Phenotype and molecular characterization of Wilson's disease in Morocco

BACKGROUND AND STUDY AIMS

In Morocco the prevalence of Wilson disease (WD) and the spectrum of mutations are not known. The aim of the present study was to estimate the prevalence of WD in Morocco, to evaluate the phenotype among a large cohort of WD patients, and to characterize ATP7B variants in a subgroup of WD patients.

PATIENTS AND METHODS

We collected data from 226 patients admitted to five university hospital centers in Morocco between 2008 and 2020. The diagnosis was based on clinical manifestations, function tests and biochemical parameters. The genotype was characterized in 18 families diagnosed at the University Hospital Center of Marrakesh, by next generation sequencing.

RESULTS

The mean annual prevalence in Morocco was 3.88 per 100,000 and the allele frequency was 0.15 %. Among the 226 patients included (121 males and 105 females), 196 were referred for a hepatic or neurological involvement and 30 were asymptomatic. The mean age at diagnosis was 13 ± 5.1 years (range: 5 - 42 years). Consanguinity was found in 63.3 % of patients. The mean duration of illness was 2.8 ± 1.9 years. Kayser-Fleischer rings were found in 131 (67.9 %) of 193 patients. Among the 196 symptomatic patients, 141/159 (88.7 %) had low serum ceruloplasmin (<0.2 g/L) and a high 24-hours urinary copper (>100 μg/day) was found in 173/182 (95.1 %) patients. The initial treatment was D-penicillamine in 207 patients, zinc acetate in five, zinc sulfate in five, and nine patients were not treated; 60/207 (29 %) patients have stopped treatment. A total of 72 patients died; the mortality rate was 31.9 %. Eight different ATP7B variants were identified among the 18 patients studied, of which two were novel (p.Cys1104Arg and p.Gln1277Hisfs*52), and six previously published (p.Gln289Ter, p.Cys305Ter, p.Thr1232Pro, p.Lys1020Arg, p.Glu583ArgfsTer25 and c.51+4A>T). All informative patients were homozygous for the disease-causing mutation.

CONCLUSION

In Morocco, a high prevalence due to consanguinity and a high mortality rate due to the difficulty of diagnosis and lack of treatment were observed in WD patients. NGS sequencing identified new ATP7B variants in WD patients from Morocco.

Histological features of liver disease development in the Atp7b-/- mouse: a model of Wilson's disease

AIMS

Wilson's disease (WD) is caused by mutations in the ATP7B gene, resulting in copper accumulation and toxicity in liver and brain tissues. Due to the initial asymptomatic liver involvement, the progression of liver injuries in WD stays primarily unknown. Atp7b-/- knockout mice have been shown to be an appropriate model of WD for liver involvement.

METHODS

A total of 138 Atp7b-/- mice were included and separated into five groups according to age as follows: 6, 20, 39 and 50 weeks without treatment, and 50 weeks with copper chelator treatment from 39 to 50 weeks of age and compared with 101 wild-type (WT) mice at the same stages. The evolution of histological liver lesions was analysed and compared between groups.

RESULTS

Significant changes were observed in Atp7b-/- mice compared with WT. Copper deposits in hepatocytes appeared as early as 6 weeks but no significant increase over time was observed. Inflammation appeared as early as 6 weeks and progressed henceforth. Lobular and periportal acidophilic bodies appeared after 20 weeks. Significant atypia was also observed at 20 weeks and increased over time to reach a severe stage at 39 weeks. Fibrosis also became apparent at 20 weeks, progressing subsequently to precirrhotic stages at 50 weeks. Copper content, inflammation and fibrosis scores were significantly reduced in the treated group. No bile duct lesions or dysplastic changes were noted.

CONCLUSIONS

Copper accumulation leads to progressive changes in Atp7b-/- mice regarding inflammation, fibrosis and atypia. The severity of liver damage is lessened by chelation therapy.

Determinants of early surgical complications after pediatric liver transplantation: A single center/single surgeon experience over 20 years

BACKGROUND

The risk of early surgical complications of liver transplantation (LT) is higher in children when compared with adults. The aims of the present retrospective study from a single center cohort/single surgeon were to identify the predictive factors for surgical complications after pediatric LT.

METHODS

All children receiving a first LT from October 1990 to October 2010 in our center were included.

RESULTS

Included 151 children (boys 55.0%), with a mean age of 4.8 ± 4.8 years, and a mean weight of 17.9 ± 14.4 kg. Thirty-seven patients were transplanted within the first year, and 59 patients had a body weight below 10 kg. The main initial liver disease was biliary atresia (49.0%). Living donor LT was performed in 39 cases (25.8%), cadaveric whole liver LT in 50 cases (33.1%), and cadaveric partial liver LT in 62 cases (41.1%). Early surgical complications included reoperation (37.8%), vascular complications (8.6%), i.e. arterial (3.3%) or portal thrombosis/stenosis (7.3%) within the first month, and biliary complications in the first 90 days occurred in 22.5% of the cases. The main indications for surgical revision were abdominal bleeding, treatment of a biliary complication, and bowel perforation. Multivariate analysis disclosed that only graft type (split and moreover from a living donor) was significantly and independently associated with the occurrence of biliary complication, and that indication for LT, period, graft type, and operative time were significantly and independently associated with the necessity of surgical revision.

CONCLUSION

Our results emphasize that surgical complications are frequent and strongly depend on patient/graft characteristics.

Evaluation of vitamin B6 supplementation in Wilson's disease patients treated with D-penicillamine

INTRODUCTION

Wilson's disease (WD) is a copper metabolism disorder characterised by a progressive accumulation of this metal mainly in the liver and the brain. Treatment is based on the removal of copper operated by the chelators, among which, D-penicillamine (DP) is prescribed as a first-line treatment in most situations. There is some evidence in linking the use of DP with a risk of vitamin B6; therefore, vitamin supplementation is sometimes recommended, although non-consensually. The objective of our study was to evaluate the level of vitamin B6 in WD patients treated with DP with and without associated supplementation.

METHODOLOGY

All WD patients followed at the National Reference Centre for WD in Lyon between January 2019 and December 2020 treated with DP for more than 1 year were included and separated in two groups according to vitamin B6 supplementation. The level of vitamin B6 was measured by the determination of pyridoxal phosphate (PLP).

RESULTS

A total of 37 patients were included. Average age of 23.3±14.8 years, 15 patients with <18 years. Median duration of treatment was 51 (55.8) months. 15 patients were under vitamin B6 supplementation and 22 had interrupted it for more than 1 year. The median PLP level was significantly higher in the group with supplementation, 137.2 (86.7) nmol/L vs 64.9 (30.8) nmol/(p<0.01). No patient had a PLP level<35 nmol/L.

CONCLUSION

Long-term stable WD patients under DP treatment probably do not need vitamin B6 supplementation.

