Proteomics and Metabolomics Approaches towards a Functional Insight onto AUTISM Spectrum Disorders: Phenotype Stratification and Biomarker Discovery.

Autism spectrum disorders (ASDs) are neurodevelopmental disorders characterized by behavioral alterations and currently affect about 1% of children. Significant genetic factors and mechanisms underline the causation of ASD. Indeed, many affected individuals are diagnosed with chromosomal abnormalities, submicroscopic deletions or duplications, single-gene disorders or variants. However, a range of metabolic abnormalities has been highlighted in many patients, by identifying biofluid metabolome and proteome profiles potentially usable as ASD biomarkers. Indeed, next-generation sequencing and other omics platforms, including proteomics and metabolomics, have uncovered early age disease biomarkers which may lead to novel diagnostic tools and treatment targets that may vary from patient to patient depending on the specific genomic and other omics findings. The progressive identification of new proteins and metabolites acting as biomarker candidates, combined with patient genetic and clinical data and environmental factors, including microbiota, would bring us towards advanced clinical decision support systems (CDSSs) assisted by machine learning models for advanced ASD-personalized medicine. Herein, we will discuss novel computational solutions to evaluate new proteome and metabolome ASD biomarker candidates, in terms of their recurrence in the reviewed literature and laboratory medicine feasibility. Moreover, the way to exploit CDSS, performed by artificial intelligence, is presented as an effective tool to integrate omics data to electronic health/medical records (EHR/EMR), hopefully acting as added value in the near future for the clinical management of ASD.

The activating p.Ser466Arg change in STAT1 causes a peculiar phenotype with features of interferonopathies.

Signal Transducer and Activator of Transcription 1 (STAT1) is a DNA-binding signal transducer that regulates transcription of specific genes in response to IFNγ and IFNα/ß stimulation. Loss-of-function mutations impairing STAT1 activity are known to confer susceptibility to intracellular bacterial and viral diseases. Conversely, the few known activating mutations of STAT1 allow predisposition to chronic mucocutaneous candidiasis disease, and occur in patients with combined immunodeficiency and defective Th1 and Th17 responses. Here, we report on a de novo gain-of-function (GoF) STAT1 mutation (c.1398C>G, p.Ser466Arg) identified by exome sequencing in an individual with brain calcification, arthritis, recurrent pericarditis, leukopenia, thrombocytopenia and low C3 levels, a phenotype resembling an interferonopathy. The Ser466Arg change affects a highly conserved residue located in the DNA binding domain of the protein and the amino acid substitution was documented to have an activating role both in vitro and in vivo. Altogether, clinical features and functional studies are compatible with hyperactivation of the Interferon pathways, highlighting a role of STAT1 GoF mutation in clinical phenotypes fitting interferonopathies.

Liver Transplantation and Gut Microbiota Profiling in a Child Colonized by a Multi-Drug Resistant Klebsiella pneumoniae: A New Approach to Move from Antibiotic to "Eubiotic" Control of Microbial Resistance.

The increase of microorganisms multi-drug resistant (MDR) to antibiotics (ATBs) is becoming a global emergency, especially in frail subjects. In chronic liver disease (LD) with indications for liver transplantation (LT), MDR colonization can significantly affect the LT outcome. However, no clear guidelines for microbial management are available. A novel approach toward MDR-colonized patients undergoing LT was developed at our Center refraining from ATBs use during the transplant waiting list, and use of an intensive perioperative prophylaxis cycle. This study aimed to couple clinical evaluation with monitoring of gut microbiota in a pediatric LD patient colonized with MDR Klebsiella pneumoniae (KP) who underwent LT. No peri-transplant complications were reported, and a decontamination from the MDR bacteria occurred during follow-up. Significant changes in gut microbiota, especially during ATB treatment, were reported by microbiota profiling. Patterns of Klebsiella predominance and microbiota diversity revealed opposite temporal trends, with Klebsiella ecological microbiota niches linked to ATB-driven selection. Our infection control program appeared to control complications following LT in an MDR-KP-colonized patient. The perioperative ATB regimen, acting as LT prophylaxis, triggered MDR-KP overgrowth and gut dysbiosis, but buffered infectious processes. Mechanisms modulating the gut ecosystem should be taken into account in MDR colonization clinical management.

