Diagnosis of different liver fibrosis characteristics by blood tests in non‐alcoholic fatty liver disease

Aims: Our aim was to develop an accurate, non‐invasive, blood‐test‐based method for identifying the main characteristics of liver fibrosis in non‐alcoholic fatty liver disease (NAFLD). Methods: Fibrosis was staged according to NASH‐CRN and Metavir systems in 226 patients with NAFLD. A fully automated algorithm measured the fractal dimension (FD) and the area of fibrosis (AOF). Independent predictors of diagnostic targets were determined using bootstrap methods. Results: (i) Development. Significant fibrosis defined by NASH‐CRN F≥2 was diagnosed by weight, glycaemia, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and prothrombin index [area under the receiver operating characteristic (AUROC)=0.867]; significant fibrosis defined by Metavir F≥2 was diagnosed by weight, age, glycaemia, AST, ALT, ferritin and platelets (FibroMeter AUROC=0.941, P<0.005). AOF was estimated by the combination of hyaluronic acid, glycaemia, AST, ALT, platelets and prothrombin index (_aR²=0.530), while FD was estimated by hyaluronic acid, glycaemia, AST/ALT, weight and platelets (_aR²=0.529). (ii) Evaluation. Although NASH‐CRN was a better system for fibrosis staging, Metavir staging was a better reference for blood test. Thus, the patient rate with predictive values≥90% by tests was 97.3% with Metavir reference vs. 66.5% with NASH‐CRN reference (P<10^?3). FibroMeter showed a significantly higher AUROC than the NAFLD fibrosis score for significant fibrosis, but not for severe fibrosis or cirrhosis, with both staging systems. Relationships between fibrosis lesions were well reflected by blood tests, e.g., the correlation between histological area and FD of fibrosis (r_s=0.971, P<10^?3) was well reflected by the relationship between respective blood tests (r_s=0.852, P<10^?3). Conclusions: Different characteristics of fibrosis in NAFLD can be diagnosed and quantified by blood tests with excellent accuracy.     

Ad36 adipogenic adenovirus in human non‐alcoholic fatty liver disease

Aims: Infection with specific pathogens may lead to increased adiposity. The human adenovirus 36 (Ad36) is a relatively new factor in promoting adipogenesis. It seems to improve the metabolic profile, expanding adipose tissue and enhancing insulin sensitivity in animal models. The aim of this study was to investigate whether any association or predictor effect of Ad36 seropositivity is present in non‐alcoholic fatty liver disease (NAFLD), a condition associated with obesity and insulin resistance (IR). Methods: Sixty‐five NAFLD patients and 114 controls were investigated. Ultrasound bright liver score (BLS), body composition, IR evaluated by homeostasis model assessment of insulin resistance index (HOMA or HOMA‐IR) and serum neutralization assay for antibodies to Ad36 were assessed. Results: Ad36‐seropositive patients have a lower risk of bright liver [OR 0.505 (95% confidence interval (CI) 0.265–0.962)]; greater IR leads to a higher risk of bright liver [OR 9.673 (95% CI 4.443–21.058)]. Among NAFLD, Ad36‐seropositive vs. Ad36‐seronegative patients did not show a significant IR difference. Ad36‐seropositive NAFLD patients, with the same levels of HOMA and BLS, had greater body mass index and body fat mass, in comparison with seronegative NAFLD patients. By a multiple linear regression model, BLS was explained by HOMA (β 0.513; P<0.0001), high density lipoprotein cholesterol (β?0.219, P<0.006) and Ad36 seropositivity (β?0.202, P<0.005); Ad36 seropositivity did not explain HOMA in the other multiple logistic regression model. Conclusions: Ad36 seropositivity is not associated with a significant difference of IR in NAFLD patients, but is associated with a greater adiposity. Ad36 seropositivity is associated with a lower occurrence of NAFLD and bright liver, which, conceivably, is not directly mediated by IR.     

Serum ferritin is a discriminant marker for both fibrosis and inflammation in histologically proven non‐alcoholic fatty liver disease patients

Introduction: Differentiation between steatosis and non‐alcoholic steatohepatitis (NASH) in non‐alcoholic fatty liver disease (NAFLD) is important as NASH progress to cirrhosis. No specific laboratory/imaging technique exists either to diagnose NASH or to select patients for liver biopsy. Patients and methods: We evaluated serum ferritin and the features of metabolic syndrome with respect to histological inflammation and/or fibrosis in NAFLD patients. The Kleiner scoring system was used to classify NAFLD in consecutive liver biopsies. One hundred and eleven patients: median age 52.6, 64 males, obesity 62, diabetes mellitus (DM) 58, arterial hypertension 26 and hyperlipidaemia 40%. Results: Histologically, 40.7 had fatty liver, 30.6% had borderline NASH, 28.7% had NASH and 11% had cirrhosis. Multivariate regression showed that diabetes, serum ferritin concentrations, body mass index (BMI) and AST were independently associated with NASH: together, the areas under the receiver operating characteristic (AUROC) was 0.91 (95% confidence interval 0.86–0.96); fibrosis was associated with ferritin concentrations and BMI: AUROC 0.87, portal inflammation with ferritin and DM: AUROC 0.82, while lobular inflammation was associated with BMI, DM and ferritin: AUROC 0.85. Conclusion: Serum ferritin concentrations and BMI are strongly associated with fibrosis, portal and lobular inflammation in NAFLD patients. Both ferritin and BMI are potential discriminant markers to select patients for liver biopsy and are associated with inflammation and fibrosis.     