Interim results from an ongoing, open-label, single-arm trial of odevixibat in progressive familial intrahepatic cholestasis

Background & Aims

PEDFIC 2, an ongoing, open-label, 72-week study, evaluates odevixibat, an ileal bile acid transporter inhibitor, in patients with progressive familial intrahepatic cholestasis.

Methods

PEDFIC 2 enrolled and dosed 69 patients across two cohorts; all received odevixibat 120 μg/kg per day. Cohort 1 comprised children from PEDFIC 1, and cohort 2 comprised new patients (any age). We report data through 15 July 2020, with Week 24 of PEDFIC 2 the main time point analysed. This represents up to 48 weeks of cumulative exposure for patients treated with odevixibat from the 24-week PEDFIC 1 study (cohort 1A) and up to 24 weeks of treatment for those who initiated odevixibat in PEDFIC 2 (patients who received placebo in PEDFIC 1 [cohort 1B] or cohort 2 patients). Primary endpoints for this prespecified interim analysis were change from baseline to Weeks 22-24 in serum bile acids (sBAs) and proportion of positive pruritus assessments (≥1-point drop from PEDFIC 2 baseline in pruritus on a 0-4 scale or score ≤1) over the 24-week period. Safety monitoring included evaluating treatment-emergent adverse events (TEAEs).

Results

In cohort 1A, mean change from PEDFIC 1 baseline to Weeks 22-24 of PEDFIC 2 in sBAs was -201 μmol/L (p <0.0001). For cohort 1B and cohort 2, mean changes from odevixibat initiation to weeks 22-24 in sBAs were -144 and -104 μmol/L, respectively. The proportion of positive pruritus assessments in the first 24-week period of PEDFIC 2 was 33%, 56%, and 62% in cohorts 1A, 1B, and 2, respectively. Most TEAEs were mild or moderate. No drug-related serious TEAEs occurred.

Conclusions

Odevixibat in patients with progressive familial intrahepatic cholestasis was generally well tolerated and associated with sustained reductions in sBAs and pruritus.

Clinical Trials Registration

This study is registered at ClinicalTrials.gov (NCT03659916).

Impact and Implications

Disrupted bile flow is a hallmark feature of patients with progressive familial intrahepatic cholestasis and can result in build-up of bile constituents in the liver with spill over into the bloodstream; other effects that patients can experience include extremely itchy skin, and because not enough bile reaches the gut, patients can have problems digesting food, which may lead to poor growth. Odevixibat is an orally administered medication that shunts bile acids away from the liver. The current study, called PEDFIC 2, suggested that odevixibat can improve the problematic signs and symptoms of progressive familial intrahepatic cholestasis and was generally safe for patients.

Human inherited complete STAT2 deficiency underlies inflammatory viral diseases

STAT2 is a transcription factor activated by type I and III IFNs. We report 23 patients with loss-of-function variants causing autosomal recessive (AR) complete STAT2 deficiency. Both cells transfected with mutant STAT2 alleles and the patients' cells displayed impaired expression of IFN-stimulated genes and impaired control of in vitro viral infections. Clinical manifestations from early childhood onward included severe adverse reaction to live attenuated viral vaccines (LAV) and severe viral infections, particularly critical influenza pneumonia, critical COVID-19 pneumonia, and herpes simplex virus type 1 (HSV-1) encephalitis. The patients displayed various types of hyperinflammation, often triggered by viral infection or after LAV administration, which probably attested to unresolved viral infection in the absence of STAT2-dependent types I and III IFN immunity. Transcriptomic analysis revealed that circulating monocytes, neutrophils, and CD8+ memory T cells contributed to this inflammation. Several patients died from viral infection or heart failure during a febrile illness with no identified etiology. Notably, the highest mortality occurred during early childhood. These findings show that AR complete STAT2 deficiency underlay severe viral diseases and substantially impacts survival.

Ustekinumab Use in Pediatric Inflammatory Bowel Disease: A French Multicenter Study From the Pediatric GETAID

OBJECTIVES

Ustekinumab is known to be efficient in adult patients suffering from moderate to severe Crohn disease (CD) and ulcerative colitis (UC) resistant to anti-tumor necrosis factor-alpha (TNF-α). Here, we described the clinical course of treatment with ustekinumab in French pediatric inflammatory bowel disease (IBD) patients treated with ustekinumab.

METHODS

This study includes all pediatric patients treated by ustekinumab injection for IBD (CD and UC), between January 2016 and December 2019.

RESULTS

Fifty-three patients were enrolled, 15 males and 38 females. Forty-eight patients (90%) had a diagnosis of CD and 5 (9.4%) had UC. Sixty-five percent of CD patients presented an ileocolitis. Perineal disease was observed in 20 out of 48 CD patients (41.7%), among them 9 were treated surgically. All patients included were resistant to anti-TNF-α treatment. Fifty-one percent had presented side effects linked to anti-TNF-α, including psoriasis and anaphylactic reaction. The average Pediatric Crohn Disease Activity Index (PCDAI) at induction was 28.7 (5-85), 18.7 (0-75) at 3 months of treatment and 10 (0-35) at the last follow-up. The average Pediatric Ulcerative Colitis Activity Index at induction was 47 (25-65), 25 (15-40) at 3 months of treatment and 18.3 (0-35) at the last follow-up. No severe side effects were observed.

CONCLUSION

In this retrospective, multicentral study, ustekinumab proved to be efficient in pediatric patients resistant to anti-TNF-α. PCDAI has been significantly improved in patients with severe disease, treated with ustekinumab.

Iterative antibody-induced bile salt export pump deficiency after successive liver transplantations successfully treated with plasmapheresis and rituximab

Post-transplantation evolution of progressive familial intrahepatic cholestasis type 2 patients can be complicated by antibody-induced bile salt export pump deficiency (AIBD). There is no consensus on its management. We describe a patient who presented two episodes, 9 years apart. The first episode was refractory to plasmapheresis and intravenous immunoglobulin (IVIG) started 2 months after AIBD onset, leading to graft loss. The second episode responded to plasmapheresis, IVIG and rituximab initiated less than 2 weeks after the beginning of symptoms, allowing for long-term recovery. This case suggests that intensive treatment with minimum delay after symptoms onset could sponsor a better evolution.

Are protocol graft biopsies after pediatric liver transplantation useful? Experience in a single center over 20 years

BACKGROUND

The role of protocol liver biopsies (PLB) in the follow-up of pediatric liver transplant recipients remains questionable. This single-center retrospective study aimed to evaluate their clinical impact on the long-term management of pediatric liver transplant recipients.

METHODS

We described histopathological lesions and clinical consequences for patient management of PLB performed 1, 5, 10, 15, 20, and 25 years after pediatric liver transplantation (LT).

