Outcomes of Pediatric Liver Transplantation in Glycogen Storage Disease Type 1b-A Single-Center Experience.

BACKGROUND: Liver transplantation (LT) normalizes fasting tolerance in glycogen storage disease type (GSD) 1b. However, reported outcomes post-LT with respect to correction of neutropenia, infection risk and growth are varied. Sodium-glucose cotransporter-2 (SGLT2) inhibitors have been recently shown to improve neutropenia in GSD1b patients. METHODS: In this single-center retrospective study, we reviewed all children who underwent LT for GSD1b. Neutropenia, dose of granulocyte colony-stimulating factor (G-CSF), unplanned hospital attendance, anthropometrics, graft rejection, survival, and the effects of dapagliflozin were analyzed. Data from protocol biopsies obtained at 1, 5, and 10 years post-LT and immunosuppression levels were collected. RESULTS: Eight children (6 female), all on G-CSF pre-transplant, underwent cadaveric LT for GSD1b at median age 3.6 years (IQR 3.3-5.1) with mean follow-up time of 10.3 years (95% CI 7.5-13.1). Neutrophil count and G-CSF requirement did not improve post-LT. Although a reduction in unplanned hospital attendance due to infection (0.98 [95% CI 0.76-1.26] vs. 0.49 [95% CI 0.41 to 0.57] per person-year, p < 0.01) was observed, gastrointestinal complaints and graft dysfunction accounted for a similar hospitalization burden pre- versus post-LT. Body mass index (BMI) reduced post-LT (Z-score 1.47 [95%CI 0.39-2.23] vs. 0.56 [95% CI -0.74 to 1.45], p = 0.02), with no significant change in height. Although all children and grafts have survived, 75% of recipients developed rejection, despite adequate immunosuppression levels, with two children having been found to have developed significant fibrosis on their 5-year protocol biopsy. Although dapagliflozin allowed cessation of G-CSF, no improvement in neutrophil count was observed. Despite this, a reduction in gastrointestinal and infection-related morbidity was noted following dapagliflozin. CONCLUSION: Although LT normalizes fasting tolerance in GSD1b and reduces hospital attendance due to infection, morbidity from infection and gastrointestinal manifestations persist. Children in our cohort experienced high rates of rejection necessitating titration of immunosuppression to balance risk of infection against organ rejection. Future studies should investigate whether early introduction of SGLT2 inhibitors post-LT impact morbidity in this group.

Management of paediatric monomorphic post-transplant lymphoproliferative disorders with low-intensity treatment: A multicentre international experience.

BACKGROUND: Monomorphic post-transplant lymphoproliferative disorder (mPTLD) is a major cause of morbidity/mortality following solid organ transplant (SOT), with infection, mPTLD progression and organ rejection presenting equal risks. Balancing these risks is challenging, and the intensity of therapy required by individual patients is not defined. Although an increasing body of evidence supports the use of a stepwise escalation of therapy through reduction in immunosuppression (RIS) to rituximab monotherapy and low-dose chemo-immunotherapy, many centres still use B-cell non-Hodgkin lymphoma (B-NHL) protocols, especially when managing Burkitt/Burkitt-like (BL) PTLD. This study sought to define outcomes for children managed in the UK or Spanish centres using low-intensity first-line treatments. PROCEDURE: Retrospective data were anonymously collected on patients younger than 18 years of age, with post-SOT mPTLD diagnosed between 2000 and 2020. Only patients given low-intensity treatment at initial diagnosis were included. RESULTS: Fifty-six patients were identified. Age range was 0.9-18 years (median 10.7). Most (62.5%) had early-onset PTLD. Haematopathological analysis showed 75% were diffuse large B-cell like, 14.3% were BL and nine of 33 (27%) harboured a MYC-rearrangement. Stage III-IV disease was present in 78.6%. All but one had RIS, 26 received rituximab monotherapy and 24 low-dose chemo-immunotherapy, mostly R-COP. Intensified B-NHL chemotherapy was required in 10/56 (17.9%). There were a total of 13 deaths in this cohort, three related to PTLD progression. The 1-year overall survival (OS), event-free survival (EFS) and progression-free survival (PFS) were 92.8%, 78.6% and 80.2%, respectively. CONCLUSIONS: R-COP provides an effective low-dose chemotherapy option. Escalation to more intensive therapies in the minority of inadequately controlled patients is an effective strategy.

