceding the study visit, years since transplant, and rejection episodes were not associated significantly with lower CIR. CIR suppression by tacrolimus was most pronounced >6 years from transplant. Overweight/obese subjects and adolescents who retained normal glucose tolerance had greater CIR than those who were IGT.

CONCLUSION

IGT after pediatric liver transplant is driven by inadequate insulin secretion. It is quite common but not detectable with fasting laboratory values-the screening recommended by current guidelines. Calcineurin inhibitors suppress insulin secretion in these patients in a dose-dependent manner. Given the recent focus on long-term outcomes and immunosuppression withdrawal in these children, longitudinal studies are warranted to investigate whether IGT is reversible with calcineurin inhibitor minimization.

Pediatric liver transplantation: a North American perspective

Liver transplantation (LT) is an important component in the therapeutic armamentarium of managing end-stage liver disease. In North American children, biliary atresia remains the most common indication for LT compared to hepatitis C in adults, while hepatoblastoma is the most common liver tumor requiring LT, versus Hepatocellular carcinoma in adults. Rejection, lymphoproliferative disease, renal insufficiency, metabolic syndrome, recurrent disease, 'de novo' autoimmune hepatitis and malignancy require careful surveillance and prompt action in adults and children after LT. In children, specific attention to EBV viremia, growth, development, adherence and transition to the adult services is also required. Antibody mediated rejection and screening for donor specific antibodies is becoming important in managing liver graft dysfunction. Biomarkers to identify and predict tolerance are being developed. Machine perfusion and stem cells (iPS) to synthesize organs are generating interest and are a focus for research.

Metabolic Syndrome Components After Pediatric Liver Transplantation: Prevalence and the Impact of Obesity and Immunosuppression

Metabolic syndrome is associated with long-term morbidity and mortality after adult liver transplantation (LT). Whether pediatric LT recipients have a higher prevalence of metabolic syndrome remains controversial. In a cross-sectional study, we evaluated pediatric LT recipients aged 8-30 years using National Health and Nutrition Examination Survey (NHANES) protocols. LT recipients were matched by gender, race/ethnicity, and age with controls from NHANES. Pediatric LT recipients (n = 83), after adjusting for overweight/obesity and glucocorticoid use, had increased prevalence of prehypertension and hypertension, impaired glucose tolerance (IGT; 2-h glucose after oral glucose tolerance test ≥140 mg/dL), and low high-density lipoprotein compared to matched NHANES controls (n = 235) despite a lower prevalence of overweight/obesity. Among LT recipients, the adjusted odds of IGT doubled for every 7.5 years taking calcineurin inhibitors (odds ratio = 2.10, 95% confidence interval 1.06-4.17 per 7.5 years taking calcineurin inhibitors, p = 0.03). Among all subjects with IGT, LT recipients had a lower prevalence of overweight/obesity and less insulin resistance (homeostatic model assessment of insulin resistance) than did controls with IGT. Among normal weight subjects, LT recipients were significantly more likely than controls to have prehypertension/hypertension, IGT, low high-density lipoprotein, and metabolic syndrome. Pediatric LT recipients have unique metabolic syndrome profiles and risk factors and will require tailored screening and management protocols.

Subclinical cardiovascular changes in pediatric solid organ transplant recipients: A systematic review and meta-analysis

CV disease is a major cause of morbidity and mortality following solid organ transplantation in adults. While the prevalence of multiple cardiometabolic risk factors is increased in pediatric solid organ transplant recipients, it is not clear whether they have subclinical CV changes. cIMT, central pWV, and CAC are indicative of subclinical CV disease, and, in adults, predict future CV events. The objective of this systematic review and meta-analysis was to investigate the prevalence of subclinical CV changes, as measured by cIMT, pWV, and CAC among pediatric solid organ transplant recipients. We searched MEDLINE(®) and EMBASE and conducted meta-analysis for studies that evaluated cIMT, central pWV, and CAC among pediatric solid organ transplant recipients (kidney, lung, intestine and liver). The search identified nine eligible studies that included a total of 259 patients and 685 healthy controls. Eight studies reported on kidney transplant recipients and one study on a combined cohort of kidney and liver transplant recipients. The mean cIMT of transplant recipients was significantly higher than that of healthy controls (mean difference = 0.05 mm, 95% CI 0.02-0.07; p < 0.0001) with an estimated pooled prevalence of elevated cIMT of 56.0% (95% CI 17.0-95.0). The one study that assessed pWV showed increased vascular stiffness in transplant recipients compared to healthy controls. No studies assessing for CAC were found. There were limited data regarding subclinical CV disease following pediatric solid organ transplantation. In conclusion, kidney transplantation in childhood is associated with a higher prevalence of subclinical CV changes compared to healthy children. Longitudinal studies are needed to determine whether children have increased CV morbidity and mortality after transplantation.

