Immunosuppression in pediatric liver transplant recipients: Unique aspects

Respiratory problems associated with liver disease in children

Respiratory manifestations of chronic liver disease have a profound impact on patient clinical outcomes. Certain conditions within paediatric liver disease have an associated respiratory pathology. This overlap between liver and respiratory manifestations can result in complex challenges when managing patients and requires clinicians to be able to recognise when referral to specialists is required. While liver transplantation is at the centre of treatment, it opens up further potential for respiratory complications. It is established that these complications place patients at risk of longer stays in hospital and reduced survival. Additionally, late post-transplant complications can occur, including post-transplant lymphoproliferative disease and immunosuppression-induced interstitial lung disease. Although rare, it is important for clinicians to recognise these conditions to allow for prompt management. Finally, as liver disease progresses in children, respiratory complications can occur. Hepatopulmonary syndrome can occur in the context of portal hypertension, resulting in increased mortality and poorer quality of life for patients. Another consequence is portopulmonary hypertension, which can be associated with poor survival. Failure to recognise these complications in children may result in poorer outcomes and therefore it is vital that clinicians can establish when referral to a paediatric respiratory medicine specialist is required.

Basiliximab Induction and Postoperative Steroid-free Immunosuppression With Tacrolimus in Pediatric Liver Transplantation: A Randomized Clinical Trial

BACKGROUND

Optimizing the immunosuppressive regimen is essential to improve the long-term outcomes of pediatric liver transplant recipients.

METHODS

We conducted a prospective, randomized, open-label study to compare the safety and efficacy of 2 treatment approaches during pediatric liver transplantation: tacrolimus monotherapy following basiliximab induction (the study group) and a dual regimen of tacrolimus plus steroids (the control group). A total of 150 patients were enrolled, with 75 patients allocated to each group.

RESULTS

In both groups, recipients achieved graft and recipient overall survival rates exceeding 93%, with no statistically significant differences between them. However, the study group exhibited a significantly lower incidence of acute cellular rejection (ACR), delayed occurrence of ACR, and an improved ACR-free survival rate at 2 y compared with the control group. Notably, the study group also showed a significant reduction in the incidence of de novo donor-specific antibodies at 3-mo and 2-y posttransplant. Furthermore, 6 mo after the transplant, the study group demonstrated significant improvements in weight-for-age Z score and height-for-age Z score. No notable differences were observed in postoperative complications or the incidence of liver fibrosis between the 2 groups.

CONCLUSIONS

Basiliximab induction combine with tacrolimus (TAC) monotherapy is a safe and effective immunosuppressive regimen to reduce the episodes of ACR without influencing the development of liver fibrosis and graft and recipient survival rate after pediatric liver transplantation.

Etiology, risk factors and management of hypertension post liver transplantation

BACKGROUND

Cardiovascular events are one of the most important causes of morbidity and mortality in the long-term follow-up of liver transplant recipients. Hypertension is a significant cardiovascular risk factor that occurs frequently after pediatric liver transplantation. Chronic use of immunosuppressants - mainly calcineurin inhibitors - plays a major role in the development of post-transplant hypertension and circadian disturbances such as flattening of the nocturnal blood pressure dip. This requires special attention in children given the long timeframe during which immunosuppressive therapy is necessary. Careful and structured blood pressure monitoring and adequate treatment of hypertension are essential to optimize the quality of life and life expectancy of pediatric liver transplant patients. However, evidence-based guidelines for monitoring and management of post-transplant hypertension and its complications are lacking.

METHODS

We conducted a comprehensive review of the current knowledge and practices concerning post-transplant hypertension. The databases Pubmed, Embase, Web of Science and Google Scholar were scanned with the following keywords: pediatric liver transplantation, immunosuppression, tacrolimus, cardiovascular effects, hypertension, heart function, kidney function, circadian rhythm, mechanism, monitoring, and management.

RESULTS

In this review, we describe the incidence and etiology of hypertension in pediatric liver transplant recipients, the underlying mechanisms and characteristics of calcineurin inhibitor-induced hypertension, and the consequences of and risk factors for post-transplant hypertension. We hereby present an overview of the current practices in blood pressure monitoring and antihypertensive treatment as well as an algorithm for the evaluation and management of hypertension post liver transplantation. Finally, we discuss knowledge gaps and suggestions for future research.

A longitudinal study of long-term renal outcome after pediatric liver transplantation in relation to CNI exposure

BACKGROUND

Chronic kidney disease (CKD) is reported in 20%-30% of children after liver transplantation (LT). One of the proposed underlying causes is the long-term exposure to tacrolimus, a calcineurin inhibitor (CNI), which is the main immunosuppressive drug used after LT. Variation in tacrolimus absolute exposure and relative dose requirements are believed to be important risk factors for developing CNI-associated nephrotoxicity.

AIM

To describe the long-term renal outcome of pediatric LT recipients and determine the effects of tacrolimus exposure on renal outcome parameters.

METHODS

Retrospective single center study of renal function (GFR, proteinuria) and pharmacokinetic parameters (C0 , AUC0-12h ) obtained during annual follow-up in children after liver transplantation, between 1998 and 2019. Relevant pharmacogenetic variants for tacrolimus disposition (CYP3A5 and ABCB1) were determined in recipients and donors. The evolution of individual renal function and tacrolimus exposure was evaluated using linear mixed models for repeated measurements.

RESULTS

Twenty-six children were included (mean follow-up: 10.4 years (range 2-18.9)). Mean estimated GFR was 109.3 (SE: 7.4), vs. measured: 91.3 mL/min/1.73 m2 (SE: 6.3), which remained stable during follow-up. CKD stage ≥2 was observed in 32.8% of the visits based on eGFR versus 50.0% on mGFR. CKD stage ≥3 was uncommon (4.1% and 6.2% resp.). Mean tacrolimus C0 was 5.3 ng/mL (SE: 2.5) with a AUC0-12h of 72.7 ng*h/mL (SE: 30.3), which demonstrated a small decrease during follow-up. There was a negative correlation between C0 and mGFR (rS  = -0.3; p < .001). We found no correlation between GFR and tacrolimus dose requirements ((ng/mL)/(mg/kg)) or pharmacogenetic background.

CONCLUSION

Renal function during long-term follow-up after pediatric LT remained stable for the majority of our cohort. However, mild CKD was relatively common, warranting follow-up into adulthood. Although absolute tacrolimus exposure has a small depressing effect on concurrent GFR, there is no progressive deterioration of GFR due to long-term exposure, dose requirements or genetic background under the current target levels. These findings should be confirmed in a larger sample set, ideally including data from multiple centers.

Live-attenuated vaccination for measles, mumps, and rubella in pediatric liver transplantation

BACKGROUND

Infections are a serious short- and long-term problem after pediatric organ transplantation. In immunocompromised patients, they can lead to transplant rejection or a severe course with a sometimes fatal outcome. Vaccination is an appropriate means of reducing morbidity and mortality caused by vaccine-preventable diseases. Unfortunately, due to the disease or its course, it is not always possible to establish adequate vaccine protection against live-attenuated viral vaccines (LAVVs) prior to transplantation. LAVVs such as measles, mumps, and rubella (MMR) are still contraindicated in solid organ transplant recipients receiving immunosuppressive therapy (IST), thus creating a dilemma.

AIM

This review discusses whether, when, and how live-attenuated MMR vaccines can be administered effectively and safely to pediatric liver transplant recipients based on the available data.

MATERIAL AND METHODS

We searched PubMed for literature on live-attenuated MMR vaccination in pediatric liver transplantation (LT).

RESULTS

Nine prospective observational studies and three retrospective case series were identified in which at least 833 doses of measles vaccine were administered to 716 liver transplant children receiving IST. In these selected patients, MMR vaccination was well tolerated and no serious adverse reactions to the vaccine were observed. In addition, an immune response to the vaccine was demonstrated in patients receiving IST.

CONCLUSION

Due to inadequate vaccine protection in this high-risk group, maximum efforts must be made to ensure full immunization. MMR vaccination could also be considered for unprotected patients after LT receiving IST following an individual risk assessment, as severe harm from live vaccines after liver transplantation has been reported only very rarely. To this end, it is important to establish standardized and simple criteria for the selection of suitable patients and the administration of the MMR vaccine to ensure safe use.