Endoscopic Surveillance of the Intestinal Allograft: Recommendations From the Intestinal Rehabilitation and Transplant Association Working Group.

Intestinal transplant (ITx) rejection lacks a reliable noninvasive biomarker and rejection surveillance relies on serial endoscopies and mucosal biopsies followed by histologic assessment. Endoscopic biopsies are also essential for identifying other ITx-related complications such as infectious, allergic, and inflammatory graft enteritis as well as post-transplant lymphoproliferative disease or graft versus host disease. In spite of its central role in ITx, published guidelines on endoscopy and biopsy are lacking and significant variability between centers in terms of timing and technical performance exists. Therefore, an international expert group convened and discussed several aspects related to the surveillance endoscopy after ITx with the aim to summarize and standardize its practice. This article summarizes these considerations on endoscopic ITx monitoring and highlights practices of surveillance and for-cause endoscopy, biopsy techniques, pathologic evaluation, potential risks and complications, outsourcing, and less-invasive monitoring techniques.

Intestinal ultrasound may be a useful tool in monitoring acute rejection following intestinal transplantation.

BACKGROUND: Acute rejection is the leading cause of mortality and morbidity for children following intestinal transplantation. Rapid detection and prompt treatment are critical; however, the only reliable method of diagnosis and monitoring is endoscopic graft biopsies. The required regular anesthetics are particularly problematic in children, and non-invasive strategies are needed. METHODS: We describe the intestinal ultrasound findings of three children before and after treatment for rejection. Ultrasounds were performed within 24 h of endoscopically obtained biopsies which were used to establish a diagnosis of rejection and to define severity. A single sonographer performed the ultrasounds and was blinded to biopsy results at the time of the scanning. These findings are provided in the context of the ultrasound appearance of seven children who had no features of rejection on surveillance biopsies. RESULTS: Intestinal ultrasound demonstrated increased bowel wall thickness, vascularity, and mesenteric inflammation during moderate to severe rejection episodes. The submucosal layer was particularly thickened, which may represent a finding more specific for rejection. All patients demonstrated improvement in all quantitative ultrasound features correlating with the resolution of acute cellular rejection on histology. Patients with no evidence of rejection on biopsy had a bowel wall thickness range of 0.9-2.8 mm, suggesting a normal upper limit of 3 mm. CONCLUSION: Moderate and severe acute rejection may be detected and response to treatment can be monitored by intestinal ultrasound and, correlating with clinical improvement, can aid in follow-up.

Acute Hepatitis of Unknown Etiology Among Young Children: Research Agenda by the ESPGHAN Hepatology Committee.

In April 2022, an increased incidence of acute hepatitis cases of unknown etiology among previously healthy children across the United Kingdom was described. Since, more than 270 cases from the United Kingdom and hundreds more from all across the world have been reported. The majority of affected children were younger than 6 years of age. The clinical presentation was nonspecific with diarrhea and vomiting usually preceding the appearance of jaundice, abdominal pain, nausea, and malaise. Approximately 5% have required liver transplantation. An infectious etiology has been considered likely given the epidemiological and clinical features of the reported cases. Between 50 and 60% of the children tested were diagnosed with adenovirus infection although a clear etiological connection has still to be demonstrated. No link with SARS-CoV-2 infection and COVID-19 vaccine was found. What is not clear to date is whether the high number of acute hepatitis cases reported is related to a true increase in incidence or heightened awareness following on from the initial reports from the United Kingdom. The Hepatology Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) developed a paper on the current outbreak of acute hepatitis of unknown etiology recognizing its importance and the need of approaching the current situation with a scientifically rigorous approach. The aims of the article are to summarize the current knowledge and to identify the most pertinent issues regarding the diagnosis and management of this condition and the research questions raised.

