Event-free survival of maralixibat-treated patients with Alagille syndrome compared to a real-world cohort from GALA

BACKGROUND AND AIMS

Alagille syndrome (ALGS) is characterized by chronic cholestasis with associated pruritus and extrahepatic anomalies. Maralixibat, an ileal bile acid transporter inhibitor, is an approved pharmacologic therapy for cholestatic pruritus in ALGS. Since long-term placebo-controlled studies are not feasible or ethical in children with rare diseases, a novel approach was taken comparing 6-year outcomes from maralixibat trials with an aligned and harmonized natural history cohort from the G lobal AL agille A lliance (GALA) study.

APPROACH AND RESULTS

Maralixibat trials comprise 84 patients with ALGS with up to 6 years of treatment. GALA contains retrospective data from 1438 participants. GALA was filtered to align with key maralixibat eligibility criteria, yielding 469 participants. Serum bile acids could not be included in the GALA filtering criteria as these are not routinely performed in clinical practice. Index time was determined through maximum likelihood estimation in an effort to align the disease severity between the two cohorts with the initiation of maralixibat. Event-free survival, defined as the time to first event of manifestations of portal hypertension (variceal bleeding, ascites requiring therapy), surgical biliary diversion, liver transplant, or death, was analyzed by Cox proportional hazards methods. Sensitivity analyses and adjustments for covariates were applied. Age, total bilirubin, gamma-glutamyl transferase, and alanine aminotransferase were balanced between groups with no statistical differences. Event-free survival in the maralixibat cohort was significantly better than the GALA cohort (HR, 0.305; 95% CI, 0.189-0.491; p <0.0001). Multiple sensitivity and subgroup analyses (including serum bile acid availability) showed similar findings.

CONCLUSIONS

This study demonstrates a novel application of a robust statistical method to evaluate outcomes in long-term intervention studies where placebo comparisons are not feasible, providing wide application for rare diseases. This comparison with real-world natural history data suggests that maralixibat improves event-free survival in patients with ALGS.

Relevance of next generation sequencing (NGS) data re-analysis in the diagnosis of monogenic diseases leading to organ failure

BACKGROUND

In 2018, our center started a program to offer genetic diagnosis to patients with kidney and liver monogenic rare conditions, potentially eligible for organ transplantation. We exploited a clinical exome sequencing approach, followed by analyses of in silico gene panels tailored to clinical suspicions, obtaining detection rates in line with what reported in literature. However, a percentage of patients remains without a definitive genetic diagnosis. This work aims to evaluate the utility of NGS data re-analysis for those patients with an inconclusive or negative genetic test at the time of first analysis considering that (i) the advance of alignment and variant calling processes progressively improve the detection rate, limiting false positives and false negatives; (ii) gene panels are periodically updated and (iii) variant annotation may change over time.

METHODS

114 patients, recruited between 2018 and 2020, with an inconclusive or negative NGS report at the time of first analysis, were included in the study. Re-alignment and variant calling of previously generated sequencing raw data were performed using the GenomSys Variant Analyzer software.

RESULTS

21 previously not reported potentially causative variants were identified in 20 patients. In most cases (n = 19), causal variants were retrieved out of the re-classification from likely benign to variants of unknown significance (VUS). In one case, the variant was included because of inclusion in the analysis of a newly disease-associated gene, not present in the original gene panel, and in another one due to the improved data alignment process. Whenever possible, variants were validated with Sanger sequencing and family segregation studies. As of now, 16 out of 20 patients have been analyzed and variants confirmed in 8 patients. Specifically, in two pediatric patients, causative variants were de novo mutations while in the others, the variant was present also in other affected relatives. In the remaining patients, variants were present also in non-affected parents, raising questions on their re-classification.

CONCLUSIONS

Overall, these data indicate that periodic and systematic re-analysis of negative or inconclusive NGS data reports can lead to new variant identification or reclassification in a small but significant proportion of cases, with benefits for patients' management.

Long-term outcomes and health-related quality of life 20 years after pediatric liver transplantation

Pediatric liver transplantation is a challenging surgical procedure requiring complex post-transplant patient management. Liver transplantation in children should ensure long-term survival and good health-related quality of life (HR-QOL), but data in the literature are conflicting. With the aim of investigating survival and psychosocial outcomes of patients transplanted during childhood, we identified 40 patients with ≥ 20-year follow-up after liver transplantation regularly followed up at our Institution. Clinical charts were reviewed to retrieve patients' data. Psychosocial aspects and HR-QOL were investigated by an in-person or telephonic interview and by administering the WHOQOL-BREF questionnaire through an online form. Ten- and 20-year patient survival was 97.5% (95% CI 92.8-100%), whereas 10- and 20-year graft survival was 77.5% (65.6-91.6%) and 74.8% (62.5-89.6%), respectively. At last follow-up visit, 31 patients (77.5%) were receiving a tacrolimus-based immunosuppression. Twelve (32.4%) patients obtained a university diploma or higher, whereas 19 (51.4%) successfully completed high school. 81.1% of patients were active workers or in education, 17.5% had children, and 35% regularly practiced sport. 25 patients answered to the WHOQOL-BREF questionnaire. More than 60% of respondents did not report any disability and the perceived physical status was invariably good or very good. Median scores for physical health, psychological health, social relationships, and environment were 16.6, 14.7, 16, and 15, respectively. Pediatric liver transplantation is associated with excellent long-term survival and good HR-QOL. Psychological health and environment represent areas in which support would be needed to further improve HR-QOL.

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.

Inadequate Hospital Practices to Prevent Mother-to-Child Transmission of Hepatitis B Virus Infection: A European Survey

OBJECTIVES

Prevention of vertical transmission of hepatitis B virus (HBV) infection is crucial to eliminate viral hepatitis as a major public health threat by 2030. We aimed to assess the current hospital policies and practices implemented before, at, and after birth, and to evaluate potential barriers to the full application of international guidelines.

METHODS

A web-based survey was supported by PENTA Foundation and distributed across Europe from October to December 2021.

RESULTS

Overall, 76 centers with delivery departments completed the survey. Hepatitis B surface antigen (HBsAg) maternal screening is performed in the first trimester of pregnancy in 53% of the centers and in the third in 46%. HBsAg positive pregnant women are tested for serologic HBV markers and HBV-DNA in 78% and 63% of the departments; 38% of the HBeAg positive women with high HBV-DNA levels are treated during the last trimester of pregnancy. At birth, 91% of the departments administer HBV vaccine to infants born to HBsAg positive mothers within 12 hours of birth; 74% test women with unknown HBsAg status and 78% of them wait for the maternal testing results before administering HBV vaccine to their newborns. After birth, 47% of the departments provide postvaccination serological testing for infants born to HBsAg positive mothers. The timing of the HBV vaccine schedule varies greatly.

CONCLUSIONS

There is significant heterogeneity in the hospital policies and correlated procedures. The implementation of a multidisciplinary clinical pathway is a must if a stronger connection between the prenatal, perinatal, and postnatal phases is to be established.

