UNC45A deficiency causes microvillus inclusion disease-like phenotype by impairing myosin VB-dependent apical trafficking

Variants in the UNC45A cochaperone have been recently associated with a syndrome combining diarrhea, cholestasis, deafness, and bone fragility. Yet the mechanism underlying intestinal failure in UNC45A deficiency remains unclear. Here, biallelic variants in UNC45A were identified by next-generation sequencing in 6 patients with congenital diarrhea. Corroborating in silico prediction, variants either abolished UNC45A expression or altered protein conformation. Myosin VB was identified by mass spectrometry as client of the UNC45A chaperone and was found misfolded in UNC45AKO Caco-2 cells. In keeping with impaired myosin VB function, UNC45AKO Caco-2 cells showed abnormal epithelial morphogenesis that was restored by full-length UNC45A, but not by mutant alleles. Patients and UNC45AKO 3D organoids displayed altered luminal development and microvillus inclusions, while 2D cultures revealed Rab11 and apical transporter mislocalization as well as sparse and disorganized microvilli. All those features resembled the subcellular abnormalities observed in duodenal biopsies from patients with microvillus inclusion disease. Finally, microvillus inclusions and shortened microvilli were evidenced in enterocytes from unc45a-deficient zebrafish. Taken together, our results provide evidence that UNC45A plays an essential role in epithelial morphogenesis through its cochaperone function of myosin VB and that UNC45A loss causes a variant of microvillus inclusion disease.

What are the clues for an inherited metabolic disorder in Reye syndrome? A single Centre study of 58 children

OBJECTIVES

Reye Syndrome is an acute encephalopathy with increased liver enzymes and blood ammonia, without jaundice. The prevalence of an underlying inherited metabolic disorder (IMD) is unclear, nor the clinical or biological factors directing toward this diagnosis. Our aims were to define these clues in a large series of patients.

PATIENTS AND METHODS

We retrospectively studied all patients with Reye admitted in our institution from 1995. We defined 3 groups: Group 1 with a confirmed IMD, Group 2 considered as free of IMD, Group 3 unclassified. Statistical analysis compared patients in Groups 1 and 2, to find criteria for a diagnosis of IMD.

RESULTS

Fifty-eight children were included; 41 (71%) had a confirmed IMD, 12 (20%) were free of IMD, and 5 remained unclassified. IMDs included Urea Cycle Disorders (51%), Fatty-Acid Oxidation Disorders (24%), ketogenesis defects (5%), other mitochondrial energy metabolism defects (10%), NBAS mutation (7%), Glycosylation Disorders (2%). In Group 2, the trigger was a viral infection, or a drug, deferasirox in three children. Univariate analysis showed that onset before 2 years-old, recurrent Reye and the association with rhabdomyolysis were significantly associated with IMD. Blood ammonia was a poor discriminating marker. All children were admitted into the intensive care unit, 23% needed continuous venovenous hemodialysis and one died from brain oedema.

CONCLUSION

Metabolic tests should be performed early in all cases of Reye, regardless of triggers. As they can be inconclusive, we suggest to systematically go to Next-Generation Sequencing study. These children should be transferred early to a specialized unit.

Systematic review of response criteria and endpoints in autoimmune hepatitis by the International Autoimmune Hepatitis Group

BACKGROUND & AIMS

Autoimmune hepatitis (AIH) has been well characterised and codified through the development of diagnostic criteria. These criteria have been adapted and simplified and are widely used in clinical practice. However, there is a need to update and precisely define the criteria for both treatment response and treatment.

METHODS

A systematic review was performed and a modified Delphi consensus process was used to identify and redefine the response criteria in autoimmune hepatitis.

RESULTS

The consensus process initiated by the International Autoimmune Hepatitis Group proposes that the term 'complete biochemical response' defined as 'normalization of serum transaminases and IgG below the upper limit of normal' be adopted to include a time point at 6 months after initiation of treatment. An insufficient response by 6 months was a failure to meet the above definition. Non-response was defined as '<50% decrease of serum transaminases within 4 weeks after initiation of treatment'. Remission is defined as liver histology with a Hepatitis Activity Index <4/18. Intolerance to treatment was agreed to stand for 'any adverse event possibly related to treatment leading to potential drug discontinuation'.

CONCLUSIONS

These definitions provide a simple and reproducible framework to define treatment response and non-response, irrespective of the therapeutic intervention. A consensus on endpoints is urgently required to set a global standard for the reporting of study results and to enable inter-study comparisons. Future prospective database studies are needed to validate these endpoints.

