Presence of Alpha 1 Antitrypsin Risk Variants is Not Associated With Histologic Severity of Pediatric NAFLD.

BACKGROUND: Among adults with nonalcoholic fatty liver disease (NAFLD), alpha-1-antitrypsin (A1AT) heterozygosity has been linked to advanced liver disease; pediatric data remain unclear. OBJECTIVE: The objective of this study is to determine whether A1AT PiZ or PiS variants are associated with liver disease severity in youth with NAFLD. METHODS: Retrospective study of youth with confirmed NAFLD. Multivariable logistic regression used to determine independent associations between A1AT risk variants and histologic severity [NAFLD activity score (NAS) ≥5 and/or significant fibrosis (stage ≥2)]. RESULTS: The cohort included 269 patients, mean age 12 [±3] years with NAFLD and A1AT phenotyping (n = 260) and/or A1AT levels (n = 261). The mean NAS of the cohort was 4.2 [±1.5]; 50% had any, and 18% had significant fibrosis. Most (86%) had the MM A1AT phenotype, while 7% had the MS and 3% the MZ phenotype (the rest had other, nonpathogenic variants). Mean A1AT level was 123 mg/dL [±20]. A1AT levels did not differ by low versus high NAS (122 ± 2 vs 126 ± 19 mg/dL, P = 0.12) or by no/mild versus significant fibrosis (123 ± 20 vs 126 ± 20 mg/dL, P = 0.23, respectively). Carriers and noncarriers of the PiS or PiZ variants had similar NAS (mean NAS 3.8 ± 1.6 vs 4.2 ± 1.4; P = 0.25, respectively). Fibrosis severity did not differ by carrier vs noncarrier group: 38% versus 52% had any fibrosis ( P = 0.17) and 14% versus 18% had significant fibrosis ( P = 0.80, respectively). Multivariable modeling showed no association between A1AT risk variants and histologic severity. CONCLUSION: While not uncommon, carriage of the A1AT PiZ or PiS risk variants was not associated with histologic severity in children with NAFLD.

Clinically Meaningful Body Mass Index Change Impacts Pediatric Nonalcoholic Fatty Liver Disease.

OBJECTIVE: To investigate the prevalence and characteristics of children with nonalcoholic fatty liver disease (NAFLD) who reduce their body mass index (BMI) z-score (BMIz) by >.25, a goal in obesity medicine, and to determine the BMIz decrease needed for serum aminotransferase normalization. STUDY DESIGN: This retrospective, single-center study included patients aged <18 years followed for NAFLD. Patients who had undergone weight loss surgery or had other reasons for weight loss/gain were excluded. Logistic regression was used to determine the odds of achieving a BMIz change of >-.25, as well as predictors of this outcome. RESULTS: Of the 784 children who met the study criteria (median age, 13 years; 66% male; 24% Hispanic), 541 had a lowest BMIz at >90 days following the baseline clinic visit. Of these children, 168 (31%) had a BMIz change of >-.25 from baseline over a median of 367 days (IQR, 201-678 days). Decreases in serum aminotransferase and lipid levels were seen in both groups (with and without a BMIz change of >-.25); however, these decreases were more pronounced in children who achieved a BMIz drop of >.25. Hemoglobin A1c concentration did not change in either group. Young age (OR, .861; 95% CI, .81-.92; P < .01) and non-Hispanic ethnicity (OR of non-Hispanic vs Hispanic, .61; 95% CI, .38-.97; P < .04) were predictors of a BMIz change >-.25. The BMIz decrease associated with normalization of serum alanine aminotransferase was .27. CONCLUSIONS: A BMIz reduction of >.25 is associated with significant changes in serum aminotransferase levels. These findings can further guide the clinical management of children with NAFLD.

Impact of adenoviral stool load on adenoviremia in pediatric hematopoietic stem cell transplant recipients.

BACKGROUND: Adenoviremia adversely affects prognosis in the post-hematopoietic stem cell transplant setting. METHODS: We sought to determine retrospectively the cutoff load of adenovirus in the stool as a predictor of adenoviremia, in children who underwent an allogeneic hematopoietic stem cell transplant. The prevalence of sapovirus, norovirus and astrovirus in the stool was also studied. RESULTS: The study cohort consisted of 117 patients, of which 71 (60%) had diarrhea. Adenovirus was detected in the stool in 39 of 71 (55%) patients. Age ≤10 years (P = 0.05; odds ratio: 2.57; 95% confidence interval: 0.98-6.75) and male sex (P = 0.04; odds ratio: 2.67; 95% confidence interval: 1.02-6.99) increased risk for detection of adenovirus in stool on univariate analysis. Coinfections with enteric pathogens were infrequent. Viral load >10 copies/g stool predicted adenoviremia with a sensitivity and specificity of 82%. Sapovirus, norovirus and astrovirus were detected in 3, 4 and 1 patient, respectively. CONCLUSIONS: Quantitative detection of adenovirus in stool may have implications for preemptive therapy. Testing for other enteric viruses may have implications for infection control.

Reduced susceptibility of DNA methyltransferase 1 hypomorphic (Dnmt1N/+) mice to hepatic steatosis upon feeding liquid alcohol diet.

BACKGROUND: Methylation at C-5 (5-mdC) of CpG base pairs, the most abundant epigenetic modification of DNA, is catalyzed by 3 essential DNA methyltransferases (Dnmt1, Dnmt3a and Dnmt3b). Aberrations in DNA methylation and Dnmts are linked to different diseases including cancer. However, their role in alcoholic liver disease (ALD) has not been elucidated. METHODOLOGY/PRINCIPAL FINDINGS: Dnmt1 wild type (Dnmt1(+/+)) and hypomorphic (Dnmt1(N/+)) male mice that express reduced level of Dnmt1 were fed Lieber-DeCarli liquid diet containing ethanol for 6 weeks. Control mice were pair-fed calorie-matched alcohol-free liquid diet, and Dnmtase activity, 5-mdC content, gene expression profile and liver histopathology were evaluated. Ethanol feeding caused pronounced decrease in hepatic Dnmtase activity in Dnmt1(+/+) mice due to decrease in Dnmt1 and Dnmt3b protein levels and upregulation of miR-148 and miR-152 that target both Dnmt1 and Dnmt3b. Microarray and qPCR analysis showed that the genes involved in lipid, xenobiotic and glutathione metabolism, mitochondrial function and cell proliferation were dysregulated in the wild type mice fed alcohol. Surprisingly, Dnmt1(N/+) mice were less susceptible to alcoholic steatosis compared to Dnmt1(+/+) mice. Expression of several key genes involved in alcohol (Aldh3b1), lipid (Ppara, Lepr, Vldlr, Agpat9) and xenobiotic (Cyp39a1) metabolism, and oxidative stress (Mt-1, Fmo3) were significantly (P<0.05) altered in Dnmt1(N/+) mice relative to the wild type mice fed alcohol diet. However, CpG islands encompassing the promoter regions of Agpat9, Lepr, Mt1 and Ppara were methylation-free in both genotypes irrespective of the diet, suggesting that promoter methylation does not regulate their expression. Similarly, 5-mdC content of the liver genome, as measured by LC-MS/MS analysis, was not affected by alcohol diet in the wild type or hypomorphic mice. CONCLUSIONS/SIGNIFICANCE: Although feeding alcohol diet reduced Dnmtase activity, the loss of one copy of Dnmt1 protected mice from alcoholic hepatosteatosis by dysregulating genes involved in lipid metabolism and oxidative stress.