Outcome of pediatric living donor liver transplant: Experience from Pakistan; a resource limited setting

INTRODUCTION

Liver transplantation (LT) has emerged as a lifesaving modality for many liver diseases in children. Pediatric LT is an established treatment in the Western world but is relatively a new procedure in resource-limited countries like Pakistan. The study aims to highlight the outcomes and survival of pediatric recipients from the first pediatric liver transplant center in Pakistan.

METHOD

A retrospective analysis of pediatric LT was done from 2012 to 2019. The study was conducted in the Hepatobiliary and liver transplant department of Shifa International Hospital (SIH), Islamabad. A detailed analysis for indications for pediatric LT, survival, and complications was done.

RESULTS

Forty-five patients under 18 years of age underwent Living donor liver transplant (LDLT) in SIH. Median age was 9 years and M:F of 2:1. Cryptogenic liver disease followed by Wilson disease were the two most common indications of LT. The majority of patients had chronic liver disease 34 (75%) while 11 (24%) had acute liver failure. The right lobe graft was the most common type of graft 19 (42.2%). Thirty days, 1-year, 3-year, and 5-year survival was 77.8%, 75.6%, 73.3%, and 60.6% respectively. Mortality was highest in patients with biliary atresia 4 (33%). Causes of death included pulmonary embolism, sepsis, surgical complications, and acute kidney injury. Mean survival was 88.850 months (±7.899) (CI 73.369-104.331).

CONCLUSION

Pediatric LDLT has offered disease-free survival for patients. Survival can improve further with nutritional rehabilitation and anticipation and management of post-operative complications.

Immunosuppression-Free Life after Pediatric Liver Transplant: A Case-Control Study from the Society of Pediatric Liver Transplant (SPLIT) Registry

OBJECTIVE

To compare long-term outcomes of pediatric liver transplant (LT) recipients off immunosuppression (IS) with matched controls on IS using data from the Society of Pediatric Liver Transplant (SPLIT) registry.

STUDY DESIGN

This was a retrospective case-control study. SPLIT participants <18 years of age, ≥4 years after isolated LT, and off IS for ≥1 year (cases) were age- and sex-matched 1:2 to patients with the same primary diagnosis and post-LT follow-up duration (controls). Primary outcomes included retransplantation, allograft rejection, IS comorbidities, and prevalence of SPLIT-derived composite ideal outcome (c-IO) achieved at the end of the follow-up period. Differences were compared using multiple linear regression for continuous outcomes and logistic regression for dichotomous data.

RESULTS

The study cohort was composed of 33 cases (42.4% male, 60.6% biliary atresia, median age at LT of 0.7 [P25, P75, 0.5, 1.6] years, median IS withdrawal time of 9 [P25, P75, 6, 12] years after LT) and 66 age- and sex-matched controls. No cases required retransplantation. Cases and controls had similar growth parameters, laboratory values, calculated glomerular filtration rates, rates of post-transplant lymphoproliferative disease, graft rejection, and attainment of c-IO.

CONCLUSIONS

No differences in allograft rejection rates, IS complications, or c-IO prevalence were seen between SPLIT patients off IS and age- and sex-matched controls remaining on IS. Discontinuation of IS most commonly occurred in the context of rigorously designed IS withdrawal trials. The available sample size was small, affecting generalizability to the broader pediatric LT population.

Balancing immunosuppression in pediatric liver transplantation: Playing the long game

The overarching goal in the care of pediatric liver transplant recipients is to optimize allograft and patient health. Balancing immunosuppression to maintain allograft health while avoiding medication side effects is essential for long-term survival and optimal quality of life in pediatric liver transplant recipients. Utilizing precision medicine to personalize immunosuppression, which includes minimization and withdrawal, is core to this effort. The unique anatomy and physiology of the liver make it more tolerant to immune-mediated injury and a more favorable organ for immunosuppression minimization and withdrawal. However, several challenges exist. Standard biochemical values and histologic features may not reliably predict allograft health after a reduction in immunosuppression. Additionally, biochemical values alone do not reliably identify which patients can successfully develop operational tolerance, as there may be occult allograft injury despite normal liver enzymes. Finally, the durability of tolerance after successful reduction in immunosuppression remains uncertain over time. Innovative tools show promise in circumventing these challenges, but more research is needed to determine actual clinical utility. While immunosuppression-free transplant may not be a current reality for most pediatric liver transplant recipients, strategies to safely minimize immunosuppression without compromising allograft health are within reach. Each liver allograft and recipient pair requires a different degree of immune modulation, and through a structured process of minimization and withdrawal, immunosuppression can indeed be tailored in a precise, personalized way to optimize outcomes. This review focuses on the progress that has been made to individualize immunosuppression in pediatric liver transplantation to ensure optimal allograft and recipient health.

Treatment of maple syrup urine disease: Benefits, risks, and challenges of liver transplantation

Maple syrup urine disease (MSUD) is caused by a deficiency in the activity of the branched-chain α-ketoacid dehydrogenase (BCKD) complex, promoting the accumulation of the branched-chain amino acids (BCAA) leucine, isoleucine, and valine, as well as their respective α-keto acids. MSUD is an autosomal recessive hereditary metabolic disorder characterized by ketoacidosis, ataxia, coma, and mental and psychomotor retardation. The mechanisms involved in the brain damage caused by MSUD are not fully understood. Early diagnosis and treatment, as well as proper control of metabolic decompensation crises, are crucial for patients' survival and for a better prognosis. The recommended treatment consists of a high-calorie diet with restricted protein intake and specific formulas containing essential amino acids, except those accumulated in MSUD. This treatment will be maintained throughout life, being adjusted according to the patients' nutritional needs and BCAA concentration. Because dietary treatment may not be sufficient to prevent neurological damage in MSUD patients, other therapeutic strategies have been studied, including liver transplantation. With transplantation, it is possible to obtain an increase of about 10% of the normal BCKD in the body, an amount sufficient to maintain amino acid homeostasis and reduce metabolic decompensation crises. However, the experience related to this practice is very limited when considering the shortage of liver for transplantation and the risks related to the surgical procedure and immunosuppression. Thus, the purpose of this review is to survey the benefits, risks, and challenges of liver transplantation in the treatment of MSUD.

Safety and Efficacy of Conversion to Once-Daily Tacrolimus from Twice-Daily Tacrolimus in Pediatric Liver Transplant Recipients

BACKGROUND

Nonadherence to immunosuppression is the most common cause of late acute rejection in pediatric liver transplant (LT) recipients. A prolonged-release once-daily tacrolimus formulation was developed to improve adherence and long-term allograft survival.

METHODS

We screened 179 pediatric LT recipients who converted from twice-daily tacrolimus (TD-TAC) to once-daily tacrolimus (OD-TAC) between February 2011 and September 2019.

RESULTS

One hundred seventy-nine recipients converted to OD-TAC and were followed for 18 months. 152 OD-TAC-converted recipients (84.9%) experienced uneventful follow-up, while 21 recipients showed LFT elevation. Four recipients had biopsy-proven acute rejection within six months of conversion, all of which were successfully treated with steroid pulse. 166 recipients (92.7%) remain on OD-TAC and 13 (7.3%) were switched back to TD-TAC. The mean tacrolimus trough level significantly decreased three months following conversion (3.14 ± 1.9 ng/mL) compared with pre-conversion levels (3.69 ± 1.98 ng/mL). Mean tacrolimus trough levels remained unchanged from 3 months to 12 months following conversion. Percent coefficient of variation of tacrolimus trough levels decreased significantly from 32.5 ± 16.4 ng/mL to 27.5 ± 15.6 ng/mL after conversion to OD-TAC, reflecting a decrease in variation of tacrolimus trough levels following conversion.

CONCLUSIONS

Conversion to OD-TAC in pediatric LT recipients with stable graft function is safe and effective.

LEVEL OF EVIDENCE

Level IV.

Cost-effectiveness analysis of liver transplantation in biliary atresia according to the severity of end-stage liver disease

BACKGROUND

Timing for liver transplantation (LT) in biliary atresia (BA) children with end-stage liver disease (ESLD) is associated with all-cause mortality. The cut-off value of pediatric end-stage liver disease (PELD) score for LT consideration varies across institutions. We aimed to determine the cost-effectiveness of LT to prevent death among BA children registered on the waiting list with different severities of ESLD.

METHODS

Subjects were BA children aged < 12 years at a transplant center between 2010 and 2021. A decision tree was developed for cost-effectiveness analysis from a hospital perspective to compare all-cause death between patients initially registered with a low PELD score (< 15) and a high PELD score (≥ 15). Each patient's direct medical cost was retrieved from the beginning of registration until 5 years after LT, adjusted with an inflation rate to 2022 Thai Baht (THB).