Macrophage recruitment by fibrocystin-defective biliary epithelial cells promotes portal fibrosis in congenital hepatic fibrosis.

UNLABELLED: Congenital hepatic fibrosis (CHF) is a disease of the biliary epithelium characterized by bile duct changes resembling ductal plate malformations and by progressive peribiliary fibrosis, in the absence of overt necroinflammation. Progressive liver fibrosis leads to portal hypertension and liver failure; however, the mechanisms leading to fibrosis in CHF remain elusive. CHF is caused by mutations in PKHD1, a gene encoding for fibrocystin, a ciliary protein expressed in cholangiocytes. Using a fibrocystin-defective (Pkhd1(del4/del4)) mouse, which is orthologous of CHF, we show that Pkhd1(del4/del4) cholangiocytes are characterized by a ß-catenin-dependent secretion of a range of chemokines, including chemokine (C-X-C motif) ligands 1, 10, and 12, which stimulate bone marrow-derived macrophage recruitment. We also show that Pkhd1(del4/del4) cholangiocytes, in turn, respond to proinflammatory cytokines released by macrophages by up-regulating αvß6 integrin, an activator of latent local transforming growth factor-ß1. While the macrophage infiltrate is initially dominated by the M1 phenotype, the profibrogenic M2 phenotype increases with disease progression, along with the number of portal myofibroblasts. Consistent with these findings, clodronate-induced macrophage depletion results in a significant reduction of portal fibrosis and portal hypertension as well as of liver cysts. CONCLUSION: Fibrosis can be initiated by an epithelial cell dysfunction, leading to low-grade inflammation, macrophage recruitment, and collagen deposition; these findings establish a new paradigm for biliary fibrosis and represent a model to understand the relationship between cell dysfunction, parainflammation, liver fibrosis, and macrophage polarization over time.

Autoimmune liver diseases and inflammatory bowel diseases in children: current issues and future perspectives.

Inflammatory bowel diseases (IBDs) represent a group of intestinal disorders with a chronic and relapsing inflammation of the gut, and with a potential risk of systemic involvement of other organs and systems. Over the pediatric age, an incidence higher than 20% of developing extraintestinal manifestation during follow-up has been reported. The liver and the biliary system are frequently involved, and primary sclerosing cholangitis (PSC) is the most predominant entity with an incidence rate of 6.4-7.8% in children. PSC recognizes a multifactorial pathogenesis, and so far a not fully known mechanism for this association. The peculiar phenotype and the distinct clinical course of patients with IBD and PSC-associated make this 'linkage' an attractive study model to better understand mechanisms underlying these diseases. Approaching to these patients is complex and multidisciplinary, and a unique therapeutic strategy has not been standardized yet. New medications are being studied; however, further studies are needed to fully understand the pathogenesis and to improve the care of these patients. The aim of this paper is to review the recent literature regarding hepatobiliary involvement in IBD patients, with particular attention to PSC, and to provide the latest information for a correct diagnosis and appropriate management.

Liver transplant in ethylmalonic encephalopathy: a new treatment for an otherwise fatal disease.

Ethylmalonic encephalopathy is a fatal, rapidly progressive mitochondrial disorder caused by ETHE1 mutations, whose peculiar clinical and biochemical features are due to the toxic accumulation of hydrogen sulphide and of its metabolites, including thiosulphate. In mice with ethylmalonic encephalopathy, liver-targeted adeno-associated virus-mediated ETHE1 gene transfer dramatically improved both clinical course and metabolic abnormalities. Reasoning that the same achievement could be accomplished by liver transplantation, we performed living donor-liver transplantation in an infant with ethylmalonic encephalopathy. Unlike the invariably progressive deterioration of the disease, 8 months after liver transplantation, we observed striking neurological improvement with remarkable achievements in psychomotor development, along with dramatic reversion of biochemical abnormalities. These results clearly indicate that liver transplantation is a viable therapeutic option for ETHE1 disease.

Clinical Features and Risk Factors of Autoimmune Liver Involvement in Pediatric Inflammatory Bowel Disease.