RESULTS

A total of 351 PLB performed on 133 patients between 1992 and 2021 were reviewed. PLB found signs of rejection in 21.7% of cases (76/351), and moderate to severe fibrosis in 26.5% of cases (93/351). Overall, 264 PLB (75.2%) did not cause any changes to patient care. Immunosuppression was enhanced after 63 PLB, including 23 cases of occult rejection. The 1-year PLB triggered significantly more changes, while biopsies at 15, 20, and 25 years produced the lowest rates of subsequent modifications. PLB had a significantly higher probability of inducing therapeutic changes if the patient had abnormal biological or imaging results (odds ratio [OR] 2.82 and 2.06), or a recent history of rejection or bacterial infection (OR 2.22 and 2.03).

CONCLUSION

Our results suggest that, although it often does not prompt any treatment changes, PLB could be performed because of its ability to detect silent rejection requiring an increase in immunosuppression. PLB could be carried out 1, 5, and 10 years after LT and then every 10 years in patients with normal biological and imaging results and no recent complications, while other patients could be kept on a 5-year protocol.

Maintenance therapy simplification using a single daily dose: A preliminary real-life feasibility study in patients with Wilson disease

BACKGROUND

Single daily dose (SDD) is a good way to improve adherence by simplifying treatment. Efficacy data concerning patients with Wilson disease (WD) taking an SDD are lacking.

AIM

To report the effectiveness of the use of SDD for the treatment of WD.

METHODS

This retrospective study included WD patients followed in the French National Network who received an SDD in maintenance phase. The treatment failure was defined as a composite criterion with the occurrence of at least one of the following criterion: death, transplantation, increase of transaminases >2xULN, hepatic decompensation, neurological aggravation, severe side effects related to treatment, and/or discontinuation of treatment.

RESULTS

A total of 26 patients received an SDD (D-penicillamine=13, trientine=8, zinc=5) after a median interval of 152 months after diagnosis. After one year, two patients had treatment failure: transaminitis in one, continuation of neurological deterioration in the other related to a poor compliance. After a median duration of 41 months on SDD, 3 other patients had treatment failure (transaminitis=2, treatment discontinuation=1). There was no death, no liver transplantation, no hepatic decompensation, and no severe side effects related to treatment during the follow-up. Moreover, transaminases and serum exchangeable copper were not significantly different 1 year post-switch and at last follow-up compared to baseline.

CONCLUSIONS

Maintenance therapy simplification through the use of an SDD could be considered in some WD patients. In this pilot study, SDD was effective in 21/26 patients (81%) without any concern regarding safety.

Epidemiology, clinical features, and mortality rate of Wilson disease in Moroccan children: A pediatric case series

BACKGROUND AND STUDY AIMS

Wilson's disease is an autosomal recessive disorder, that affects copper metabolism, leading to copper accumulation in the liver, nervous system, and cornea. Data are lacking on the epidemiology, the clinical and laboratory characteristics, treatment, and survival of Wilson's disease in Morocco. The aim of this study was to examine these features and the cause of death in a Moroccan pediatric population.

PATIENTS AND METHODS

The study was carried out at the University Hospital Center of Marrakesh, Morocco; 46 children were diagnosed with Wilson's disease from 2008 to 2019. The diagnosis was based on low serum ceruloplasmin, increased urinary copper concentrations, the presence of Kayser-Fleischer rings, a family history of Wilson's disease, and a Leipzig score of ≥ 4.

RESULTS

A total of 42 patients were referred to the center for hepatic or neurological manifestations; four patients were asymptomatic. Consanguineous marriage was found in 67.4% of the cases. The mean duration of illness (42 patients) was 4.9 ± 3.9 years. Kayser-Fleischer rings were found in 60.9% of 46 patients. Of the 42 symptomatic patients: 28 of 30 (93.3%) patients had low serum ceruloplasmin (<0.2 g/L), and 24 h urinary copper >100 μg/day was found in 34 of 35 (97.1%) cases. The treatment was established with D-penicillamine for 43 of the 46 patients, with zinc acetate for one patient and with zinc sulfate in for one patient, while one patient was not treated. D-penicillamine was discontinued in nine patients because of adverse effects such as thrombocytopenia, neurological deterioration, pancytopenia, severe vomiting and severe hypersensitivity. In total 28 patients were clinically and biologically stabilized, two patients experienced vision loss, and 16 patients died (38%). The main cause of death was diagnosis made at an advanced stage of disease and stopping treatment.

CONCLUSION

Wilson's disease is a rare condition associated with treatement efficacy, but late diagnosis and stopping treatment can lead to a high mortality rate.

Maralixibat for the treatment of PFIC: Long-term, IBAT inhibition in an open-label, Phase 2 study

Children with progressive familial intrahepatic cholestasis, including bile salt export pump (BSEP) and familial intrahepatic cholestasis–associated protein 1 (FIC1) deficiencies, suffer debilitating cholestatic pruritus that adversely affects growth and quality of life (QoL). Reliance on surgical interventions, including liver transplantation, highlights the unmet therapeutic need. INDIGO was an open‐label, Phase 2, international, long‐term study to assess the efficacy and safety of maralixibat in children with FIC1 or BSEP deficiencies. Thirty‐three patients, ranging from 12 months to 18 years of age, were enrolled. Eight had FIC1 deficiency and 25 had BSEP deficiency. Of the latter, 6 had biallelic, protein truncating mutations (t)‐BSEP, and 19 had ≥ 1 nontruncating mutation (nt)‐BSEP. Patients received maralixibat 266 μg/kg orally, once daily, from baseline to Week 72, with twice‐daily dosing permitted from Week 72. Long‐term efficacy was determined at Week 240. Serum bile acid (sBA) response (reduction in sBAs of > 75% from baseline or concentrations <102.0 μmol/L) was achieved in 7 patients with nt‐BSEP, 6 during once‐daily dosing, and 1 after switching to twice‐daily dosing. sBA responders also demonstrated marked reductions in sBAs and pruritus, and increases in height, weight, and QoL. All sBA responders remained liver transplant–free after > 5 years. No patients with FIC1 deficiency or t‐BSEP deficiency met the sBA responder criteria during the study. Maralixibat was generally well‐tolerated throughout the study. Conclusion: Response to maralixibat was dependent on progressive familial intrahepatic cholestasis subtype, and 6 of 19 patients with nt‐BSEP experienced rapid and sustained reductions in sBA levels. The 7 responders survived with native liver and experienced clinically significant reductions in pruritus and meaningful improvements in growth and QoL. Maralixibat may represent a well‐tolerated alternative to surgical intervention.

Therapeutic Approach of Very Early-Onset Inflammatory Bowel Disease in a Loeys-Dietz Syndrome Child

Heterozygous TGFBR2 loss-of-function mutation is an extremely rare cause of very-early onset inflammatory bowel disease (VEOIBD) as, so far, only three cases have been reported in the literature. VEOIBD therapeutic management remains a real challenge for clinicians. Here, we described an interesting new case of Loeys-Dietz syndrome presenting severe, very early intestinal inflammation associated with dysmorphic features, aortic arch tortuosity joint hyper laxity and severe scoliosis. TGFBR2 Sanger sequencing revealed a missense mutation c.1583G>A (p.Arg528His). As endoscopy confirmed a severe colitis, we chose a classical IBD therapeutic approach. We finally obtained remission under Ustekinumab (90 mg/6 weeks).

