Association Between Cytokines and Liver Histology in Children with Nonalcoholic Fatty Liver Disease.

BackgroundReliable non-invasive markers to characterize inflammation, hepatocellular ballooning, and fibrosis in nonalcoholic fatty liver disease (NAFLD) are lacking. We investigated the relationship between plasma cytokine levels and features of NAFLD histology to gain insight into cellular pathways driving NASH and to identify potential non-invasive discriminators of NAFLD severity and pattern.MethodsCytokines were measured from plasma obtained at enrollment in pediatric participants in NASH Clinical Research Network studies with liver biopsy-proven NAFLD. Cytokines were chosen a priori as possible discriminators of NASH and its components. Minimization of Akaike Information Criterion (AIC) was used to determine cytokines retained in multivariable models.ResultsOf 235 subjects, 31% had "Definite NASH" on liver histology, 43% had "Borderline NASH", and 25% had NAFLD but not NASH. Total plasminogen activator inhibitor 1 (PAI1) and activated PAI1 levels were higher in pediatric participants with Definite NASH and with lobular inflammation. Interleukin-8 (IL-8) was higher in those with stage 3-4 fibrosis and lobular inflammation. sIL-2rα was higher in children with stage 3-4 fibrosis and portal inflammation. In multivariable analysis, PAI1 variables were discriminators of Borderline/Definite NASH, definite NASH, lobular inflammation and ballooning. IL-8 increased with steatosis and fibrosis severity; sIL-2rα increased with fibrosis severity and portal inflammation. IL-7 decreased with portal inflammation and fibrosis severity.ConclusionsPlasma cytokines associated with histology varied considerably among NASH features, suggesting promising avenues for investigation. Future, more targeted analysis is needed to identify the role of these markers in NAFLD and to evaluate their potential as non-invasive discriminators of disease severity

Histologic Abnormalities in Children with Nonalcoholic Fatty Liver Disease and Normal or Mildly Elevated Alanine Aminotransferase Levels.

Objectives: To investigate the histological spectrum of nonalcoholic fatty liver disease (NAFLD) in children with normal, mildly elevated (26–50 U/L boys, 23–44 U/L girls), or elevated (> 50 boys, > 44 girls) serum alanine aminotransferase (ALT) levels. Study design: The Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) enrolls children 5–18 years with NAFLD. We analyzed baseline clinical and histological data from 91 children with suspected NAFLD and normal or mildly elevated ALT and liver biopsy within 180 days of ALT, and compared them with 392 children with elevated ALT. Results: Of 91 children, 17 (19%) had normal and 74 (81%) had mildly elevated ALT levels. Overall, 45% of biopsies had ≥ 33% steatosis, lobular inflammation grade was ≥ 2 in 22%, 81% had portal inflammation, 29% had ballooned hepatocytes, 35% had “suspicious/borderline” steatohepatitis, and 8% had definite NASH, 34% had NAFLD activity score (NAS) ≥ 4. Overall, 46% had fibrosis (38% mild/moderate and 8% bridging/cirrhosis). Marked steatosis (50% vs 24%) and fibrosis (54% vs 12%) were significantly more common in mildly elevated vs normal, with no difference in ballooning, inflammation, or NAS ≥ 4. Fibrosis stage 3/4 was seen in none of the children with normal ALT, and in 9% of the mildly elevated and 15% of the elevated. Conclusions: Liver biopsies of children with NAFLD with normal or mildly elevated ALT levels show significant histologic abnormalities, including advanced fibrosis in children with mildly elevated ALT. ALT thus may underestimate liver injury in NAFLD. Appropriate ALT cut-off levels can help identify children at risk for more severe disease

Construct-level predictive validity of educational attainment and intellectual aptitude tests in medical student selection: meta-regression of six UK longitudinal studies