OBJECTIVES: Autoimmune liver disease is reported in up to 7.8% of children with inflammatory bowel disease. A distinct inflammatory bowel disease phenotype has been suggested in adults and in small pediatric cohorts. The aim of the study was to evaluate the features of inflammatory bowel disease associated with autoimmune liver diseases and to analyze the characteristics of the liver disease. METHODS: Information on patients was obtained from the Italian Pediatric Inflammatory Bowel Disease Registry. Data of patients with and without autoimmune liver disease were compared. RESULTS: Autoimmune liver disease was detected in 6.8% of the 677 patients enrolled and was significantly associated with the diagnosis of ulcerative colitis (83%), with pancolonic involvement (84%), and with perinuclear antineutrophil cytoplasmic antibody positivity (41%) (all Ps < 0.05). Autoimmune liver disease was defined as sclerosing cholangitis in 61% of the patients and as an overlap syndrome in 33%. Concomitant intra- and extrahepatic biliary involvement was reported in 61% of cases, whereas exclusive extrahepatic lesions were reported in 21%. Hepatobiliary complications were observed in 9% of the patients during follow-up. CONCLUSIONS: Autoimmune liver disease, especially sclerosing cholangitis, was significantly more common in patients with extensive ulcerative colitis. Although complications are relatively rare in the pediatric age, monitoring is recommended.

MEDNIK syndrome: a novel defect of copper metabolism treatable by zinc acetate therapy.

MEDNIK syndrome-acronym for mental retardation, enteropathy, deafness, neuropathy, ichthyosis, keratodermia-is caused by AP1S1 gene mutations, encoding σ1A, the small subunit of the adaptor protein 1 complex, which plays a crucial role in clathrin coat assembly and mediates trafficking between trans-Golgi network, endosomes and the plasma membrane. MEDNIK syndrome was first reported in a few French-Canadian families sharing common ancestors, presenting a complex neurocutaneous phenotype, but its pathogenesis is not completely understood. A Sephardic-Jewish patient, carrying a new AP1S1 homozygous mutation, showed severe perturbations of copper metabolism with hypocupremia, hypoceruloplasminemia and liver copper accumulation, along with intrahepatic cholestasis. Zinc acetate treatment strikingly improved clinical conditions, as well as liver copper and bile-acid overload. We evaluated copper-related metabolites and liver function retrospectively in the original French-Canadian patient series. Intracellular copper metabolism and subcellular localization and function of copper pump ATP7A were investigated in patient fibroblasts. Copper metabolism perturbation and hepatopathy were confirmed in all patients. Studies in mutant fibroblasts showed abnormal copper incorporation and retention, reduced expression of copper-dependent enzymes cytochrome-c-oxidase and Cu/Zn superoxide dismutase, and aberrant intracellular trafficking of Menkes protein ATP7A, which normalized after rescue experiments expressing wild-type AP1S1 gene. We solved the pathogenetic mechanism of MEDNIK syndrome, demonstrating that AP1S1 regulates intracellular copper machinery mediated by copper-pump proteins. This multisystem disease is characterized by a unique picture, combining clinical and biochemical signs of both Menkes and Wilson's diseases, in which liver copper overload is treatable by zinc acetate therapy, and can now be listed as a copper metabolism defect in humans. Our results may also contribute to understand the mechanism(s) of intracellular trafficking of copper pumps.

Long-term outcome of home parenteral nutrition in patients with ultra-short bowel syndrome.

