Evaluation of Body Mass Index, Overweight and Obesity Status, and Cholesterol Levels in Younger Children.

This cohort study examines cholesterol levels in children with overweight or obesity.

Direct LDL-C estimation in preschoolers: Practicable first step for FH screening.

BACKGROUND: Individuals with FH develop cardiovascular disease due to lifelong cumulative exposure to elevated LDL-C. Effective screening for FH is not yet established. OBJECTIVE: To evaluate the practicability of a FH screening by measuring directly the LDL-C in preschoolers. METHODS: LDL-C measurement through capillary blood sampling during the compulsory routine check-ups by the pediatrician in children aged 2 to 6 years including information on family history as dyslipidemia and/or premature cardiovascular disease in first and second grade of pedigrees. RESULTS: 15,009 children (52.2% males, median age 3.9 years [IQR 3.0-5.1]) participated in the study. Positive family history for hyperlipidemia was stated in 40.9% cases, in 12.0% also in at least one 1st degree relative. In the total cohort, median LDL-C was 93 mg/dL [IQR 79-109 mg/dL]. Boys had significantly higher LDL-C levels than girls (p < 0.0001), whereas there was no difference regarding their age (p = 0.757). Children from families with a positive history for hypercholesterolemia/dyslipidemia had significantly higher LDL-C levels (p < 0.001) and were more frequently among those with LDL-C values above 135 mg/dL (3.5 mmol/L, 96th percentile; 53.2% vs. 40.3%, p < 0.001) and those with LDL-C levels above 160 mg/dL (4.1 mmol/L, 99th percentile; 45.3% vs. 40.7%, p < 0.001) than children without positive family history. CONCLUSIONS: Direct measurement of LDL-C levels in children at ages 2-6 years during the compulsory routine check-ups as well as at any voluntary visits to the pediatrician's office is practicable and delivers reliable information, which can be used for a FH screening strategy in the general population.

Universal screening for familial hypercholesterolemia in 2 populations.

PURPOSE: In Europe, >2 million individuals with familial hypercholesterolemia (FH) are currently undiagnosed. Effective screening strategies for FH diagnosis in childhood are urgently needed. We assessed the overall performances of 2 different FH screening programs in children: universal screening program with opt-out and opt-in type participation. METHODS: We analyzed the data from 2 independent populations based on >166,000 individuals screened for hypercholesterolemia. Genetic analyses of FH-related genes were finalized in 945 children and 99 parents. RESULTS: A total of 305 (32.3%) children were genotyped as positive or with a variant of uncertain significance in FH-related genes. For low-density lipoprotein cholesterol levels of 3.5 mmol L (135.3 mg/dL), the overall sensitivity and specificity for confirming FH were 90.5% and 55.3%, respectively. As part of child-parent screening, in >90% of the families, the parent with reported higher cholesterol levels was positive for the familial genetic variant. The cohort-based prevalence of FH from the opt-out universal screening program was estimated to be 1 in 431 individuals (95% CI = 1/391-1/472). CONCLUSION: Universal 3-step FH screening approach in children enabled detection of most children and their parents in every generation screened at reasonable costs. Opt-out screening strategy might be preferable over opt-in screening strategy.

Phenotypic spectrum and diagnostic pitfalls of ABCB4 deficiency depending on age of onset.

Genetic variants in the adenosine triphosphate-binding cassette subfamily B member 4 (ABCB4) gene, which encodes hepatocanalicular phosphatidylcholine floppase, can lead to different phenotypes, such as progressive familial intrahepatic cholestasis (PFIC) type 3, low phospholipid-associated cholelithiasis, and intrahepatic cholestasis of pregnancy. The aim of this multicenter project was to collect information on onset and progression of this entity in different age groups and to assess the relevance of this disease for the differential diagnosis of chronic liver disease. Clinical and laboratory data of 38 patients (17 males, 21 females, from 29 families) with homozygous or (compound) heterozygous ABCB4 mutations were retrospectively collected. For further analysis, patients were grouped according to the age at clinical diagnosis of ABCB4-associated liver disease into younger age (<18 years) or adult age (≥18 years). All 26 patients diagnosed in childhood presented with pruritus (median age 1 year). Hepatomegaly and splenomegaly were present in 85% and 96% of these patients, respectively, followed by jaundice (62%) and portal hypertension (69%). Initial symptoms preceded diagnosis by 1 year, and 13 patients received a liver transplant (median age 6.9 years). Of note, 9 patients were misdiagnosed as biliary atresia, Alagille syndrome, or PFIC type 1. In the 12 patients with diagnosis in adulthood, the clinical phenotype was generally less severe, including intrahepatic cholestasis of pregnancy, low phospholipid-associated cholelithiasis, or (non)cirrhotic PFIC3. Conclusion: ABCB4 deficiency with onset in younger patients caused a more severe PFIC type 3 phenotype with the need for liver transplantation in half the children. Patients with milder phenotypes are often not diagnosed before adulthood. One third of the children with PFIC type 3 were initially misdiagnosed, indicating the need for better diagnostic tools and medical education. (Hepatology Communications 2018;2:504-514).