Systematic review of performance of non‐invasive biomarkers in the evaluation of non‐alcoholic fatty liver disease

This systematic review evaluates the many studies carried out to discover and evaluate non‐invasive markers of non‐alcoholic fatty liver disease (NAFLD). Many different strategies and methods have been used in this task, from the discovery of new markers by global ‘shotgun’ studies to hypothesis‐driven approaches, to the development of algorithm tests based on routinely available clinical and biochemical parameters. We examined the various different approaches, summarising the findings in an attempt to give an overview of the field of non‐invasive markers in NAFLD, encompassing markers of steatosis, necro‐inflammation and fibrosis. The body of literature surrounding this topic is complex and varied, encompassing not only different methodologies but also different patient characteristics, different disease definitions, as well as different end points. This reflects the heterogeneity of NAFLD, which, however, introduces considerably difficulty when trying to draw a conclusion between studies. We have divided this review into three main chapters based on the characteristics of the studies. The Genomics/Proteomics chapter reviews studies using a non‐hypothesis‐driven approach to biomarker discovery. Thereafter, we evaluate studies of association – studies that target‐specific markers, comparing levels between disease and control groups. Finally, we examine the algorithm tests – mathematical systems developed on the basis of previously described markers and assessed, usually, by receiver operator curve analysis. While radiological examination and investigations offer important diagnostic information, such studies are not discussed in this review – the body of literature surrounding blood and anthropological markers is complex and varied, demanding close attention.     

The roles of obesity and gender on the relationship between metabolic risk factors and non‐alcoholic fatty liver disease in Koreans

Background The effect of gender and weight status on the association between metabolic risk factors and NAFLD has not been well established. This study aimed to assess the relationships among obesity, gender, metabolic risk factors, and non‐alcoholic fatty liver disease (NAFLD) in Korean adults. Methods Abdominal ultrasounds, anthropometric measurements, and biochemical tests were performed on 13 768 Korean adults (7313 men and 6455 women) recruited from a health promotion centre between 2005 and 2006. Results Of 13 768 subjects, 25% were diagnosed with NAFLD. Weight status (obesity vs non‐obesity, odds ratio (OR) 4.4–9.7) and gender (women vs men, OR 0.6) were associated with NAFLD after adjusting for age, metabolic risk factors (high blood pressure, high glucose, high TG, low HDL, high LDL, and high uric acid), and gamma‐glutamyl transferase (γGT). For subjects with any one risk factor, the OR (95% CI) for mild fatty liver was 27 (19.3–37.8) in men and 7.9 (6.1–10.2) in women who were obese compared to non‐obese individuals having no risk factors. The ORs in men and women who were not obese were 4.7 (3.9–5.6) and 2.5 (2.2–3.0), respectively. The sensitivity and specificity for NAFLD with any one risk factor without obesity was 90–91 and 32–49%, respectively; any one risk factor combined with obesity changed the sensitivity and specificity to 64–67 and 77–85%, respectively. Conclusions Gender and weight status appear to modify the relationship between metabolic risk factors and NAFLD. Copyright © 2008 John Wiley & Sons, Ltd.     

Association of chitotriosidase genotype with the development of non‐alcoholic fatty liver disease

Aim: Based on the role of chitotriosidase (CHIT‐1) in the evolution of non‐alcoholic fatty liver disease, we explored whether CHIT‐1 mutant allele plays a role in NAFLD progression. Methods: We genotyped 200 patients with NAFLD (110 with non‐alcoholic steatohepatitis [NASH] and 90 with simple steatosis) and 100 control subjects. The χ²‐test was performed for a case–control study. Odds ratios (OR) were adjusted for age, sex and body mass index (BMI) by using multiple logistic regression analysis with genotypes (additive model), age, sex and BMI as the independent variables. Multiple linear regression analysis was performed to test the independent effect of risk allele on clinical parameters while considering the effects of other variables (age, sex and BMI), which were assumed to be independent of the effect of the single nucleotide polymorphism. Results: The risk allele frequency of CHIT‐1 wild type (Wt) was 0.71 in the control subjects, 0.77 in simple steatosis and 0.92 in patients with NASH. The OR (95% confidence interval) adjusted for age and BMI was 1.73. Multiple linear regression analysis indicated that the CHIT‐1 Wt was significantly associated with increases in ferritin levels (P = 0.014) and the fibrosis stage (P = 0.011) in the patients with NASH, even after adjustment for age, sex and BMI, corroborating that the presence of the CHIT‐1 Wt allele was an independent predictor of fibrotic NAFLD. In contrast, the steatosis grade was not associated with CHIT‐1 mutant allele. Conclusion: These findings suggest that a functional polymorphism in the CHIT‐1 gene protects against NAFLD progression.