OBJECTIVE: The patients with ultra-short bowel syndrome (U-SBS) have been considered potential candidates for a preemptive/rehabilitative intestinal transplantation owing to the high risk of death from the underlying disease. We hypothesized that children with U-SBS, in the absence of intestinal failure-associated liver disease (IFALD), could also have a good rate of survival on home parenteral nutrition (HPN). METHODS: A prospective database from the "Bambino Gesù" Artificial Nutrition and Intestinal Failure Program was used to evaluate outcomes and morbidities of consecutive patients with ≤ 10 cm of small bowel enrolled since 2000. RESULTS: Eleven patients were identified with a median bowel length of 7.5 (3-9) cm. Eight patients developed IFALD, which reversed in 7 of them; the IFALD progressively worsened in 1 patient until death. One patient underwent isolated intestinal transplantation and 1 patient is no longer receiving parenteral nutrition (PN) and both are fully enterally fed. The other patients remained at least partially dependent on HPN. The number of days of inpatient care decreased in all of the patients except for the 1 who had repeated episodes of central line infections. CONCLUSIONS: The survival of patients with U-SBS receiving HPN was good. Although IFALD was frequent, it had been manageable in most of the patients, but in a single complex case, it led to death. The multidisciplinary management warranted to these patients to approach the school age, to grow, and to maintain the oral intake. Patients with U-SBS are rare, and to better understand their long-term survival, further studies, including more large patient populations, are required.

Characterization of the Gut Microbiota and Mycobiota in Italian Pediatric Patients With Primary Sclerosing Cholangitis and Ulcerative Colitis.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic, fibroinflammatory, cholestatic liver disease of unknown etiopathogenesis, often associated with inflammatory bowel diseases. Recent evidence ascribes, together with immunologic and environmental components, a significant role to the intestinal microbiota or its molecules in the PSC pathogenesis. METHODS: By metagenomic sequencing of 16S rRNA and ITS2 loci, we describe the fecal microbiota and mycobiota of 26 pediatric patients affected by PSC and concomitant ulcerative colitis (PSC-UC), 27 patients without PSC but with UC (UC), and 26 healthy subjects (CTRLs). RESULTS: Compared with CTRL, the bacterial and fungal gut dysbiosis was evident for both PSC-UC and UC groups; in particular, Streptococcus, Saccharomyces, Sporobolomyces, Tilletiopsis, and Debaryomyces appeared increased in PSC-UC, whereas Klebsiella, Haemophilus, Enterococcus Collinsella, Piptoporus, Candida, and Hyphodontia in UC. In both patient groups, Akkermansia, Bacteroides, Parabacteroides, Oscillospira, Meyerozyma and Malassezia were decreased. Co-occurrence analysis evidenced the lowest number of nodes and edges for fungi networks compared with bacteria. Finally, we identified a specific patient profile, based on liver function tests, bacterial and fungal signatures, that is able to distinguish PSC-UC from UC patients. CONCLUSIONS: We describe the gut microbiota and mycobiota dysbiosis associated to PSC-UC disease. Our results evidenced a gut imbalance, with the reduction of gut commensal microorganisms with stated anti-inflammatory properties (ie, Akkermansia, Bacteroides, Parabacteroides, Oscillospira, Meyerozyma, and Malassezia) and the increase of pathobionts (ie, Streptococcus, Saccharomyces, and Debaryomyces) that could be involved in PSC progression. Altogether, these events may concur in the pathophysiology of PSC in the framework of UC.

In this study, we report the gut microbiota and mycobiota dysbiosis in pediatric patients affected by primary sclerosing cholangitis (PSC) associated with ulcerative colitis (UC), with an increase in pro-inflammatory pathobionts and a reduction in anti-inflammatory commensals.

Cranioectodermal Dysplasia, Sensenbrenner syndrome, is a ciliopathy caused by mutations in the IFT122 gene.

Cranioectodermal dysplasia (CED) is a disorder characterized by craniofacial, skeletal, and ectodermal abnormalities. Most cases reported to date are sporadic, but a few familial cases support an autosomal-recessive inheritance pattern. Aiming at the elucidation of the genetic basis of CED, we collected 13 patients with CED symptoms from 12 independent families. In one family with consanguineous parents two siblings were affected, permitting linkage analysis and homozygosity mapping. This revealed a single region of homozygosity with a significant LOD score (3.57) on chromosome 3q21-3q24. By sequencing candidate genes from this interval we found a homozygous missense mutation in the IFT122 (WDR10) gene that cosegregated with the disease. Examination of IFT122 in our patient cohort revealed one additional homozygous missense change in the patient from a second consanguineous family. In addition, we found compound heterozygosity for a donor splice-site change and a missense change in one sporadic patient. All mutations were absent in 340 control chromosomes. Because IFT122 plays an important role in the assembly and maintenance of eukaryotic cilia, we investigated patient fibroblasts and found significantly reduced frequency and length of primary cilia as compared to controls. Furthermore, we transiently knocked down ift122 in zebrafish embryos and observed the typical phenotype found in other models of ciliopathies. Because not all of our patients harbored mutations in IFT122, CED seems to be genetically heterogeneous. Still, by identifying CED as a ciliary disorder, our study suggests that the causative mutations in the unresolved cases most likely affect primary cilia function too.