Functionally deficient TRPV6 variants contribute to hereditary and familial chronic pancreatitis

The recent discovery of TRPV6 as a pancreatitis susceptibility gene served to identify a novel mechanism of chronic pancreatitis (CP) due to Ca²⁺ dysregulation. Herein, we analyzed TRPV6 in 81 probands with hereditary CP (HCP), 204 probands with familial CP (FCP), and 462 patients with idiopathic CP (ICP) by targeted next-generation sequencing. We identified 25 rare nonsynonymous TRPV6 variants, 18 of which had not been previously reported. All 18 variants were characterized by a Ca²⁺ imaging assay, with 8 being identified as functionally deficient. Evaluation of functionally deficient variants in the three CP cohorts revealed two novel findings: (i) functionally deficient TRPV6 variants appear to occur more frequently in HCP/FCP patients than in ICP patients (3.2% vs. 1.5%) and (ii) functionally deficient TRPV6 variants found in HCP and FCP probands appear to be more frequently coinherited with known risk variants in SPINK1, CTRC, and/or CFTR than those found in ICP patients (66.7% vs 28.6%). Additionally, genetic analysis of available HCP and FCP family members revealed complex patterns of inheritance in some families. Our findings confirm that functionally deficient TRPV6 variants represent an important contributor to CP. Importantly, functionally deficient TRPV6 variants account for a significant proportion of cases of HCP/FCP.

A novel mutation of PCSK1 responsible for PC1/3 deficiency in two siblings

Proprotein convertase 1 (PCSK1, PC1/3) deficiency is an uncommon cause of neonatal malabsorptive diarrhoea associated with endocrinopathies that are due to the disrupted processing of a large number of prohormones, including proinsulin. To date, only 26 cases have been reported. Herein, we describe two siblings with typical features including severe congenital diarrhoea, central diabetes insipidus, growth hormone deficiency, and hypoadrenalism. Next generation sequencing found a homozygous missense mutation in exon 5 of PCSK1 gene, c.500A>C (p.Asp167Ala), located within the catalytic domain. Both patients presented a high level of proinsulin. In the first years of life they required parenteral nutrition and hormone replacement therapy. The patients, aged 3 and 1.5 years, experienced several infectious episodes associated with septic shocks. While the mechanism underlying intestinal failure remains poorly investigated, parenteral nutrition is essential in order to ensure normal growth in early childhood.

Determinants of short-term outcomes after pediatric liver transplantation: a single centre experience over 20 years

BACKGROUND

Liver transplantation (LT) is a standard-of-care therapeutic modality for selected patients with life-threatening liver disease, including children. In addition to specific clinical characteristics of pediatric LT recipients due to initial liver disease (and related comorbidities) and level of liver failure, early postoperative outcome may be dependent on the surgical technique used, related to the type of organ donor and graft. Therefore, the aims of the present retrospective study from a large single centre cohort were to identify the prognostic factors for both 1-year patient and graft survival.

METHODS

Between October 1990 and October 2010, 151 children underwent a first LT in our centre.

RESULTS

The mean age was 5.3 ± 7.4 years, and the main indication was biliary atresia (BA) (49.0%). Living donor liver transplantation (LDLT) was performed in 39 cases (25.8%). Cadaveric liver graft was a whole liver in 50 cases (33.1%) and a partial liver (reduced or split) in 62 cases (41.1%). One-year patient and graft survival rates were 88.7% and 86.1%, respectively. Multivariate analysis disclosed that initial liver disease, location at time of LT, donor/recipient (D/R) delta age, early post-transplant hemodialysis and initial immunosuppression (induction) were significantly associated with patient survival and that D/R delta age, primary non-function, early post-transplant hemodialysis and initial immunosuppression (induction) were significantly associated with graft survival.

CONCLUSION

The results of our single-centre experience of pediatric LT emphasize that early patient and graft survivals depend on pre-operative/operative factors such as initial liver disease, D/R delta age and immunosuppressive regimen. Awareness of these factors can help in the decision making for children requiring LT.

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.

Inflammatory Bowel Disease in Patients with Congenital Chloride Diarrhoea

BACKGROUND

Congenital chloride diarrhoea [CLD] is a rare autosomal recessive disease caused by mutations in the solute family carrier 26 member 3 [SLC26A3] gene. Patients suffer from life-long watery diarrhoea and chloride loss. Inflammatory bowel disease [IBD] has been reported in individual patients with CLD and in scl26a3-deficient mice.

METHODS

We performed an international multicentre analysis to build a CLD cohort and to identify cases with IBD. We assessed clinical and genetic characteristics of subjects and studied the cumulative incidence of CLD-associated IBD.

RESULTS

In a cohort of 72 patients with CLD caused by 17 different SLC26A3 mutations, we identified 12 patients [17%] diagnosed with IBD. Nine patients had Crohn's disease, two ulcerative colitis and one IBD-unclassified [IBD-U]. The prevalence of IBD in our cohort of CLD was higher than the highest prevalence of IBD in Europe [p < 0.0001]. The age of onset was variable [13.5 years, interquartile range: 8.5-23.5 years]. Patients with CLD and IBD had lower z-score for height than those without IBD. Four of 12 patients had required surgery [ileostomy formation n = 2, ileocaecal resection due to ileocaecal valve stenosis n = 1 and colectomy due to stage II transverse colon cancer n = 1]. At last follow-up, 5/12 were on biologics [adalimumab, infliximab or vedolizumab], 5/12 on immunosuppressants [azathioprine or mercaptopurine], one on 5-ASA and one off-treatment.

CONCLUSIONS

A substantial proportion of patients with CLD develop IBD. This suggests the potential involvement of SL26A3-mediated anion transport in IBD pathogenesis. Patients with CLD-associated IBD may require surgery for treatment failure or colon cancer.

ATP7B variant spectrum in a French pediatric Wilson disease cohort

BACKGROUND/AIM

The spectrum of ATP7B variants varies significantly according to geographic distribution, and there is insufficient data on the variants observed in the French population.

METHODS

Clinical data of 113 children included in the French WD national registry were gathered from March 01, 1995 to July 01, 2020. Data included epidemiological, clinical, laboratory, genetics.

RESULTS

Diagnosis was made at a mean age of 11.0 ± 4.1 years (range 1-18 years). At diagnosis, 91 patients (79.8 %) had hepatic manifestations, 18 (15.8 %) presented neurological manifestations, and 4 patients (3.5 %) were asymptomatic. Only 29 patients (25 %) were homozygous for a variant. We have found a total of 102 different variants including 14 novel variants. Recurrent variant p.His1069Gln was the most prevalent, n = 31 alleles (14,2%), with only seven homozygous; in contrast 55% of variants are identified in only one family. 45% were truncating variants. In respect of mutated exon, the three most prevalent were exon 14 (16.5%), exon 8 (13.8%), and exon 3 (11.5%). When considering patients with two Nonsense / Frameshift variants as a group and those with two Missense variants, we found significantly lower ceruloplasmin for the former: 2.8 ± 0.7 mg/dl vs 8.4 ± 5mg/dl (p<0.05).