Jansen-de Vries syndrome: Expansion of the PPM1D clinical and phenotypic spectrum in 34 families

Jansen-de Vries syndrome (JdVS) is a neurodevelopmental condition attributed to pathogenic variants in Exons 5 and 6 of PPM1D. As the full phenotypic spectrum and natural history remain to be defined, we describe a large cohort of children and adults with JdVS. This is a retrospective cohort study of 37 individuals from 34 families with disease-causing variants in PPM1D leading to JdVS. Clinical data were provided by treating physicians and/or families. Of the 37 individuals, 27 were male and 10 female, with median age 8.75 years (range 8 months to 62 years). Four families document autosomal dominant transmission, and 32/34 probands were diagnosed via exome sequencing. The facial gestalt, including a broad forehead and broad mouth with a thin and tented upper lip, was most recognizable between 18 and 48 months of age. Common manifestations included global developmental delay (35/36, 97%), hypotonia (25/34, 74%), short stature (14/33, 42%), constipation (22/31, 71%), and cyclic vomiting (6/35, 17%). Distinctive personality traits include a hypersocial affect (21/31, 68%) and moderate-to-severe anxiety (18/28, 64%). In conclusion, JdVS is a clinically recognizable neurodevelopmental syndrome with a characteristic personality and distinctive facial features. The association of pathogenic variants in PPM1D with cyclic vomiting bears not only medical attention but also further pathogenic and mechanistic evaluation.

A Case of Paradoxical Arthralgia Following Anti-TNF Monoclonal Antibody Administration in a Patient With New-Onset Pediatric Crohn's Disease

Anti-TNF antibodies have become a first-line therapy in moderate-to-severe inflammatory bowel diseases. However, there may be some rare paradoxical events and those affecting joints causing severe symptoms need a scrupulous differential diagnosis. When these events occur, it may be necessary to discontinue treatment and shift to another drug class. Herein, we report the case of a 15-year-old boy affected by Crohn's disease, who developed a paradoxical reaction after the second dose of infliximab. Clinical remission was achieved shifting to budesonide and azathioprine and continuing maintenance therapy with azathioprine alone. To date, no other paradoxical events have occurred.

Natural history of liver disease in a large international cohort of children with Alagille syndrome: Results from the GALA study

BACKGROUND AND AIMS

Alagille syndrome (ALGS) is a multisystem disorder, characterized by cholestasis. Existing outcome data are largely derived from tertiary centers, and real-world data are lacking. This study aimed to elucidate the natural history of liver disease in a contemporary, international cohort of children with ALGS.

APPROACH AND RESULTS

This was a multicenter retrospective study of children with a clinically and/or genetically confirmed ALGS diagnosis, born between January 1997 and August 2019. Native liver survival (NLS) and event-free survival rates were assessed. Cox models were constructed to identify early biochemical predictors of clinically evident portal hypertension (CEPH) and NLS. In total, 1433 children (57% male) from 67 centers in 29 countries were included. The 10 and 18-year NLS rates were 54.4% and 40.3%. By 10 and 18 years, 51.5% and 66.0% of children with ALGS experienced ≥1 adverse liver-related event (CEPH, transplant, or death). Children (>6 and ≤12 months) with median total bilirubin (TB) levels between ≥5.0 and <10.0 mg/dl had a 4.1-fold (95% confidence interval [CI], 1.6-10.8), and those ≥10.0 mg/dl had an 8.0-fold (95% CI, 3.4-18.4) increased risk of developing CEPH compared with those <5.0 mg/dl. Median TB levels between ≥5.0 and <10.0 mg/dl and >10.0 mg/dl were associated with a 4.8 (95% CI, 2.4-9.7) and 15.6 (95% CI, 8.7-28.2) increased risk of transplantation relative to <5.0 mg/dl. Median TB <5.0 mg/dl were associated with higher NLS rates relative to ≥5.0 mg/dl, with 79% reaching adulthood with native liver ( p < 0.001).

CONCLUSIONS

In this large international cohort of ALGS, only 40.3% of children reach adulthood with their native liver. A TB <5.0 mg/dl between 6 and 12 months of age is associated with better hepatic outcomes. These thresholds provide clinicians with an objective tool to assist with clinical decision-making and in the evaluation of therapies.

Gluten-free diet affects fecal small non-coding RNA profiles and microbiome composition in celiac disease supporting a host-gut microbiota crosstalk

Current treatment for celiac disease (CD) is adhering to a gluten-free diet (GFD), although its long-term molecular effects are still undescribed. New molecular features detectable in stool may improve and facilitate noninvasive clinical management of CD. For this purpose, fecal small non-coding RNAs (sncRNAs) and gut microbiome profiles were concomitantly explored in CD subjects in relation to strict (or not) GFD adherence over time. In this observational study, we performed small RNA and shotgun metagenomic sequencing in stool from 63 treated CD (tCD) and 3 untreated subjects as well as 66 sex- and age-matched healthy controls. tCD included 51 individuals on strict GFD and with negative transglutaminase (TG) serology (tCD-TG-) and 12 symptomatic with not strict/short-time of GFD adherence and positive TG serology (tCD-TG+). Samples from additional 40 healthy adult individuals and a cohort of 19 untreated pediatric CD subjects and 19 sex/age matched controls were analyzed to further test the outcomes. Several miRNA and microbial profiles were altered in tCD subjects (adj. p < .05). Findings were validated in the external group of adult controls. In tCD-TG-, GFD duration correlated with five miRNA levels (p < .05): for miR-4533-3p and miR-2681-3p, the longer the diet adherence, the less the expression differed from controls. tCD-TG+ and untreated pediatric CD patients showed a similar miRNA dysregulation. Immune-response, trans-membrane transport and cell death pathways were enriched in targets of identified miRNAs. Bifidobacterium longum, Ruminococcus bicirculans, and Haemophilus parainfluenzae abundances shifted (adj. p < .05) with a progressive reduction of denitrification pathways with GFD length. Integrative analysis highlighted 121 miRNA-bacterial relationships (adj. p < .05). Specific molecular patterns in stool characterize CD subjects, reflecting either the long-term GFD effects or the gut inflammatory status, in case of a not strict/short-time adherence. Our findings suggest novel host-microbial interplays and could help the discovery of biomarkers for GFD monitoring over time.

New case of syncytial giant-cell variant of hepatocellular carcinoma in a pediatric patient with HNF1B deficiency: does it fit with the syndrome?

BACKGROUND

Hepatocyte nuclear factor 1B (HNF1B) is a member of the homeodomain-containing family of transcription factors located on 17q12. HNF1B deficiency is associated with a clinical syndrome (kidney and urogenital malformations, maturity-onset diabetes of the young, exocrine pancreatic insufficiency) and to an underdiagnosed liver involvement. Differently from HNF1A, the correlation between hepatocellular carcinoma (HCC) and germline HNF1B deficiency has been poorly evaluated.

CASE REPORT

Here, we report a novel case of a syndromic HNF1B-deficient paediatric patient that developed HCC with unique histopathological features characterised by neoplastic syncytial giant cells, which was observed only in one additional case of paediatric cholestatic liver disease of unknown origin.

CONCLUSIONS

Our case highlights the influence of HNF1B deficiency in liver disease progression and its putative association with a rare yet specific HCC histotype. We hypothesised that HCC could be secondary to the repressive effect of HNF1B variant on the HNF1A transcriptional activity.

Genotype-phenotype relationships of truncating mutations, p.E297G and p.D482G in bile salt export pump deficiency

Background & Aims

Bile salt export pump (BSEP) deficiency frequently necessitates liver transplantation in childhood. In contrast to two predicted protein truncating mutations (PPTMs), homozygous p.D482G or p.E297G mutations are associated with relatively mild phenotypes, responsive to surgical interruption of the enterohepatic circulation (siEHC). The phenotype of patients with a compound heterozygous genotype of one p.D482G or p.E297G mutation and one PPTM has remained unclear. We aimed to assess their genotype-phenotype relationship.

Methods

From the NAPPED database, we selected patients with homozygous p.D482G or p.E297G mutations (BSEP1/1; n = 31), with one p.D482G or p.E297G, and one PPTM (BSEP1/3; n = 30), and with two PPTMs (BSEP3/3; n = 77). We compared clinical presentation, native liver survival (NLS), and the effect of siEHC on NLS.