RESULTS

Among 176 children, 138 (78.4%) were initially registered with the high PELD score. The cost and mortality rate of the low PELD score group (THB1,413,424 or USD41,904 per patient and 31.6% mortality) were less than the high PELD score group (THB1,781,180 or USD52,807 per patient and 47.9% mortality), demonstrating the incremental cost-effectiveness ratio (ICER) of THB2,259,717 or USD66,994 per death prevented. The cost of early post-operative admission had the highest effect on the ICER. Considering the break-even analysis, cost among children initially registered at the low PELD score was also less expensive over time.

CONCLUSIONS

Registration for LT at PELD score < 15 was more cost-effective to prevent death among BA children with ESLD.

Improving medication adherence monitoring and clinical outcomes through mHealth: A randomized controlled trial protocol in pediatric stem cell transplant

Medication non-adherence rates in children range between 50% and 80% in the United States. Due to multifaceted outpatient routines, children receiving hematopoietic stem cell transplant (HCT) are at especially high risk of non-adherence, which can be life-threatening. Although digital health interventions have been effective in improving non-adherence in many pediatric conditions, limited research has examined their benefits among families of children receiving HCT. To address this gap, we created the BMT4me© mobile health app, an innovative intervention serving as a "virtual assistant" to send medication-taking reminders for caregivers and to track, in real-time, the child's medication taking, barriers to missed doses, symptoms or side effects, and other notes regarding their child's treatment. In this randomized controlled trial, caregivers will be randomized to either the control (standard of care) group or the intervention (BMT4me© app) group at initial discharge post-HCT. Both groups will receive an electronic adherence monitoring device (i.e., medication event monitoring system "MEMS" cap, Medy Remote Patient Management "MedyRPM" medication adherence box) to store their child's immunosuppressant medication. Caregivers who agree to participate will be asked to complete enrollment, weekly, and monthly parent-proxy measures of their child's medication adherence until the child reaches Day 100 or complete taper from immunosuppression. Caregivers will also participate in a 15 to 30-minute exit interview at the conclusion of the study. Descriptive statistics and correlations will be used to assess phone activity and use behavior over time. Independent samples t-tests will examine the efficacy of the intervention to improve adherence monitoring and reduce readmission rates. The primary expected outcome of this study is that the BMT4me© app will improve the real-time monitoring and medication adherence in children receiving hematopoietic stem cell transplant following discharge, thus improving clinical outcomes.

Anti-thymocyte globulin induction with delayed introduction of tacrolimus preserves renal function in pediatric liver transplant recipients

BACKGROUND

Tacrolimus (TAC)-mediated renal disease occurs in up to 70% of pediatric liver transplant (LT) recipients. The safety and efficacy of renal-sparing immunosuppression using anti-thymocyte globulin (ATG) induction and delayed TAC administration has not been studied in children. We evaluated the safety and efficacy of ATG induction on preserving renal function in children within the first year (Y1) post-LT in a single-center retrospective cohort study.

METHODS

Children under age 18 years of who received isolated LT from 2008 to 2020 with a GFR < 70 received renal-sparing (RS) protocol consisting of ATG with methylprednisolone (MP), delayed TAC administration, lower initial TAC trough goals, and mycophenolate mofetil (MMF). The RS group was matched 1:2 by age and LT indication with standard immunosuppression (SI) group. Changes in renal function as well as adverse events within Y1 post-LT were compared.

RESULTS

Forty-four pediatric patients were included in the analysis, of which 13 received RS. As expected, the RS group had significantly lower mean TAC trough levels at 30 days (10.3 vs. 13.2, p = .001) post-LT. Renal function was significantly preserved at 6 (-0.26 vs. 0.21, p = .004) and 12 months (-0.33 vs. 0.11, p = .003) post-LT in the RS versus SI group as measured by mean change in serum creatinine, with similar trends observed in eGFR and cystatin C. ACR, sepsis, viremia, graft loss and mortality occurred at similar rates in both RS and SI groups.

CONCLUSION

Induction immunosuppression with ATG and delayed TAC administration in children with renal impairment is safe and effectively preserves renal function during Y1 post-LT.

Differences in Physical Activity Levels between Healthy and Transplanted Children: Who Needs More Tips?

BACKGROUND

Advances in the medical-surgical field have significantly increased the life expectancy of patients undergoing solid organ transplantation but this exposes patients to long-term complications due to chronic therapies and changes in lifestyle. It is known that children affected by pathology tend to be more sedentary and inactivity represents a further risk factor for the onset of non-communicable diseases. The aim of the present study was to compare the lifestyle of two groups of young patients: one group of healthy subjects (HG) and one group of kidney or liver transplant recipients (TG).

METHODS

Patients were asked to complete Physical Activity Questionnaire for Older Children (PAQ-C).

RESULTS

A total of 104 subjects were recruited (50.9% male, mean age 12.8 ± 3.16 years old). No significant differences were observed in the final score between groups when comparing subjects based on health condition (Healthy 2.69 ± 0.65 vs. Transplant Group 2.42 ± 0.88), the intensity of sports activities (Competitive 2.82 ± 0.59 vs. Not Competitive 2.53 ± 0.7) or type of transplant (Liver 2.51 ± 0.91 vs. Kidney 2.16 ± 0.75).

CONCLUSION

The results of this study showed a worrying reality: children are engaged in low levels of physical activity regardless of their health status and in general the level of activity does not reach the recommended values even in the absence of contraindications. So, it is necessary to encourage healthy children to practice more PA and to introduce PA prescriptions for transplanted children to prevent their health from deteriorating due to sedentariness.

Adjuvant conditioning induces an immunosuppressive milieu that delays the alloislet rejection through the expansion of myeloid derived suppressor cells

Advances in immunosuppression have been relatively stagnant over the last 2 decades and transplant recipients continue to experience long term morbidity associated with immunosuppression regimens. Strategies to reduce or eliminate the dosage of immunosuppression medications are needed. We discovered a novel administration strategy utilizing the classic adjuvant alum to condition murine islet transplant recipients, known as adjuvant conditioning or AC, to expand both polymorphonuclear and monocytic myeloid derived suppressive cells (MDSCs) in vivo. These AC MDSCs potently suppress T cell proliferation when cultured together in vitro. AC MDSCs also facilitate naïve CD4⁺ T cells to differentiate into regulatory T cells. In addition, we were able to demonstrate a significant delay in alloislet rejection compared to saline-treated control following adjuvant treatment in a MDSC dependent manner. Furthermore, AC MDSCs produce significantly more IL-10 compared to saline-treated controls, which we demonstrated to be critical for the increased T cell suppressor function of AC MDSCs, as well as the observed protective effect of AC against alloislet rejection. Our data suggest that adjuvant related therapeutics designed to expand MDSCs could be a useful strategy to prevent transplant rejection and curb the use of toxic immunosuppressive regimens currently employed in transplant patients.

Innate immune cellular therapeutics in transplantation

Successful organ transplantation provides an opportunity to extend the lives of patients with end-stage organ failure. Selectively suppressing the donor-specific alloimmune response, however, remains challenging without the continuous use of non-specific immunosuppressive medications, which have multiple adverse effects including elevated risks of infection, chronic kidney injury, cardiovascular disease, and cancer. Efforts to promote allograft tolerance have focused on manipulating the adaptive immune response, but long-term allograft survival rates remain disappointing. In recent years, the innate immune system has become an attractive therapeutic target for the prevention and treatment of transplant organ rejection. Indeed, contemporary studies demonstrate that innate immune cells participate in both the initial alloimmune response and chronic allograft rejection and undergo non-permanent functional reprogramming in a phenomenon termed "trained immunity." Several types of innate immune cells are currently under investigation as potential therapeutics in transplantation, including myeloid-derived suppressor cells, dendritic cells, regulatory macrophages, natural killer cells, and innate lymphoid cells. In this review, we discuss the features and functions of these cell types, with a focus on their role in the alloimmune response. We examine their potential application as therapeutics to prevent or treat allograft rejection, as well as challenges in their clinical translation and future directions for investigation.

Prope tolerance after pediatric liver transplantation: Experience at Shiraz Organ Transplant Center

BACKGROUND

Children receive transplants at a younger age, and the period of immunosuppression therapy may extend over decades. However, immunosuppression seems to be responsible for long-term mortality and morbidity. Pediatric liver transplant recipients can benefit from achieving immune tolerance and the opportunity of freedom from lifelong immunosuppression. This study aimed to investigate the frequency of prope tolerance among pediatric liver transplant recipients and the characteristics of these patients.

