Background/Aims Currently the diagnosis and severity of hepatic steatosis can be established accurately only by liver biopsy. Previous small studies found that steatosis measured by magnetic ...resonance spectroscopy (MRS) and imaging (MRI) correlated with histological assessment of liver triglyceride content. However, the accuracy of MRS/MRI for grading the severity of steatosis has not been addressed. The aims of this study were (1) to determine whether MRS and MRI can discriminate grades of steatosis in a large cohort of consecutive patients with a wide spectrum of liver disease aetiology and severity (2) to evaluate the effect of hepatic fibrosis, inflammation and iron on quantitation of intrahepatocellular lipid (IHCL) by these techniques. Methods Ninety-four sequential patients who underwent percutaneous liver biopsy or liver resection had MRS and MRI (Dixon in phase/out of phase (Dixon IP/OP) and with/without fat saturation (±FS) images) to determine IHCL. Histology was used as the reference standard. Results Close relationships were observed between the percentage of steatosis estimated by histology and MRS/MRI ( rs = 0.88 p < 0.001 for all techniques). However, separate equations were required for the percentage of steatosis to avoid underestimation by imaging for patients with moderate or advanced fibrosis. All techniques had good diagnostic accuracy for mild steatosis (AUROC ⩾ 0.87) as well as moderate/severe steatosis (AUROC ⩾ 0.89). Hepatic inflammation and mild iron deposition (Perls’ grade 1 and 2) did not interfere with estimation of steatosis by imaging. Conclusions MRS and MRI had good accuracy for grading the severity of steatosis in subjects with liver disease, provided that stage of fibrosis was considered.
AIM:To develop a model of stress-induced senescence to study the hepatocyte senescence associated secretory phenotype(SASP).METHODS:Hydrogen peroxide treatment was used to induce senescence in the ...human Hep G2 hepatocyte cell line.Senescence was confirmed by cytochemical staining for a panel of markers including Ki67,p21,heterochromatin protein 1β,and senescence-associated-β-galactosidase activity.Senescent hepatocytes were characterised by gene expression arrays and quantitative polymerase chain reaction(q PCR),and conditioned media was used in proteomic analyses,a human chemokine protein array,and cell migration assays to characterise the composition and function of the hepatocyte SASP.RESULTS:Senescent hepatocytes induced classical markers of senescence(p21,heterochromatin protein1β,and senescence-associated-β-galactosidase activity);and downregulated the proliferation marker,Ki67.Hepatocyte senescence induced a 4.6-fold increase in total secreted protein(P=0.06)without major alterations in the protein profile.Senescence-induced genes were identified by microarray(Benjamini Hochbergcorrected P<0.05);and,consistent with the increase in secreted protein,gene ontology analysis revealed a significant enrichment of secreted proteins among inducible genes.The hepatocyte SASP included characteristic factors such as interleukin(IL)-8 and IL-6,as well as novel components such as SAA4,IL-32and Fibrinogen,which were validated by q PCR and/or chemokine protein array.Senescent hepatocyteconditioned medium elicited migration of inflammatory(granulocyte-macrophage colony stimulating factor,GM-CSF-derived),but not non-inflammatory(CSF-1-derived)human macrophages(P=0.022),which could contribute to a pro-inflammatory microenvironment in vivo,or facilitate the clearance of senescent cells.CONCLUSION:Our novel model of hepatocyte senescence provides insights into mechanisms by which senescent hepatocytes may promote chronic liver disease pathogenesis.
Up to 10% of cystic fibrosis (CF) children develop cirrhosis by the first decade. We evaluated the utility of two simple biomarkers, aspartate aminotransferase to platelet ratio index (APRI) and ...FIB‐4, in predicting degree of fibrosis in pediatric CF liver disease (CFLD) validated by liver biopsy. In this retrospective, cross‐sectional study, 67 children with CFLD had dual‐pass liver biopsies and 104 age‐ and sex‐matched CF children without liver disease (CFnoLD) had serum to calculate APRI and FIB‐4 collected at enrollment. CFLD was defined as having two of the following: (1) hepatomegaly ± splenomegaly; (2) >6 months elevation of ALT (>1.5× upper limit of normal ULN); or (3) abnormal liver ultrasound findings. Biopsies were staged according to Metavir classification by two blinded pathologists. Receiver operating characteristic (ROC) analysis and continuation ratio logistic regression were performed to assess the predictability of these biomarkers to distinguish CFLD from CFnoLD and determine fibrosis stage‐specific cut‐off values. The AUC for APRI was better than FIB‐4 (0.75 vs. 0.60; P = 0.005) for predicting CFLD and severe CFLD (F3‐F4) (0.81). An APRI score >0.264 demonstrated a sensitivity (95% confidence interval CI) of 73.1% (60.9, 83.2) and specificity of 70.2% (60.4, 78.8) in predicting CFLD. A 50% increase in APRI was associated with a 2.4‐fold (95% CI: 1.7, 3.3) increased odds of having CFLD. APRI demonstrated full agreement with histology staging 37% of the time, but was within one stage 73% of the time. Only FIB‐4 predicted portal hypertension at diagnosis (area under the receiver operator characteristic curve AUC = 0.91; P < 0.001). Conclusion: This is the first liver biopsy‐validated study of APRI and FIB‐4 in pediatric CFLD. APRI appears superior to FIB‐4 in differentiating CFLD versus CFnoLD. APRI also exhibited a high AUC in predicting severe liver fibrosis with specific cutoffs for lower stages. (Hepatology 2015;62:1576–1583)
In non-alcoholic fatty liver disease (NAFLD), hepatic steatosis is intricately linked with a number of metabolic alterations. We studied substrate utilisation in NAFLD during basal, ...insulin-stimulated and exercise conditions, and correlated these outcomes with disease severity.
