Crosstalk between adipose tissue insulin resistance and liver macrophages in non-alcoholic fatty liver disease.

BACKGROUND & AIMS: The pathogenesis of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) is likely due to the interaction between a deranged metabolic milieu and local mediators of hepatic inflammation and fibrosis. We undertook this study to elucidate the interplay between macrophage activation, insulin resistance (IR) in target organs/tissues and hepatic damage. METHODS: In 40 non-diabetic patients with biopsy-proven NAFLD we assessed: i) endogenous glucose production (EGP), glucose clearance and indexes of IR in the adipose tissue (Adipo-IR and Lipo-IR) and in the liver (Hep-IR) by tracer infusion ([6,6-2H2]glucose and [2H5]glycerol); ii) macrophage activity (by soluble sCD163) and iii) hepatic expression of CD163 (hCD163). RESULTS: We found that sCD163 levels paralleled both the plasma free fatty acid (FFA) levels and lipolysis from adipose tissue. Consistently, sCD163 significantly correlated with adipose tissue IR (Adipo-IR: r = 0.32, p = 0.042; Lipo-IR: r = 0.39, p = 0.012). At multiple regression analysis, sCD163 levels were associated with FFA levels (rp = 0.35, p = 0.026). In vitro exposure of human monocyte-derived macrophages to palmitate enhanced sCD163 secretion. Conversely, sCD163 did not correlate with EGP or with Hep-IR. In the liver, hCD163 positively correlated with sCD163 (r = 0.58, p = 0.007) and the degree of steatosis (r = 0.34, p = 0.048), but not with EGP or Hep-IR (r = -0.27 and r = 0.11, respectively, p >0.10, both). CONCLUSIONS: Our findings suggest a link between deranged metabolism in the adipose tissue and activation of hepatic macrophages in patients with NAFLD, possibly in response to FFA overflow and independent of obesity and diabetes. Conversely, our findings do not support a link between activated hepatic macrophages and glucose metabolism (EGP or Hep-IR). The relationship between adipose tissue IR and hepatic macrophages should be considered to define therapeutic targets for NAFLD. LAY SUMMARY: The pathogenesis of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) is likely due to the interaction between a deranged metabolic milieu and local mediators of hepatic inflammation and fibrosis in the insulin resistant state. This study provides in vivo support for a possible link between deranged metabolism in the adipose tissue and activation of hepatic macrophages in patients with NAFLD, most likely in response to free fatty acid overflow and independent of obesity and diabetes.

Is there a link between periampullary diverticula and biliopancreatic disease? An EUS approach to answer the question.

BACKGROUND: Many studies, almost all in an Endoscopic Retrograde Cholangiopancreatography (ERCP) setting, have been conducted to establish if a link exists between periampullary diverticula (PADs) and biliopancreatic diseases but the issue is still debated. AIMS: The objective was to clarify the link between PADs and biliopancreatic disease, for the first time using Endoscopic Ultrasound (EUS). METHODS: We retrospectively reviewed our database seeking patients scheduled for EUS with an indication that entailed the exploration of the second duodenum. For each patient with a PAD enrolled in the study, 6 controls were randomly selected. RESULTS: 2475 patients met the inclusion criteria. Among them, 185 subjects with a PAD were found (prevalence 7.5%), 1110 subjects served as controls. Patients with a PAD had more frequently a history of cholangitis (8.1 vs 2.2%; OR 3.99, p < 0.001), a higher prevalence of common bile duct (CBD) dilation (44.3 vs 28.2%; OR 2, p < 0.0001) and a higher prevalence of CBD stones (34.1 vs 19.6%; OR 2.1, p < 0.0001). No differences were found about history of jaundice, acute/recurrent pancreatitis or EUS signs of chronic pancreatitis. CONCLUSION: Whereas PADs were linked with history of cholangitis, CBD stones and dilation, no association was found with pancreatic diseases.