METHODS

In this retrospective cohort study of pediatric liver transplant recipients, the medical records of transplant recipients treated at Shiraz Organ Transplant Center between 1994 and 2017 were reviewed. Prope tolerance was defined as normal laboratory values and stable clinical status on low-dose monotherapy. Children treated with low-dose monotherapy were categorized as the prope tolerant group. We compared the characteristics of prope tolerant recipients on low-dose monotherapy with patients on standard immunosuppression, i.e. full-dose tacrolimus plus steroids and mycophenolate mofetil. The data were analyzed with the t-test, chi-squared test, and a Cox proportional hazard model at a 5% significance level in SPSS software version 16.

RESULTS

A total of 585 children with a mean age of 8.32 ± 5.23 years were enrolled. 341 patients were categorized as prope tolerant and 244 comprised the full immunosuppression regimen group. Mean age at transplantation and rejection frequency were lower in the prope tolerant group (p < 0.001, p < 0.001). Based on the underlying diseases, metabolic/genetic, biliary tract, and cryptogenic liver diseases were significantly more prevalent in the prope tolerant group (p < 0.001). However, autoimmune liver disease was found to be more prevalent in the full immunosuppression regimen group. Also, those who received living organs (p = 0.001) and recipients of organs from female donors had a greater likelihood of achieving prope tolerant. According to the multiple Cox regression results, age at transplantation (p = 0.022), rejection frequency (p < 0.001), and autoimmune liver diseases (p = 0.028) had a prognostic effect on prope tolerance.

CONCLUSION

Factors as underlying disease, age at transplantation, and rejection frequency were factors that were predictive of prope tolerance in this sample of children. However, the risk of rejection should be considered during the tapering period.

Immunosuppression after pediatric liver transplant: The parents' perspective

BACKGROUND

For children with liver transplants (LT), achieving an "ideal outcome" is a balancing act: too little immunosuppression begets graft injury; too much begets systemic complications. We aimed to delineate the parental perspective on this tightrope.

METHODS

Parents of children with LT completed an internet-based survey about their child's immunosuppression.

RESULTS

Children of respondents (n = 82) were a median 4 years from primary LT (range 0-22); 73% were on immunosuppression monotherapy. Parents' top concerns were related to immunosuppression complications; 46% were more concerned about immunosuppression complications than rejection; only 17% were more concerned about rejection than immunosuppression complications. Among parents of children on immunosuppression monotherapy, 29% still worried more about immunosuppression complications than rejection, 48% expressed equal concern for both. Time since LT (0-4 vs. >4 years) was not associated with concern level for rejection or immunosuppression complications. Caregivers were significantly more certain that their child's immunosuppression regimen was correct to prevent rejection than to mitigate complications (p < .005).

CONCLUSION

Caregivers of children with LTs reported higher levels of concern and uncertainty about immunosuppression complications than rejection risk. Understanding parent and patient perspectives on IS, and incorporating them into immunosuppression counseling and decision-making, is critical to achieving truly "ideal" long-term outcomes.

Incidence and risk factors of subclinical rejection after pediatric liver transplantation, and impact on allograft fibrosis

INTRODUCTION

Subclinical rejection (SCR) is a common injury in protocol biopsy after pediatric liver transplantation (pLT), but its effect on the recipient is not clearly understood. We herein investigated the incidence and risk factors involved in SCR and analyzed the relationship between SCR and allograft fibrosis (AF).

METHODS

We retrospectively reviewed the biopsy results from 507 children between May 2013 and May 2019, and 352 patients underwent protocol biopsy 2 years after pLT, 203 underwent protocol biopsy 5 years after pLT, and 48 underwent protocol biopsy both 2 and 5 years after pLT.

RESULTS

The incidence of SCR in the 5-year group was higher than that in the 2-year group (20.2% vs.13.4%, respectively, p = .033). The number of patients with mild and moderate SCR in the 5-year group was also higher than that in the 2-year group (p = .039). Logistic regression analysis showed that acute rejection before liver biopsy and deceased donor liver transplantation (DDLT) were independent risk factors for SCR in the two groups, and that the incidence and severity of AF in protocol biopsies at both periods in the SCR group were higher than those in the non-SCR group (p < .05).

CONCLUSIONS

The incidence and severity of SCR increased with the prolongation of protocol biopsy time. We postulate that acute rejection and DDLT are independent risk factors for SCR after transplantation. As the occurrence of SCR also augmented the incidence and severity of AF.

Preliminary Evaluation of Sedentary Lifestyle in Italian Children after Solid Transplant: What Role Could Physical Activity Play in Health? It Is Time to Move

BACKGROUND

Advances in the medical-surgical field have significantly increased survival after solid organ transplantation in the pediatric population. However, these patients are predisposed to the development of long-term complications (e.g., cardiovascular disease). The therapeutic role of physical activity (PA) to counteract these complications is well known. The purpose of the study was to investigate the level of PA in a pediatric population after solid organ transplantation.

METHODS

In the first 4 weeks at the beginning of the school year, the Physical Activity Questionnaire for Older Children and Adolescents was administered to young patients who had previously undergone solid transplants at our institute.

RESULTS

Questionnaires of 49 patients (57.1% female, mean age 13.2 ± 3.5 years) were analyzed and 32.7% of subjects did not perform any exercise during school physical education classes. Only 24% practiced a moderate quantity of exercise in the previous week (2-3 times/week) and 72% engaged in sedentary behaviors during weekends.

CONCLUSIONS

Preliminary data confirmed that young recipients are still far from meeting the minimum indications of the World Health Organization on PA and sedentary behavior. It will be necessary to increase their involvement in PA programs in order not only to increase their life expectancy but also to improve their quality of life.

Case report: One pediatric liver-transplant recipient with SARS-CoV-2 infection suffering unexplained mixed acidosis

Background

The management of LT patients during COVID-19 pandemic is important. Immunosuppressants (IS) are key therapy agents after liver transplant. Different ISs have different side effects. Calcineurin inhibitor (CNI) may lead to metabolic acidosis while mycophenolate mofetil (MMF) showed rare nephrotoxicity. We report a post-liver transplant girl who was infected with SARS-CoV-2, developing a severe mixed acidosis 3 months after the transplantation. Her acidosis was improved after withdrawing of MMF, leading the suspicion that acidosis maybe a rare side effect of MMF.

Case presentation

A girl was admitted to our hospital due to SARS-CoV-2 infection, 3 months before admission the patient received LT due to Niemann-Pick disease (NPD). During hospitalization, blood gas analysis showed severe mixed acidosis. To relieve mixed acidosis, the patient was given oral rehydration salt and liquid replacement therapy. Considering that immunosuppressants may cause metabolic acidosis, dose of CsA was decreased and MMF was discontinued.

Results

However, liquid replacement therapy and decreased CsA dose cannot improve the condition. As an attempt, MMF was discontinued, and 3 days later, the girl's acidosis was relieved, the latest blood gas analysis was normal with the original dose of CsA and no use of MMF or other IS. In addition, we used Naranjo Scale to see if adverse drug reactions (ADRs) existed. The final score was 6 which means MMF contributes to acidosis probably.

Conclusion

The girl's mixed acidosis cannot be explained by Niemann-Pick disease and SARS-CoV-2 infection. CNIs could cause metabolic acidosis but declining the dose of CsA didn't improve her acidosis while withdrawing MMF showed a good effect. Together with the Naranjo Scale result, we suspect that acidosis maybe a rare side effect of MMF.