Keys to long-term care of the liver transplant recipient

Improvements in overall survival early after liver transplantation result in a growing number of patients with the potential for long-term survival. Data available on long-term survival, to date, reflect the situation of patients who received their liver transplant during a very different health-care era. Translating these data into the current medical era of liver transplantation is an important task, as a better understanding of aspects associated with morbidity and mortality is fundamental in improving the long-term outcome of liver transplant recipients. Malignancy screening, optimal treatment of recurrent disease and adequate management of metabolic disease are crucial contributions to advance patient care. In this Review, data specific to the liver transplant recipient will be evaluated and, in the absence of sufficient evidence at this time, recommendations and guidelines for the general population on management of long-term concerns will be assessed for their applicability after liver transplantation. In addition, other preventive strategies relating to pregnancy, contraception and vaccination are reviewed in detail.

Medical management of children after liver transplantation

PURPOSE OF REVIEW

Successful outcomes in patient, graft survival, and quality of life depend on the prevention, early detection, and treatment of possible complications. The aim of the study was to highlight the common outcomes focusing on the unique features in children. Medical follow-up of children after liver transplantation includes monitoring of surgical complications: biliary and vascular, rejection, infections, posttransplant lymphoproliferative disease, other malignancies, recurrent disease, graft function, hypertension, diabetes, renal failure, among other conditions. The goal is to maintain normal graft function on minimal immunosuppression to avoid medication-induced side-effects.

RECENT FINDINGS

Recent findings include the importance of meticulous follow-up of Epstein-Barr virus and Cytomegalic virus viral load, leading to early diagnosis and improved prognosis, increased prevalence of renal toxicity, cognitive dysfunction, autoimmune, atopic and eosinophilic disease, oral hygiene and chronic hepatitis, and fibrosis of allografts.

SUMMARY

Caring for children after liver transplantation is extremely rewarding; however, careful attention must be paid to a variety of systems with understanding of the distinctiveness of pediatrics to assure optimal outcomes.

"Current state and prospects in managing liver transplanted children"

Pediatric liver transplantation (LTx) has revolutionized life chances and perspectives of children with liver disease. Following rapid establishment of the therapeutic concept in the early years of pediatric transplant medicine, more aspects beyond plain survival become increasingly important. In addition to improving the short to medium-term survival rates, researchers are focusing on themes such as rehabilitation, adherence and quality of life, long-term graft fibrosis and dysfunction, as well as the consequences of long-term immunosuppression. Also, more protocol biopsy data are available to evaluate increasing graft fibrosis. To manage their conditions, patients will need access to highly experienced pediatric liver transplant centers where clinical research will examine modulators of renal disease, endocrine and cardiovascular comorbidity and the development of graft fibrosis and malignancies. Assessment and evaluation of health-related quality of life and factors which influence clinical tolerance, adherence and transition from child to adult care will also be investigated. The analysis of multi-national registry data and more than 40years of experience with large patient cohorts will provide important clues to treatment and will thus get increasing attention. In the future, longitudinal assessment of the outcome for pediatric LTx patients should include more functional aspects than plain survival rates or laboratory parameters.

Posttransplant metabolic syndrome in the withdrawal of immunosuppression in Pediatric Liver Transplant Recipients (WISP-R) pilot trial

Posttransplant metabolic syndrome (PTMS)-obesity, hypertension, elevated triglycerides, low HDL and glucose intolerance-is a major contributor to morbidity after adult liver transplant. This analysis of the Withdrawal of Immunosuppression in Pediatric Liver Transplant Recipients (WISP-R) pilot trial is the first prospective study of PTMS after pediatric liver transplant. Twenty children were enrolled in WISP-R, at median age 8.5 years (IQR 6.4-10.8), and weaned from calcineurin-inhibitor monotherapy. The 12 children who tolerated complete immunosuppression withdrawal were compared to matched historical controls. At baseline, 45% of WISP-R subjects and 58% of controls had at least one component of PTMS. Calcineurin-inhibitor withdrawal in the WISP-R subjects did not impact the prevalence of PTMS components compared to controls. At 5 years, despite weaning off of immunosuppression, 92% of the 12 tolerant WISP-R subjects had at least one PTMS component and 58% had at least two; 33% were overweight or obese, 50% had dyslipidemia, 33% glucose intolerance and 42% systolic hypertension. Overweight/obesity increased the risk of hypertension in all children. Compared to controls, WISP-R tolerant subjects had similar GFR at baseline but did have higher GFR at 2, 3 and 4 years. Further study of PTMS and immunosuppression withdrawal after pediatric liver transplant is warranted.