LAY SUMMARY

Consensus among international experts on response criteria and endpoints in autoimmune hepatitis is lacking. A consensus on endpoints is urgently required to set a global standard for the reporting of study results and to enable the comparison of results between clinical trials. Therefore, the International Autoimmune Hepatitis Group (IAIHG) herein presents a statement on 5 agreed response criteria and endpoints: complete biochemical response, insufficient response, non-response, remission, and intolerance to treatment, which can be used to guide future reporting.

Preservation of native sigmoid colon for secondary continent cystostomy after multivisceral transplantation for chronic intestinal pseudo-obstruction

Chronic intestinal pseudo-obstruction (CIPO) is characterized by severe digestive +/- urinary dysmotility. If the conservative management fails, multivisceral transplantation (MVT) may be needed. However, urinary dysmotility remains after MVT and requires to continue urinary catheterizations and/or drainage. We report on a boy with severe CIPO complicated by (1) chronic intestinal obstruction requiring total parenteral nutrition, decompression gastrostomy, and ileostomy; (2) recurrent line infections; (3) hepatic fibrosis; and (4) distension of the bladder and upper urinary tract, and recurrent urinary infections, leading to non-continent cystostomy for urinary drainage. He underwent MVT at the age of 5 years. The transplant included the liver, stomach, duodenum and pancreas, small bowel, and right colon. The distal native sigmoid colon was preserved. Fifteen months later, he underwent a pull through of the transplanted right colon (Duhamel's procedure), together with a tube continent cystostomy (Monti's procedure) using the native sigmoid. Postoperative course was uneventful, and the remaining ileostomy was closed 3 months later. Five years post-transplant, he is alive and well. He is fed by mouth with complementary gastrostomy feeding at night. He has 3-6 stools per day, with occasional soiling. The cystostomy is used for intermittent urinary catheterization 4 times/day and continuous drainage at night. He is dry, with rare afebrile urinary infections, normal renal function, and un-dilated upper urinary tract. Conclusion: in severe CIPO with urinary involvement, preservation of the distal native sigmoid colon during MVT allows secondary creation of a continent tube cystostomy, which is useful to manage persistent urinary disease.

Systemic inflammatory syndrome in children with FARSA deficiency

Variants in aminoacyl-tRNA synthetases (ARSs) genes are associated to a broad spectrum of human inherited diseases. Patients with defective PheRS, encoded by FARSA and FARSB, display brain abnormalities, interstitial lung disease and facial dysmorphism. We investigated four children from two unrelated consanguineous families carrying two missense homozygous variants in FARSA with significantly reduced PheRS-mediated aminoacylation activity. In addition to the core ARS-phenotype, all patients showed an inflammatory profile associated with autoimmunity and interferon score, a clinical feature not ascribed to PheRS-deficient patients to date. JAK inhibition improved lung disease in one patient. Our findings expand the genetic and clinical spectrum of FARSA-related disease. This article is protected by copyright. All rights reserved.

Sebelipase alfa enzyme replacement therapy in Wolman disease: a nationwide cohort with up to ten years of follow-up

BACKGROUND

Wolman disease (WD), the rapidly progressive phenotype of lysosomal acid lipase (LAL) deficiency, presents in neonates with failure to thrive and hepatosplenomegaly, and leads to multi-organ failure and death before 12 months of age. In clinical trials, enzyme replacement therapy (ERT) with sebelipase alfa led to improved survival, growth and biological parameters in WD patients followed up to 5 years. Long-term follow-up and health-related quality of life (HRQoL) evaluation are lacking.

RESULTS

We performed a nationwide, retrospective study of sebelipase alfa in WD patients. Five patients with abolished LAL activity and bi-allelic LIPA mutations were included with a median follow-up of 7 years (1-10). ERT was initiated at a median age of 1 month (0-4). Infusion tolerance was excellent on the long-term with only one patient requiring systematic pre-medication. Cholestyramine, fat-soluble vitamin supplements and a specific diet (high in medium-chain triglycerides and low in long-chain fatty acids) were prescribed. Liver function tests, plasma lipid profiles, fat-soluble vitamin levels and growth parameters improved. Three patients transiently exhibited a neuromyopathic phenotype (footdrop gait, waddling walk or muscle fatigue) but electromyography and muscle strength testing were normal. At last follow-up, all patients were alive with normal growth parameters and a satisfactory HRQoL, no patient had special education needs, and one patient required parenteral nutrition since an acute gastroenteritis.