Results

The groups had a similar median age at presentation (0.7-1.3 years). Overall NLS at age 10 years was 21% in BSEP1/3 vs. 75% in BSEP1/1 and 23% in BSEP3/3 (p <0.001). Without siEHC, NLS in the BSEP1/3 group was similar to that in BSEP3/3, but considerably lower than in BSEP1/1 (at age 10 years: 38%, 30%, and 71%, respectively; p = 0.003). After siEHC, BSEP1/3 and BSEP3/3 were associated with similarly low NLS, while NLS was much higher in BSEP1/1 (10 years after siEHC, 27%, 14%, and 92%, respectively; p <0.001).

Conclusions

Individuals with BSEP deficiency with one p.E297G or p.D482G mutation and one PPTM have a similarly severe disease course and low responsiveness to siEHC as those with two PPTMs. This identifies a considerable subgroup of patients who are unlikely to benefit from interruption of the enterohepatic circulation by either surgical or ileal bile acid transporter inhibitor treatment.

Impact and implications

This manuscript defines the clinical features and prognosis of individuals with BSEP deficiency involving the combination of one relatively mild and one very severe BSEP deficiency mutation. Until now, it had always been assumed that the mild mutation would be enough to ensure a relatively good prognosis. However, our manuscript shows that the prognosis of these patients is just as poor as that of patients with two severe mutations. They do not respond to biliary diversion surgery and will likely not respond to the new IBAT (ileal bile acid transporter) inhibitors, which have recently been approved for use in BSEP deficiency.

Renal outcome and plasma methylmalonic acid levels after isolated or combined liver or kidney transplantation in patients with methylmalonic acidemia: A multicenter analysis

BACKGROUND

Methylmalonic acidemia (MMAemia) is characterized by accumulation of methylmalonic acid (MMA) in all body tissues. To minimize disease-related complications, isolated kidney (KTx), liver (LTx) or combined liver-kidney transplantation (LKTx) have been suggested. However, the impact of these different transplant strategies on outcome are unclear.

METHODS

In this multicenter retrospective observational study, we compared plasma MMA levels and estimated glomerular filtration rate (eGFR) data of 83 patients. Sixty-eight patients (82%) had a mut⁰-type MMAemia, one patient had a mut^--type MMAemia, and seven (7.3%) had an inherited defect in cobalamin metabolism (cblA- or cblB-type MMAemia). Median observation period was 3.7 years (0-15.1 years).

RESULTS

Twenty-six (31%) patients underwent KTx, 24 (29%) LTx and 33 (40%) LKTx. Posttransplant, mean plasma MMA concentration significantly decreased in all three cohorts; but at month 12, plasma MMA in KTx (1372 ± 1101 μmol/L) was 7.8-fold higher than in LTx (176 ± 103 μmol/L; P < 0.001) and 6.4-fold higher than in LKTx (215 ± 110 μmol/L; P < 0.001). Comparable data were observed at month 24. At time of transplantation, mean eGFR in KTx was 18.1 ± 24.3 mL/min/1.73 m², in LTx 99.8 ± 29.9 mL/min/1.73 m², and in LKTx 31.5 ± 21.2 mL/min/1.73 m². At month 12 posttransplant, mean eGFR in KTx (62.3 ± 30.3 mL/min/1.73 m²) was 33.4% lower than in LTx (93.5 ± 18.3 mL/min/1.73 m²; P = 0.0053) and 25.4% lower than in LKTx (83.5 ± 26.9 mL/min/1.73 m²; P = 0.0403).

CONCLUSIONS

In patients with isolated MMAemia, LTx and LKTx lead to markedly lower plasma MMA levels during the first 2 years posttransplant than KTx and are associated with a better preservation of kidney function. LTx should therefore be part of the transplant strategy in MMAemia.

Diagnostic approach to neonatal and infantile cholestasis: A position paper by the SIGENP liver disease working group

Neonatal and infantile cholestasis (NIC) can represent the onset of a surgically correctable disease and of a genetic or metabolic disorder worthy of medical treatment. Timely recognition of NIC and identification of the underlying etiology are paramount to improve outcomes. Upon invitation by the Italian National Institute of Health (ISS), an expert working grouped was formed to formulate evidence-based positions on current knowledge about the diagnosis of NIC. A systematic literature search was conducted to collect evidence about epidemiology, etiology, clinical aspects and accuracy of available diagnostic tests in NIC. Evidence was scored using the GRADE system. All recommendations were approved by a panel of experts upon agreement of at least 75% of the members. The final document was approved by all the panel components. This position document summarizes the collected statements and defines the best-evidence diagnostic approach to cholestasis in the first year of life.

Monitoring Tacrolimus Concentrations in Whole Blood and Peripheral Blood Mononuclear Cells: Inter- and Intra-Patient Variability in a Cohort of Pediatric Patients

Tacrolimus (TAC) is a first-choice immunosuppressant for solid organ transplantation, characterized by high potential for drug-drug interactions, significant inter- and intra-patient variability, and narrow therapeutic index. Therapeutic drug monitoring (TDM) of TAC concentrations in whole blood (WB) is capable of reducing the incidence of adverse events. Since TAC acts within lymphocytes, its monitoring in peripheral blood mononuclear cells (PBMC) may represent a valid future alternative for TDM. Nevertheless, TAC intracellular concentrations and their variability are poorly described, particularly in the pediatric context. Therefore, our aim was describing TAC concentrations in WB and PBMC and their variability in a cohort of pediatric patients undergoing constant immunosuppressive maintenance therapy, after liver transplantation. TAC intra-PBMCs quantification was performed through a validated UHPLC–MS/MS assay over a period of 2–3 months. There were 27 patients included in this study. No significant TAC changes in intracellular concentrations were observed (p = 0.710), with a median percent change of −0.1% (IQR −22.4%–+46.9%) between timings: this intra-individual variability was similar to the one in WB, −2.9% (IQR −29.4–+42.1; p = 0.902). Among different patients, TAC weight-adjusted dose and age appeared to be significant predictors of TAC concentrations in WB and PBMC. Intra-individual seasonal variation of TAC concentrations in WB, but not in PBMC, have been observed. These data show that the intra-individual variability in TAC intracellular exposure is comparable to the one observed in WB. This opens the way for further studies aiming at the identification of therapeutic ranges for TAC intra-PBMC concentrations.

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.

Overexpression of endogenous retroviruses in children with celiac disease

Human endogenous retroviruses (HERVs) represent 8% of our genome. Although no longer infectious, they can regulate transcription of adjacent cellular genes, produce retroviral RNAs, and encode viral proteins that can modulate both innate and adaptive immune responses. Based on this, HERVs have been studied and proposed as contributing factors in various autoimmune disorders. Celiac disease (CD) is considered an autoimmune disease, but HERV expression has not been studied in celiac patients. The aim of this study is to assess the transcription levels of pol genes of HERV-H, -K, and -W and of their TRIM28 repressor in WBCs from celiac children and age-matched control subjects. A PCR real-time TaqMan amplification assay was used to evaluate HERV and TRIM28 transcripts with normalization of the results to glyceraldehyde-3-phosphate dehydrogenase. The RNA levels of pol genes of the three HERV families were significantly higher in WBCs from 38 celiac patients than from 51 control subjects. TRIM28 transcription was comparable between the two study populations.Conclusion: Present results show, for the first time, that pol genes of HERV-H, -K, and -W are overexpressed in patients with CD. Given their proinflammatory and autoimmune properties, this suggests that HERVs may contribute to the development of CD in susceptible individuals. What is Known: • Based on this, HERVs have been studied and proposed as contributing factors in various autoimmune disorders. What is New: • Present results show, for the first time, that pol genes of HERV-H, -K, and -W are overexpressed in patients with CD.