Clinical Spectrum of Children with Acute Hepatitis of Unknown Cause.

BACKGROUND: Since January 2022, there has been an increase in reports of cases of acute hepatitis of unknown cause in children. Although cases have been reported across multiple continents, most have been reported in the United Kingdom. Investigations are ongoing to identify the causative agent or agents. METHODS: We conducted a retrospective study involving children referred to a single pediatric liver-transplantation center in the United Kingdom between January 1 and April 11, 2022. These children were 10 years of age or younger and had hepatitis that met the case definition of the U.K. Health Security Agency for confirmed acute hepatitis that was not hepatitis A through E and did not have a metabolic, inherited or genetic, congenital, or mechanical cause, in the context of a serum aminotransferase level greater than 500 IU per liter. We reviewed medical records and documented demographic characteristics, clinical features, and results of liver biochemical, serologic, and molecular tests for hepatotropic and other viruses, as well as radiologic and clinical outcomes. The outcomes were classified as an improving condition, liver transplantation, or death. RESULTS: A total of 44 children had hepatitis that met the confirmed case definition, and most were previously healthy. The median age was 4 years (range, 1 to 7). Common presenting features were jaundice (in 93% of the children), vomiting (in 54%), and diarrhea (in 32%). Among the 30 patients who underwent molecular testing for human adenovirus, 27 (90%) were positive. Fulminant liver failure developed in 6 patients (14%), all of whom received a liver transplant. None of the patients died. All the children, including the 6 who received liver transplants, were discharged home. CONCLUSIONS: In this series involving 44 young children with acute hepatitis of uncertain cause, human adenovirus was isolated in most of the children, but its role in the pathogenesis of this illness has not been established.

Bridging Liver Transplantation in the Treatment of Intestinal Failure Associated Liver Disease in Infants-A Bridge Too Far?

Infants with intestinal failure associated liver disease (IFALD) requiring liver and bowel transplant have a high mortality on the transplant waiting list due to the scarcity of the size-matched donor organs. Bridging liver transplantation has been used to allow the children to grow to a reasonable size so that a combined liver and small bowel transplant could be performed in the future. We report on two children with irreversible intestinal failure (ultra-short bowel syndrome secondary to gastroschisis and microvillous inclusion disease) with IFALD who underwent bridging liver transplantation at our institution. Both patients made a good recovery from their initial surgery. One patient died 6 months following surgery from generalized sepsis, and the other patient survived in good condition to undergo a combined liver and small bowel transplant but died a few days post-transplant. In the current era of scarcity of donor organs, this raises an ethical dilemma for the team involved regarding appropriate utilisation of a scarce resource.

Cystic fibrosis associated liver disease in children.

Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CF transmembrane conductance regulator gene. CF liver disease develops in 5%-10% of patients with CF and is the third leading cause of death among patients with CF after pulmonary disease or lung transplant complications. We review the pathogenesis, clinical presentations, complications, diagnostic evaluation, effect of medical therapies especially CF transmembrane conductance regulator modulators and liver transplantation in CF associated liver disease.

Physical Growth of Patients with Hereditary Tyrosinaemia Type I: A Single-Centre Retrospective Study.

