Jérôme Boursier

Determination of reliability criteria for liver stiffness evaluation by transient elastography

Liver stiffness evaluation (LSE) is usually considered as reliable when it fulfills all the following criteria: ≥10 valid measurements, ≥60% success rate, and interquartile range / median ratio (IQR/M) ≤0.30. However, such reliable LSE have never been shown to be more accurate than unreliable LSE. Thus, we aimed to evaluate the relevance of the usual definition for LSE reliability, and to improve reliability by using diagnostic accuracy as a primary outcome in a large population. 1,165 patients with chronic liver disease from 19 French centers were included. All patients had liver biopsy and LSE. 75.7% of LSE were reliable according to the usual definition. However, these reliable LSE were not significantly more accurate than unreliable LSE with, respectively: 85.8% versus 81.5% well‐classified patients for the diagnosis of cirrhosis (P = 0.082). In multivariate analyses with different diagnostic targets, LSE median and IQR/M were independent predictors of fibrosis staging, with no significant influence of ≥10 valid measurements or LSE success rate. These two reliability criteria determined three LSE groups: “very reliable” (IQR/M ≤0.10), “reliable” (0.10< IQR/M ≤0.30, or IQR/M >0.30 with LSE median <7.1 kPa), and “poorly reliable” (IQR/M >0.30 with LSE median ≥7.1 kPa). The rates of well‐classified patients for the diagnosis of cirrhosis were, respectively: 90.4%, 85.8%, and 69.5% (P < 10−3). According to these new reliability criteria, 9.1% of LSE were poorly reliable (versus 24.3% unreliable LSE with the usual definition, P < 10−3), 74.3% were reliable, and 16.6% were very reliable. Conclusion: The usual definition for LSE reliability is not relevant. LSE reliability depends on IQR/M according to liver stiffness median level, defining thus three reliability categories: very reliable, reliable, and poorly reliable LSE. (HEPATOLOGY 2013)

Comparison of blood tests for liver fibrosis specific or not to NAFLD

BACKGROUND/AIMS To compare blood tests of liver fibrosis specific for NAFLD: the FibroMeter NAFLD and the NAFLD fibrosis score (NFSA) with a non-specific test, APRI. METHODS Two hundred and thirty-five NAFLD patients with liver Metavir staging and blood markers from two independent centres were randomly assigned to a test (n=121) or a validation population (n=114). RESULTS The highest accuracy--91%--for significant fibrosis was obtained with the FibroMeter whose (i) AUROC (0.943) was significantly higher than those of NFSA (0.884, p=0.008) and APRI (0.866, p<10(-3); p=0.309 vs NFSA) in the whole population, and (ii) misclassification rate (9%) was significantly lower than those of NFSA (14%, p=0.04) and APRI (16%, p=0.002) and did not vary according to centre (14 vs 7%, p=0.07), unlike those of NFSA (25 vs 9%, p=0.001) and APRI (29 vs 11%, p<10(-3)). By using thresholds of 90% predictive values, liver biopsy could have been avoided in most patients: FibroMeter: 97.4% vs NFSA: 86.8% (p<10(-3)) and APRI: 80.0% (p<10(-3)). A new classification provided three reliable diagnosis intervals: F0/1, F0/1/2, F2/3/4 with 91.4% accuracy for FibroMeter, avoiding biopsy in all patients. CONCLUSIONS FibroMeter NAFLD had high performance and provided reliable diagnosis for significant fibrosis, significantly outperforming NFSA and APRI.