IPEX due to an exon 7 skipping FOXP3 mutation with autoimmune diabetes mellitus cured by selective TReg cell engraftment.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare inherited disorder leading to severe organ-specific autoimmunity. IPEX is caused by hemizygous mutations in FOXP3, which codes for a master transcription factor of regulatory T (TReg) cell development and function. We describe a four-year-old boy with typical but slightly delayed-onset of IPEX with autoimmune diabetes mellitus, enteropathy, hepatitis and skin disease. We found the unreported FOXP3 splice site mutation c.816+2T>A that leads to the loss of leucine-zipper coding exon 7. RNA-Seq revealed that FOXP3Δ7 leads to differential expression of FOXP3 regulated genes. After myeloablative conditioning the patient underwent allogeneic HSCT from a matched unrelated donor. HSCT led to the resolution of all IPEX symptoms including insulin requirement despite persisting autoantibody levels. After initial full donor engraftment nearly complete autologous reconstitution was documented, but donor-derived TReg cells persisted with a lineage-specific chimerism of >70% and the patient remained in clinical remission.

The EHEC-host interactome reveals novel targets for the translocated intimin receptor.

Enterohemorrhagic E. coli (EHEC) manipulate their human host through at least 39 effector proteins which hijack host processes through direct protein-protein interactions (PPIs). To identify their protein targets in the host cells, we performed yeast two-hybrid screens, allowing us to find 48 high-confidence protein-protein interactions between 15 EHEC effectors and 47 human host proteins. In comparison to other bacteria and viruses we found that EHEC effectors bind more frequently to hub proteins as well as to proteins that participate in a higher number of protein complexes. The data set includes six new interactions that involve the translocated intimin receptor (TIR), namely HPCAL1, HPCAL4, NCALD, ARRB1, PDE6D, and STK16. We compared these TIR interactions in EHEC and enteropathogenic E. coli (EPEC) and found that five interactions were conserved. Notably, the conserved interactions included those of serine/threonine kinase 16 (STK16), hippocalcin-like 1 (HPCAL1) as well as neurocalcin-delta (NCALD). These proteins co-localize with the infection sites of EPEC. Furthermore, our results suggest putative functions of poorly characterized effectors (EspJ, EspY1). In particular, we observed that EspJ is connected to the microtubule system while EspY1 appears to be involved in apoptosis/cell cycle regulation.

Rac function is crucial for cell migration but is not required for spreading and focal adhesion formation.

Cell migration is commonly accompanied by protrusion of membrane ruffles and lamellipodia. In two-dimensional migration, protrusion of these thin sheets of cytoplasm is considered relevant to both exploration of new space and initiation of nascent adhesion to the substratum. Lamellipodium formation can be potently stimulated by Rho GTPases of the Rac subfamily, but also by RhoG or Cdc42. Here we describe viable fibroblast cell lines genetically deficient for Rac1 that lack detectable levels of Rac2 and Rac3. Rac-deficient cells were devoid of apparent lamellipodia, but these structures were restored by expression of either Rac subfamily member, but not by Cdc42 or RhoG. Cells deficient in Rac showed strong reduction in wound closure and random cell migration and a notable loss of sensitivity to a chemotactic gradient. Despite these defects, Rac-deficient cells were able to spread, formed filopodia and established focal adhesions. Spreading in these cells was achieved by the extension of filopodia followed by the advancement of cytoplasmic veils between them. The number and size of focal adhesions as well as their intensity were largely unaffected by genetic removal of Rac1. However, Rac deficiency increased the mobility of different components in focal adhesions, potentially explaining how Rac - although not essential - can contribute to focal adhesion assembly. Together, our data demonstrate that Rac signaling is essential for lamellipodium protrusion and for efficient cell migration, but not for spreading or filopodium formation. Our findings also suggest that Rac GTPases are crucial to the establishment or maintenance of polarity in chemotactic migration.

GSTP1 and MDR1 genotypes and central nervous system relapse in childhood acute lymphoblastic leukemia.

The probability of event-free survival of childhood acute lymphoblastic leukemia (ALL) approaches 80% or more with the use of modern multiagent chemotherapeutic regimens. One major contribution to this success has been reduction of the rate of central nervous system (CNS) relapses to less than 5%. However, heterogeneity is observed with regard to the incidence of CNS relapse in homogenously treated patient populations. One potential explanation for this heterogeneity is variation in the genetic background of these populations. Glutathione S-transferase P1 and P-glycoprotein are implicated in resistance to a variety of chemotherapeutic agents and have been localized to the blood-brain barrier. In a matched case-control study, we investigated the associations between CNS relapse in childhood ALL and the presence of phenotypically relevant single nucleotide polymorphisms within the GSTP1 (codon 105 and 114) and MDR1 genes (ABCB1; coding for Pgp; exon 26, C3435T). Significant reductions in risk of CNS relapse were observed for patients homozygous for the GSTP1 Val105 allele as well as for patients with the MDR1 3435T/T or C/T genotype. For both genotypes, the effect was restricted to patients at intermediate or high risk of treatment failure. These results suggested a modulating role for host genetic variation in the development of CNS relapse in childhood ALL treated according to Berlin-Frankfurt-Münster protocols.