In a retrospective review, we aimed to assess long-term growth in 17 patients (n = 11 males) with hereditary tyrosinaemia type I (HTI). Median age at assessment was 15.6 years (5.7-26.6 years) and median age at diagnosis was 1 month (range: 0-16 months), with 35% (n = 6/17) symptomatic on presentation. From the age of 8 years, there was a noticeable change in median height, weight, and body-mass-index [BMI]-z-scores. Median height-for-age z-scores were consistently ≤ -1 (IQR -1.6, -0.5) during the first 8 years of life but increased with age. Weight-for-age z-scores ranged between -1 to 0 (IQR -1.2, 0.1) in the first 8 years; then increased to > 0.5 (IQR -0.3, 1.3) by age 16 years, and BMI-for-age z-scores ranged from 0 to 1 (IQR -0.7, 1.3) up to 8 years, and >1 (IQR -0.2, 1.9) until 16 years. The percentage of overweight and obesity was lowest in children aged < 5 years, and consistently > 40% in patients aged between 7 to 16 years. The prescribed total protein intake was associated with improved height growth (p < 0.01). Impaired growth in early life improved with age achieving normal population standards. Further studies are needed to investigate factors that influence growth outcome in HTI patients.

Clinical management of sickle cell liver disease in children and young adults.

Liver involvement in sickle cell disease (SCD) is often referred to as sickle cell hepatopathy (SCH) and is a complication of SCD which may be associated with significant mortality. This review is based on a round-table workshop between paediatric and adult hepatologists and haematologists and review of the literature. The discussion was prompted by the lack of substantial data and guidance in managing these sometimes very challenging cases. This review provides a structured approach for the diagnosis and management of SCH in children and young adults. The term SCH describes any hepatobiliary dysfunction in the context of SCD. Diagnosis and management of biliary complications, acute hepatic crisis, acute hepatic sequestration and other manifestations of SCH are discussed, as well as the role of liver transplantation and haemopoietic stem cell transplantation in the management of SCH.

An uncommon cause of early infantile liver disease and raised chitotriosidase.

Our subject presented at 11 months of age, following a varicella zoster infection, with acute on chronic liver disease and was found to have raised serum chitotriosidase. White cell enzyme analysis for Gaucher, Niemann Pick A, B and lysosomal acid lipase deficiency were normal. Niemann Pick type C (NPC) disease was considered as a provisional diagnosis and liver transplantation assessment deferred until recovery from varicella and results of mutational analysis of NPC gene were available. Liver biopsy at a later date showed findings suggestive of glycogen storage disease (GSD) type IV but he was too unstable for an urgent liver transplantation and sadly passed away at the age of 13 months. The classic hepatic subtype of glycogen storage disorder type IV (GSD IV) is a rare metabolic cause of early-onset liver disease and raised chitotriosidase. There are very few reports of raised chito in GSD IV. Liver transplantation has a favourable outcome for the hepatic subtype of GSD IV and early diagnosis in our subject could have potentially altered the outcome.

Natural Protein Tolerance and Metabolic Control in Patients with Hereditary Tyrosinaemia Type 1.

In a longitudinal retrospective study, we aimed to assess natural protein (NP) tolerance and metabolic control in a cohort of 20 Hereditary Tyrosinaemia type I (HTI) patients. Their median age was 12 years ([3.2-17.7 years], n = 11 female, n = 8 Caucasian, n = 8 Asian origin, n = 2 Arabic and n = 2 Indian). All were on nitisinone (NTBC) with a median dose of 0.7 g/kg/day (range 0.4-1.5 g/kg/day) and were prescribed a tyrosine (Tyr)/phenylalanine (Phe)-restricted diet supplemented with Tyr/Phe-free L-amino acids. Data were collected on clinical signs at presentation, medical history, annual dietary prescriptions, and blood Phe and Tyr levels from diagnosis until transition to the adult service (aged 16-18 years) or liver transplantation (if it preceded transition). The median age of diagnosis was 2 months (range: 0 to 24 months), with n = 1 diagnosed by newborn screening, n = 3 following phenylketonuria (PKU) screening and n = 7 by sibling screening. Five patients were transplanted (median age 6.3 years), and one died due to liver cancer. The median follow-up was 10 years (3-16 years), and daily prescribed NP intake increased from a median of 5 to 24 g/day. Lifetime median blood Tyr (370 µmol/L, range 280-420 µmol/L) and Phe (50 µmol/L, 45-70 µmol/L) were maintained within the target recommended ranges. This cohort of HTI patients were able to increase the daily NP intake with age while maintaining good metabolic control. Extra NP may improve lifelong adherence to the diet.