Overweight, central obesity, and cardiometabolic risk factors in pediatric liver transplantation

PTMS describes the presence of ≥3 cardiometabolic risk factors that include obesity, hypertension, dyslipidemia, and IR. The prevalence of the clustering of ≥3 cardiometabolic risk factors or central obesity has not been studied in pediatric LT recipients. Single-center, cross-sectional study.

INCLUSION CRITERIA

LT recipients 2-18 yr-old, at least one yr post-LT.

EXCLUSION CRITERIA

recipients of liver retransplants or multivisceral transplants. Eighty-seven patients were identified. Median age was 9.8 yr (range 2-18), median time since LT was 6.9 yr (range 1-17). The most common indication for LT was biliary atresia (56%), and the most frequently used immunosuppressant was tacrolimus (80%). The prevalence of overweight and obesity was 21% and 5%, respectively. Central obesity affected 14%, hypertension 44%, IR 27%, low HDL 20%, and hypertriglyceridemia 39% of patients. The prevalence of ≥3 cardiometabolic risk factors was 19%. Fifty percent of the overweight/obese patients had ≥3 risk factors. Time since transplant, immunosuppression and renal function were not different between those with <3 or ≥3 risk factors. Clustering of cardiometabolic risk factors is prevalent in pediatric LT recipients, suggesting an increased risk of future CV events.

Cardiovascular risk factors and cardiac disorders in long-term survivors of pediatric liver transplantation

The MetS and cardiovascular disease are leading causes of late morbidity in adult liver transplantation recipients; however, limited data are available in pediatric liver transplantation. A single-center retrospective review was undertaken for patients who had a liver transplantation before 18 yr of age and were >5 yr post-transplantation, to study the prevalence of MetS, its components, and cardiac disorders. Fifty-eight patients were included in the study with a mean age at transplantation of 6.3 ± 6.1 yr and mean follow-up of 14.1 ± 6.0 yr. Of the study group, 41.4% were overweight or obese, with ongoing prednisone use and increased duration of follow-up being significant risk factors. Fifty-three patients had sufficient data for determining MetS, which was present in 17% of the patients. Although the prevalence of MetS is low in pediatric liver transplant recipients, it is associated with CKD and prednisone therapy (p < 0.05). Echocardiography data were available for 23 patients, of whom 43.4% had LVH and 13% had evidence of PH. The spectrum of cardiac disorders in this population is much wider than in adults.

Long-term survivors after pediatric liver transplatation are at increased risk for development of cardiovascular disease events: analysis of 30 cases

BACKGROUND

Liver transplantation (LT) in adult patients is associated with a higher incidence of cardiovascular risk factors (CVRF), chronic kidney disease (CKD), and cardiovascular disease mortality than the general population. Available information about these problems in adult patients with LT from a pediatric age is limited. The aim of this study was to analyze the incidence of CVRF, risk of developing CKD, and risk of 10-year coronary event in adult patients who received LT in childhood.

METHODS

Thirty adult patients (11 female, 19 male; mean age, 29.3 years) who underwent LT in childhood were analyzed, and CVRF, estimated glomerular filtration rate, and current immunosuppressive regimen were recordered. The risk of 10-year coronary event was calculated with the use of validated equations (Framingham and Regicor) and compared with the estimated risk in the general population.

RESULTS

None of the patients had CVRF before LT, except 1 patient who received a transplant because of familial hypercholesterolemia. Median age of patients at the time of study was 28.6 years (range, 19.3-43.1 y), and mean follow-up after LT was 17.83 ± 5.21 years. Twenty-nine patients (96.7%) were receiving a calcineurin inhibitor (69% tacrolimus, 31% cyclosporine), along with steroids in 13 of them. The average CVRF per patient was 2, and 11 patients (43.33%) had ≥3. Thirteen patients (43.33%) had CKD. The estimated risk of developing a coronary event at 10 years according to the Framingham score was 3%, higher than expected in the general population of same age and sex. With the use of the Regicor equation, adapted to the Spanish population, the estimated cardiovascular risk was 1.6%, corresponding to Spanish men without CVRF aged 50-55 years. None of the patients had cardiovascular events during the follow-up.