Meso-Rex bypass as an alternative technique for portal vein reconstruction at or after liver transplantation in children: review and perspectives.

Direct portal revascularization can be achieved by interposing a vascular graft between the SMV and the Rex recessus (left portal vein system): the MRB. To review indications and results of the procedure in the setting of pediatric liver transplantation, reports were selected from the English literature. Previously reported series were updated to analyze long-term outcome. A new series was added and analyzed as a complementary set of cases. A total of 51 cases were analyzed. With a 96% overall patient survival rate and a 100% long-term patency rate when the IJV is used for the bypass, MRB achieves a very successful physiologic cure of chronic portal hypertension and restores the portal flow into and through the liver graft. It also has been used successfully for primary revascularization of liver grafts, as well as for managing early acute portal vein thrombosis episodes. The use of this procedure in conjunction with other strategies and techniques might be of interest for transplant surgeons, particularly those caring for children.

Gene and functional up-regulation of the BCRP/ABCG2 transporter in hepatocellular carcinoma.

BACKGROUND: The Breast Cancer Resistance Protein (BCRP/ABCG2) is one member of ABC transporters proteins super family responsible of drug resistance. Since data on ABCG2 expression in liver malignances are scanty, here we report the expression of ABCG2 in adult human hepatocellular carcinoma (HCC) in both in vivo and in vitro models with different degree of malignancy. METHODS: In cell lines derived from human hepatocellular carcinoma, ABCG2 gene expression was assessed by reverse transcription quantitative real time PCR and function by Hoechst 33342 efflux assay; protein content was assessed by SDS-PAGE Western blot. RESULTS: ABCG2 expression was found to be highest in the most undifferentiated cell lines, and this was related with a higher functional activity. ABCG2 expression was sensitive to antineoplastic drugs since exposure to 5 µM doxorubicin for 24 hours resulted in significant up-regulations of ABCG2 in all cell lines, particularly in those lines with low basal ABCG2 expression (p<0.01). The gene expression was also investigated in 51 adult liver tissues with HCC and related cirrhosis; normal liver tissue was used as control. ABCG2 gene expression was higher in HCC than both cirrhotic paired tissue and normal tissue. This up-regulation was greater (p<0.05) in pathological poorly differentiated grade G3/G4 than in well-differentiated G1/G2 HCC. CONCLUSIONS: Our results suggest a correlation of ABCG2 gene expression and differentiation stage both in human and HCC derived cell lines. The rapid up-regulation of ABCG2 to exposure to doxorubicin emphasizes the importance of this transporter in accounting for drug resistance in liver tumors.

Autoimmune hepatitis type 2 associated with an unexpected and transient presence of primary biliary cirrhosis-specific antimitochondrial antibodies: a case study and review of the literature.

BACKGROUND: Unlike other autoimmune liver diseases, primary biliary cirrhosis (PBC) has never been reported in early childhood, while type 2 autoimmune hepatitis (AIH) is eminently a paediatric disease. CASE PRESENTATION: We describe a case of type 2 AIH with serological positivity for PBC-specific anti-mitochondrial antibodies (AMA) in a 3-year old girl. We found this observation intriguing as AMA and indeed an overlap with PBC are virtually absent in Type 2 AIH, a pediatric form of AIH which is distinct precisely because it is characterized by pathognomonic anti-liver kidney microsomal type 1 (LKM-1) showing a remarkable antigen-specificity directed against cytochrome P4502D6. We also review the literature in relation to AMA positivity in paediatric age and adolescence. In our case, the presence of AIH-2-specific anti-LKM-1 and PBC-specific AMA was confirmed by indirect immunofluorescence (IIF), and immunoblotting and ELISA based on recombinant mitochondrial antigens. The clinical, laboratory and histological features of the child are given in detail. Interestingly the mother was AMA positive without other features of PBC. The child was successfully treated with immunosuppression and five years after the original diagnosis is on a low dose of prednisolone and azathioprine, with no signs of relapse. Anti-LKM-1 antibodies are still present in low titres. AMA were detectable for the first 4 years after the diagnosis and disappeared later. CONCLUSION: This is the first case report in the literature of AIH type 2 with an unexpected PBC-specific AMA positivity in a young child. Response to immunosuppressive treatment was satisfactory and similar to that described in AIH. A review of published reports on AMA positivity in paediatric age shows that the antibody may arise in the context of immunodeficiency and is variably associated with liver damage.