Altered amino acid concentrations in NAFLD: Impact of obesity and insulin resistance.

Plasma concentrations of amino acids (AAs), in particular, branched chain AAs (BCAAs), are often found increased in nonalcoholic fatty liver disease (NAFLD); however, if this is due to increased muscular protein catabolism, obesity, and/or increased insulin resistance (IR) or impaired tissue metabolism is unknown. Thus, we evaluated a) if subjects with NAFLD without obesity (NAFLD-NO) compared to those with obesity (NAFLD-Ob) display altered plasma AAs compared to controls (CTs); and b) if AA concentrations are associated with IR and liver histology. Glutamic acid, serine, and glycine concentrations are known to be altered in NAFLD. Because these AAs are involved in glutathione synthesis, we hypothesized they might be related to the severity of NAFLD. We therefore measured the AA profile of 44 subjects with NAFLD without diabetes and who had a liver biopsy (29 NAFLD-NO and 15 NAFLD-Ob) and 20 CTs without obesity, by gas chromatography-mass spectrometry, homeostasis model assessment of insulin resistance, hepatic IR (Hep-IR; Hep-IR = endogenous glucose production × insulin), and the new glutamate-serine-glycine (GSG) index (glutamate/[serine + glycine]) and tested for an association with liver histology. Most AAs were increased only in NAFLD-Ob subjects. Only alanine, glutamate, isoleucine, and valine, but not leucine, were increased in NAFLD-NO subjects compared to CTs. Glutamate, tyrosine, and the GSG-index were correlated with Hep-IR. The GSG-index correlated with liver enzymes, in particular, gamma-glutamyltransferase (R = 0.70), independent of body mass index. Ballooning and/or inflammation at liver biopsy were associated with increased plasma BCAAs and aromatic AAs and were mildly associated with the GSG-index, while only the new GSG-index was able to discriminate fibrosis F3-4 from F0-2 in this cohort. CONCLUSION: Increased plasma AA concentrations were observed mainly in subjects with obesity and NAFLD, likely as a consequence of increased IR and protein catabolism. The GSG-index is a possible marker of severity of liver disease independent of body mass index. (Hepatology 2018;67:145-158).

Usefulness of the index of NASH - ION for the diagnosis of steatohepatitis in patients with non-alcoholic fatty liver: An external validation study.

BACKGROUND & AIMS: The non-invasive identification of steatohepatitis (NASH) in patients with Non-Alcoholic Fatty Liver Disease is an unmet need in clinical practice. Index of NASH (ION) is a new tool for the prediction of NASH. We aimed to externally validate ION and to compare it with CK-18. Since necroinflammation precedes fibrosis, we also tested ION in combination with non-invasive tools for fibrosis. METHODS: We analysed data from 292 Italian patients (169 Southern cohort, and 123 Northern cohort) with an histological diagnosis of NAFLD. The ION, FIB-4 and NFS scores were calculated according to published algorithms. Serum cytokeratin18-Aspartate396 levels and liver stiffness (LS) by Fibroscan were assessed within three months from liver biopsy. RESULTS: The diagnostic accuracy of ION for the identification of NASH was not as satisfactory as reported (area under the ROC curve, AUROC = 0.687 [95% CI = 0.62-0.75]). The proposed cut-off value ≥50 showed a poor sensitivity (Se) (28%) and a good specificity (Sp) (92%), with a positive predictive value (PPV) of 91% and a negative predictive value (NPV) of 30%. A new cut-off value >26 improved Se (73%) but decreased Sp (60%) (PPV of 84% and a NPV of 43%). ION performed slightly better in obese NAFLD (AUROC = 0.700). The combination of ION and markers of fibrosis did not improve the identification of advanced liver disease. CONCLUSIONS: ION is not feasible for the non-invasive diagnosis of NASH across different populations of NAFLD patients, mainly because its limited reproducibility in non-obese subjects.