Background: Measures used for medical student selection should predict future performance during training. A problem for any selection study is that predictor-outcome correlations are known only in those who have been selected, whereas selectors need to know how measures would predict in the entire pool of applicants. That problem of interpretation can be solved by calculating construct-level predictive validity, an estimate of true predictor-outcome correlation across the range of applicant abilities. Methods: Construct-level predictive validities were calculated in six cohort studies of medical student selection and training (student entry, 1972 to 2009) for a range of predictors, including A-levels, General Certificates of Secondary Education (GCSEs)/O-levels, and aptitude tests (AH5 and UK Clinical Aptitude Test (UKCAT)). Outcomes included undergraduate basic medical science and finals assessments, as well as postgraduate measures of Membership of the Royal Colleges of Physicians of the United Kingdom (MRCP(UK)) performance and entry in the Specialist Register. Construct-level predictive validity was calculated with the method of Hunter, Schmidt and Le (2006), adapted to correct for right-censorship of examination results due to grade inflation. Results: Meta-regression analyzed 57 separate predictor-outcome correlations (POCs) and construct-level predictive validities (CLPVs). Mean CLPVs are substantially higher (.450) than mean POCs (.171). Mean CLPVs for first-year examinations, were high for A-levels (.809; CI: .501 to .935), and lower for GCSEs/O-levels (.332; CI: .024 to .583) and UKCAT (mean = .245; CI: .207 to .276). A-levels had higher CLPVs for all undergraduate and postgraduate assessments than did GCSEs/O-levels and intellectual aptitude tests. CLPVs of educational attainment measures decline somewhat during training, but continue to predict postgraduate performance. Intellectual aptitude tests have lower CLPVs than A-levels or GCSEs/O-levels. Conclusions: Educational attainment has strong CLPVs for undergraduate and postgraduate performance, accounting for perhaps 65% of true variance in first year performance. Such CLPVs justify the use of educational attainment measure in selection, but also raise a key theoretical question concerning the remaining 35% of variance (and measurement error, range restriction and right-censorship have been taken into account). Just as in astrophysics, ‘dark matter’ and ‘dark energy’ are posited to balance various theoretical equations, so medical student selection must also have its ‘dark variance’, whose nature is not yet properly characterized, but explains a third of the variation in performance during training. Some variance probably relates to factors which are unpredictable at selection, such as illness or other life events, but some is probably also associated with factors such as personality, motivation or study skills

Relationship of ELF and PIIINP With Liver Histology and Response to Vitamin E or Pioglitazone in the PIVENS Trial

Enhanced liver fibrosis score (ELF) and one of its components, amino-terminal propeptide of type III procollagen (PIIINP) are promising noninvasive biomarkers of liver histology in patients with nonalcoholic steatohepatitis (NASH). We evaluated the association of ELF and PIIINP with fibrosis stages at baseline and end of treatment (EOT) with vitamin E or pioglitazone in the PIVENS trial (Pioglitazone vs. Vitamin E vs. Placebo for the Treatment of Nondiabetic Patients With NASH) and characterized ELF and PIIINP changes and their associations with changes in the histological endpoints. ELF and PIIINP were measured at baseline and weeks 16, 48, and 96 on sera from 243 PIVENS participants. Baseline and EOT ELF were significantly associated with fibrosis stage (P < 0.001). The area under the curve for ELF's detection of clinically significant and advanced fibrosis in baseline biopsies was 0.74 and 0.79, respectively (P < 0.001). There was a significant drop in ELF score at weeks 48 and 96 in patients who achieved the NAFLD activity score (NAS)-based primary end point (P = 0.007) but not in those who experienced NASH resolution (P = 0.24) or fibrosis improvement (P = 0.50). Change in PIIINP was significantly associated with NASH resolution and improvement in NAS-based histological endpoint and fibrosis (P < 0.05 for all). Over the study period, both ELF and PIIINP significantly decreased with vitamin E (P < 0.05), but only PIIINP decreased with pioglitazone (P < 0.001). Conclusion: ELF is significantly associated with clinically significant and advanced fibrosis in patients with NASH, but its longitudinal changes were not associated with improvement in fibrosis or NASH resolution. PIIINP, one of its components, appears promising for identifying longitudinal histologic changes in patients with NASH and is worthy of further investigation