20 patients with NAFLD (mean ± SD body mass index (BMI) 34.1 ± 6.7 kg/m(2)) and 15 healthy controls (BMI 23.4 ± 2.7 kg/m(2)) were assessed. Respiratory quotient (RQ), whole-body fat (Fat ox) and carbohydrate (CHO ox) oxidation rates were determined by indirect calorimetry in three conditions: basal (resting and fasted), insulin-stimulated (hyperinsulinaemic-euglycaemic clamp) and exercise (cycling at an intensity to elicit maximal Fat ox). Severity of disease and steatosis were determined by liver histology, hepatic Fat ox from plasma β-hydroxybutyrate concentrations, aerobic fitness expressed as VO2 peak, and visceral adipose tissue (VAT) measured by computed tomography.
Within the overweight/obese NAFLD cohort, basal RQ correlated positively with steatosis (r=0.57, p=0.01) and was higher (indicating smaller contribution of Fat ox to energy expenditure) in patients with NAFLD activity score (NAS) ≥ 5 vs <5 (p=0.008). Both results were independent of VAT, % body fat and BMI. Compared with the lean control group, patients with NAFLD had lower basal whole-body Fat ox (1.2 ± 0.3 vs 1.5 ± 0.4 mg/kg FFM/min, p=0.024) and lower basal hepatic Fat ox (ie, β-hydroxybutyrate, p=0.004). During exercise, they achieved lower maximal Fat ox (2.5 ± 1.4 vs. 5.8 ± 3.7 mg/kg FFM/min, p=0.002) and lower VO2 peak (p<0.001) than controls. Fat ox during exercise was not associated with disease severity (p=0.79).
Overweight/obese patients with NAFLD had reduced hepatic Fat ox and reduced whole-body Fat ox under basal and exercise conditions. There was an inverse relationship between ability to oxidise fat in basal conditions and histological features of NAFLD including severity of steatosis and NAS.
The presentation pathways by which allogeneic peptides induce graft-versus-host disease (GVHD) are unclear. We developed a bone marrow transplant (BMT) system in mice whereby presentation of a ...processed recipient peptide within major histocompatibility complex (MHC) class II molecules could be spatially and temporally quantified. Whereas donor antigen presenting cells (APCs) could induce lethal acute GVHD via MHC class II, recipient APCs were 100-1,000 times more potent in this regard. After myeloablative irradiation, T cell activation and memory differentiation occurred in lymphoid organs independently of alloantigen. Unexpectedly, professional hematopoietic-derived recipient APCs within lymphoid organs had only a limited capacity to induce GVHD, and dendritic cells were not required. In contrast, nonhematopoietic recipient APCs within target organs induced universal GVHD mortality and promoted marked alloreactive donor T cell expansion within the gastrointestinal tract and inflammatory cytokine generation. These data challenge current paradigms, suggesting that experimental lethal acute GVHD can be induced by nonhematopoietic recipient APCs.
Histological subtyping of hepatocellular carcinoma (HCC) is challenging in the presence of histological heterogeneity, where distinctly different morphological patterns are present within the same ...tumor. Current approaches rely on percent cut-offs. We hypothesized that morphologic intratumor heterogeneity is a non-random biological feature and that incorporating recurrent patterns would improve histological subtyping of HCC. Resected HCC were studied and the overall frequency of morphologic intratumor heterogeneity was 45% in 242 specimens. Steatohepatitic HCC (SH-HCC) had the highest frequency of morphologic intratumor heterogeneity (91%); this was confirmed in additional cohorts of SH-HCC from different medical centers (overall frequency of 78% in SH-HCC). Morphologic intratumor heterogeneity in SH-HCC showed distinct and recurrent patterns that could be classified as early, intermediate, and advanced. Incorporating these patterns into the definition of SH-HCC allowed successful resolution of several persistent challenges: the problem of the best cut-off for subtyping SH-HCC, the problem of the relationship between SH-HCC and scirrhous HCC, and the classification for HCC with abundant microvesicular steatosis. This approach also clarified the relationship between SH-HCC and CTNNB1 mutations, showing that CTNNB1 mutations occur late in a subset of SH-HCC. In summary, there is a high frequency of morphologic intratumor heterogeneity in HCC. Incorporating this finding into histological subtyping resolved several persistent problems with the SH-HCC subtype.
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