CONCLUSIONS

Early ERT initiation allowed 100% survival with positive outcomes. Very long-term follow-up and hematopoietic stem cell transplantation while on ERT should be evaluated to strengthen the benefits of sebelipase alfa.

Efficacy and safety of maralixibat treatment in patients with Alagille syndrome and cholestatic pruritus (ICONIC): a randomised phase 2 study

BACKGROUND

Alagille syndrome is a rare genetic disease that often presents with severe cholestasis and pruritus. There are no approved drugs for management. Maralixibat, an apical, sodium-dependent, bile acid transport inhibitor, prevents enterohepatic bile acid recirculation. We evaluated the safety and efficacy of maralixibat for children with cholestasis in Alagille syndrome.

METHODS

ICONIC was a placebo-controlled, randomised withdrawal period (RWD), phase 2b study with open-label extension in children (aged 1-18 years) with Alagille syndrome (NCT02160782). Eligible participants had more than three times the normal serum bile acid (sBA) levels and intractable pruritus. After 18 weeks of maralixibat 380 μg/kg once per day, participants were randomly assigned (1:1) to continue maralixibat or receive placebo for 4 weeks. Subsequently, all participants received open-label maralixibat until week 48. During the long-term extension (204 weeks reported), doses were increased up to 380 μg/kg twice per day. The primary endpoint was the mean sBA change during the RWD in participants with at least 50% sBA reduction by week 18. Cholestastic pruritus was assessed using observer-rated, patient-rated, and clinician-rated 0-4 scales. The safety population was defined as all participants who had received at least one dose of maralixibat. This trial was registered with ClinicalTrials.gov, NCT02160782, and is closed to recruitment.

FINDINGS

Between Oct 28, 2014, and Aug 14, 2015, 31 participants (mean age 5·4 years [SD 4·25]) were enrolled and 28 analysed at week 48. Of the 29 participants who entered the randomised drug withdrawal period, ten (34%) were female and 19 (66%) were male. In the RWD, participants switched to placebo had significant increases in sBA (94 μmol/L, 95% CI 23 to 164) and pruritus (1·7 points, 95% CI 1·2 to 2·2), whereas participants who continued maralixibat maintained treatment effect. This study met the primary endpoint (least square mean difference -117 μmol/L, 95% CI -232 to -2). From baseline to week 48, sBA (-96 μmol/L, -162 to -31) and pruritus (-1·6 pts, -2·1 to -1·1) improved. In participants who continued to week 204 (n=15) all improvements were maintained. Maralixibat was generally safe and well tolerated throughout. The most frequent adverse events were gastrointestinal related. Most adverse events were self-limiting in nature and mild-to-moderate in severity.

INTERPRETATION

In children with Alagille syndrome, maralixibat is, to our knowledge, the first agent to show durable and clinically meaningful improvements in cholestasis. Maralixibat might represent a new treatment paradigm for chronic cholestasis in Alagille syndrome.

FUNDING

Mirum Pharmaceuticals.

Methionine supplementation for multi-organ dysfunction in MetRS-related pulmonary alveolar proteinosis

INTRODUCTION

Pulmonary alveolar proteinosis related to mutations in the methionine tRNA synthetase (MARS1) gene is a severe, early-onset disease that results in death before the age of 2 years in one-third of patients. It is associated with a liver disease, growth failure and systemic inflammation. As methionine supplementation in yeast models restored normal enzymatic activity of the synthetase, we studied the tolerance, safety and efficacy of daily oral methionine supplementation in patients with severe and early disease.

METHODS

Four patients received methionine supplementation and were followed for respiratory, hepatic, growth, and inflammation-related outcomes. Their course was compared to those of historical controls. Reactive oxygen species (ROS) production by patient monocytes before and after methionine supplementation was also studied.

RESULTS

Methionine supplementation was associated with respiratory improvement, clearance of the extracellular lipoproteinaceous material, and discontinuation of whole-lung lavage in all patients. The three patients who required oxygen or non-invasive ventilation could be weaned off within 60 days. Liver dysfunction, inflammation, and growth delay also improved or resolved. At a cellular level, methionine supplementation normalised the production of reactive oxygen species by peripheral monocytes.

CONCLUSION

Methionine supplementation was associated with important improvements in children with pulmonary alveolar proteinosis related to mutations in the MARS1 gene. This study paves the way for similar strategies for other tRNA synthetase deficiencies.

Therapeutic plasma exchange for life-threatening pediatric disorders

INTRODUCTION

Therapeutic plasma exchange (TPE) is acknowledged to be an effective treatment in life-threatening pediatric disorders. Apheresis for pediatric diseases has been poorly investigated, and most studies to date featured small numbers of patients and lacked control groups. The objective of the present study was to evaluate the tolerance of TPE in pediatric patients.