The severity of nonalcoholic fatty liver disease is associated with gut dysbiosis and shift in the metabolic function of the gut microbiota

Several animal studies have emphasized the role of gut microbiota in nonalcoholic fatty liver disease (NAFLD). However, data about gut dysbiosis in human NAFLD remain scarce in the literature, especially studies including the whole spectrum of NAFLD lesions. We aimed to evaluate the association between gut dysbiosis and severe NAFLD lesions, that is, nonalcoholic steatohepatitis (NASH) and fibrosis, in a well‐characterized population of adult NAFLD. Fifty‐seven patients with biopsy‐proven NAFLD were enrolled. Taxonomic composition of gut microbiota was determined using 16S ribosomal RNA gene sequencing of stool samples. Thirty patients had F0/F1 fibrosis stage at liver biopsy (10 with NASH), and 27 patients had significant F≥2 fibrosis (25 with NASH). Bacteroides abundance was significantly increased in NASH and F≥2 patients, whereas Prevotella abundance was decreased. Ruminococcus abundance was significantly higher in F≥2 patients. By multivariate analysis, Bacteroides abundance was independently associated with NASH and Ruminococcus with F≥2 fibrosis. Stratification according to the abundance of these two bacteria generated three patient subgroups with increasing severity of NAFLD lesions. Based on imputed metagenomic profiles, Kyoto Encyclopedia of Genes and Genomes pathways significantly related to NASH and fibrosis F≥2 were mostly related to carbohydrate, lipid, and amino acid metabolism. Conclusion: NAFLD severity associates with gut dysbiosis and a shift in metabolic function of the gut microbiota. We identified Bacteroides as independently associated with NASH and Ruminococcus with significant fibrosis. Thus, gut microbiota analysis adds information to classical predictors of NAFLD severity and suggests novel metabolic targets for pre‐/probiotics therapies. (Hepatology 2016;63:764–775)

Prednisolone With vs Without Pentoxifylline and Survival of Patients With Severe Alcoholic Hepatitis: A Randomized Clinical Trial

IMPORTANCE Prednisolone or pentoxifylline is recommended for severe alcoholic hepatitis, a life-threatening disease. The benefit of their combination is unknown. OBJECTIVE To determine whether the addition of pentoxifylline to prednisolone is more effective than prednisolone alone. DESIGN, SETTING, AND PARTICIPANTS Multicenter, randomized, double-blind clinical trial conducted between December 2007 and March 2010 in 1 Belgian and 23 French hospitals of 270 patients aged 18 to 70 years who were heavy drinkers with severe biopsy-proven alcoholic hepatitis, as indicated by recent onset of jaundice in the prior 3 months and a Maddrey score of at least 32. Duration of follow-up was 6 months. The last included patient completed the study in October 2010. None of the patients were lost to follow-up for the main outcome. INTERVENTION Patients were randomly assigned to receive either a combination of 40 mg of prednisolone once a day and 400 mg of pentoxifylline 3 times a day (n=133) for 28 days, or 40 mg of prednisolone and matching placebo (n=137) for 28 days. MAIN OUTCOMES AND MEASURES Six-month survival, with secondary end points of development of hepatorenal syndrome and response to therapy based on the Lille model, which defines treatment nonresponders after 7 days of initiation of treatment. RESULTS In intention-to-treat analysis, 6-month survival was not different in the pentoxifylline-prednisolone and placebo-prednisolone groups (69.9% [95% CI, 62.1%-77.7%] vs 69.2% [95% CI; 61.4%-76.9%], P = .91), corresponding to 40 vs 42 deaths, respectively. In multivariable analysis, only the Lille model and the Model for End-Stage Liver Disease score were independently associated with 6-month survival. At 7 days, response to therapy assessed by the Lille model was not significantly different between the 2 groups (Lille model score, 0.41 [95% CI, 0.36-0.46] vs 0.40 [95% CI, 0.35-0.45], P = .80). The probability of being a responder was not different in both groups (62.6% [95% CI, 53.9%-71.3%] vs 61.9% [95% CI, 53.7%-70.3%], P = .91). The cumulative incidence of hepatorenal syndrome at 6 months was not significantly different in the pentoxifylline-prednisolone and the placebo-prednisolone groups (8.4% [95% CI, 4.8%-14.8%] vs 15.3% [95% CI, 10.3%-22.7%], P = .07). CONCLUSION AND RELEVANCE In patients with alcoholic hepatitis, 4-week treatment with pentoxifylline and prednisolone, compared with prednisolone alone, did not result in improved 6-month survival. The study may have been underpowered to detect a significant difference in incidence of hepatorenal syndrome, which was less frequent in the group receiving pentoxifylline. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01214226.