Intestinal Dominance by Multidrug-Resistant Bacteria in Pediatric Liver Transplant Patients

Pediatric liver transplantation (PLTx) is commonly associated with extensive antibiotic treatments that can produce gut microbiome alterations and open the way to dominance by multidrug-resistant organisms (MDROs). In this study, the relationship between intestinal Relative Loads (RLs) of β-lactamase genes, antibiotic consumption, microbiome disruption, and the extraintestinal dissemination of MDROs among PLTx patients is investigated. 28 PLTx patients were included, from whom 169 rectal swabs were collected. Total DNA was extracted and bla_{CTX-M-1-Family}, bla_OXA-1, bla_OXA-48, and bla_VIM were quantified via quantitative polymerase chain reaction (qPCR) and normalized to the total bacterial load (16SrRNA) through LogΔΔCt to determine the RLs. 16SrRNA sequencing was performed for 18 samples, and metagenomic sequencing was performed for 2. Patients' clinical data were retrieved from the hospital's database. At least one of the genes tested were detected in all of the patients. The RLs for bla_{CTX-M-1-Family}, bla_OXA-1, bla_OXA-48, and bla_VIM were higher than 1% of the total bacterial population in 67 (80.73%), 56 (78.87%), 57 (77.03%) and 39 (61.9%) samples, respectively. High RLs for bla_{CTX-M-1-Family}, bla_OXA-1, and/or bla_OXA-48, were positively associated with the consumption of carbapenems with trimethoprim-sulfamethoxazole and coincided with low diversity in the gut microbiome. Low RLs were associated with the consumption of noncarbapenem β-lactams with aminoglycosides (P < 0.05). Extraintestinal isolates harboring the same gene(s) as those detected intraintestinally were found in 18 samples, and the RLs of the respective swabs were high. We demonstrated a relationship between the consumption of carbapenems with trimethoprim-sulfamethoxazole, intestinal dominance by MDROs and extraintestinal spread of these organisms among PLTx patients. IMPORTANCE In this study, we track the relative intestinal loads of antibiotic resistance genes among pediatric liver transplant patients and determine the relationship between this load, antibiotic consumption, and infections caused by antibiotic-resistant organisms. We demonstrate that the consumption of broad spectrum antibiotics increase this load and decrease the gut microbial diversity among these patients. Moreover, the high loads of resistance genes were related to the extraintestinal spread of multidrug-resistant organisms. Together, our data show that the tracking of the relative intestinal loads of antibiotic resistance genes can be used as a biomarker that has the potential to stop the extraintestinal spread of antibiotic-resistant bacteria via the measurement of the intestinal dominance of these organisms, thereby allowing for the application of preventive measures.

Pediatric Liver Transplantation: Caregivers' Quality of Life

PURPOSE

The survival rate of pediatric patients undergoing liver transplantation has increased considerably. Despite this, the period after transplantation is still complex and poses several challenges to the recipient's family, which is responsible for care management. Recently, more attention has been paid to the impact of this complex procedure on the quality of life of caregivers. Hence, this study is aimed at assessing the quality of life of caregivers of patients who have undergone liver transplantation and the aspects that influence it.

METHODS

This was an observational and cross-sectional study. From November 2020 to January 2021, short-form-36 questionnaires and additional questions were given to the main caregivers of children and adolescents who underwent pediatric liver transplantation.

RESULTS

Thirty-eight questionnaires were completed and the results revealed a lower quality of life in comparison to Brazilian standards, primarily in the mental domains (41.8±14.1 vs. 51.1±2.8; p<0.001). It did not show a significant association with socioeconomic or transplant-related factors, but it did show a negative impact on parents' perception of the child's health. Parents who reported worse health status for their children had a lower mental quality of life (44.1±13.8 vs. 33.3±12.6; p<0.05).

CONCLUSION

The caregivers of transplanted children have a lower quality of life than those of the local population. Psychological assistance should be routinely provided to parents for long-term follow-up to mitigate potential negative effects on the transplanted child's care.

Advances in medical management of acute liver failure in children: promoting native liver survival

Paediatric acute liver failure (PALF) is defined as a biochemical evidence of acute liver injury in a child with no previous history of chronic liver disease characterised by an international normalised ratio (INR) of 1·5 or more unresponsive to vitamin K with encephalopathy, or INR of 2·0 or more with or without encephalopathy. PALF can rapidly progress to multiorgan dysfunction or failure. Although the transplant era has substantially changed the outlook for these patients, transplantation itself is not without risks, including those associated with life-long immunosuppression. Consequently, there has been an increased focus on improving medical management to prioritise bridging of patients to native liver survival, which is possible due to improved understanding of the underlying pathophysiology of multiorgan involvement in PALF. In this Review, we discuss recent advances in the medical management of PALF with an aim of reducing the need for liver transplantation. The Review will focus on the non-specific immune-mediated inflammatory response, extracorporeal support devices, neuromonitoring and neuroprotection, and emerging cellular and novel future therapeutic options.

CYP3A4/5 genotypes and age codetermine tacrolimus concentration and dosage in pediatric heart transplant recipients

Tacrolimus (TAC) is the cornerstone of immunosuppressive therapy for pediatric heart transplantation (HTx) recipients. However, little information is known on the interaction of developmental and genetic variants on TAC disposition in this population, which makes TAC dose optimization more difficult. The aim of study was to investigate the relationship between genotypes and age on TAC concentrations and dosage during the early post-operation period in pediatric HTx recipients. Sixty-six pediatric HTx recipients were enrolled and divided into three groups according to the age (<6, ≥6-≤12, 12-18 years old). CYP3A4/5, POR and ABCB1 polymorphisms were genotyped. The associations between genotypes and age on TAC dose-adjusted trough concentrations (C₀/D), dose requirement as well as acute kidney injury (AKI) were evaluated. CYP3A5*3 and CYP3A4*1G were significantly correlated with TAC C₀/D and dose requirement in the pediatric recipients ≥ 6 years. The C₀/D in children aged ≥ 6-≤12 years and 12-18 years is 2.8 and 4.2 fold of these < 6 years old, respectively. TAC dose requirements in children aged < 6 years were 2.4 times and 3.5 times of these aged ≥ 6-≤12 years and 12-18 years, respectively. Among the same CYP3A5*3 or CYP3A4*1G genotypes, age was positively increased with TAC C₀/D and negatively correlated with targeted dose. No genetic variants were found to be associated with AKI during the early post-operation period. CYP3A4/5 genotypes and age should be taken into consideration to TAC dosage in pediatric HTx recipients.

Pediatric Liver Transplantation

Liver transplantation (LT) for children results in excellent short- and long-term patient and graft survival. LT is a lifesaving procedure in children with acute or chronic liver disease, hepatic tumors, and select genetic metabolic diseases in which it can significantly improve quality of life. In this article, the authors discuss the unique aspects of pediatric LT, including the indications, appropriate patient selection and evaluation, allocation of organs, transplant surgery including the use of variant grafts, posttransplant care including immunosuppression management, prognosis, and transition of care.

Pediatric Liver Transplantation: Long-Term Follow-Up Issues

Pediatric liver transplant is an established life-saving procedure for children with end-stage liver diseases, achieving excellent graft and patient survival but with effects on quality of life and psychological welfare in the long-term. With the natural increase in the number of pediatric transplant patients becoming adults, it is essential to successfully plan and manage issues affecting late outcomes in the vulnerable pediatric transplant population. This study offers an overview of the long-term surgical complications, the consequences of immunosuppression (such as posttransplant diabetes, hypertension, cardiovascular disease, and renal dysfunction), and the infection and malignancy risks. Finally, because quality of life is now an inclusive measurement of patient satisfaction, guidance on how to facilitate the transition to adulthood, empowering transplant recipients, is also provided.

The effect of liver transplantation for argininemia-the largest experiences in a single center

BACKGROUND

Argininemia, a rare urea cycle disorder resulting from an arginase-1 deficiency, is characterized by a progressive spastic paraplegia. While advances in diagnosis and treatment have increased the management of this condition, not all symptoms are resolved in response to traditional therapies. Interestingly, there exist some rare reports on the use of liver transplantation (LT) for the treatment of argininemia.

METHODS

We conducted a retrospective study of eleven patients with argininemia receiving a LT as performed at our center over the period from January 2015 to November 2019. These patients were included due to their poor responses to protein restriction diets and alternative therapies of nitrogen scavengers. Detailed information on coagulation, liver function, histopathological and morphological examination of liver samples, and other clinical presentations were extracted from these patients. A grading scale was used for evaluating the neurological status, classification of physical growth and quality of life of these patients in response to the LT.

RESULTS

Prior to LT, high levels of arginine were detected in all of argininemia patients and liver enzymes were elevated in nine of those patients. Nine patients presented with coagulation dysfunction without bleeding symptoms. Spastic paraplegia, irritability, intellectual developmental disability, and growth deficits were hallmarks of these nine patients, while four patients showed repeated, generalized tonic-clonic seizures before the operation. Seven novel mutations were found in these patients. The indication for LT in this series of patients was a presentation of progressive neurological impairments. After LT, the coagulation index and plasma arginine levels returned to normal and episodes of seizure were controlled in four patients. To date, all patients have survived and their LT has resulted a restoration of arginine metabolism and liver function, along with preventing further neurological deterioration, all of which provided an opportunity for future recuperation. Overall, the neurological status, growth deficits and quality of life were all significantly improved after LT with no evidence of severe complications.