CONCLUSION

p.His1069Gln is the most frequent variant (14,2%) and exons 14, 8, and 2 of the ATP7B gene account for 41.7% of total variants. However, there is significant heterogeneity in the French population concerning the other ATP7B variants. Nonsense / Frameshift variants were associated with lower ceruloplasmin levels.

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 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.

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.

A prospective case-control pilot study to evaluate bone microarchitecture in children and teenagers on long-term parenteral nutrition using HR-pQCT

Long-term parenteral nutrition (PN) may induce bone complications. Tridimensional bone imaging techniques such as high-resolution peripheral quantitative computed tomography (HR-pQCT) allow the assessment of both compartmental volumetric densities and microarchitecture. Our aim was to evaluate these parameters in children and teenagers receiving long-term PN. This cross-sectional, case–control study included children older than 9 years undergoing PN for at least 2 years. They were age-, gender- and puberty-matched with healthy controls (1:2). Evaluation included biological assessment of bone metabolism (serum calcium, phosphate, and albumin; urinary calcium and creatinine; 25-OH vitamin D, osteocalcin and PTH), dual X-ray absorptiometry (DXA) and HR-pQCT at the ultradistal tibia and radius. Results are presented as median [range]. Eleven patients (3 girls) with a median age of 16 [9–19] years were included. Bone parameters assessed by HR-pQCT at the ultradistal radius and tibia were similar in patients and controls. Parathyroid hormone (PTH) levels were higher (14 [7–115] vs 16 [12–27]) and osteocalcin levels were lower (44 [15–65] vs 65 [38–142]) in patients than in controls, although within the normal range. Conclusions: there were no differences for compartmental bone densities and microarchitecture in patients undergoing chronic PN. Further longitudinal studies are required to confirm these quite reassuring preliminary results.

Hepatocyte proteomes reveal the role of protein disulfide isomerase 4 in alpha 1-antitrypsin deficiency

Background & Aims

A single point mutation in the Z-variant of alpha 1-antitrypsin (Z-AAT) alone can lead to both a protein folding and trafficking defect, preventing its exit from the endoplasmic reticulum (ER), and the formation of aggregates that are retained as inclusions within the ER of hepatocytes. These defects result in a systemic AAT deficiency (AATD) that causes lung disease, whereas the ER-retained aggregates can induce severe liver injury in patients with ZZ-AATD. Unfortunately, therapeutic approaches are still limited and liver transplantation represents the only curative treatment option. To overcome this limitation, a better understanding of the molecular basis of ER aggregate formation could provide new strategies for therapeutic intervention.

Methods

Our functional and omics approaches here based on human hepatocytes from patients with ZZ-AATD have enabled the identification and characterisation of the role of the protein disulfide isomerase (PDI) A4/ERP72 in features of AATD-mediated liver disease.

Results

We report that 4 members of the PDI family (PDIA4, PDIA3, P4HB, and TXNDC5) are specifically upregulated in ZZ-AATD liver samples from adult patients. Furthermore, we show that only PDIA4 knockdown or alteration of its activity by cysteamine treatment can promote Z-AAT secretion and lead to a marked decrease in Z aggregates. Finally, detailed analysis of the Z-AAT interactome shows that PDIA4 silencing provides a more conducive environment for folding of the Z mutant, accompanied by reduction of Z-AAT-mediated oxidative stress, a feature of AATD-mediated liver disease.

Conclusions

PDIA4 is involved in AATD-mediated liver disease and thus represents a therapeutic target for inhibition by drugs such as cysteamine. PDI inhibition therefore represents a potential therapeutic approach for treatment of AATD.

Lay summary

Protein disulfide isomerase (PDI) family members, and particularly PDIA4, are upregulated and involved in alpha 1-antitrypsin deficiency (AATD)-mediated liver disease in adults. PDI inhibition upon cysteamine treatment leads to improvements in features of AATD and hence represents a therapeutic approach for treatment of AATD-mediated liver disease.

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PDIA4 is upregulated and involved in alpha 1-antitrypsin deficiency (AATD)-mediated liver disease in adults.

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Knockdown of PDIA4 by siRNA or inhibition upon cysteamine treatment leads to improvements in features of AATD.

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RNA interference against PDIA4 or cysteamine represent approaches for treatment of AATD-mediated liver disease.

The reversion variant (p.Arg90Leu) at the evolutionarily adaptive p.Arg90 site in CELA3B predisposes to chronic pancreatitis

A gain-of-function missense variant in the CELA3B gene, p.Arg90Cys (c.268C>T), has recently been reported to cause pancreatitis in an extended pedigree. Herein, we sequenced the CELA3B gene in 644 genetically unexplained French chronic pancreatitis (CP) patients (all unrelated) and 566 controls. No obvious loss-of-function variants were identified. None of the six low-frequency or common missense variants detected showed significant association with CP. Nor did the aggregate rare/very rare missense variants (n = 14) show any significant association with CP. However, p.Arg90Leu (c.269G>T), which was found in four patients but no controls, and affects the same amino acid as p.Arg90Cys, serves to revert p.Arg90 to the human elastase ancestral allele. As p.Arg90Leu has previously been shown to exert a similar functional effect to that of p.Arg90Cys, our findings not only confirm the involvement of CELA3B in the etiology of CP but also pinpoint a new evolutionarily adaptive site in the human genome.

The blood copper isotopic composition is a prognostic indicator of the hepatic injury in Wilson disease

Wilson disease (WD) is an autosomal recessive disorder of copper (Cu) metabolism. The gene responsible for WD, ATP7B, is involved in the cellular transport of Cu, and mutations in the ATP7B gene induce accumulation of Cu in the liver and ultimately in the brain. In a pilot study, the natural variations of copper stable isotope ratios (⁶⁵Cu/⁶³Cu) in the serum of WD patients have been shown to differ from that of healthy controls. In the present study, we challenged these first results by measuring the ⁶⁵Cu/⁶³Cu ratios in the blood of treated (n = 25), naïve patients (n = 11) and age matched healthy controls (n = 75). The results show that naïve patients and healthy controls exhibit undistinguishable ⁶⁵Cu/⁶³Cu ratios, implying that the Cu isotopic ratio cannot serve as a reliable diagnostic biomarker. The type of treatment (d-penicillamine vs. triethylenetetramine) does not affect the ⁶⁵Cu/⁶³Cu ratios in WD patients, which remain constant regardless of the type and duration of the treatment. In addition, the ⁶⁵Cu/⁶³Cu ratios do not vary in naïve patients after the onset of the treatment. However, the ⁶⁵Cu/⁶³Cu ratios decrease with the degree of liver fibrosis and the gradient of the phenotypic presentation, i.e. presymptomatic, hepatic and neurologic. To get insights into the mechanisms at work, we study the effects of the progress of the WD on the organism by measuring the Cu concentrations and the ⁶⁵Cu/⁶³Cu ratios in the liver, feces and plasma of 12 and 45 week old Atp7b^-/- mice. The evolution of the ⁶⁵Cu/⁶³Cu ratios is marked by a decrease in all tissues. The results show that ⁶³Cu accumulates in the liver preferentially to ⁶⁵Cu due to the preferential cellular entry of ⁶³Cu and the impairment of the ⁶³Cu exit by ceruloplasmin. The hepatic accumulation of monovalent ⁶³Cu⁺ is likely to fuel the production of free radicals, which is potentially an explanation of the pathogenicity of WD. Altogether, the results suggest that the blood ⁶⁵Cu/⁶³Cu ratio recapitulates WD progression and is a potential prognostic biomarker of WD.