A new Caucasian case of neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD): a clinical, molecular, and functional study.

Citrin is the liver-specific isoform of the mitochondrial aspartate/glutamate carrier (AGC2). AGC2 deficiency is an autosomal recessive disorder with two age related phenotypes: neonatal intrahepatic cholestasis (NICCD, OMIM#605814) and adult-onset type II citrullinemia (CTLN2, OMIM#603471). NICCD arises within the first few weeks of life resulting in prolonged cholestasis and metabolic abnormalities including aminoacidemia and galactosuria. Usually symptoms disappear within the first year of life, thus making a diagnosis difficult after this time. In this study we report a new Caucasian case of NICCD, a seven week old Romanian boy with prolonged jaundice. Sequencing of the AGC2 gene showed a novel homozygous missense double-nucleotide (doublet) mutation, which produces the change of the glycine at position 437 into glutamate. Functional studies, carried out on the recombinant mutant protein, for the first time demonstrated, that NICCD is caused by a reduced transport activity of AGC2. The presence of AGC2 deficiency in other ethnic groups besides Asian population suggests further consideration for NICCD diagnosis of any neonate with an unexplained cholestasis; a prompt diagnosis is crucial to resolve the metabolic decompensation with an appropriate dietary treatment.

Fludarabine, cyclophosphamide, doxorubicin (FCD), and rituximab: a remission induction therapy for aggressive pediatric post-transplant lymphoproliferative disease (PTLD).

Management of aggressive, usually late-occurring, post-transplant lymphoproliferative disorders (PTLDs), a life-threatening complication after solid organ transplants, remains controversial. Four children affected by aggressive CD20+ PTLDs received a chemo-immunotherapy regimen for remission induction based on fludarabine, cyclophosphamide, doxorubicin, and rituximab, associated with a rapid discontinuation of immunosuppression (IS). Subsequent consolidation chemotherapy consisted of Berlin-Frankfurt-Münster-modified blocks. All patients achieved a complete remission, which persisted for 25, 68+, 80+, and 103+ months after diagnosis. Therapy was well tolerated. No patients developed allograft rejection during PTLD treatment. Our experience suggests that this chemo-immunotherapeutic approach may be an effective treatment strategy while allowing for a concomitant discontinuation of IS.

Plasma citrulline as surrogate marker of intestinal inflammation in pediatric and adolescent with Crohn's disease: preliminary report.

PURPOSE: Several researchers have found that plasma citrulline could be a marker of reduced enterocyte mass. The aim of this study was to assess the relationship between plasma citrulline and bowel inflammation and/or disease location in pediatric and adolescent Crohn's disease (CD) patients. METHODS: Between January 2008 and January 2010, 31 CD patients and 44 controls were included in our study, and 15 out of the 31 CD patients continued a prospective survey. We evaluated the differences between groups, at baseline, in plasma citrulline and glutamine and between their baseline and final values during the prospective survey, and correlation between baseline values of citrulline and duration of disease, C-reactive protein, and fecal calprotectin. RESULTS: Mean citrulline value was 33.0 ± 7.5 µmol/L in controls and 23.5 ± 8.4 µmol/L in CD patients (P < 0.0001). Plasma citrulline was significantly lower in patients with small bowel (SB) location than in patient with only ileo-colon disease (14.2 ± 5.5 and 24.7 ± 8.0, respectively; P = 0.0037). Citrulline ≤22 µmol/L reached sensitivity of 100% (95% confidence interval (CI) 54-100) and specificity of 98% (CI 89-99) in differentiating control subjects from CD with SB location. CONCLUSIONS: CD patients have reduced concentration of plasma citrulline than controls. Intestinal damage rather than inflammation seems to be responsible for the reduced biosynthesis of citrulline, which decreases particularly in CD patients with SB location. This finding suggests the potential role of citrulline as marker of disease location, but future works will be needed to confirm this suggestion.