CONCLUSIONS

LT can serve as an effective treatment for argininemia in patients who respond poorly to traditional therapy. An early intervention of LT should be conducted in these patients to prevent neurological damage and improve their quality of life.

Ex vivo generation of regulatory T cells from liver transplant recipients using costimulation blockade

The potential of adoptive cell therapy with regulatory T cells (Tregs) to promote transplant tolerance is under active exploration. However, the impact of specific transplant settings and protocols on Treg manufacturing is not well-delineated. Here, we compared the use of peripheral blood mononuclear cells (PBMCs) from patients before or after liver transplantation to the use of healthy control PBMCs to determine their suitability for Treg manufacture using ex vivo costimulatory blockade with belatacept. Despite liver failure or immunosuppressive therapy, the capacity for Treg expansion during the manufacturing process was preserved. These experiments did not identify performance or quality issues that disqualified the use of posttransplant PBMCs-the currently favored protocol design. However, as Treg input correlated with output, significant CD4-lymphopenia in both pre- and posttransplant patients limited Treg yield. We therefore turned to leukapheresis posttransplant to improve absolute yield. To make deceased donor use feasible, we also developed protocols to substitute splenocytes for PBMCs as allostimulators. In addition to demonstrating that this Treg expansion strategy works in a liver transplant context, this preclinical study illustrates how characterizing cellular input populations and their performance can both inform and respond to clinical trial design and Treg manufacturing requirements.

Liver Transplantation in Children with Urea Cycle Disorders: The Importance of Minimizing Waiting Time

Liver transplantation (LT) for children with urea cycle disorders (UCDs) is capable of correcting the enzymatic defect and preventing progressive neurologic injury. We describe the characteristics and outcomes of pediatric LT recipients with UCDs. We identified all pediatric (<18 years) LT candidates with UCDs in the United Network for Organ Sharing (UNOS) database (February 2002 to September 2020). Multivariable Cox and logistic regression were used to determine risk factors for graft loss and cognitive delay, respectively. Of 424 patients, 1.9% (8/424) experienced waitlist mortality and 95.0% underwent LT (403/424). The most frequently encountered UCDs in our cohort were ornithine transcarbamylase deficiency (46.2%), citrullinemia (20.3%), and argininosuccinic aciduria (ASA; 12.9%). The 1-, 3-, and 5-year graft survival rates were 90.4%, 86.3%, and 85.2%, respectively. Multivariable analysis showed a decreased risk of graft loss with increasing weight at LT (adjusted hazard ratio [aHR], 0.96; 95% confidence interval [CI], 0.94-0.99; P = 0.02), male sex (aHR, 0.49; 95% CI, 0.28-0.85; P = 0.01), and ASA diagnosis (aHR, 0.29; 95% CI, 0.09-0.98; P = 0.047), when adjusting for location (intensive care/hospital/home) and graft type (both P ≥ 0.65). In multivariable logistic regression, waitlist time (adjusted odds ratio [aOR], 1.10; 95% CI, 1.02-1.17; P = 0.009) and male sex (aOR, 1.71; 95% CI, 1.02-2.88; P = 0.04) were associated with increased odds of long-term cognitive delay. Waitlist duration is associated with a long-term risk of cognitive delay. Given excellent long-term outcomes, early LT evaluation should be considered in all children with UCDs to prevent progressive neurologic injury and optimize cognitive outcomes.

Liver transplantation for pediatric inherited metabolic liver diseases

Liver transplantation (LT) remains the gold standard treatment for end stage liver disease in the pediatric population. For liver based metabolic disorders (LBMDs), the decision for LT is predicated on a different set of paradigms. With improved outcomes post-transplantation, LT is no longer merely life saving, but has the potential to also significantly improve quality of life. This review summarizes the clinical presentation, medical treatment and indications for LT for some of the common LBMDs. We also provide a practical update on the dilemmas and controversies surrounding the indications for transplantation, surgical considerations and prognosis and long terms outcomes for pediatric LT in LBMDs. Important progress has been made in understanding these diseases in recent years and with that we outline some of the new therapies that have emerged.

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

The aim of this study was to determine the long-term efficacy and safety of tacrolimus (Tac) and cyclosporine immunosuppression in pediatric liver transplantation (LTx).

Life long follow up and management strategies of patients living with native livers after Kasai portoenterostomy

We present a 37 years’ experience in the management of biliary atresia (BA) and discuss long-term complications after Kasai portoenterostomy (KPE). A retrospective territory-wide study from 1980 to 2017 on 231 patients with open KPE from three tertiary paediatric surgical centres was performed. Outcome parameters were clearance of jaundice (COJ), native liver survival (NLS) and long-term complications. Factors affecting the operative outcomes were analyzed. The median duration of follow up was 17.5 (IQR: 13.5–22) years. Over 66% of patients became jaundice-freed at 1 year after KPE. Seventy patients (30.3%) received liver transplant (LT) at a median age of 6.2 (IQR: 4.3–8.4) years. The NLS rates at 10 and 20 years were 70.7% and 61.5% respectively with no significant change over the study period. The median age at KPE was 59 (IQR: 49–67) days. KPE performed before 70 days was associated with higher odd ratios for successful drainage but the age of KPE did not have an impact on the long-term NLS. Among all native liver survivors (n = 153), the median bilirubin level was 24 (IQR: 16–36) µmol/L. Portal hypertension (PHT) and recurrent cholangitis were found in 51.6% and 27.5% of them respectively. With a vigilant follow up program, more than 60% of BA patients could remain stable with the disease and achieve long-term survival without LT. Although cholestasis, portal hypertension and recurrent cholangitis are common in long-term NLS, with a comprehensive follow management strategy, they do not always necessitate LT. Our study serves as an example for countries where deceased donor organs are scarce due to very low donation rate.

Adherence to laboratory testing in pediatric liver transplant recipients

BACKGROUND

The objectives of this retrospective cohort study are to describe rates of adherence to laboratory testing 6 months to 3 years post-liver transplantation and to examine demographic and clinical factors related to lab non-adherence and the association with medication adherence and clinical outcomes.

METHODS

Medical chart review was conducted for 54 youth (mean age = 5.0 years) transplanted between 2003 and 2014. Lab adherence (≥80%) was measured as the proportion of completed labs out of the number expected. Immunosuppressant drug-level variability was used as a proxy for medication adherence. Clinical outcomes included LAR, viral infection, hospitalization, and non-routine clinic visit ≥12 months after transplant.

RESULTS

Lab adherence decreased substantially over time. Single-parent household (aOR 5.86; 95% CI: 1.38-24.93) and no history of early rejection (aOR 3.96; 95% CI: 1.04-15.24) were independently associated with non-adherence. Lab non-adherence was significantly associated with medication non-adherence (P < .05), LAR (P = .02), and non-routine clinic visits (P = .03).

CONCLUSIONS

Systematic monitoring of lab adherence may help in identifying pediatric LT recipients at increased risk for excessive healthcare use and adverse outcomes possibly due to poor disease management.

Severe Liver Disorder Following Liver Transplantation in STING-Associated Vasculopathy with Onset in Infancy

PURPOSE

STING-associated vasculopathy with onset in infancy (SAVI) is a type-I interferonopathy, characterized by systemic inflammation, peripheral vascular inflammation, and pulmonary manifestations. There are three reports of SAVI patients developing liver disease, but no report of a SAVI patient requiring liver transplantation. Therefore, the relevance of liver inflammation is unclear in SAVI. We report a SAVI patient who developed severe liver disorder following liver transplantation.

METHODS

SAVI was diagnosed in a 4-year-old girl based on genetic analysis by whole-exome sequencing. We demonstrated clinical features, laboratory findings, and pathological examination of her original and transplanted livers.

RESULTS

At 2 months of age, she developed bronchitis showing resistance to bronchodilators and antibiotics. At 10 months of age, she developed liver dysfunction with atypical cholangitis, which required liver transplantation at 1 year of age. At 2 years of age, multiple biliary cysts developed in the transplanted liver. At 3.9 years of age, SAVI was diagnosed by whole-exome sequencing. Inflammatory cells from the liver invaded the stomach wall directly, leading to fatal gastrointestinal bleeding unexpectedly at 4.6 years of age. In pathological findings, there were no typical findings of liver abscess, vasculitis, or graft rejection, but biliary cysts and infiltration of inflammatory cells, including plasmacytes around the bile duct area, in the transplanted liver were noted, which were findings similar to those of her original liver.