Esophageal perforation in eosinophilic esophagitis: five cases in children

Background and study aims  Eosinophilic esophagitis (EoE) is a chronic immune disease with increasing incidence. It is clinically defined by symptoms of esophageal dysfunction and histologically by eosinophilic polynuclear cell infiltration of the esophageal mucosa. Symptoms are not specific and include gastroesophageal reflux disease (GERD), dysphagia, vomiting or dietary blockages. Chronic inflammation of the mucosa may lead to narrowing of the esophageal lumen responsible for impactions. Extraction procedures can be complicated by dissection and perforation. Rare spontaneous ruptures of the esophagus known as Boerhaave syndrome are also possible. We report five cases of esophageal perforation in children with EoE, three with spontaneous rupture and two after an endoscopic procedure. The evolution was favorable under medical treatment.

Infliximab induces clinical resolution of sacroiliitis that coincides with increased circulating FOXP3+ T cells in a patient with IPEX syndrome

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare monogenic primary immunodeficiency due to mutations of FOXP3, a master transcription factor of regulatory T cells (Treg). IPEX syndrome leads to fatal course in most cases during early childhood or severe multi-organ immune-mediated disorders in patients who survive. Currently hematopoietic stem cell transplantation represents the only known effective cure for IPEX syndrome. However, older patients with a mild disease not severe enough to justify transplantation, raise concerns regarding the appropriate therapeutic management, which is therefore based on supportive and replacement therapies combined with pharmacological immunosuppression. Herein, we report the case of a 22-year-old man with an incomplete IPEX syndrome without endocrine disorders having suffered from severe enteropathy since his birth treated with a combination of various immunosuppressant agents. He developed severe exacerbation of inflammatory low back pain in relation to sacroiliitis. Eventually, infliximab was initiated to control his back pain with rapid resolution as well as digestive improvement and also reduced biological inflammatory markers. In parallel, flow cytometry analysis revealed an increase in the frequency of circulating FOXP3+ CD4+ Treg cells. Altogether these data highlight that anti-TNF may represent a promising therapeutic option in patients with IPEX syndrome.

Liver transplantation as a rescue therapy for severe neurologic forms of Wilson disease

OBJECTIVE

To evaluate the effect of liver transplantation (LT) in patients with Wilson disease (WD) with severe neurologic worsening resistant to active chelation.

METHODS

French patients with WD who underwent LT for pure neurologic indication were retrospectively studied. Before LT and at the last follow-up, neurologic impairment was evaluated with the Unified Wilson's Disease Rating Scale (UWDRS) score, disability with the modified Rankin Scale (mRS) score, and hepatic function with the Model for End-stage Liver Disease score, together with the presence of a Kayser-Fleischer ring (KFR), brain MRI scores, and copper balance. The survival rate and disability at the last follow-up were the coprimary outcomes; evolution of KFR and brain MRI were the secondary outcomes. Prognosis factors were further assessed.

RESULTS

Eighteen patients had LT. All were highly dependent before LT (median mRS score 5). Neurologic symptoms were severe (median UWDRS score 105), dominated by dystonia and parkinsonism. The cumulated survival rate was 88.8% at 1 year and 72.2% at 3 and 5 years. At the last follow-up, 14 patients were alive. Their mRS and UWDRS scores improved (p < 0.0001 and p = 0.0003). Eight patients had a major improvement (78% decrease of the UWDRS score), 4 a moderate one (41% decrease), and 2 a stable status. KFR and brain MRI scores improved (p = 0.0007). Severe sepsis (p = 0.011) and intensive care unit admission (p = 0.001) before LT were significantly associated with death.

CONCLUSIONS

LT is a rescue therapeutic option that should be carefully discussed in selected patients with neurologic WD resistant to anticopper therapies (chelators or zinc salts) as it might allow patients to gain physical independency with a reasonable risk.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for patients with WD with severe neurologic worsening resistant to active pharmacologic therapy, LT might decrease neurologic impairment.

Children with eosinophilic esophagitis in real life: 10 years' experience with a focus on allergic management

INTRODUCTION AND OBJECTIVES

Eosinophilic esophagitis (EoE) is frequently miss-diagnosed or overlooked for several years because of the invasiveness of investigations and the non-specificity of symptoms in childhood. Due to the lack of specific recommendations in children, its management remains very heterogeneous, especially concerning allergy testing. The aim of this study is to analyze our population and practices, in comparison with the literature, with a focus on allergic management, to harmonize and optimize our practice.

MATERIAL AND METHODS

We included all children with a diagnosis of EoE at the Hospital Femme Mere Enfant, Bron, France. Data were collected via retrospective chart review.

RESULTS

108 patients were included with an average age of 9.5 years. Average delay before diagnosis was 6.65 years. Symptoms varied with age, with a predominance of vomiting (60% of patients), feeding difficulties (72%) and growth difficulties (24%) in children <5 years, whereas older children often presented with feeding blockage (64%) and dysphagia (61%). Cough was frequent in our cohort (18.5%), especially in children <10 years (38.5% between three and five years). The allergic background was frequent (70.3%) and 80% of our patients benefited from allergy testing. Allergy testing was particularly useful to guide therapy as elimination diet represented an effective treatment in 60% of our patients CONCLUSIONS: Allergy testing has to be harmonized to include major allergens (egg, milk, peanut, fish, wheat, and soy), including prick and patch tests. Allergy-testing based diet seemed to be the best compromise between efficiency and constraints, especially in mono-sensitized patients.

Comprehensive and comparative exploration of the Atp7b−/− mouse plasma proteome

Wilson's disease (WD) is a rare genetic disease caused by mutations in the ATP7B gene. In this study, we used MS-based proteomics to explore the plasma proteome of the Atp7b^−/− mouse, a genetic and phenotypic model for WD.