MATERIALS AND METHODS

A retrospective cohort study via a web-based electronic case report form including pediatric patients referred for TPE between January 2005 and December 2014.

RESULTS

A total of 78 patients (median [range] age: 9.8 [0.53-17.93]) and 731 TPE procedures were analyzed. The indications were antibody-mediated rejection (n = 33; 42%) and desensitization therapy (n = 5; 6%) after solid organ or hematopoietic stem cell transplantation, thrombotic microangiopathy (n = 17; 22%), pediatric inflammatory diseases (n = 16; 21%), kidney diseases (n = 6; 8%), and hyperviscosity syndrome (n = 1; 1%). On average, each patient underwent six procedures during the first session [range: 1-19]. In the 2 weeks following the start of a session, 72 patients (92%) presented a total of 311 adverse events (AEs) potentially related to TPE. The risk of AEs was not related to the indication for TPE, the intensity of care, venous access, plasma substitute use, or body weight. None of the deaths was related to the TPE.

CONCLUSION

We studied one of the largest retrospective pediatric cohorts described to date. Our experience of TPE children's TPE feasibility concerned specific, life-threatening conditions and otherwise treatment-refractory diseases.

Biliary and duodenal complications after « en bloc» liver-small bowel transplantation in children. A single center cohort study

BACKGROUND

The technique of « en bloc» liver and small bowel transplantation (L-BT) spares a biliary anastomosis, but does not protect against biliary complications. We analyze biliary and duodenal complications (BDC) in our pediatric series.

METHODS

Between 1994 and 2020, 54 L-BT were performed in 53 children. The procurement technique included in situ vascular dissection and pancreatic reduction to the head until 2009 (group A). Thereafter, the whole pancreas was recovered (group B).

RESULTS

Nine BDCs occurred in 8/53 (15%) patients (7 in group A and 1 in group B): leak of the donor's duodenal stump (2), stenosis of the extra-pancreatic bile duct (5), and intra-pancreatic bile duct stenosis (2). Median delay for diagnosis of stricture was 8 months (4-168). Interventional radiology was successful in one child only, the others required reoperations. Two patients died, of biliary cirrhosis or cholangitis, 15-month and 12-year post-L-BT. One was listed and liver re-transplanted 13 years post-L-BT. At last follow-up, two patients only had normal liver tests and ultrasound.

CONCLUSION

BDC after L-BT can cause severe morbidities. Pancreatic reduction might increase this risk. Early surgical complications or chronic pancreatic rejection might be co-factors. Early diagnosis and treatment are key to the long-term prognosis.

Effects of odevixibat on pruritus and bile acids in children with cholestatic liver disease: Phase 2 study

PURPOSE

Ileal bile acid transporter inhibition is a novel therapeutic concept for cholestatic pruritus and cholestatic liver disease progression. Odevixibat, a potent, selective, reversible ileal bile acid transporter inhibitor, decreases enteric bile acid reuptake with minimal systemic exposure. Oral odevixibat safety, tolerability, and efficacy in pediatric patients with cholestatic liver disease and pruritus were evaluated.

PATIENTS AND METHODS

In this phase 2, open-label, multicenter study, children received 10‒200 μg/kg oral odevixibat daily for 4 weeks. Changes in serum bile acid levels (primary efficacy endpoint), pruritus, and sleep disturbance were explored.

RESULTS

Twenty patients were enrolled (8 females; 1‒17 years; 4 re-entered at a different dose). Diagnoses included progressive familial intrahepatic cholestasis (n = 13; 3 re-entries), Alagille syndrome (n = 6), biliary atresia (n = 3), and other intrahepatic cholestasis causes (n = 2; 1 re-entry). Mean baseline serum bile acid levels were high (235 µmol/L; range, 26‒564) and were reduced in the majority (-123.1 μmol/L; range, -394 to 14.5, reflecting reductions of up to 98%). Patient-reported diary data documented improved pruritus (3 scales) and sleep. With 100 μg/kg, mean (SEM) decrease was 2.8 (1.1) points for pruritus (visual analogue itch scale 0-10) and 2.9 (0.9) points for sleep disturbance (Patient-Oriented Scoring Atopic Dermatitis scale 0-10). Reduced pruritus correlated significantly with reduced serum bile acids (P ≤ 0.007). Significant correlations were also observed between autotaxin levels and pruritus. All patients completed the study. No serious adverse events were treatment related; most adverse events, including increased transaminases, were transient.