Combined liver kidney transplantation for primary hyperoxaluria type 1: Will there still be a future? Current transplantation strategies and monocentric experience

Combined liver-kidney transplantation is a therapeutic option for children affected by type 1 primary hyperoxaluria. Persistently high plasma oxalate levels may lead to kidney graft failure. It is debated whether pre-emptive liver transplantation, followed by kidney transplantation, might be a better strategy to reduce kidney graft loss. Our experience of 6 pediatric combined liver-kidney transplants for primary hyperoxaluria type 1 in pediatric recipients was retrospectively analyzed. Plasma oxalate levels were monitored before and after transplantation. All the recipients were on hemodialysis at transplantation. Median [IQR] recipient's age at transplantation was 11 [1-14] years; in all cases, a compatible graft from a pediatric brain-dead donor aged 8 [2-16] years was used. In a median follow-up of 7 [2-19] years after combined liver-kidney transplantation, no child died and no liver graft failure was observed; three kidney grafts were lost, due to chronic rejection, primary non-function, and early renal oxalate accumulation. Liver and kidney graft survival remained stable at 1, 3, and 5 years, at 100% and 85%, respectively. Kidney graft loss was the major complication in our series. Risk is higher with very young, low-weight donors. The impact of treatment with glyoxalate pathway enzyme inhibitors treatment in children with advanced disease as well as of donor kidney preservation by ex vivo machine perfusion needs to be evaluated. At present, a case-by-case discussion is needed to establish an optimal treatment strategy.

Diagnostic Approach to Acute Liver Failure in Children: A Position Paper by the SIGENP Liver Disease Working Group

Acute liver failure (ALF) is a clinical condition characterized by the abrupt onset of coagulopathy and biochemical evidence of hepatocellular injury, leading to rapid deterioration of liver cell function. In children, ALF has been characterized by raised transaminases, coagulopathy, and no known evidence of pre-existing chronic liver disease; unlike in adults, the presence of hepatic encephalopathy is not required to establish the diagnosis. Although rare, ALF has a high mortality rate without liver transplantation (LT). Etiology of ALF varies with age and geographical location, although it may remain indeterminate in a significant proportion of cases. However, identifying its etiology is crucial to undertake disease-specific management and evaluate indication to LT. In this position statement, the Liver Disease Working Group of the Italian Society of Gastroenterology, Hepatology and Nutrition (SIGENP) reviewed the most relevant studies on pediatric ALF to provide recommendations on etiology, clinical features and diagnostic work-up of neonates, infants and children presenting with ALF. Recommendations on medical management and transplant candidacy will be discussed in a following consensus conference.

Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy in Two Siblings: Same Mutations but Very Different Phenotypes

Autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy (APECED), caused by mutations in the AIRE gene, is mainly characterized by the triad of hypoparathyroidism, primary adrenocortical insufficiency and chronic mucocutaneous candidiasis, but can include many other manifestations, with no currently clear genotype–phenotype correlation. We present the clinical features of two siblings, a male and a female, with the same mutations in the AIRE gene associated with two very different phenotypes. Interestingly, the brother recently experienced COVID-19 infection with pneumonia, complicated by hypertension, hypokalemia and hypercalcemia. Although APECED is a monogenic disease, its expressiveness can be extremely different. In addition to the genetic basis, epigenetic and environmental factors might influence the phenotypic expression, although their exact role remains to be elucidated.

Efficacy of Sofosbuvir/Ledipasvir in Adolescents With Chronic Hepatitis C Genotypes 1, 3, and 4: A Real-world Study

OBJECTIVES

Sofosbuvir/Ledipasvir (SOF/LDV) has been approved by the European Medicine Agency (EMA) for the treatment of children and adolescents (at least 3 years of age) with chronic hepatitis C (CHC) genotype 1, 3, and 4 infection. The aim of this study was to evaluate the efficacy and safety of SOF/LDV in adolescents (12 to <18 years old) with CHC in the real-world setting.

METHODS

Prospective, open-label, multicentre study involving 12 Italian centres. Patients received the fixed-dose combination of SOF/LDV (400/90 mg) once daily ± ribavirin as per EMA approval and recommendations. The key efficacy endpoint was sustained virological response 12 weeks after the end of treatment (SVR12) as per intention-to-treat analysis. Safety was assessed by adverse events and clinical/laboratory data.

RESULTS

Seventy-eight consecutive adolescents (median age 15.2 years, range 12-17.9; girls 53.8%) were enrolled and treated between June 2018 and December 2019. Genotype distribution was as follows: genotype 1 (82.1%), 3 (2.5%), and 4 (15.4%). Seventy-six (97.4%) patients completed treatment and follow-up. Overall, SVR12 was 98.7%. One patient was lost to follow-up after 4 weeks of treatment; 1 patient completed treatment and missed the follow-up visit. No virological breakthrough or relapse were observed. No patient experienced grade 3 to 4 adverse event or serious adverse event.

CONCLUSIONS

The results of this real-world study confirmed the high efficacy and the optimal safety profile of SOF/LDV for treatment of CHC in adolescents.

Prevention of perinatal hepatitis B virus transmission: are we missing something?

Background

The prevention of perinatal Hepatitis B virus (HBV) is crucial to reach the WHO's challenge to eliminate viral hepatitis as public health threat by 2030. After diagnosing 2 infants infected by vertical transmission, a retrospective analysis of policies and practices to prevent HBV congenital infection was conducted to assess any potential risk.

Methods

Paired maternal-infant medical records between 2017 and 2019 were reviewed at A.O.U Città della Salute e Scienza di Torino, the italian hospital with the highest number of deliveries. Data included maternal HBSAg and coinfection (HIV, HCV) status and the administration of prophylaxis in newborns at risk. Other serologic markers of HBV maternal infection were not available.

Results

132 (0,6%) newborns from HBsAg positive mothers were identified between 2017-2019 among 21143 newborns. In this group pre-natal HBSAg status was known in 127 (96,2%), the remaining were tested during the hospitalization. Regarding maternal coinfection 130 (98%) were tested for HIV (1 positive), only 60 (45.1%) for HCV (all negative). All newborns received immunoprophylaxis consisting in the administration of vaccination and immunoglobulin: 119 (89%) within 24 hours (63% within 12 hours), 12 (9%) between 24-36 hours and 2 (1,6%) after 36 hours. The 2 cases of vertical transmission, even if correctly vaccinated, show a vaccination failure of 1,5%.

Conclusions

Although most of the mothers were tested for HBSAg status and all newborns were given immunoprophylaxis, vaccination failure seems to explain the 2 cases of vertical transmission. Since the lack in early maternal serologic screening and the late vaccination time could increase the risk of HBV infection, to achieve WHO goal we suggest to implement a multidisciplinary pathway to identify HBV positive mothers, to treat in case of high viral load, to provide a timely immunoprophylaxis considering a early vaccination and to set up a structured postnatal serologic check for newborns at risk.

Key messages

Vaccination failure must be considered in the service organization, a structured postnatal serologic check for all newborns at risk should be implemented to detect potential vaccination failure. A multidisciplinary pathway to identify HBV positive mothers, with a full serological markers set, should be implemented to give a correct maternal therapy and newborn prophylaxis.

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.

Etiology, presenting features and outcome of children with non-cirrhotic portal vein thrombosis: A multicentre national study

OBJECTIVES

Non-cirrhotic portal vein thrombosis (PVT) is a main cause of portal hypertension in children. We describe the characteristics at presentation and outcome of a cohort of patients with PVT to determine clinical features and predictors of outcome.