Acoustic radiation force impulse: a new ultrasonographic technology for the widespread noninvasive diagnosis of liver fibrosis.

Background/aims As a module of a standard ultrasound imaging device, acoustic radiation force impulse (ARFI) is a new technology for liver stiffness evaluation (LSE). We aimed to evaluate accuracy, feasibility, reproducibility, and training effect of ARFI for liver fibrosis evaluation. Methods One hundred and one patients with chronic liver disease had LSE by Fibroscan and ARFI. LSE by ARFI was performed in the two liver lobes by two operators: an expert and a novice. Correlation and agreement were evaluated by the Pearson (Rp) and intraclass (Ric) correlation coefficients. The independent reference for liver fibrosis was fibrosis blood tests. Results ARFI results, ranging from 0.7 to 4.6 m/s, were well correlated with Fibroscan results (Rp=0.76). Fibroscan had a significantly higher area under the receiver operating characteristic curve (AUROC) than ARFI for the perprotocol diagnosis of significant fibrosis: 0.890±0.034 versus 0.795±0.047 (P=0.04). However, LSE failure occurred in zero patients using ARFI versus six patients using Fibroscan (P=0.03). Thus, on an intention-to-diagnose basis, Fibroscan and ARFI AUROCs for the diagnosis of significant fibrosis were not different: 0.791±0.049 versus 0.793±0.046 (P=0.98). Interobserver agreement was very good (Ric=0.84) and excellent for ARFI interquartile range (IQR)≤0.30 (Ric=0.91). Indeed, agreement was independently predicted only by ARFI IQR, but not by LSE result as earlier observed for Fibroscan. ARFI AUROC was 0.876±0.057 in patients with ARFI IQR ratio≤0.30, and Fibroscan AUROC was 0.912±0.034 in patients with Fibroscan IQR ratio less than 0.21 (P=0.59). Intersite ARFI agreement between the two liver lobes was fair (Ric=0.60). There was no training effect for LSE by ARFI. Conclusion ARFI is highly feasible and reproducible, and provides diagnostic accuracy similar to Fibroscan. This new device seems noteworthy for the widespread noninvasive diagnosis of liver fibrosis.

Evaluating the accuracy and increasing the reliable diagnosis rate of blood tests for liver fibrosis in chronic hepatitis C.

Background: The reliable diagnosis rate of diagnostic tests is provided by their intervals with acceptable accuracy (e.g. ≥90%) where a liver biopsy can be avoided.

The combination of a blood test and Fibroscan improves the non‐invasive diagnosis of liver fibrosis

Background and aims: Blood tests and liver stiffness evaluation (LSE) by ultrasonographic elastometry are accurate tools for diagnosing liver fibrosis. We evaluated whether their synchronous combination in new scores could improve the diagnostic accuracy and reduce liver biopsy requirement in algorithm.

Reproducibility of liver stiffness measurement by ultrasonographic elastometry.

BACKGROUND & AIMS Fibroscan is a noninvasive device that assesses liver fibrosis by liver stiffness evaluation (LSE) with ultrasonographic elastometry. We evaluated LSE reproducibility and its influencing factors. METHODS LSE was performed by 4 experienced physicians (>100 LSEs) in 46 patients with chronic liver disease at 4 different anatomic sites. Additional LSEs were performed for ancillary aims, so that 534 LSEs were available. RESULTS Overall interobserver agreement for LSE results was considered as excellent, with intraclass coefficient correlation (Ric) of 0.93. Low LSE level, nonrecommended sites, LSE interquartile range >25%, and body mass index > or =25 independently decreased agreement. Thus, agreement was fair (Ric = 0.53) for LSE <9 kilopascals and excellent (Ric = 0.90) beyond. The best measurement site for LSE reproducibility was the median axillary line on the first intercostal space under the liver dullness upper limit, with the patient lying in dorsal decubitus. When LSE results were categorized into fibrosis Metavir stages, interobserver discordance was noticed in about 25% of the cases and was the highest for F2 and F3 stages and the lowest for F4. Intraobserver (Ric = 0.94), intersite (Ric = 0.92-0.98), and interequipment (Ric = 0.92) agreements for LSE results were excellent. Preliminary standard ultrasonography or probe pressure changes did not improve interobserver agreement. CONCLUSIONS The best measurement site for LSE is the one generally used for liver biopsy. Reproducibility of LSE is globally excellent but is fair in patient with low liver stiffness. The fibrosis diagnosis by ultrasonographic elastometry in low stages or categorized into fibrosis Metavir stages must be interpreted with caution.