Efficacy and safety of tacrolimus in de novo pediatric transplant recipients randomized to receive immediate- or prolonged-release tacrolimus

BACKGROUND AND AIMS

This multicenter trial compared immediate-release tacrolimus (IR-T) vs prolonged-release tacrolimus (PR-T) in de novo kidney, liver, and heart transplant recipients aged <16 years. Each formulation had similar pharmacokinetic (PK) profiles. Follow-up efficacy and safety results are reported herein.

MATERIALS AND METHODS

Patients, randomized 1:1, received once-daily, PR-T or twice-daily, IR-T within 4 days of surgery. After a 4-week PK assessment, patients continued randomized treatment for 48 additional weeks. At Year 1, efficacy assessments included the number of clinical acute rejections, biopsy-confirmed acute rejection (BCAR) episodes (including severity), patient and graft survival, and efficacy failure (composite of death, graft loss, BCAR, or unknown outcome). Adverse events were assessed throughout.

RESULTS

The study included 44 children. At Year 1, mean ± standard deviation tacrolimus trough levels were 6.6 ± 2.2 and 5.4 ± 1.6 ng/mL, and there were 2 and 7 acute rejection episodes in the PR-T and IR-T groups, respectively. No cases of graft loss or death were reported during the study. The overall efficacy failure rate was 18.2% (PR-T n = 1; IR-T n = 7).

CONCLUSIONS

In pediatric de novo solid organ recipients, the low incidence of BCAR and low efficacy failure rate suggest that PR-T-based immunosuppression is effective and well tolerated to 1-year post-transplantation.

Liver disease related to alpha1-antitrypsin deficiency in French children: The DEFI-ALPHA cohort

BACKGROUND & AIMS

To identify prognostic factors for liver disease in children with alpha-1 antitrypsin deficiency, irrespective of phenotype, using the DEFI-ALPHA cohort.

METHODS

Retrospective, then prospective from 2010, multicentre study including children known to have alpha-1 antitrypsin blood concentration below 0.8 g/L, born in France since 1989. Clinical and biological data were collected. Liver disease was classified as "severe" (portal hypertension, liver failure, liver transplantation or death); "moderate" (persistent abnormal liver biology without portal hypertension); and "mild/none" (normal or almost normal liver biology and native liver). Prognostic factors for severe liver disease were evaluated using a Cox semiparametric model.

RESULTS

In January 2017, 153 patients from 19 centres had been included; genotypes were PIZZ in 81.9%, PISZ in 8.1%, other in 10.0%. Mean ± SD follow-up was 4.7 ± 2.1 years. Half of patients had moderate liver disease. Twenty-eight children (18.3%) had severe liver disease (mean age 2.5 years, range: 0-11.6): diagnosis of alpha-1 antitrypsin deficiency was made before two months of age in 65.4%, genotypes were PIZZ in 25 (89.3%), PISZ in 2, PIM_like Z in 1, 15 children underwent liver transplantation, 1 child died at 3 years of age. Neonatal cholestasis was significantly associated with severe liver disease (P = 0.007).

CONCLUSION

Alpha-1 antitrypsin-deficient patients presenting with neonatal cholestasis were likely to develop severe liver disease. Some patients with non-homozygous ZZ genotype can develop severe liver disease, such as PISZ and M variants, when associated with predisposing factors. Further genetic studies will help to identify other factors involved in the development of liver complications.

Normal serum ApoB48 and red cells vitamin E concentrations after supplementation in a novel compound heterozygous case of abetalipoproteinemia

BACKGROUND AND AIMS

Abetalipoproteinemia (ABL) is a rare recessive monogenic disease due to MTTP (microsomal triglyceride transfer protein) mutations leading to the absence of plasma apoB-containing lipoproteins. Here we characterize a new ABL case with usual clinical phenotype, hypocholesterolemia, hypotriglyceridemia but normal serum apolipoprotein B48 (apoB48) and red blood cell vitamin E concentrations.

METHODS

Histology and MTP activity measurements were performed on intestinal biopsies. Mutations in MTTP were identified by Sanger sequencing, quantitative digital droplet and long-range PCR. Functional consequences of the variants were studied in vitro using a minigene splicing assay, measurement of MTP activity and apoB48 secretion.

RESULTS

Intestinal steatosis and the absence of measurable lipid transfer activity in intestinal protein extract supported the diagnosis of ABL. A novel MTTP c.1868G>T variant inherited from the patient's father was identified. This variant gives rise to three mRNA transcripts: one normally spliced, found at a low frequency in intestinal biopsy, carrying the p.(Arg623Leu) missense variant, producing in vitro 65% of normal MTP activity and apoB48 secretion, and two abnormally spliced transcripts resulting in a non-functional MTP protein. Digital droplet PCR and long-range sequencing revealed a previously described c.1067+1217_1141del allele inherited from the mother, removing exon 10. Thus, the patient is compound heterozygous for two dysfunctional MTTP alleles. The p.(Arg623Leu) variant may maintain residual secretion of apoB48.

CONCLUSIONS

Complex cases of primary dyslipidemia require the use of a cascade of different methodologies to establish the diagnosis in patients with non-classical biological phenotypes and provide better knowledge on the regulation of lipid metabolism.

Assessment of liver fibrosis by transient elastography (Fibroscan®) in patients with A1AT deficiency

BACKGROUND

Alpha-1-antitrypsin deficiency (A1ATD) is a common genetic condition which predisposes to emphysema and liver disorders. It is estimated that 10-15% of homozygous individuals for the Z allele (PiZZ) may develop liver fibrosis. The optimal modalities to detect liver disease in PiZZ adult patients need to be defined. The aim of this prospective study was to perform a systematic non-invasive evaluation of the liver fibrosis by elastometry using Fibroscan^® in a cohort of A1ATD patients with emphysema.

METHODS

Patients followed in our respiratory unit were enrolled in this prospective study and underwent on the same day a physical examination, a biochemical profiling, an abdominal ultrasound (US) and a Fibroscan^®.

RESULTS

Twenty-nine PiZZ adults (19 male) were included. Median age was 50.4 yrs (21.5-67.2). Median serum A1AT level was 0.20 g/L (0.15-0.33). Liver Function Tests (LFT) were not normal in 2 patients and US was abnormal in 6 patients. Two patients had both abdnormal LFT and US. Fibroscan^® was technically feasible in 28/29 (97%) patients. Median liver stiffness was 4.5 kPa (2.8-32.8), and was > 7.2 kPa in 5/28 (18%) and > 14 kPa in 2/28 (7%) patients. Liver stiffness was increased in 2/2 (100%) patients with abnormal LFT and US, in 1/4 (25%) with abnormal LFT or US and in 2/22 (10%) patients with normal LFT and US.

CONCLUSIONS

Fibroscan^® is an easy and repeatable tool which can be used in PiZZ patients to screen for the presence of significant liver fibrosis and to identify patients at higher risk to develop liver complications in the future and who may benefit from a closer surveillance.

Screening of esophageal varices in children using esophageal capsule endoscopy: a multicenter prospective study

BACKGROUND

Esophagogastroduodenoscopy (EGD) is the standard method for diagnosis of esophageal and gastric varices in children. In this prospective study we evaluated the use of PillCam esophageal capsule endoscopy (ECE) in pediatric patients.