METHODS

We recorded: (1) Associated factors: prematurity, congenital malformations, neonatal illnesses, umbilical vein catheterization (UVC), deep infections, surgery; (2) congenital and acquired prothrombotic disorders; (3) features at last follow up including survival rate and need for surgery.

RESULTS

187 patients, mean age at diagnosis 4 ± 3.7 years, had a history of prematurity (61%); UVC (65%); neonatal illnesses (79%). The diagnosis followed the detection of splenomegaly (40%), gastrointestinal bleeding (36%), hypersplenism (6%), or was incidental (18%). Of 71 patients who had endoscopy at presentation 62 (87%) had oesophageal varices. After 11.3 years' follow up 63 (34%) required surgery or TIPS. Ten-year survival rate was 98%, with 90% shunt patency. Spleen size, variceal bleeding and hypersplenism at presentation were predictors of surgery or TIPS (p < 0.05).

CONCLUSION

PVT is associated with congenital and acquired co-morbidities. History of prematurity, neonatal illnesses and UVC should lead to rule out PVT. Large spleen, variceal bleeding and hypersplenism at presentation predict the need for eventual surgery in a third of cases.

Not only Alagille syndrome. Syndromic paucity of interlobular bile ducts secondary to HNF1β deficiency: a case report and literature review

Background

paucity of interlobular bile ducts is an important observation at liver biopsy in the diagnostic work-up of neonatal cholestasis. To date, other than in the Alagille syndrome, syndromic paucity of interlobular bile ducts has been documented in four cholestatic neonates with HFN1β mutations. A syndromic phenotype, known as renal cysts and diabetes syndrome (RCAD), has been identified. This is usually characterized by a wide clinical spectrum, including renal cysts, maturity-onset diabetes of the young, exocrine pancreatic insufficiency, urogenital abnormalities and a not well established liver involvement. Herein we report a novel case of paucity of interlobular bile ducts due to an HFN1β defect.

Case presentation

A 5-week-old boy was admitted to our department for cholestatic jaundice with increased gamma-glutamyl transpeptidase and an unremarkable clinical examination. He had been delivered by Caesarian section at 38 weeks’ gestation from unrelated parents, with a birth weight of 2600 g (3rd percentile). Screening for cholestatic diseases, including Alagille syndrome, was negative except for a minor pulmonary artery stenosis at echocardiography and a doubt of a thoracic butterfly hemivertebra. The finding of hyperechogenic kidneys with multiple bilateral cortical cysts at ultrasound examination, associated with moderately impaired renal function with proteinuria, polyuria and metabolic acidosis, was suggestive of ciliopathy. A liver biopsy was performed revealing paucity of interlobular bile ducts, thus the diagnosis of Alagille syndrome was reconsidered. Although genetic tests for liver cholestatic diseases were performed with negative results for Alagille syndrome (JAG1 and NOTCH2), a de-novo missense mutation of HNF1β gene was detected. At 18 months of age our patient has persistent cholestasis and his itching is not under satisfactory control.

Conclusions

Alagille syndrome may not be the only syndrome determining paucity of interlobular bile ducts in neonates presenting with cholestasis and renal impairment, especially in small for gestational age newborns. We suggest that HNF1β deficiency should also be ruled out, taking into consideration HNF1β mutations, together with Alagille syndrome, in next generation sequencing strategies in neonates with cholestasis, renal impairment and/or paucity of interlobular bile ducts at liver biopsy.

Diagnosis and treatment of Helicobacter pylori in the pediatric population

Although about 35 years have elapsed since the discovery of the Helicobacter pylori, its diagnosis and the choice of optimal eradication therapy are still to be defined. Over time, there has been an increase in interest, publications, recommendations and guidelines. Moreover, management of the disease in pediatric subjects differs somewhat to that of adults and requires a more delicate approach leading to alternative strategies for both diagnosis and treatment. Which patient should be investigated for H. pylori, when to perform noninvasive or invasive tests, what are the proper therapeutic options and best antibiotics regimen to eradicate the infection are practices changing with evidences through time. Therefore, an updated guideline was published by the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) in 2017. The aim of this review is to highlight what is new and what differs between adult and pediatric population regarding the management of H. pylori infection after the ESPGHAN/NASPGHAN guidelines, enriched with updates from literature reviews published over the last two years.

Transient elastography for non-invasive evaluation of post-transplant liver graft fibrosis in children

As graft survival in pediatric LT is often affected by progressive fibrosis, numerous centers carry out protocol liver biopsies. Follow-up biopsy protocols differ from center to center, but all biopsies are progressively spaced out, as time from transplant increases. Therefore, there is a need for non-invasive techniques to evaluate graft fibrosis progression in those children who have no clinical or serological signs of liver damage. Indirect markers, such as the APRI, should be relied on with caution because their sensitivity in predicting fibrosis can be strongly influenced by the etiology of liver disease, severity of fibrosis, and patient age. A valid alternative could be TE, a non-invasive technique already validated in adults, which estimates the stiffness of the cylindrical volume of liver tissue, 100-fold the size of a standard needle biopsy sample. The aims of this study were to evaluate the reliability of TE in children after LT and to compare both the TE and the APRI index results with the histological scores of fibrosis on liver biopsies. A total of 36 pediatric LT recipients were studied. All patients underwent both TE and biopsy within a year (median interval -0.012 months) at an interval from LT of 0.36 to 19.47 years (median 3.02 years). Fibrosis was assessed on the biopsy specimens at histology and staged according to METAVIR. There was a statistically significant correlation between TE stiffness values and METAVIR scores (P = .005). The diagnostic accuracy of TE for the diagnosis of significant fibrosis (F ≥ 2) was measured as the area under the curve (AUROC = 0.865), and it demonstrated that the method had a good diagnostic performance. APRI was not so accurate in assessing graft fibrosis when compared to METAVIR (AUROC = 0.592). A liver stiffness cutoff value of 5.6 kPa at TE was identified as the best predictor for a significant graft fibrosis (METAVIR F ≥ 2) on liver biopsy, with a 75% sensitivity, a 95.8% specificity, a 90% positive predictive value, and an 88.5% negative predictive value. These data suggest that TE may represent a non-invasive, reliable tool for the assessment of graft fibrosis in the follow-up of LT children, alerting the clinicians to the indication for a liver biopsy, with the aim of reducing the number of protocol liver biopsies.

NBAS mutations cause acute liver failure: when acetaminophen is not a culprit

Background

Pediatric acute-liver-failure due to acetaminophen (APAP) administration at therapeutic dosage is rare, while viral infections and metabolic defects are the prevalent causes. Yet, as acetaminophen is routinely used in febrile illnesses, it may be mistakenly held responsible for the acute liver damage.

Case presentation

An 11 month old boy had been on acetaminophen for 10 days (total dose 720 mg = 72 mg/kg) when he developed acute-liver-failure with encephalopathy. As he rapidly improved on N-acetylcysteine (NAC) infusion, it was concluded that chronic acetaminophen administration in an infant had lead to acute-liver-failure even at therapeutic doses, that N-acetylcysteine infusion had been life-saving and should be immediately started in similar circumstances. The child, however, had two further episodes of acute liver damage over a 34-month period, without having been given acetaminophen, as the parents carefully avoided using it. His clinical, laboratory and radiological findings between the acute episodes were unremarkable. His features and skeletal surveys were not suggestive of a syndromic condition. He then went on to suffer another episode of acute-liver-failure with multi-organ failure, necessitating an urgent liver transplant. All efforts to come to a diagnosis for the causes of his recurrent episodes of liver failure had been unsuccessful, until a biallelic mutation in the NBAS gene was reported to be associated with recurrent acute-liver-failure in children. The boy’s DNA analysis revealed compound heterozygous pathogenic mutations in the NBAS gene. Liver failure episodes in these patients are triggered and worsened by fever, most likely due to thermal susceptibility of hepatocytes, hence APAP, rather than being a culprit, is part of the supportive treatment.