Preemptive liver transplantation in a child with familial hypercholesterolemia.

Familial hypercholesterolemia is an autosomal codominant disorder associated with markedly elevated plasma concentration of LDL-cholesterol and increased cardiovascular risk. Homozygous patients have rapid development of atherosclerosis with death from cardiovascular disease even in childhood. Life-long recurrent apheresis to reduce plasma LDL-cholesterol is considered the gold standard for treatment. Liver transplantation can be curative for this condition, but is usually only considered after the development of cardiovascular disease. We report a 5.5-yr-old child initially misdiagnosed with heterozygous familial hypercholesterolemia and treated by low-fat diet only. In view of persistent hypercholesterolemia and development of xanthomatosis, new molecular studies indicated the presence of two different mutations in the LDL receptor gene, with one being a deletion of two exons not identifiable with standard sequencing analysis. Recurrent plasma apheresis in combination with statins lowered, but did not normalize plasma LDL-cholesterol levels. It caused progressive reduction of the size of xanthomas and prevented the development of vascular complications. After two yr, liver transplantation normalized LDL-cholesterol levels and completely resolved the skin lesions. Preemptive liver transplantation is a definitive cure of familial homozygous hypercholesterolemia and might be more effective if performed before development of vascular complications.

Plasma citrulline as marker of bowel adaptation in children with short bowel syndrome.

PURPOSE: The aim of this study is to determine if prospective determinations of citrulline could be predictive of the bowel adaptation in children with short bowel syndrome (SBS). METHODS: Between March 2005 and March 2010, we prospectively included 28 SBS patients on parenteral nutrition. The citrulline and the enteral intake determinations were scheduled at the inclusion and at 6-month intervals. We assessed the correlation between citrulline and bowel length as well as enteral caloric intake, longitudinal trend of citrulline and association between patients characteristics according to the course of bowel adaptation. RESULTS: Citrulline significantly correlated with the residual duodenum-jejunum length (r (2) = 0.22, P = 0.0113) and with enteral intake (r (2) = 0.20, P = 0.016 and r (2) = 0.48, P = 0.0001). Baseline citrulline at the cutoff >10 µmol/L and a longitudinal increase >25% provided a weak association with bowel adaptation (likelihood ratio (LR), 2.6 and 2.4, respectively), unlike residual small bowel length ≥20 cm and the presence of >50% of the colon (LR, 10 and 6, respectively). CONCLUSIONS: Citrulline seems to be a powerful biomarker of the intestinal function, showed by the correlation with the residual duodenum-jejunum length and the enteral absorption, but not of its prospective changes during the bowel adaptation process. Future studies may be necessary to confirm this finding.

Clinical accuracy of anti-tissue transglutaminase as screening test for celiac disease under 2 years.

AIM: To investigate, in patients with suspected celiac disease (CD) younger than 2 years, the clinical value of anti-tissue transglutaminase (tTG) in diagnostic work-up of CD. METHODS: Between June 2005 and June 2009, 169 patients aged <2 years, with symptoms suggestive of CD, were submitted to biopsy. CD diagnosis was based on the revised criteria of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition. RESULTS: Of the 169 patients enrolled, 155 were included: 108 of them showed mucosal atrophy and 47 negative histology. Sensitivity and specificity of tTG, at the cut-off of 8 AU/mL, were 0.96 (CI 0.91-0.99) and 0.91 (CI 0.80-0.98), respectively, with likelihood ratio (LR) of 11.31; at the cut-off of 16 AU/mL, they were 0.79 (CI 0.70-0.86) and 1.00, respectively (CI 0.92-1.00), with LR 4.50. CONCLUSIONS: In patients younger than 2 years, suspected for CD, tTG is very valuable in selecting for small intestinal biopsy.