CONCLUSIONS

Orally administered odevixibat was well tolerated, reduced serum bile acids, and improved pruritus and sleep disturbance in children with cholestatic diseases.

Impact of Genotype, Serum Bile Acids, and Surgical Biliary Diversion on Native Liver Survival in FIC1 Deficiency

BACKGROUND AND AIMS

Mutations in ATPase phospholipid transporting 8B1 (ATP8B1) can lead to familial intrahepatic cholestasis type 1 (FIC1) deficiency, or progressive familial intrahepatic cholestasis type 1. The rarity of FIC1 deficiency has largely prevented a detailed analysis of its natural history, effects of predicted protein truncating mutations (PPTMs), and possible associations of serum bile acid (sBA) concentrations and surgical biliary diversion (SBD) with long-term outcome. We aimed to provide insights by using the largest genetically defined cohort of patients with FIC1 deficiency to date.

APPROACH AND RESULTS

This multicenter, combined retrospective and prospective study included 130 patients with compound heterozygous or homozygous predicted pathogenic ATP8B1 variants. Patients were categorized according to the number of PPTMs (i.e., splice site, frameshift due to deletion or insertion, nonsense, duplication), FIC1-A (n = 67; no PPTMs), FIC1-B (n = 29; one PPTM), or FIC1-C (n = 34; two PPTMs). Survival analysis showed an overall native liver survival (NLS) of 44% at age 18 years. NLS was comparable among FIC1-A, FIC1-B, and FIC1-C (% NLS at age 10 years: 67%, 41%, and 59%, respectively; P = 0.12), despite FIC1-C undergoing SBD less often (% SBD at age 10 years: 65%, 57%, and 45%, respectively; P = 0.03). sBAs at presentation were negatively associated with NLS (NLS at age 10 years, sBAs < 194 µmol/L: 49% vs. sBAs ≥ 194 µmol/L: 15%; P = 0.03). SBD decreased sBAs (230 [125-282] to 74 [11-177] μmol/L; P = 0.005). SBD (HR 0.55, 95% CI 0.28-1.03, P = 0.06) and post-SBD sBA concentrations < 65 μmol/L (P = 0.05) tended to be associated with improved NLS.

CONCLUSIONS

Less than half of patients with FIC1 deficiency reach adulthood with native liver. The number of PPTMs did not associate with the natural history or prognosis of FIC1 deficiency. sBA concentrations at initial presentation and after SBD provide limited prognostic information on long-term NLS.

Lipids Responsible for Intestinal or Hepatic Disorder: When to Suspect a Familial Intestinal Hypocholesterolemia?

ABSTRACT

Familial intestinal hypocholesterolemias, such as abetalipoproteinemia, hypobetalipoproteinemia, and chylomicron retention disease, are rare genetic diseases that result in a defect in the synthesis or secretion of lipoproteins containing apolipoprotein B.In children, these conditions present with diarrhoea and growth failure, whereas adults present with neuromuscular, ophthalmological, and hepatic symptoms. Simple laboratory investigations have shown that diagnosis can be made from findings of dramatically decreased cholesterol levels, deficiencies in fat-soluble vitamins (mostly vitamin E), endoscopic findings of the characteristic white intestinal mucosa, and fat-loaded enterocytes in biopsy samples. Genetic analysis is used to confirm the diagnosis. Treatment is based on a low-fat diet with essential fatty acid supplementation, high doses of fat-soluble vitamins, and regular and life-long follow-up.The present study examines cases and literature findings of these conditions, and emphasises the need to explore severe hypocholesterolemia and deficiencies in fat-soluble vitamins to not miss these rare, but easy to diagnose and treat, disorders.

Long-Term Results of Laparoscopic Adjustable Gastric Banding in French adolescents: The Utmost Importance of Follow-Up

OBJECTIVES

To investigate the long-term follow-up (FU) and effectivity of laparoscopic adjustable gastric banding (LAGB) in a French adolescent cohort.

METHODS

We retrospectively analyzed the results of LAGB at our institution. We collected information on FU, adjustable gastric banding (AGB) status, weight-related parameters, and comorbidity at multiple timepoints.

RESULTS

Fifty-six patients (77% female) with a mean age of 16.5 years and a mean body mass index (BMI) of 45 kg/m2 underwent LAGB over a period of 12 years. The mean postpediatric FU was 23 months. FU decreased progressively from 96% at 3 years to 54% and 29% at 6 and 9 years, respectively. The loss to FU was 39% at last contact. AGB was removed in 17 patients (30%) and 12 patients (21%) underwent a second bariatric procedure. Mean BMI decreased by 11 kg/m2 at last contact (P < 0.001). The prevalence of most comorbidities also decreased significantly after 3 years. The mean excess weight loss (to reach a BMI of 25 kg/m2) was 47% during the first year postsurgery and further increased to 55% at last contact.