Clinically Actionable Hypercholesterolemia and Hypertriglyceridemia in Children with Nonalcoholic Fatty Liver Disease

OBJECTIVE: To determine the percentage of children with nonalcoholic fatty liver disease (NAFLD) in whom intervention for low-density lipoprotein cholesterol or triglycerides was indicated based on National Heart, Lung, and Blood Institute guidelines. STUDY DESIGN: This multicenter, longitudinal cohort study included children with NAFLD enrolled in the National Institute of Diabetes and Digestive and Kidney Diseases Nonalcoholic Steatohepatitis Clinical Research Network. Fasting lipid profiles were obtained at diagnosis. Standardized dietary recommendations were provided. After 1 year, lipid profiles were repeated and interpreted according to National Heart, Lung, and Blood Institute Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction. Main outcomes were meeting criteria for clinically actionable dyslipidemia at baseline, and either achieving lipid goal at follow-up or meeting criteria for ongoing intervention. RESULTS: There were 585 participants, with a mean age of 12.8 years. The prevalence of children warranting intervention for low-density lipoprotein cholesterol at baseline was 14%. After 1 year of recommended dietary changes, 51% achieved goal low-density lipoprotein cholesterol, 27% qualified for enhanced dietary and lifestyle modifications, and 22% met criteria for pharmacologic intervention. Elevated triglycerides were more prevalent, with 51% meeting criteria for intervention. At 1 year, 25% achieved goal triglycerides with diet and lifestyle changes, 38% met criteria for advanced dietary modifications, and 37% qualified for antihyperlipidemic medications. CONCLUSIONS: More than one-half of children with NAFLD met intervention thresholds for dyslipidemia. Based on the burden of clinically relevant dyslipidemia, lipid screening in children with NAFLD is warranted. Clinicians caring for children with NAFLD should be familiar with lipid management

Haptoglobin 2 Allele is Associated With Histologic Response to Vitamin E in Subjects With Nonalcoholic Steatohepatitis

Background: Haptoglobin (Hp) genotype has been linked to oxidative stress and response to vitamin E (VitE) in patients with dyslipidemia. Its effect on histological response to VitE in nonalcoholic steatohepatitis (NASH) is unknown. Goals: Our objective was to determine if Hp genotype associates with response to VitE in patients with NASH. Study: A post hoc analysis of 228 patients receiving VitE or placebo in two clinical trials was performed. Regression analysis was used to assess the effect of VitE versus placebo, by Hp genotype (1–1, 2–1, or 2–2), on histologic features and laboratory markers of liver disease, comparing baseline to end of treatment values. An interaction term was included in the regression models to assess differential treatment effect across Hp genotype. Results: Hp 2–2 patients treated with VitE versus placebo showed significant histologic improvement (51% versus 20%, OR=4·2, p=0·006), resolution of steatohepatitis (44% versus 12%, OR=6.2, p=0·009), decrease in NAFLD Activity Score (NAS) (−2·2 versus −0·6, p=0·001), and decrease in liver enzymes alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and γ-glutamyl transpeptidase. Hp 2–1 patients on VitE versus placebo showed improved resolution of steatohepatitis, NAS and liver enzymes. Hp 1–1 patients showed no significant improvement in histology or liver enzymes. VitE had no effect on fibrosis stage in any group. Regression analysis showed incremental benefit of having Hp 2–2 or 2–1 versus 1–1 for all liver enzymes. Conclusion: Hp 2 allele is associated with greater histological and biological improvement in NASH with VitE treatment compared to the Hp 1 allele