Atypical malignancies after intestinal transplantation in children: A European single-centre experience.

BACKGROUND: Post-transplant malignancies, that is, lymphomas, are a recognized complication in intestinal transplant recipients but are mostly secondary to EBV infection. There is an increased risk for malignancies in unusual sites in intestinal transplant recipients as compared to other solid organ transplants and the general population. OBJECTIVE: To evaluate the incidence, course, and outcome of unusual malignancies in children after ITx. METHODS: Retrospective analysis of children who underwent ITx for primary digestive disorders at Birmingham Children's Hospital between January 1989 and December 2017. RESULTS: Ninety-eight intestinal transplants were performed in 90 children (49 males and 41 females) with an underlying primary digestive disorder. Median age was 2.7 years (0.6-16.2), and median weight was 14.5 kg (5.7-53.2) at the time of transplant. Within this cohort, we identified four cases of unusual malignancies at rare sites of presentation. One patient developed cerebral PTLD, two patients were diagnosed with SMT, located at the stomal orifice and in cervicothoracic paravertebral area, respectively, and the last patient developed a retroperitoneal angiosarcoma. Unfortunately, the overall patient outcome was poor in all but one child with SMT, who currently survives with cytotoxic T-cell therapy. CONCLUSION: Unusual malignancies can occur in approximately 5% of children following ITx. A high index of suspicion is required for a timely diagnosis and adequate treatment.

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

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

Comparison of Clinical Features and Outcome of Pediatric Posttransplant Lymphoproliferative Disorder in Recipients of Small Bowel Allograft Versus Isolated Liver Transplantation.

BACKGROUND: Higher incidence of posttransplant lymphoproliferative disorder (PTLD) is reported in the pediatric small bowel transplant (SBTx) population, which may be associated with more aggressive disease and poorer outcome as compared to liver transplant (LTx) recipients. We aim to compare the characteristics and outcome of PTLD in pediatric SBTx against LTx patients at a single center. METHODS: Retrospective review of pediatric SBTx and LTx patients diagnosed with PTLD from 1989 to 2016 was conducted. Diagnosis of PTLD was biopsy-proven based on World Health Organization histologic criteria. Treatment protocol consisted of reduction of immunosuppression (RIS), rituximab (from 2000), cytotoxic T-lymphocyte (CTL) therapy (available in 1999-2004 and from 2011), and chemotherapy. RESULTS: Thirty-seven PTLD patients were included following LTx (n = 23, incidence = 2.8%) and SBTx (n = 14, incidence = 14.9%). Monomorphic PTLD made up 64% of SBTx and 43% of LTx cases. RIS alone resulted in remission in 50% of LTx patients but none of the SBTx patients (P = 0.002). Poorer overall remission (57% versus 96%, P = 0.004), 2-year (46% versus 91%, P = 0.003), and 5-year survival rates (39% versus 90%, P = 0.002) were observed in the SBTx group. Risk factors associated with mortality following PTLD were SBTx (odds ratio [OR], 12.00; 95% confidence interval [CI], 2.34-61.45; P = 0.003), monomorphic histology (OR, 10.63; 95% CI, 1.88-60.25; P = 0.008), multisite involvement (OR, 6.38; 95% CI, 1.35-30.14; P = 0.019), and tumor involvement of allograft (OR, 5.33; 95% CI, 1.14-24.90; P = 0.033). Introduction of CTL therapy was associated with improved survival. CONCLUSIONS: Majority of PTLD following pediatric SBTx are of monomorphic subtype and associated with poorer outcome as compared to LTx patients. RIS is inadequate as a single strategy in managing PTLD in SBTx and prompt escalation to rituximab and CTL is recommended.

Hypogammaglobulinemia and bacterial infections following pediatric post-transplant lymphoproliferative disorder in the rituximab era.