CONCLUSION

Overall, AGB resulted in significant weight loss; however, the increase in heterogeneity suggests that LAGB is more effective in some individuals than in others in the long-term. This study confirmed that LAGB is a valuable bariatric procedure in adolescents, either as a long term-term efficient or bridging method that would be replaced at the time of transition to adult care. The importance of a standardized long-term follow-up should always be emphasized.

Long-term results of pediatric liver transplantation for autoimmune liver disease

BACKGROUND

Autoimmune hepatitis (AIH) and primary sclerosing cholangitis (PSC) are rare indications for liver transplantation (LT) in children. The aim of the present retrospective multicenter study was to evaluate long-term outcome after LT for autoimmune liver disease in childhood.

METHODS

Retrospective data from 30 children who underwent a first LT from 1988 to 2018 were collected.

RESULTS

The study population consisted of 18 girls and 12 boys, transplanted for AIH type 1 (n=14), AIH type 2 (n=7) or PSC (n=9). Mean age at LT was 11.8±5.2 years. The main indications for LT were acute (36.7%) or chronic end-stage liver failure (63.3%). Graft rejection occurred in 19 patients (63.3%); 6 pts required retransplantation for chronic rejection. Recurrence of initial disease was observed in 6 patients (20.0%), all of them with type 1 AIH, after a median time of 42 months, requiring retransplantation in 2 cases. Overall patient survival rates were 96.4%, 84.6%, 74.8%, 68.0%, 68.0%, 68.0% and 68.0% at 1, 5, 10, 15, 20, 25 and 30 years, respectively. Age at LT<1year (p<0.0001), LT for fulminant failure (p=0.023) and LT for type 2 AIH (p=0.049) were significant predictive factors of death.

CONCLUSION

Long-term outcome after LT for pediatric autoimmune liver disease is impaired in patients with AIH because of consistent complications such as rejection and disease recurrence.

Arterial abnormalities identified in kidneys transplanted into children during the COVID-19 pandemic

Graft artery stenosis can have a significant short- and long-term negative impact on renal graft function. From the beginning of the COVID-19 pandemic, we noticed an unusual number of graft arterial anomalies following kidney transplant (KTx) in children. Nine children received a KTx at our center between February and July 2020, eight boys and one girl, of median age of 10 years. Seven presented Doppler features suggesting arterial stenosis, with an unusual extensive pattern. For comparison, over the previous 5-year period, persistent spectral Doppler arterial anomalies (focal anastomotic stenoses) following KTx were seen in 5% of children at our center. We retrospectively evidenced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in five of seven children with arterial stenosis. The remaining two patients had received a graft from a deceased adolescent donor with a positive serology at D0. These data led us to suspect immune postviral graft vasculitis, triggered by SARS-CoV-2. Because the diagnosis of COVID-19 is challenging in children, we recommend pretransplant monitoring of graft recipients and their parents by monthly RT-PCR and serology. We suggest balancing the risk of postviral graft vasculitis against the risk of prolonged dialysis when considering transplantation in a child during the pandemic.

Quality of life in long term survivors of pediatric intestinal transplantation compared with liver transplantation and home parenteral nutrition: A prospective single-center pilot study

Health-related quality of life (HRQOL) after intestinal transplantation (IT) is important, as many psychological troubles have been reported in these patients on the long term. Our aim was to assess and compare HRQOL of patients after IT to patients after liver transplantation (LT) or on home parenteral nutrition (HPN) for intestinal failure. A cross-sectional study included patients and their parents between 10 and 18 years of age, on HPN for more than 2 years, or who underwent IT or LT, with a graft survival longer than 2 years. Quality of life was explored by Child Health Questionnaire. Thirteen children-parents dyads after IT, 10 after LT, and eight children on HPN completed the survey. Patients were a median age of 14 years old, a median of 10 years post-transplantation or on HPN. Patients after IT scored lower than patients after LT or on HPN in "social limitations due to behavioral difficulties" and in "behavior." They scored higher than those on HPN in "global health." Parents of children after IT scored lower than those after LT in many domains. No relevant correlation with clinical data was found. Our study showed the multi-level impact of IT on quality of life of patients and their parents. It highlights the importance of a regular psychological follow-up for patients, but also of a psychological support for families. Helping the patients to overcome the difficulties at adolescence may improve their mental health in adulthood.