Conclusions

We suggest that, in acute-liver-failure with a history of acetaminophen exposure at therapeutic dosage, clinicians should not be contented with administering NAC, but should consider an alternative etiology, above all if the episodes are recurrent, and actively start supportive and antipyretic treatment while seeking the advice of a specialist unit.

An Unexplained Congenital Disorder of Glycosylation-II in a Child with Neurohepatic Involvement, Hypercholesterolemia and Hypoceruloplasminemia

We report on a 12-year-old adopted boy with psychomotor disability, absence seizures, and normal brain MRI. He showed increased (but initially, at 5 months, normal) serum cholesterol, increased alkaline phosphatases, transiently increased transaminases and hypoceruloplasminemia with normal serum and urinary copper. Blood levels of immunoglobulins, haptoglobin, antithrombin, and factor XI were normal. A type 2 serum transferrin isoelectrofocusing and hypoglycosylation of apoCIII pointed to a combined N- and O-glycosylation defect. Neither CDG panel analysis with 79 CDG-related genes, nor whole exome sequencing revealed the cause of this CDG. Whole genome sequencing was not performed since the biological parents of this adopted child were not available.

First UHPLC-MS/MS method coupled with automated online SPE for quantification both of tacrolimus and everolimus in peripheral blood mononuclear cells and its application on samples from co-treated pediatric patients

Tacrolimus (TAC, FK-506) and everolimus (EVE, RAD001) are immunosuppressors used to treat pediatric patients undergoing liver transplantation. Their hematic TDM by liquid chromatography became standard practice. However, it does not always reflect concentrations at their active site. Our aim was to develop and validate a new method for the simultaneous TAC and EVE quantification into target cells: peripheral blood mononuclear cells (PBMCs). Peripheral blood mononuclear cells were collected using cell preparation tubes; cells number and mean cell volume were evaluated by an automatic cell counter. TAC and EVE were quantified using UHPLC-MS/MS coupled with an automated online solid-phase extraction platform. Chromatographic run was performed on an Acquity UPLC® BEH C18 1.7 μm (2.1 × 50 mm) column at 45 °C, for 6 min at 0.5 ml/min. Mobile phases were water and methanol, both with 2 mm ammonium acetate and 1 ml/l formic acid). XBridge® C8 10 μm (1 × 10 mm) SPE cartridges were used, and the internal standard was ascomycin. Following Food and Drug Administration guidelines, method validation resulted in high sensitivity and specificity. Calibration curves were linear (r²  = 0.998) and intra-day and inter-day imprecision and inaccuracy were <15%. A reproducible matrix effect was observed, with a good recovery for all compounds. Drug amounts in 15 'real' PBMCs samples from five pediatric patients in co-treatment resulted within the calibration range (0.039-5 ng). Concentrations from each patient were standardized using their evaluated mean cell volume: intra-PBMCs concentration was meanly 19.23 and 218.61 times higher than the hematic one for TAC and EVE, respectively. This method might be useful in clinical routine, giving reliable data on drugs concentration at the active site. Copyright © 2017 John Wiley & Sons, Ltd.

Donor CYP3A5 genotype influences tacrolimus disposition on the first day after paediatric liver transplantation

AIM

The aim of the present study was to investigate the influence of the cytochrome P450 (CYP) 3A4/5 genotype in paediatric liver transplant recipients and donors, and the contribution of age and gender to tacrolimus disposition on the first day after transplantation.

METHODS

The contribution of the CYP3A4/5 genotype in paediatric liver transplant recipients and donors to the tacrolimus blood trough concentrations (C₀ ) and the tacrolimus concentration/weight-adjusted dose ratio on day 1 was evaluated in 67 liver-transplanted children: 33 boys and 34 girls, mean age 4.5 years.

RESULTS

Donor CYP3A5 genotype appears to be significantly associated with tacrolimus disposition on the first day after liver transplantation (P < 0.0002). Other physiological factors, such as recipient age and donor gender may also play a role and lead to significant differences in tacrolimus C₀ and tacrolimus concentration/weight-adjusted dose ratio on day 1. However, according to the general linear model, only recipient age appears to be independently associated with tacrolimus disposition on the first day after liver transplantation (P < 0.03). Indeed, there was a faster tacrolimus metabolism in children under 6 years of age (P < 0.02).

CONCLUSIONS

Donor CYP3A5 genotype, recipient age and, to a lesser extent, donor gender appear to be associated with tacrolimus disposition on day 1 after transplant. This suggests that increasing the starting tacrolimus doses in paediatric patients under 6 years of age who receive a graft from a male extensive metabolizer may enhance the possibility of their tacrolimus levels reaching the therapeutic range sooner.

Efficacy of intravenous immunoglobulin therapy in giant cell hepatitis with autoimmune hemolytic anemia: A multicenter study

BACKGROUND AND OBJECTIVE

Giant cell hepatitis with autoimmune hemolytic anemia (GCH-AHA) is a rare disease of infancy, of possible autoimmune mechanism with poor prognosis due to its scarce response to immunosuppressive drugs. The aim of this retrospective multicenter study was to evaluate the efficacy and safety of intravenous immunoglobulin (IVIg) treatment in inducing and maintaining remission of the liver disease, in patients with GCH-AHA.

METHODS

Seven children with GCH-AHA, four newly diagnosed, and three in relapse, being treated with different therapies, received one to three IVIg infusions (0.5 to 2g/kg) in association with other immunosuppressive drugs. Subsequently five of them received monthly sequential IVIg infusions (mean 13.4, range 7-24).

RESULTS

IVIg infusions as first-line therapy associated with prednisone and other immunosuppressive drugs significantly (P=0.04) reduced the aminotransferase activity in all patients and normalized prothrombin activity in the only patient with severe liver dysfunction. Sequential monthly IVIg infusions determined a steroid-sparing effect and allowed a complete or partial remission in all patients, although with temporary efficacy, since relapse of the hemolytic anemia and/or of liver disease occurred in all patients. IVIg infusions were associated with mild side effects in two patients.

CONCLUSIONS

IVIg infusion can be safely and effectively administered in patients with severe GCH-AHA at diagnosis, or in case of relapse, in association with other immunosuppressive drugs. Repeated IVIg infusions may help maintain remission, however, due to their temporary efficacy, they should not be routinely employed.

Early Liver Transplantation for Neonatal-Onset Methylmalonic Acidemia

With conventional dietary treatment, the clinical course of methylmalonic acidemia due to cobalamin-unresponsive methylmalonyl-CoA mutase (MCM) deficiency is characterized by the persistent risk of recurrent life-threatening decompensation episodes with metabolic acidosis, hyperammonemia, and coma. Liver transplant has been proposed as an alternative treatment and anecdotally attempted in the last 2 decades with inconsistent results. Most criticisms of this approach have been directed at the continuing risk of neurologic and renal damage after transplant. Here, we report the perioperative and postoperative clinical and biochemical outcomes of 2 patients with severe MCM deficiency who underwent early liver transplant. In both cases, liver transplant allowed prevention of decompensation episodes, normalization of dietary protein intake, and a marked improvement of quality of life. No serious complications have been observed at 12 years' and 2 years' follow-up, respectively, except for mild kidney function impairment in the older patient. On the basis of our experience, we strongly suggest that liver transplant should be offered as a therapeutic option for children with cobalamin-unresponsive MCM deficiency at an early stage of the disease.