Mouse Models of Diet-Induced Nonalcoholic Steatohepatitis Reproduce the Heterogeneity of the Human Disease

Background and aims Non-alcoholic steatohepatitis (NASH), the potentially progressive form of nonalcoholic fatty liver disease (NAFLD), is the pandemic liver disease of our time. Although there are several animal models of NASH, consensus regarding the optimal model is lacking. We aimed to compare features of NASH in the two most widely-used mouse models: methionine-choline deficient (MCD) diet and Western diet. Methods Mice were fed standard chow, MCD diet for 8 weeks, or Western diet (45% energy from fat, predominantly saturated fat, with 0.2% cholesterol, plus drinking water supplemented with fructose and glucose) for 16 weeks. Liver pathology and metabolic profile were compared. Results The metabolic profile associated with human NASH was better mimicked by Western diet. Although hepatic steatosis (i.e., triglyceride accumulation) was also more severe, liver non-esterified fatty acid content was lower than in the MCD diet group. NASH was also less severe and less reproducible in the Western diet model, as evidenced by less liver cell death/apoptosis, inflammation, ductular reaction, and fibrosis. Various mechanisms implicated in human NASH pathogenesis/progression were also less robust in the Western diet model, including oxidative stress, ER stress, autophagy deregulation, and hedgehog pathway activation. Conclusion Feeding mice a Western diet models metabolic perturbations that are common in humans with mild NASH, whereas administration of a MCD diet better models the pathobiological mechanisms that cause human NAFLD to progress to advanced NASH.

Liver stiffness in nonalcoholic fatty liver disease: A comparison of supersonic shear imaging, FibroScan, and ARFI with liver biopsy

Nonalcoholic fatty liver disease (NAFLD) has become a major public health issue. The goal of this study was to assess the clinical use of liver stiffness measurement (LSM) evaluated by supersonic shear imaging (SSI), FibroScan, and acoustic radiation force impulse (ARFI) in a cohort of NAFLD patients who underwent liver biopsy. A total of 291 NAFLD patients were prospectively enrolled from November 2011 to February 2015 at 2 French university hospitals. LSM was assessed by SSI, FibroScan (M probe), and ARFI within two weeks prior to liver biopsy. Calculations of the area under the receiver operating curve (AUROC) were performed and compared for the staging of liver fibrosis. AUROC for SSI, FibroScan, and ARFI were 0.86, 0.82, and 0.77 for diagnoses of ≥F2; 0.89, 0.86, and 0.84 for ≥F3; and 0.88, 0.87, and 0.84 for F4, respectively. SSI had a higher accuracy than ARFI for diagnoses of significant fibrosis (≥F2) (P = 0.004). Clinical factors related to obesity such as body mass index ≥ 30 kg/m2, waist circumference ≥102 cm or increased parietal wall thickness were associated with LSM failures when using SSI or FibroScan and with unreliable results when using ARFI. In univariate analysis, FibroScan values were slightly correlated with NAFLD activity score and steatosis (R = 0.28 and 0.22, respectively), whereas SSI and ARFI were not; however, these components of NAFLD did not affect LSM results in multivariate analysis. The cutoff values for SSI and FibroScan for staging fibrosis with a sensitivity ≥90% were very close: 6.3/6.2 kPa for ≥F2, 8.3/8.2 kPa for ≥F3, and 10.5/9.5 kPa for F4. Conclusion: Although obesity is associated with an increase in LSM failure, the studied techniques and especially SSI provide high value for the diagnosis of liver fibrosis in NAFLD patients. (Hepatology 2016;63:1817‐1827)