Long term results of liver transplantation for alpha-1 antitrypsin deficiency

INTRODUCTION

Liver transplantation (LT) is the therapeutic option for end-stage liver disease associated with alpha1 antitrypsin (A1AT) deficiency. The aim of the present retrospective study was to report on long-term outcomes following LT for A1AT deficiency.

METHODS

The medical records of 90 pediatric and adult patients transplanted between 1982 and 2017 in France and Geneva (Switzerland) were reviewed.

RESULTS

The study population consisted of 32 adults and 58 children; median age at transplant was 13.0 years (range: 0.2-65.1), and 65 were male (72.2%). Eighty-two patients (94.8% of children and 84.4% of adults) had the PI*ZZ genotype/phenotype and eight patients (8.9%) had the Pi*SZ genotype/phenotype. Eighty-four patients (93.3%) were transplanted for end-stage liver disease and six (all Pi*ZZ adults) for HCC. Median follow-up after LT was 13.6 years (0.1-31.7). The overall cumulative patient survival rates post-transplant were 97.8% at 1 year, and 95.5%, 95.5%, 92.0%, 89.1% at 5, 10, 15, 20 years respectively. The overall cumulative graft survival rates were 92.2% at 1 year, and 89.9%, 89.9%, 84.4%, 81.5% at 5, 10, 15 and 20 years, respectively.

CONCLUSIONS

In a representative cohort of patients having presented with end-stage-liver disease or HCC secondary to A1AT, liver transplantation offered very good patient and graft survival rates.

Large-scale screening of lipase acid deficiency in at risk population

BACKGROUND

Lysosomal acid lipase deficiency (LALD, OMIM#278000) is a rare lysosomal disorder with an autosomal recessive inheritance. The main clinical manifestations are related to a progressive accumulation of cholesteryl esters, triglycerides or both within the lysosome in different organs such as the liver, spleen, and cardiovascular system. A wide range of clinical severity is associated with LALD including a severe very rare antenatal/neonatal/infantile phenotype named Wolman disease and a late-onset form named cholesteryl ester storage disease (CESD).

METHODS

This study aimed to investigate a cohort of at-risk patients (4174) presenting with clinical or biological signs consistent with LALD using the assessment of LAL activity on dried blood spots.

RESULTS

LAL activity was lower than 0.05 nmol/punch/L (cut-off: 0.12) in 19 patients including 13 CESD and 6 Wolman. Molecular study has been conducted in 17 patients and succeeded in identifying 34 mutated alleles. Fourteen unique variants have been characterized, 7 of which are novel.

CONCLUSION

This study allowed to identify a series of patients and expanded the molecular spectrum knowledge of LALD. Besides, a new screening criteria grid based on the clinical/biological data from our study and the literature has been proposed in order to enhance the diagnosis rate in at risk populations.

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.

Long term outcome of MPI-CDG patients on D-mannose therapy

Mannose phosphate isomerase MPI-CDG (formerly CDG-1b) is a potentially fatal inherited metabolic disease which is readily treatable with oral D-mannose. We retrospectively reviewed long-term outcomes of patients with MPI-CDG, all but one of whom were treated with D-mannose. Clinical, biological, and histological data were reviewed at diagnosis and on D-mannose treatment. Nine patients were diagnosed with MPI-CDG at a median age of 3 months. The presenting symptoms were diarrhea (n = 9), hepatomegaly (n = 9), hypoglycemia (n = 8), and protein loosing enteropathy (n = 7). All patients survived except the untreated one who died at 2 years of age. Oral D-mannose was started in eight patients at a median age of 7 months (mean 38 months), with a median follow-up on treatment of 14 years 9 months (1.5-20 years). On treatment, two patients developed severe portal hypertension, two developed venous thrombosis, and 1 displayed altered kidney function. Poor compliance with D-mannose was correlated with recurrence of diarrhea, thrombosis, and abnormal biological parameters including coagulation factors and transferrin profiles. Liver fibrosis persisted despite treatment, but two patients showed improved liver architecture during follow-up. This study highlights (i) the efficacy and safety of D-mannose treatment with a median follow-up on treatment of almost 15 years (ii) the need for life-long treatment (iii) the risk of relapse with poor compliance, (iii) the importance of portal hypertension screening (iv) the need to be aware of venous and renal complications in adulthood.

Beyond 10 years, with or without an intestinal graft: Present and future?