Interleukin 28B rs12979860 single-nucleotide polymorphism predicts spontaneous clearance of hepatitis C virus in children

OBJECTIVE

Recent genome-wide association studies performed in adults correlated single-nucleotide polymorphisms (SNPs rs12979860 and rs8099917) located on chromosome 19, upstream of the interleukin 28B gene, with spontaneous clearance of hepatitis C virus and with response to treatment with paginated interferon and ribavirin. The aim of the present collaborative study was to evaluate the rs12979860 SNP in a large cohort of Italian children with perinatal acquisition of hepatitis C.

METHODS

Children were prospectively enrolled in 2 Italian centers. The interleukin 28B rs12979860 SNP was studied according to the diagnosis of chronic infection or spontaneous clearance.

RESULTS

One hundred thirty children (86.7%) with chronic infection and 23 (13.3%) with spontaneous clearance of the virus were enrolled. Overall, the interleukin 28B C/C and C/T-T/T genotypes were found in 57 (37.3%) and 96 (62.7%) children, respectively. The proportion of C/C genotype was higher among children who cleared infection (14/23; 60.9%) compared with children with chronic infection (43/130; 33.1%; P = 0.01; odds ratio 3.15; 90% confidence intervals 1.34-7.53).

CONCLUSIONS

The present study showed that, as already demonstrated in adults, children with the rs12979860 C/C SNP of the interleukin 28B gene have a higher probability of spontaneous clearance of hepatitis C virus.

Liver transplantation in defects of cholesterol biosynthesis: the case of lathosterolosis

We report the outcome of liver transplantation (LT) in the only surviving patient with lathosterolosis, a defect of cholesterol biosynthesis characterized by high lathosterol levels associated with progressive cholestasis, multiple congenital anomalies and mental retardation. From her diagnosis at age 2 she had shown autistic behavior, was unable to walk unaided and her sight was impaired by cataracts. By age 7 she developed end-stage liver disease. After a soul-searching discussion within the transplantation team, she was treated with LT as this represented her only lifesaving option. At 1-year follow-up, her lathosterol levels had returned to normal (0.61 mg/dL from 13.04 ± 2.65) and her nutrition improved. She began exploring her environment and walking by holding onto an adult's hand and then independently. Her brain magnetic resonance imaging (MRI) had shown a normal picture at age 1, whereas a volume reduction of white matter with ex vacuo ventricular dilatation and defective myelinization were observed before transplant. At 5-year follow-up, a complete biochemical recovery, an arrest of mental deterioration and a stable MRI picture were achieved, with a return to her every day life albeit with limitations. Timely liver transplant in defects of cholesterol biosynthesis might arrest the progression of neurological damage.

Comparative analysis of rs12979860 SNP of the IFNL3 gene in children with hepatitis C and ethnic matched controls using 1000 Genomes Project data

The rs12979860 single nucleotide polymorphism located on chromosome 19q13.13 near the interferon L3 gene (formerly and commonly known as interleukin 28B gene) has been associated in adults with both spontaneous and treatment induced clearance of hepatitis C virus. Although the exact mechanism of these associations remains unclear, it suggests that variation in genes involved in the immune response against the virus favours viral clearance. Limited and preliminary data are available on this issue in children. The aim of the present study was to evaluate, in a representative cohort of children with perinatal infection, the potential association between rs12979860 single nucleotide polymorphism and the outcome of hepatitis C virus infection. Alleles and genotypes frequencies were evaluated in 30 children who spontaneously cleared the virus and in 147 children with persistent infection and were compared with a population sample of ethnically matched controls with unknown hepatitis C status obtained using the 1000 Genomes Project data. The C allele and the C/C genotype showed greater frequencies in the clearance group (76.7% and 56.7%, respectively) when compared with both children with viral persistence (C allele 56.5%, p = 0.004; C/C genotype 32.7%, p = 0.02) and with the ethnically matched individuals (C allele 59.7%, p = 0.02; C/C genotype 34.7%, p = 0.03). Children with the C/C genotype were 2 times more likely to clear hepatitis C virus relative to children with the C/T and T/T genotypes combined (odds ratio: 2.7; 90% confidence intervals: 1.3-5.8). The present study provides the evidence that the rs12979860 single nucleotide polymorphism influences the natural history of hepatitis C virus in children.

Thiopurine S-methyltransferase pharmacogenetics in a large-scale healthy Italian-Caucasian population: differences in enzyme activity

AIMS

To investigate the influence of genotype, age and gender on the thiopurine S-methyltransferase (TPMT) phenotype in healthy Italian-Caucasian subjects.

MATERIALS & METHODS

The study investigated the TPMT genotype and the TPMT phenotype of 943 healthy Italian-Caucasian subjects of different age and gender (age range: 0.08-68 years; 623 males 320 females). TPMT red blood cell activity was measured in all samples and genotype was determined for the TPMT alleles *2, *3A, *3B and *3C.

RESULTS

TPMT activity levels in our whole population ranged from 1.6 up to 75.2 U/gHb. Significant TPMT activity differences between wild-type and heterozygous subjects were observed. We divided our TPMT activity into four categories according to our frequency distribution: low (0.1%), intermediate (32.9%), normal (60%) and high (7%), with arbitrary cut-off values of 8.0, 19.4 and 37.0 U/gHb, respectively. The whole population had a total of 94.5% of homozygous wild-type subjects, 5.4% heterozygous variants and one (0.1%) compound heterozygous variant TPMT*3B/*3C. The overall concordance rate between TPMT genotypes and phenotypes was 71.6%. The TPMT activity was significantly higher in wild-type children (0.08-17 years) than in wild-type adults (aged 18-68 years). Moreover, it was noted that wild-type infants from 0.08 to 5 years had a 9% higher average TPMT activity than the other wild-type groups, and only in children from 0.08 to 2 years was the TPMT activity higher in males than in females.

CONCLUSION

The data obtained in this study show that genetic factors seem to be the major aspect in TPMT phenotype variability in adults, whilst, in children, other physiological factors should be taken into consideration when assessing the TPMT phenotype, such as age and gender.

Long-standing mild hypertransaminasaemia caused by congenital disorder of glycosylation (CDG) type IIx

A 32 year-old asymptomatic male came to our attention with a 21-year history, documented elsewhere, of puzzling increases in his serum transaminase level. At first, very low serum ceruloplasmin level suggested Wilson disease. Two liver biopsies showed mild portal inflammation, steatosis and mild fibrosis. Further investigation revealed low levels of the glycoproteins AT III and clotting factor XI, leading to a diagnosis of congenital disorder of glycosylation (CDG) type II. Further studies as to the cause of this 'apparently new' CDG, are ongoing. On the basis of our data and a literature review, we suggest that subjects with asymptomatic hypertransaminasaemia be screened for CDG.

Hepatitis C virus heteroduplex tracking assay : application to genotype determination, quasispecies analysis, and molecular evolution studies

The heteroduplex tracking assay (HTA) is a tool that can be used for determining genotype, quasispecies analysis, molecular evolution, and epidemiological studies (1-7). By hybridizing a labeled, single-stranded DNA probe to colinear, reverse transcriptase (RT) PCR products from a sample of interest, the probe will either form a homoduplex with identical molecules or a heteroduplex with nonidentical sequences. The hybridization products are separated on MDE or polyacrylamide gels and visualized. Delwart et al., the developers of the HTA technique (1,2,7), have previously shown that the migration of heteroduplexes relative to the homoduplex on gels are approximately proportional to the percent nucleotide divergence between two species, and therefore, the genetic distance between two species can be determined. Genetic rearrangements, deletions, and/or insertions can alter the migration of heteroduplexes in a manner that disturbs the direct relationship between relative migration and genetic distance. Typically, heteroduplexes of 0.176-1.8 kb containing >1.4-3% to ~30% nucleotide substitutions, which lack genetic alterations, can be identified as unique species on MDE gels (1,4,6). The number and distribution of unique bands indicates the genetic complexity of viral species in each sample.