CONCLUSION

Although further studies to clarify the mechanisms of the various liver disorders described in SAVI patients are needed, inflammatory liver manifestations may be amplified in the context of SAVI.

Immune cell function assays in the diagnosis of infection in pediatric liver transplantation: an open-labeled, two center prospective cohort study

BACKGROUND

Limited studies have been performed in assessment of immune status of pediatric liver transplants (PLTs). We conducted this study to evaluate Cylex immune cell function assay in diagnosis of infection and its potential clinical application in Chinese infant PLTs.

METHODS

In this prospective cohort study, 227 infant PLTs from two medical centers were enrolled, and 216 completed the study. Cylex ATP values were measured before and after liver transplantation (LT) at week 1, 2, 3, 4, 8, 12 and 24 respectively. Accordingly, patients' clinical records, including demographic data, liver function results, tacrolimus dosages and concentrations were collected and analyzed.

RESULTS

One hundred and sixty of 216 PLTs (74.1%) were diagnosed infection based on the parameters including abnormal vital signs, imaging changes, and pathogens detection, while 44 (20.4%) were clinically stable and 12 (5.6%) experienced acute rejection. The median Cylex ATP value in infant PLTs post-surgery reduced significantly in infection group compared to stable group (median, 137 vs. 269 ng/mL, P<0.001). Receiver operating characteristic (ROC) curve analysis determined that the cut-off value of Cylex ATP was 152 ng/mL in diagnosis of infection [area under the curve (AUC): 0.784, 95% CI: 0.720-0.848]. Meanwhile, Cylex ATP value showed no correlation to tacrolimus dosage, blood concentration, dose-normalized concentration/dose ratio or Kaup index. However, it tended to correlate weakly with the white blood cell (WBC) number (R =0.462, P<0.0001) and lymphocyte counts (R =0.363, P<0.0001).

CONCLUSIONS

In this study, we demonstrated that low Cylex ATP represented partly over-immunosuppression and had diagnostic value in infant PLTs with infections, which might assist individualized immunosuppression in PLT patients.

Survival and Complication of Liver Transplantation in Infants: A Systematic Review and Meta-Analysis

Background: Modern surgical techniques and scientific advancements have made liver transplant (LT) in infants feasible. However, there are only a small number of studies examining the short- as well as long-term outcomes of LT in this vulnerable subset of children. Methods: Comprehensive searches were done systematically through the PubMed, Scopus, and Google scholar databases. Studies that were retrospective record based or adopted a cohort approach and reported either patient survival rates or graft survival rates or complications of LT in infants were included in the meta-analysis. Statistical analysis was done using STATA version 13.0. Results: A total of 22 studies were included in the meta-analysis. The overall pooled patient survival rate at 1 year, >1-5 years, and >5 years post-transplantation was 85% (95% CI: 78--92%), 71% (95% CI: 59-83%), and 80% (95% CI: 69-91%), respectively. The overall pooled graft survival rate at 1 year, >1-5 years, and >5 years post-transplantation was 72% (95% CI: 68-76%), 62% (95% CI: 46-78%), and 71% (95% CI: 56-86%), respectively. The overall pooled rate for vascular complications, need for re-transplantation, biliary complications, and infection/sepsis was 12% (95% CI: 10-15%), 16% (95% CI: 12-20%), 15% (95% CI: 9-21%), and 50% (95% CI: 38-61%), respectively. Conclusion: The current meta-analysis showed modest patient and graft survival rates for infant liver transplantation. However, the complication rates related to infection/sepsis were high. More comprehensive evidence is required from studies with larger sample sizes and a longer duration of follow-up.

Liver Transplantation in Children: An Overview of Organ Allocation and Surgical Management

Liver transplantation is the standard treatment for children with end-stage liver disease, primary hepatic neoplasms, or liver-localized metabolic defects. Perioperative mortality is almost absent, and long-term survival exceeds 90%. Organ shortage is managed thanks to advances in organ retrieval techniques; living donation and partial liver transplantation almost eliminated waiting list mortality, thus leading to expanding indications for transplantation. The success of pediatric liver transplantation depends on the prompt and early referral of patients to transplant Centers and on the close and integrated multidisciplinary collaboration between pediatricians, hepatologists, surgeons, intensivists, oncologists, pathologists, coordinating nurses, psychologists, and social workers.

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.

High Intrapatient Variability in Tacrolimus Exposure Is Not Associated With Immune-mediated Graft Injury After Liver Transplantation

BACKGROUND

A high intrapatient variability (IPV) in tacrolimus exposure is associated with impaired long-term clinical outcome after kidney transplantation. It remains to be determined if this is equally detrimental for liver transplant recipients. The objective of this study was to investigate the association between IPV in tacrolimus exposure and immune-mediated graft injury after liver transplantation.

METHODS

For 326 liver transplant recipients, transplanted between 2000 and 2015, tacrolimus IPV was calculated from at least 5 tacrolimus trough samples obtained between months 6 and 18 after liver transplantation and expressed as the coefficient of variation. Primary composite endpoint consisted of immune-mediated graft injury (chronic rejection, biopsy proven, and suspected late acute rejection) after month 6. Secondary outcomes were the association between tacrolimus IPV on (1) loss of renal function per year of follow-up and (2) cytomegalovirus viremia after month 6.

RESULTS

Of the 326 included liver transplant recipients, 70 patients (21.5%) reached the primary endpoint. Median tacrolimus coefficient of variation was 28%. There was no significant difference in reaching the primary composite endpoint between the low- and high-IPV groups (P = 0.068). Model for End-Stage Liver Disease score pretransplantation and the number of acute rejections were identified as independent predictors for immune-mediated graft injury (P = 0.049 and 0.016). A higher IPV in combination with a low kidney function at baseline (estimated glomerular filtration rate < 40 mL/min) was associated with greater loss of renal function per year of follow-up (P = 0.007). Tacrolimus variability was not associated with late cytomegalovirus viremia.

CONCLUSIONS

High IPV in tacrolimus exposure beyond month 6 postliver transplantation was not associated with immune-mediated graft injury.

Clinical characteristics of emergency surgery patients infected with coronavirus disease 2019 (COVID-19) pneumonia in Wuhan, China

Background

We aimed to investigate clinical symptoms and epidemiologic features of emergency surgery patients infected with the 2019 novel coronavirus disease (COVID-19). More than 5 million people worldwide have been diagnosed with COVID-19 since December 2019 to the time of this publication. Thousands of emergency operations have been carried out since December 2019. To date, however, no literature has focused on the clinical symptoms of emergency surgery patients with COVID-19 pneumonia.

Methods

We conducted a retrospective cohort study of 164 emergency surgery patients with or without COVID-19 pneumonia in Zhongnan Hospital of Wuhan University in Wuhan, China, from January 1, 2020, to January 20, 2020. For this report, the final date of follow-up was February 5, 2020. The associated clinical, laboratory, epidemiologic, demographic, radiologic, and outcome data were collected and analyzed.

Results

Of the 164 emergency surgery patients, the median age was 41 years (interquartile range, 29–89), and 136 (82.9%) were women. The associated main clinical symptom included fever (93 [56.7%])，dry cough (56 [34.2%]), fatigue (86 [52.4%]), nausea (78 [47.6%]), and dizziness (77 [47%]). Of 54 emergency surgery patients infected with COVID-19, the median age was 46 years (interquartile range: 25–89), and 45 (83.3%) were women. The pathologic clinical symptoms investigated included fever (54 [100%]), fatigue (48 [88.9%]), nausea (52 [96.3%]), dizziness (46 [85.2%]), and dry cough (44 [81.5%]). The lymphopenia (0.37 × 10⁹/L [interquartile range: 0.23-0.65]) and increased C-reactive protein (24.7 × 10⁹/L [interquartile range: 13.57-38]) were observed. The preoperative fever and postoperative fever in emergency surgery patients with or without COVID-19 pneumonia were analyzed in this study. Of 54 emergency surgery patients with COVID-19, 15 (27.8%) showed preoperative fever, 54 (100%) had postoperative fever. Of 110 emergency surgery patients without COVID-19, 5 (4.5%) had preoperative fever, 31 (28.2%) patients had postoperative fever. In emergency surgery patients with COVID-19, the fever lasted more than 7 days, markedly exceeded the length of time non–COVID-19 patients experienced fever (approximately 3 days). Furthermore, 43 health care workers were exposed to emergency surgery patients with COVID-19 pneumonia and were infected with COVID-19 pneumonia.