CONCLUSIONS

Our data show a high incidence of CVRF and CKD in young adults who received LT in childhood, resulting in an increased risk of cardiovascular disease.

Metabolic syndrome after pediatric liver transplantation

Half of adult liver transplantation (LT) recipients develop metabolic syndrome, but the prevalence after childhood LT remains unknown. We conducted a national cross-sectional study of all living patients who had undergone LT between 1987 and 2007 at an age less than 18 years. We gathered information on blood pressure, body composition, serum lipids, glucose metabolism, and histological liver fat content. The diagnostic criteria for metabolic syndrome of the American Heart Association and the International Diabetes Federation were used. After a median post-LT follow-up time of 12 years, half of all patients had no components of metabolic syndrome. The prevalence of overweight/obesity was 20%, and the prevalence of hypertension was 24%. Serum triglycerides were high in 9%, and high-density lipoprotein levels were low in 23%. Fasting glucose levels were impaired in 14%, but none had diabetes. Altogether, 9 patients (14%) had metabolic syndrome. Moderate liver steatosis found in protocol liver biopsy samples was associated with the accumulation of metabolic syndrome features (P = 0.01). No significant associations were found between immunosuppressive medications and metabolic syndrome. In conclusion, the prevalence of metabolic syndrome after childhood LT is similar to the prevalence in the general population of the same age. Guidelines for the general population, therefore, seem valid for the prevention and treatment of metabolic syndrome after pediatric LT as well.

Tips and hints for the transition: What adult hepatologists should know when accept teens with a pediatric hepatobiliary disease

The number of children with chronic hepatobiliary disease surviving into adulthood is more and more increasing, but no established model of transition does exist in this category of patients. Here, we summarize medical problems expected at the time of their transition, and any impacts on morbidity and mortality in adulthood. Information provided would turn useful to adult hepatologists and practitioners responsible for ensuring continuity of care for young adults affected by diseases they are not usually accustomed to.

Clinical research in pediatric organ transplantation

Solid organ transplantation has greatly improved survival in children with end-stage disease, becoming one of the main treatment options in this population. Nonetheless, there are significant challenges associated with validating and optimizing the effects of these interventions in clinical trials. Therefore, we reviewed the main issues related to conducting clinical transplantation research in children. We divided these challenges into three different categories: (i) challenges related to surgical techniques and anesthetic procedures, (ii) challenges related to post-transplant care and (iii) challenges specific to a particular population group and disease type. Some of the observed burdens for clinical research in this field are related to the limitations of conducting studies with a placebo or sham procedure, determining the standard of care for a control group, low prevalence of cases, ethical concerns related to use of a placebo control group and lack of generalizability from animal studies and clinical trials conducted in adult populations. To overcome some of these barriers, it is necessary to utilize alternative clinical trial designs, such as observational studies or non-inferiority trials, and to develop multicenter collaborations to increase the recruitment rate. In conclusion, the lack of robust data related to pediatric transplantation remains problematic, and further clinical trials are needed to develop more efficacious and safer treatments.

Pediatric post-transplant metabolic syndrome: new clouds on the horizon

Liver transplantation (LT) is a standard treatment for children with end-stage liver disease, standing at more than 90% survival rate after one yr, and at over a 70% survival rate after five yr. The majority of transplanted children enjoy an excellent quality of life but complications can occur in the long term, and can develop subclinically in otherwise well children; there are various underestimated nutritional and metabolic aspects, including the so-called post-transplant metabolic syndrome (PTMS). During the post-transplant period, the use of immunosuppressants, corticosteroids, calcineurin inhibitors, and the presence of risk factors, including non-alcoholic fatty liver disease (NAFLD), and kidney and bone complications have been largely implicated in PTMS development. Strategies to reduce the progression of PMTS should include careful screening of patients for diabetes, dyslipidemia, and obesity, and to support weight reduction with a carefully constructed program, particularly based on diet modification and exercise. With early identification and appropriate and aggressive management, excellent long-term health outcomes and acceptable graft survival can be achieved.