Evaluation of proton density fat fraction (PDFF) obtained from a vendor-neutral MRI sequence and MRQuantif software.

OBJECTIVE: To validate the proton density fat fraction (PDFF) obtained by the MRQuantif software from 2D chemical shift encoded MR (CSE-MR) data in comparison with the histological steatosis data. METHODS: This study, pooling data from 3 prospective studies spread over time between January 2007 and July 2020, analyzed 445 patients who underwent 2D CSE-MR and liver biopsy. MR derived liver iron concentration (MR-LIC) and PDFF was calculated using the MRQuantif software. The histological standard steatosis score (SS) served as reference. In order to get a value more comparable to PDFF, histomorphometry fat fraction (HFF) were centrally determined for 281 patients. Spearman correlation and the Bland and Altman method were used for comparison. RESULTS: Strong correlations were found between PDFF and SS (rs = 0.84, p < 0.001) or HFF (rs = 0.87, p < 0.001). Spearman's coefficients increased to 0.88 (n = 324) and 0.94 (n = 202) when selecting only the patients without liver iron overload. The Bland and Altman analysis between PDFF and HFF found a mean bias of 5.4% ± 5.7 [95% CI 4.7, 6.1]. The mean bias was 4.7% ± 3.7 [95% CI 4.2, 5.3] and 7.1% ± 8.8 [95% CI 5.2, 9.0] for the patients without and with liver iron overload, respectively. CONCLUSION: The PDFF obtained by MRQuantif from a 2D CSE-MR sequence is highly correlated with the steatosis score and very close to the fat fraction estimated by histomorphometry. Liver iron overload reduced the performance of steatosis quantification and joint quantification is recommended. This device-independent method can be particularly useful for multicenter studies. CLINICAL RELEVANCE STATEMENT: The quantification of liver steatosis using a vendor-neutral 2D chemical-shift MR sequence, processed by MRQuantif, is well correlated to steatosis score and histomorphometric fat fraction obtained from biopsy, whatever the magnetic field and the MR device used. KEY POINTS: • The PDFF measured by MRQuantif from 2D CSE-MR sequence data is highly correlated to hepatic steatosis. • Steatosis quantification performance is reduced in case of significant hepatic iron overload. • This vendor-neutral method may allow consistent estimation of PDFF in multicenter studies.

Reduced lipoapoptosis, hedgehog pathway activation and fibrosis in caspase-2 deficient mice with non-alcoholic steatohepatitis.

OBJECTIVE: Caspase-2 is an initiator caspase involved in multiple apoptotic pathways, particularly in response to specific intracellular stressors (eg, DNA damage, ER stress). We recently reported that caspase-2 was pivotal for the induction of cell death triggered by excessive intracellular accumulation of long-chain fatty acids, a response known as lipoapoptosis. The liver is particularly susceptible to lipid-induced damage, explaining the pandemic status of non-alcoholic fatty liver disease (NAFLD). Progression from NAFLD to non-alcoholic steatohepatitis (NASH) results, in part, from hepatocyte apoptosis and consequential paracrine-mediated fibrogenesis. We evaluated the hypothesis that caspase-2 promotes NASH-related cirrhosis. DESIGN: Caspase-2 was localised in liver biopsies from patients with NASH. Its expression was evaluated in different mouse models of NASH, and outcomes of diet-induced NASH were compared in wild-type (WT) and caspase-2-deficient mice. Lipotoxicity was modelled in vitro using hepatocytes derived from WT and caspase-2-deficient mice. RESULTS: We showed that caspase-2 is integral to the pathogenesis of NASH-related cirrhosis. Caspase-2 is localised in injured hepatocytes and its expression was markedly upregulated in patients and animal models of NASH. During lipotoxic stress, caspase-2 deficiency reduced apoptosis, inhibited induction of profibrogenic hedgehog target genes in mice and blocked production of hedgehog ligands in cultured hepatocytes. CONCLUSIONS: These data point to a critical role for caspase-2 in lipid-induced hepatocyte apoptosis in vivo for the production of apoptosis-associated fibrogenic factors and in the progression of lipid-induced liver fibrosis. This raises the intriguing possibility that caspase-2 may be a promising therapeutic target to prevent progression to NASH.

The CUPIC algorithm: an accurate model for the prediction of sustained viral response under telaprevir or boceprevir triple therapy in cirrhotic patients.

Triple therapy using boceprevir or telaprevir remains the reference treatment for genotype 1 chronic hepatitis C in countries where new interferon-free regimens have not yet become available. Antiviral treatment is highly required in cirrhotic patients, but they represent a difficult-to-treat population. We aimed to develop a simple algorithm for the prediction of sustained viral response (SVR) in cirrhotic patients treated with triple therapy. A total of 484 cirrhotic patients from the ANRS CO20 CUPIC cohort treated with triple therapy were randomly distributed into derivation and validation sets. A total of 52.1% of patients achieved SVR. In the derivation set, a D0 score for the prediction of SVR before treatment initiation included the following independent predictors collected at day 0: prior treatment response, gamma-GT, platelets, telaprevir treatment, viral load. To refine the prediction at the early phase of the treatment, a W4 score included as additional parameter the viral load collected at week 4. The D0 and W4 scores were combined in the CUPIC algorithm defining three subgroups: 'no treatment initiation or early stop at week 4', 'undetermined' and 'SVR highly probable'. In the validation set, the rates of SVR in these three subgroups were, respectively, 11.1%, 50.0% and 82.2% (P < 0.001). By replacing the variable 'prior treatment response' with 'IL28B genotype', another algorithm was derived for treatment-naïve patients with similar results. The CUPIC algorithm is an easy-to-use tool that helps physicians weigh their decision between immediately treating cirrhotic patients using boceprevir/telaprevir triple therapy or waiting for new drugs to become available in their country.