INTRODUCTION: Treatment of PTLD using immune-depleting agents such as RTX may be associated with increased risk of infections. The aim of this report was to describe the incidence of hypogammaglobulinemia and bacterial infections in children with PTLD after SOT at a single center since the introduction of RTX. METHODS: A retrospective review was conducted over a study period of 2000-2016 in pediatric patients diagnosed with biopsy-proven PTLD based on the WHO histologic criteria. Hypogammaglobulinemia was defined by serum IgG <4 g/L; CPBI was defined by clinically significant infection by an identified pathogenic bacteria isolated from a normally sterile body site. RESULTS: Twenty-eight patients were included, comprising 16 LTx and 12 ITx patients, and 17 patients received RTX therapy. Total of 31 episodes of CPBI occurred in 16 patients. Incidence of CPBI was 31.4 infections per 100 patient-years in RTX-treated patients, as compared to 8.4 infections per 100 patient-years in non-RTX-treated patients (P < 0.001). Hypogammaglobulinemia was significantly more prevalent after 6 months (P = 0.001) and 2 years (P = 0.005) in RTX-treated patients, as compared to none in the group that did not receive RTX. Hypogammaglobulinemia (P = 0.047), ITx (P = 0.027), and monomorphic PTLD (P = 0.024) were significantly associated with recurrent (≥2) CPBI and/or CPBI-related deaths within the first year post-PTLD. CONCLUSION: While RTX is an effective treatment for PTLD, hypogammaglobulinemia can persist for up to 2 years following RTX therapy, which may be associated with the higher cumulative rates of CPBI observed in RTX-treated patients.

Cytotoxic T-lymphocyte therapy for post-transplant lymphoproliferative disorder after solid organ transplantation in children.

EBV-CTL immunotherapy targets EBV antigens expressed by tumor cells in PTLD. Data on outcome of EBV-CTL in pSOT patients are limited. The aim of the study is to describe our experience with allogeneic, third-party EBV-CTL for the treatment of PTLD in pSOT patients in a single tertiary center. Retrospective review was performed of all pSOT patients who received EBV-CTL for PTLD. PTLD was diagnosed using World Health Organization histologic criteria. EBV-CTLs were derived from human leukocyte antigen-typed, EBV-seropositive third-party donors, and cryopreserved and maintained by an accredited national blood transfusion service. Ten patients received EBV-CTL for histologically proven PTLD from 1999 to 2016 following liver (n=5), combined intestinal/liver (n=4), and liver/kidney (n=1) transplantation. PTLD occurred at median age of 40 months (range: 12-144) and median post-transplant interval of 8 months (range: 2-107). Seven had monomorphic, two had polymorphic, and one had Hodgkin-type PTLD. All were of B-cell origin and EBV-positive on histology. EBV-CTL achieved an overall remission rate of 80% (8 of 10). Transient adverse effects included fever, tachycardia, and vomiting. None developed graft-versus-host disease or opportunistic infections. EBV-CTL is an effective treatment for PTLD in pSOT patients, with good remission rate and minimal toxicity.

Intestinal Failure in Children.

Children with intestinal failure have had improved survival, particularly those with extreme short bowel syndrome, over the last 10-15 y. This has been attributed to better understanding of the pathophysiology of intestinal failure, improvement in line care, recognition of the importance of a team approach as well as the progress of intestinal transplant as a viable option. Parenteral nutrition remains the cornerstone for the continual survival of these patients. This review will cover contemporary approaches to intestinal failure including post surgical approaches, non-transplant surgery, dietetic and medication approaches during the adaptation process, considerations for home parenteral nutrition and latest in intestinal transplantation.

Fixed dilated pupils and tacrolimus toxicity in paediatric liver transplant patients.

We report a case series of four children who developed fixed dilated pupils associated with high tacrolimus levels (>30 nanograms/millilitre [ng/mL]) in the immediate post-operative period following isolated liver or liver and small bowel transplantation.