Conclusion

In our study, the clinical symptoms of emergency surgery patients infected with COVID-19 displayed marked differences from those reporting common COVID-19 pneumonia. In addition, the health care workers were suspected to have been exposed to a great risk when caring for emergency surgery patients with COVID-19 pneumonia. Management guidelines of emergency surgery patients are described in in this report.

Health-Related Quality of Life in Pediatric Liver Transplant Recipients

BACKGROUND

Health-related quality of life (HRQoL) of liver transplantation (LT) recipients has been widely studied because of increased patient longevity. However, studies in developing countries are scanty. We aimed to evaluate psychometric properties of the Thai version of the PedsQL Transplant Module and used it to determine the HRQoL in LT children.

METHODS

We included children aged 2 to 18 years who underwent LT more than 1 year previously. The phase 1 study included a cognitive interview with 20 LT children and their parents using the Thai version of PedsQL Transplant Module and revised the module accordingly. Then, the finalized version was evaluated for psychometric properties in 50 LT children. In phase 2, HRQoL was evaluated in 52 LT children who did not participate in the phase 1 study.

RESULTS

In the Thai PedsQL Transplant Module, both parent report and child self-report had good internal consistency (α = 0.94 and 0.93, respectively) and substantial reliability (interclass correlation coefficient = 0.82 and 0.77, respectively). Median HRQoL scores from the parent report and child self-report were 80 (interquartile range [IQR], 70, 88) and 77 (IQR, 71, 88), respectively. From the parent report, lower HRQoL was associated with opportunistic viral infection (P = .004) and correlated with a greater number of immunosuppressive agents (ρ = -0.346, P = .014). However, none of these factors were significant according to the child self-report.

CONCLUSIONS

The Thai PedsQL Transplant Module has satisfactory psychometric properties. Post-LT children have good HRQoL. To improve their HRQoL, specific attention should be focused on managing viral infection and optimizing immunosuppressive therapy.

Etiology of liver dysfunction after liver transplantation in children with metabolic disorders

AIM

It has been reported that the long-term outcome for children with metabolic disorders after liver transplantation (LT) is excellent. However, there are several reports citing LT patients with metabolic disorders developing liver dysfunction early after LT. We examined the pathogenesis of liver dysfunction observed after LT in recipients with metabolic disorders at the National Center for Child Health and Development.

METHODS

Of 106 children (aged <18 years) with metabolic disorders who underwent LT at our center, 36 patients who underwent liver biopsy within 60 days after LT were enrolled. The underlying diseases were urea cycle disorders (14 patients), methylmalonic acidemia (11 cases), Wilson's disease (3 patients), mitochondrial hepatopathy (3 patients), and others (5 patients). The median age was 1 year 2 months at LT. The reasons for biopsy were liver dysfunction (31 patients) and ascites (5 patients).

RESULTS

The main findings of graft liver biopsy were diffuse steatosis (21 patients), rejection (8 patients), infection (3 patients), and others (4 patients). Of 21 patients who received graft biopsy showing steatosis, all the donor livers originally showed no steatosis or only mild steatosis. The liver function improved immediately after biopsy in 18 of 21 patients that showed diffuse steatosis.

CONCLUSIONS

The major cause of liver dysfunction after LT in recipients with metabolic disorders was steatosis and the risk of rejection was low. It is important to take a liver biopsy and examine the cause of liver dysfunction to avoid administration of excess immunosuppressant, and select the right therapy for recipients with metabolic disorders.

Efficacy of Antithymocyte Globulin Treatment for Severe Centrilobular Injury Following Pediatric Liver Transplant: Clinical Significance of Monitoring Lymphocyte Subset

OBJECTIVES

Central perivenulitis can occur in association with T-cell-mediated rejection and can sometimes require strong immunosuppressant therapy as refractory rejection. Furthermore, patients with central perivenulitis are more likely to have subsequent episodes of T-cell-mediated rejection and develop chronic rejection than those without central perivenulitis. We retrospectively analyzed clinical data of pediatric patients with episodes of T-cell-mediated rejection according to severity of central perivenulitis and monitored HLA-DR-positive CD8-positive T cells and recent thymic emigrants during treatment for T-cell-mediated rejection.

MATERIALS AND METHODS

We identified biopsy-proven T-cell-mediated rejection in 50 liver transplant recipients (45 with living-related donors, 5 with deceased donors) between September 2014 and August 2018. Lymphocyte subsets in peripheral blood samples were analyzed.

RESULTS

Of 50 pediatric patients, 30 were boys and 20 were girls (median age at transplant of 1.1 y; interquartile range, 0.6-6.2 y). Central perivenulitis was found in 46 patients (92%), which was mild in 13, moderate in 16, and severe in 17. Antithymocyte globulin was more frequently administered to patients with severe central perivenulitis than others (P < .05). Patients with antithymocyte globulin treatment were less likely to have subsequent episodes of T-cell-mediated rejection than those without this treatment (P < .05). The absolute number of CD8-positive HLA-DR-positive T cells in patients during treatment was significantly higher than in control patients (P < .05). The absolute number of recent thymic emigrants in patients with active infection was significantly lower than in patients without infection (P < .05).

CONCLUSIONS

Our results suggest the efficacy and safety of antithymocyte globulin for treating T-cell-mediated rejection with severe central perivenulitis in pediatric liver transplant recipients and suggest that antithymocyte globulin can prevent subsequent episodes of T-cell-mediated rejection. Analyzing lymphocyte subsets during treatment for rejection may help highlight viable therapeutic strategies for achieving a good outcome.

Contemporary management of hepatoblastoma

PURPOSE OF REVIEW

Hepatoblastoma is the most common primary pediatric liver malignancy. The goal of treatment in hepatoblastoma is complete surgical resection. Recently published multinational collaborative studies are better defining risk factors for disease recurrence and guide optimal treatment strategy.

RECENT FINDINGS

Successful margin-negative resection of hepatoblastoma is dependent on the location and extent of disease as defined by the PRETEXT classification. Liver transplantation is an appropriate treatment modality when complete oncological resection requires total hepatectomy. In general, advanced PRETEXT class as well as histologic features, age at presentation, tumoral production of α-feto protein and the presence of metastatic disease adversely affect outcome. Hepatoblastoma is chemosensitive and significant downstaging can occur with the use of neoadjuvant chemotherapy allowing for less extensive hepatectomy. In addition, patients at moderate-to-high risk of postresection recurrence should receive neoadjuvant chemotherapy. Cisplatin-based chemotherapy can allow for resection of transplantation of patients with metastatic disease when complete metasatectomy can be achieved albeit with inferior results.

SUMMARY

Treatment of hepatoblastoma with surgical resection or liver transplantation is associated with excellent long-term results in the setting of modern chemotherapy.

Impact of EBV infection and immune function assay for lymphoproliferative disorder in pediatric patients after liver transplantation: A single-center experience

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is a lethal complication after pediatric liver transplantation, but information regarding risk factors for the development of PTLD remains unclear. This study was to identify characteristics and risk factors of PTLD.

METHODS

A total of 705 pediatric patients who underwent liver transplantation between January 2017 and October 2018 were studied. Impact of clinical characteristics and Epstein-Barr virus (EBV) infection on the development of PTLD was evaluated. In addition, ImmuKnow assay was adopted in partial patients to analyze the immune status.

RESULTS

Twenty-five (3.5%) patients suffered from PLTD with a median time of 6 months (3-14 months) after transplantation. Extremely high tacrolimus (TAC) level was found in 2 fatal cases at PTLD onset. EBV infection was found in 468 (66.4%) patients. A higher peak EBV DNA loads (>9590 copies/mL) within 3 months was a significant indicator for the onset of PTLD. In addition, the ImmuKnow assay demonstrated that overall immune response was significantly lower in patients with EBV infection and PTLD (P<0.0001). The cumulative incidence of PTLD was also higher in patients with lower ATP value (≤187 ng/mL, P<0.05).

CONCLUSIONS

A careful monitoring of EBV DNA loads and tacrolimus concentration might be supportive in prevention of PTLD in pediatric patients after liver transplantation. In addition, application of the ImmuKnow assay may provide guidance in reducing immunosuppressive agents in treatment of PTLD.