Global burden of NAFLD and NASH: trends, predictions, risk factors and prevention.

NAFLD is one of the most important causes of liver disease worldwide and will probably emerge as the leading cause of end-stage liver disease in the coming decades, with the disease affecting both adults and children. The epidemiology and demographic characteristics of NAFLD vary worldwide, usually parallel to the prevalence of obesity, but a substantial proportion of patients are lean. The large number of patients with NAFLD with potential for progressive liver disease creates challenges for screening, as the diagnosis of NASH necessitates invasive liver biopsy. Furthermore, individuals with NAFLD have a high frequency of metabolic comorbidities and could place a growing strain on health-care systems from their need for management. While awaiting the development effective therapies, this disease warrants the attention of primary care physicians, specialists and health policy makers.

[Non-alcoholic fatty liver disease (NAFLD)]. / Non-alcoholic fatty liver disease (NAFLD).

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in adults and in the pediatric population of the western world; in a substantial proportion of subjects it takes on the characteristics of non-alcoholic steatohepatitis (NASH). The clinical significance of NAFLD is motivated by epidemiological data and its impact on liver-related morbidity and mortality on one hand and on the cardiovascular one on the other. The presence and extent of fibrosis on liver biopsy is the most relevant feature in predicting liver mortality, but the concept that the "simple steatosis" is benign has been recently questioned, especially in the presence of type 2 diabetes. Because the diagnosis of NASH is made by liver biopsy, the efforts of the scientific community are currently oriented to the search of non-invasive biomarkers of liver injury applicable on a large scale and of genetic polymorphisms associated to NASH in order to properly address the screening programs, follow-up and therapeutic attempts. Next to the therapy directed to the treatment of concomitant metabolic disorders, new drugs are being evaluated in clinical trials having as target the histologic resolution of NASH and regression of fibrosis.

Non-Alcoholic Fatty Liver Disease and Extra-Hepatic Cancers.

Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease but the second cause of death among NAFLD patients are attributed to malignancies at both gastrointestinal (liver, colon, esophagus, stomach, and pancreas) and extra-intestinal sites (kidney in men, and breast in women). Obesity and related metabolic abnormalities are associated with increased incidence or mortality for a number of cancers. NAFLD has an intertwined relationship with metabolic syndrome and significantly contributes to the risk of hepatocellular carcinoma (HCC), but recent evidence have fuelled concerns that NAFLD may be a new, and added, risk factor for extra-hepatic cancers, particularly in the gastrointestinal tract. In this review we critically appraise key studies on NAFLD-associated extra-hepatic cancers and speculate on how NAFLD may influence carcinogenesis at these sites.

Endoscopic ultrasound in common bile duct dilatation with normal liver enzymes.

In recent years, the description of isolated bile duct dilatation has been increasingly observed in subjects with normal liver function tests and nonspecific abdominal symptoms, probably due to the widespread use of high-resolution imaging techniques. However, there is scant literature about the evolution of this condition and the impact of endoscopic ultrasound (EUS) in the diagnostic work up. When noninvasive imaging tests (transabdominal ultrasound, computed tomography or magnetic resonance cholangiopancreatography) fail to identify the cause of dilatation and clinical or biochemical alarm signs are absent, the probability of having biliary disease is considered low. In this setting, using EUS, the presence of pathologic findings (choledocholithiasis, strictures, chronic pancreatitis, ampullary or pancreatic tumors, cholangiocarcinoma), not always with a benign course, has been observed. The aim of this review has been to evaluate the prevalence of disease among non-jaundiced patients without signs of cytolysis and/or cholestasis and the assessment of EUS yield. Data point out to a promising role of EUS in the identification of a potential biliary pathology. EUS is a low invasive technique, with high accuracy, that could play a double cost-effective role: identifying pathologic conditions with dismal prognosis, in asymptomatic patients with negative prior imaging tests, and excluding pathologic conditions and further follow-up in healthy subjects.