Long-term outcomes in children undergoing intestinal transplantation remain unclear. Seventy-one children underwent intestinal transplantation in our center from 1989 to 2007. We report on 10-year posttransplant outcomes with (group 1, n = 26) and without (group 2, n = 9) a functional graft. Ten-year patient and graft survival rates were 53% and 36%, respectively. Most patients were studying or working, one third having psychiatric disorders. All patients in group 1 were weaned off parenteral nutrition with mostly normal physical growth and subnormal energy absorption. Graft histology from 15 late biopsies showed minimal abnormality. However, micronutrient deficiencies and fat malabsorption were frequent; biliary complications occurred in 4 patients among the 17 who underwent liver transplantation; median renal clearance was 87 mL/min/1.73 m² . Four patients in group 1 experienced late acute rejection. Among the 9 patients in group 2, 4 died after 10 years and 2 developed significant liver fibrosis. Liver transplantation and the use of a 3-drug regimen including sirolimus or mycophenolate mofetil were associated with improved graft survival. Therefore, intestinal transplantation may enable a satisfactory digestive function in the long term. The prognosis of graft removal without retransplantation is better than expected. Regular monitoring of micronutrients, early psychological assessment, and use of sirolimus are recommended.

Donor-targeted serotherapy as a rescue therapy for steroid-resistant acute GVHD after HLA-mismatched kidney transplantation

Acute graft-versus-host disease (GVHD) is a rare but frequently lethal complication after solid organ transplantation. GVHD occurs in unduly immunocompromised hosts but requires the escalation of immunosuppression, which does not discriminate between host and donor cells. In contrast, donor-targeted therapy would ideally mitigate graft-versus-host reactivity while sparing recipient immune functions. We report two children with end-stage renal disease and severe primary immune deficiency (Schimke syndrome) who developed severe steroid-resistant acute GVHD along with full and sustained donor T cell chimerism after isolated kidney transplantation. Facing a therapeutic dead end, we used a novel strategy based on the adoptive transfer of anti-HLA donor-specific antibodies (DSAs) through the transfusion of highly selected plasma. After approval by the appropriate regulatory authority, an urgent nationwide search was launched among more than 3800 registered blood donors with known anti-HLA sensitization. Adoptively transferred DSAs bound to and selectively depleted circulating donor T cells. The administration of DSA-rich plasma was well tolerated and notably did not induce antibody-mediated rejection of the renal allografts. Acute GVHD symptoms promptly resolved in one child. This report provides a proof of concept for a highly targeted novel therapeutic approach for solid organ transplantation-associated GVHD.

Genotype correlates with the natural history of severe bile salt export pump deficiency

BACKGROUND & AIMS

Mutations in ABCB11 can cause deficiency of the bile salt export pump (BSEP), leading to cholestasis and end-stage liver disease. Owing to the rarity of the disease, the associations between genotype and natural history, or outcomes following surgical biliary diversion (SBD), remain elusive. We aimed to determine these associations by assembling the largest genetically defined cohort of patients with severe BSEP deficiency to date.

METHODS

This multicentre, retrospective cohort study included 264 patients with homozygous or compound heterozygous pathological ABCB11 mutations. Patients were categorized according to genotypic severity (BSEP1, BSEP2, BSEP3). The predicted residual BSEP transport function decreased with each category.

RESULTS

Genotype severity was strongly associated with native liver survival (NLS, BSEP1 median 20.4 years; BSEP2, 7.0 years; BSEP3, 3.5 years; p <0.001). At 15 years of age, the proportion of patients with hepatocellular carcinoma was 4% in BSEP1, 7% in BSEP2 and 34% in BSEP3 (p = 0.001). SBD was associated with significantly increased NLS (hazard ratio 0.50; 95% CI 0.27-0.94: p = 0.03) in BSEP1 and BSEP2. A serum bile acid concentration below 102 μmol/L or a decrease of at least 75%, each shortly after SBD, reliably predicted NLS of ≥15 years following SBD (each p <0.001).

CONCLUSIONS

The genotype of severe BSEP deficiency strongly predicts long-term NLS, the risk of developing hepatocellular carcinoma, and the chance that SBD will increase NLS. Serum bile acid parameters shortly after SBD can predict long-term NLS.

LAY SUMMARY

This study presents data from the largest genetically defined cohort of patients with severe bile salt export pump deficiency to date. The genotype of patients with severe bile salt export pump deficiency is associated with clinical outcomes and the success of therapeutic interventions. Therefore, genotypic data should be used to guide personalized clinical care throughout childhood and adulthood in patients with this disease.