METHODS

Patients aged 7 to 18 years presenting with portal hypertension and/or cirrhosis underwent ECE (PillCam ESO 2, Given Imaging Ltd.) followed by EGD.

RESULTS

102 patients were screened, 81 (52 boys; mean age 13.96 ± 0.25 years) were included and 21 were excluded (16 for "candy test" failure). Esophageal varices were identified by EGD in 62 patients (77 %) and by ECE in 57 patients (70 %) using the de Franchis classification (DFC). The sensitivity of ECE for esophageal varices was 92 % and the specificity was 100 % using DFC. Based upon 57/81 patients with small, medium, and large varices on both ECE and EGD, using DFC, the sensitivity, specificity, positive (PPV) and negative predictive value (NPV) were 55 %, 92 %, 89 %, and 63 %, respectively, giving a total overall accuracy of 72 %. To improve sensitivity and specificity in classification of esophageal varices, we propose using a modified score. This score detected esophageal varices with 100 % sensitivity, 93 % specificity, 94 % PPV, and 100 % NPV, giving a total overall accuracy of 97 %. All patients preferred ECE over EGD. No capsule retention was recorded.

CONCLUSIONS

ECE is a well-tolerated and safe procedure in children. Using the modified score, the sensitivity of ECE is currently sufficient to detect esophageal varices and replace EGD in infants with suspicion of esophageal varices or when EGD is refused.

Red Blood cell IMPDH activity in adults and children with or without azathioprine: Relationship between thiopurine metabolites, ITPA and TPMT activities

Inosine monophosphate dehydrogenase (IMPDH) is considered as the limiting enzyme of thiopurine metabolism for the formation of 6-thioguanine nucleotides (6-TGN). No data are available on the influence of RBC IMPDH activity on the metabolism of thiopurine drugs in individuals with IBD. The aims of this study were as follows: (a) to carry out a phenotypic study of RBC IMPDH activity in adults and children treated or not with azathioprine (AZA) for autoimmune diseases, and (b) to investigate the relationship between the activities of IMPDH, thiopurine metabolites, inosine triphosphatase (ITPA) and thiopurine methyltransferase (TPMT). IMPDH activity was determined in 97 adults and 67 children treated or not with AZA. 6-Thioguanine nucleotides (6-TGN), 6-methylmercaptopurine nucleotide (6-MeMPN) levels, and ITPA as well as TPMT activities were measured in RBCs by HPLC. Using the Gaussian mixture model, distribution of IMPDH activity was evaluated. Influence of age, sex and AZA treatment on IMPDH activity was also assessed. A bimodal distribution in IMPDH activity was found with 87% of patients exhibiting normal activity and 13% of patients with high activity. No influence of age, sex and AZA therapy was found. There is no relationship between TPMT, ITPA and IMPDH activities. A negative correlation between IMPDH activity and 6-MeMPN was shown in adults and children (rs = -0.335 P = 0.014 and rs = -0.383 P = 0.012, respectively). Our results suggest that AZA-treated patients exhibiting lower IMPDH activity could have higher Me-6MPN levels with higher risk of hepatotoxicity. We demonstrated that RBC matrix could be an interesting alternative to lymphocyte matrix to monitor thiopurine metabolites and enzyme activity.

Comparative pharmacokinetics of tacrolimus in de novo pediatric transplant recipients randomized to receive immediate- or prolonged-release tacrolimus

Phase 2, parallel-group, multicenter, open-label, 4-week study, comparing PK of PR-T vs IR-T in de novo pediatric patients undergoing primary kidney, liver, or heart transplantation. Patients randomized 1:1 to receive once daily, PR-T-, or twice-daily, IR-T-based regimens; dose adjustments permitted after Day 1. Twenty-four-hour PK profiles collected on Days 1, 7, and 28. Primary endpoint: tacrolimus AUC₂₄ . Secondary end points included tacrolimus C₂₄ and C_max . Endpoints compared between PR-T and IR-T on Days 1, 7, and 28. Predefined similarity interval for CIs of LSM ratios: 80%-125%. PK analysis set comprised 33 patients (PR-T, n = 15; IR-T, n = 18). Overall, AUC₂₄ and C_max were lower on Day 1 vs 7 and 28. Geometric LSM ratios of PR-T:IR-T on Days 1, 7, and 28 were 66.3%, 92.5%, 99.9%, respectively, for AUC₂₄ ; 66.3%, 82.2%, 90.9% for C₂₄ ; and 77.3%, 120.3%, 92.2% for C_max . AUC₂₄ 90% CI within predefined similarity interval on Day 28; other 90% CIs fell outside. Linear relationship was similar between AUC₂₄ and C₂₄ , and between tacrolimus formulations, suggesting that the same therapeutic drug monitoring method can be used with both formulations in de novo pediatric allograft recipients.

Evaluation of the accuracy of exchangeable copper and relative exchangeable copper (REC) in a mouse model of Wilson's disease

Wilson's disease (WD) is caused by mutations in the ATP7B gene responsible for a toxic copper overload mainly in the liver and the central nervous system. Phenotypic heterogeneity may challenge the diagnostic confirmation. Exchangeable copper (CuEXC) has recently been proposed as a new marker of WD, and its ratio to the total serum copper (Cus), Relative Exchangeable Copper (REC = CuEXC/Cus), as a diagnostic marker. This study aimed to investigate whether this could be confirmed in Atp7b^-/- mice, an engineered WD animal model. Atp7b^-/- (n = 137) and wild type (WT; n = 101) mice were investigated under the same conditions at 6-8, 20, 39, or 50 weeks of age. Twenty-four Atp7b^-/- mice received D-penicillamine treatment from 39 to 50 weeks of age. Serum and liver [histology and intrahepatic copper (IHCu)] data were evaluated. In the WT group, all serum and liver data were normal. Atp7b^-/- livers developed a chronic injury from isolated moderate inflammation (6-8 weeks: 16/33 = 48%) to inflammatory fibrosis with cirrhosis (50 weeks: 25/25 = 100% and 16/25 = 64% respectively). Cus and CuEXC increased until week 39, whereas IHCu and REC were stable with increasing age and much higher than in WT mice (mean ± SD: 669 ± 269 vs. 13 ± 3 μg/g dry liver and 39 ± 12 vs. 11 ± 3%, respectively). A threshold value of 20% for REC provided a diagnostic sensitivity and specificity of 100%, regardless of sex, age, or the use of D-penicillamine. Eleven weeks of 100 mg/kg D-penicillamine reduced liver fibrosis (p = 0.001), IHCu (p = 0.026) and CuEXC (p = 0.175). In conclusion, this study confirms REC as a WD diagnostic marker in a mouse model of chronic liver disease caused by copper overload. Further studies are needed to assess the usefulness of CuEXC to monitor the evolution of WD, particularly during treatment.