Incidence of Type 2 Diabetes in Children With Nonalcoholic Fatty Liver Disease

Background &amp; aimsType 2 diabetes (T2D) is a growing problem in children. Children with NAFLD are at potentially high risk for developing T2D; however, the incidence of T2D in this population is unknown. This study aimed to determine the incidence of T2D in children with NAFLD and identify associated risk factors.MethodsChildren with NAFLD enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network were followed longitudinally. Incidence of T2D was determined by using clinical history and fasting laboratory values. Cumulative incidence curves were developed for time to T2D. A Cox regression multivariable model was constructed using best subsets Akaike's Information Criteria selection.ResultsThis study included 892 children with NAFLD and with a mean age of 12.8 years (2.7) followed for 3.8 years (2.3) with a total 3234 person-years at risk. The incidence rate of T2D was 3000 new cases per 100,000 person-years at risk. At baseline, 63 children had T2D, and during follow-up, an additional 97 children developed incident T2D, resulting in a period prevalence of 16.8%. Incident T2D was significantly higher in females versus males (hazard ratio [HR], 1.8 [1.0-2.8]), associated with BMI z-score (HR, 1.8 [1.0-3.0]), and more severe liver histology including steatosis grade (HR, 1.3 [1.0-1.7]), and fibrosis stage (HR, 1.3 [1.0-1.5]).ConclusionsChildren with NAFLD are at high risk for existing and incident T2D. In addition to known risk factors for T2D (female and BMI z-score), severity of liver histology at the time of NAFLD diagnosis was independently associated with T2D development. Targeted strategies to prevent T2D in children with NAFLD are needed

Vitamin D Induction of the Human Antimicrobial Peptide Cathelicidin in the Urinary Bladder

The urinary tract is frequently being exposed to potential pathogens and rapid defence mechanisms are therefore needed. Cathelicidin, a human antimicrobial peptide is expressed and secreted by bladder epithelial cells and protects the urinary tract from infection. Here we show that vitamin D can induce cathelicidin in the urinary bladder. We analyzed bladder tissue from postmenopausal women for expression of cathelicidin, before and after a three-month period of supplementation with 25-hydroxyvitamin D3 (25D3). Cell culture experiments were performed to elucidate the mechanisms for cathelicidin induction. We observed that, vitamin D per se did not up-regulate cathelicidin in serum or in bladder tissue of the women in this study. However, when the bladder biopsies were infected with uropathogenic E. coli (UPEC), a significant increase in cathelicidin expression was observed after 25D3 supplementation. This observation was confirmed in human bladder cell lines, even though here, cathelicidin induction occurred irrespectively of infection. Vitamin D treated bladder cells exerted an increased antibacterial effect against UPEC and colocalization to cathelicidin indicated the relevance of this peptide. In the light of the rapidly growing problem of resistance to common urinary tract antibiotics, we suggest that vitamin D may be a potential complement in the prevention of UTI

ENM2020 : A FREE ONLINE COURSE AND SET OF RESOURCES ON MODELING SPECIES NICHES AND DISTRIBUTIONS

The field of distributional ecology has seen considerable recent attention, particularly surrounding the theory, protocols, and tools for Ecological Niche Modeling (ENM) or Species Distribution Modeling (SDM). Such analyses have grown steadily over the past two decades-including a maturation of relevant theory and key concepts-but methodological consensus has yet to be reached. In response, and following an online course taught in Spanish in 2018, we designed a comprehensive English-language course covering much of the underlying theory and methods currently applied in this broad field. Here, we summarize that course, ENM2020, and provide links by which resources produced for it can be accessed into the future. ENM2020 lasted 43 weeks, with presentations from 52 instructors, who engaged with >2500 participants globally through >14,000 hours of viewing and >90,000 views of instructional video and question-and-answer sessions. Each major topic was introduced by an "Overview" talk, followed by more detailed lectures on subtopics. The hierarchical and modular format of the course permits updates, corrections, or alternative viewpoints, and generally facilitates revision and reuse, including the use of only the Overview lectures for introductory courses. All course materials are free and openly accessible (CC-BY license) to ensure these resources remain available to all interested in distributional ecology.Peer reviewe