Characterization of antimitochondrial antibodies in health adults

The detection of antimitochondrial antibodies (AMAs) is an important criterion for the diagnosis of primary biliary cirrhosis (PBC). During the last decade, the mitochondrial autoantigens have been cloned, sequenced, and identified as members of the 2-oxo-acid dehydrogenase pathway, including the E2 subunits of pyruvate dehydrogenase (PDC-E2), branched-chain 2-oxo-acid dehydrogenase (BCOADC-E2), and 2-oxo-glutarate dehydrogenase (OGDC-E2). We have developed a rapid and sensitive diagnostic test for use in PBC based on a triple hybrid recombinant molecule (r-MIT3) that contains the autoepitopes of PDC-E2, BCOADC-E2, and OGDC-E2. To help understand the frequency and antigen specificity of AMAs in an asymptomatic population and to identify patients with early disease, we investigated the prevalence of AMA, by enzyme-linked immunosorbent assay (ELISA), in a cohort of 1,530 people from northern Italy. Positive sera were further analyzed for immunoglobulin (Ig) isotypes, subclasses, and epitopes of AMA by a combination of ELISA and immunoblotting. In this cohort of 1,530 people, 9 (0.5%) reacted to r-MIT3 by ELISA. Of the 9 reactive sera, 2 recognized PDC-E2, 2 of 9 recognized BCOADC-E2, 1 of 9 recognized OGDC-E2, 2 of 9 recognized both PDC-E2 and BCOADC-E2, and 1 of 9 recognized PDC-E2 and OGDC-E2. AMA reactivity was primarily IgM and IgA. Epitope mapping revealed an AMA pattern of reactivity to PDC-E2 that differed from that found in patients with histologically proven PBC in most of the sera. However, 1 sera of a 72-year-old female with a normal alkaline phosphatase had an AMA profile identical to typical PBC. After a variable follow-up period (8-14 months), sera from 8 of 9 of these people were re-obtained for AMA and relative epitope mapping. Interestingly, the reactivity had a wider AMA pattern than before.

Hepatitis C virus heteroduplex tracking assay for genotype determination reveals diverging genotype 2 isolates in Italian hemodialysis patients

A heteroduplex tracking assay (HTA) was developed for genetic analyses of the hepatitis C virus (HCV) using single-stranded probes from the core (C)/E1 region. Nucleotide sequencing of reverse transcriptase (RT)-PCR products from 15 Italian dialysis patients confirmed the specificity and accuracy of the HTA genotyping method, which identified 5 of 15 (33.3%) 1b, 7 of 15 (46.7%) 3a, and 3 of 15 (20%) type 2 infections. The genotypes of an additional 12 HCV antibody-positive blood donors from different geographical locations were also in agreement with the genotypes determined by the Inno-LiPA HCV II kit (Innogenetics) and/or restriction fragment length polymorphism (RFLP). Isolates which had between 35 to 40% nucleotide divergence from control subtype 1a, 1b, 2a, 2b, or 3a standards could be typed. Surprisingly, HTA detected one 1b-2 coinfection which was missed by DNA sequencing. Three samples that were designated non-2a or 2b type 2 by HTA were found to be type 2a by both RFLP and direct nucleotide sequencing of the 5' untranslated region. The genetic distance between patient type 2 and control 2a, 2b, and 2c isolates indicated that a new subtype was present in the population being studied. Serotyping (RIBA serotyping strip immunoblot assay kit) of 23 dialysis patients showed that the genotype could be determined in 6 of 8 (75%) C/E1 RT-PCR-negative and 15 of 23 (65.2%) RT-PCR-positive samples, indicating that the two tests complement each other.

Hepatitis C virus infection and liver disease

Hepatitis C Virus (HCV) is a RNA virus that lacks the retroviral properties of surviving in infected hosts by integration into cellular DNA, nevertheless it is capable to cause chronic infection and disease in a considerable number of infected individuals (30-70% of cases). This results in a worldwide prevalence of chronic HCV carriers similar to those of hepatitis B virus carriers. We review and discuss here some of the peculiar aspects of chronic HCV infection and associated disease.

Quantitative analysis of wild-type and HBeAg minus hepatitis B viruses by a sequence-dependent primer extension assay

The ratio between wild-type hepatitis B virus (HBV) and HBV mutant, unable to secrete "e" antigen (HBeAg minus HBV) appears to be an important determinant of the outcome of chronic hepatitis B. Quantitative analysis of wild-type and HBeAg minus HBVs in the blood could be useful to monitor chronic hepatitis B patients. We developed a solid-phase minisequencing assay for both viruses using a primer-guided incorporation of a single labeled nucleotide on an affinity captured biotinylated amplified HBV-DNA template. A standard curve was constructed by mixing increasing quantities of wild type and mutant virus DNAs. The detection of wild-type and HBeAg minus sequences, ranging from 10% to 90% of overall viremia, was linear and reproducible till 0.1 pg/microliter of serum HBV-DNA. The assay yields numerical values and the ratio of incorporated nucleotides defines the relative proportions (%) of the two viral sequences with accuracy. We tested the sensitivity and accuracy of the minisequencing on mixed end point dilutions of wild-type and HBeAg minus reference sera and amplified products. The feasibility and reproducibility of the assay were tested in 35 sera from 21 HBsAg positive patients with chronic hepatitis B using both minisequencing and oligo-hybridization assays. A high correlation was found between the two assays (r = 0.957 P < 0.0001). In conclusion, the minisequencing assay provides a precise and reproducible quantitative analysis of wild-type and HBeAg minus HBVs in clinical specimens. It is proposed to study the relations between HBV heterogeneity and the course of hepatitis B and its response to therapy.

Hepatitis C virus infection and liver disease: peculiar epidemiological and clinicopathological features

Hepatitis C virus (HCV) infection is associated with a wide spectrum of liver disease ranging from asymptomatic carriage to severe forms of chronic hepatitis. HCV is not invariably pathogenic and genetic heterogeneity of HCV could be a major cause of such a variability. In clinical practice this means that presence and replication of the virus do not invariably imply a virus-induced liver damage. IgM antibodies that are the best diagnostic tools for the other forms of viral hepatitis are not sensitive and specific enough for hepatitis C, therefore we have to look for alternatives. Detection of anti-HCV does not help to distinguish past from present infections and only anti-HCV seroconversion in previously negative patients can indicate a recent HCV infection. However, the significant association between serum anti-C100-3 and HCV-RNA suggests that anti-HCV can be considered an indirect marker of HCV infectivity. In anti-HCV-negative infections and early acute hepatitis cases HCV-RNA detection will represent a valid diagnostic alternative. In patients undergoing antiviral therapy monitoring anti-HCV by immunoblotting assays and HCV-RNA by quantitative assays represent a valid tool to predict response that invariably has occurred in patients who had undetectable serum HCV-RNA and/or decreasing anti-HCV titres. Assays that detect multiple anti-HCV antibodies all together appear unsuitable for monitoring because they miss the disappearance of single antibodies. Anti-C22 appears the most frequent and earliest to be detected and usually it has the highest titre. Anti-C100 titres decrease earlier than anti-C33 and anti-C22 in patients with chronic HCV hepatitis who respond to antiviral therapy. The natural course of HCV infection appears to be characterized by three consecutive phases: disease, asymptomatic carrier and recovery. If transition from the first to the last occurs very slowly or the disease phase persists for years it may warrant in susceptible hosts severe forms of liver disease.