Quantification of hepatitis B surface antigen with the novel DiaSorin LIAISON XL Murex HBsAg Quant: correlation with the ARCHITECT quantitative assays.

BACKGROUND: Recent technologic innovations allow for quantitative assessment of hepatitis B surface antigen (HBsAg) levels in serum; this has been used to monitor the course of chronic HBV hepatitis (CHB) and predict treatment response. LIAISON-XL Murex HBsAg Quant assay (DiaSorin, Saluggia, I) is the newest immunoassay CE approved to quantify HBsAg. OBJECTIVES: To compare LIAISON-XL performances with ARCHITECT-QT HBsAg (Abbott Diagnostics, IL, USA), as reference test. STUDY DESIGN: Sequential serum samples (n=152) from 14 HBe-negative patients with CHB, the majority of them infected by HBV genotype D undergoing antiviral treatment, were retrospectively tested with both assays. The 2nd WHO Standard 00/588 for HBsAg was used as reference. RESULTS: LIAISON-XL and ARCHITECT-QT correlated by r=0.95, p<0.0001; by Bland-Altman analysis agreement of mean difference was 0.21 ± 0.15 log 10 IU/mL, 95% CI: -0.07 to 0.5). Performance of LIAISON-XL against the 2nd WHO Standard was r=0.998, p<0.0001 (95% CI: 0.993-0.999) with results nearer to the expected WHO values compared to ARCHITECT-QT. Median baseline HBsAg level was similar with the two methods before antiviral treatment, throughout fluctuations of HBsAg level in treatment non-responders and during the decrease of HBsAg titer in treatment responders. Correlation between HBsAg levels and HBV DNA was statistically significant for both the two immunoassays (LIAISON-XL: r=0.4988, 95% CI: 0.3452-0.6264, p<0.0001; ARCHITECT-QT: r=0.480, 95% CI: 0.3233-0.6111, p<0.0001). CONCLUSIONS: Correlation between HBsAg measurement with LIAISON-XL and ARCHITECT-QT was high. LIAISON-XL accurately quantified HBsAg in clinical samples at baseline or during antiviral therapy; it can be applied for HBsAg quantification in clinical practice and decision making in CHB.

Clinical and virological response to entecavir in HBV-related chronic hepatitis or cirrhosis: data from the clinical practice in a single-centre cohort.

BACKGROUND: Limited data are available on entecavir in Caucasian patients with HBV cirrhosis or chronic hepatitis B who are treated in the clinical practice. The aim was to evaluate the efficacy of entecavir in an Italian cohort of unselected patients with different stages of liver fibrosis, comparing the virological and clinical results obtained between patients with and without liver cirrhosis. METHODS: Efficacy and safety of entecavir were retrospectively evaluated in 100 patients recruited in the Gastro-Hepatology Unit, San Giovanni Battista Hospital (Turin, Italy). A pharmacokinetic analysis was performed in 34 participants to assess whether cirrhosis may affect entecavir metabolism. Participants were followed-up for a median (range) duration of 21 months (2-108). RESULTS: Rates of virological response (negative viraemia by PCR for ≥ 2 consecutive determinations) after 12, 24 and 36 months were 91.7%, 97.5% and 93.7%, respectively. In the 84 patients who were treated for ≥ 12 months, presence of cirrhosis (OR 1.730, 95% CI 1.082, 2.766; P=0.022) and absence of hepatitis B e antigen (OR 0.479, 95% CI 0.273, 0.842; P=0.011) were independent predictors of earlier clearance of serum HBV DNA. There were no differences between the serum concentrations in the steady-state level of entecavir between patients with or without cirrhosis. No significant differences were detected between the average area under the curve in the means of the two groups (P=0.55). CONCLUSIONS: Entecavir represents an excellent therapy in patients with HBV-related liver disease and particularly with cirrhosis where it showed a good profile of tolerability, higher efficacy and an earlier virological response.