A not so solitary fibrous tumor of the liver.

Solitary fibrous tumor (SFT) is a rare neoplasm. Liver parenchyma is a rare location of SFT and, in this case, it usually follows a benign course. We report here the case of a 54-year-old man who presented a large SFT tumor of the right hepatic lobe. The tumor was surgically resected. Local recurrence occurred 6 years later as a 15 cm diameter liver tumor. Histological examination of the resected lesion showed features of an aggressive form of SFT. Two years later, the patient presented with complaints of neck pain and ensuing examinations revealed a tumor of the cranial base. A new surgical resection was performed and histological examination confirmed a metastasis of the SFT. Few weeks later, the patient presented an irreducible psoitis due to an iliac bone metastasis. He died within 1 month.

Treatment of liver fibrosis: clinical aspects.

The main objective of antifibrotic treatment is to avoid the complications of chronic liver disease where its cause cannot be treated. Three main therapeutic endpoints can be targeted: cause; comorbidity; and fibrosis. Antifibrotic treatment is any intervention independent of cause that is intended to modify the course and/or level of fibrosis through direct action on the mechanisms of fibrosis. Several modalities are here considered: reduction of fibrosis course; reversion of fibrosis; and reversion of cirrhosis. Semiquantitative histological staging and morphometry are complementary techniques for monitoring fibrosis. The degree of fibrosis should preferentially be estimated by fibrosis progression based on measurements taken at baseline and during treatment, rather than by raw static measurements. Surrogate markers are the only tools for assessing drug efficacy in clinical practice, and are especially useful for checking compliance and identifying poor or non-responders. We propose to define non-response as no decrease in fibrosis progression. The renin-angiotensin system is a good candidate target for antifibrotic treatment, and angiotensin-II type-1 receptor blockers, such as sartans, are probably effective. Clinical trials are currently ongoing using marketed drugs, while new multitargeted drugs are likely to emerge from basic research.

Endoscopic treatment of painful chronic pancreatitis: evaluation of a new flexible multiperforated plastic stent.

OBJECTIVES: Endoscopic stents are a validated treatment for painful chronic calcifying pancreatitis (CCP). Biliary-type stents are the most commonly used, but have certain drawbacks. The aim of this single-center retrospective study was to evaluate the feasibility, and the short- and medium-term efficacy of a new pancreatic stent (Johlin model, Cook) for pain relief. METHODS: Thirteen patients with painful CCP were treated with a Johlin stent. Stent specifications were studied as well as feasibility and efficacy. Success was defined as relief of pain. RESULTS: There was no placement failure with the initial stent, which was 13.4+/-2.1cm in length and 9.8+/-0.6 Fr in diameter. Immediate total pain relief following stenting occurred in 11 patients. The average follow-up time was 11+/-7 months (range 1.5-24 months). Stents were left in place for 4.5+/-3 months (range 0.5-13.5 months). At the end of follow-up, endoscopic treatment was considered effective in 12 patients. Endoscopic retrograde cholangiopancreatographic (ERCP) complications consisted of uncomplicated acute pancreatitis (10%). CONCLUSION: Pancreatic stenting using the Johlin stent (Cook) is feasible, has no particular adverse events and is effective for immediate as well as medium-term pain improvement.

Evaluation and improvement of a reliable diagnosis of cirrhosis by blood tests.

OBJECTIVE: To evaluate the rates of reliable diagnosis of cirrhosis by two usual blood tests. METHODS: Reliable diagnosis was mainly evaluated by comparing rates of positive (PPV) and negative (NPV) predictive values with FibroTest and FibroMeters, as either standard test or specifically designed for cirrhosis, in 1056 patients with chronic hepatitis C. RESULTS: Using the diagnostic limits provided by fibrosis stage scales, the PPV for cirrhosis was: standard FibroMeters: 68.5% versus FibroTest: 37.1%. Using 95% PPV, the cirrhosis detection rate was: specific FibroMeter: 26.1% versus FibroTest: 2.0% (P<10(-3)). The cirrhosis detection rate increased from 26 to 65% by performing liver biopsy in 8% of patients with indeterminate results on specific FibroMeter between 95% NPV and PPV. On the other hand, specific FibroMeter provided three intervals of 95% reliable diagnosis with no biopsy: less than or equal to 95% NPV: no cirrhosis (threshold: diagnosis); significant fibrosis; and greater than or equal to 95% PPV: cirrhosis. CONCLUSION: The detection rate and PPV for cirrhosis using fibrosis scales were fair for standard FibroMeter and poor for FibroTest. Around one-fourth of cases of cirrhosis are detected by the 95% PPV of specific FibroMeter, and around two-thirds by performing an additional liver biopsy in only 8% of patients. Finally, specific FibroMeter can avoid liver biopsy by classifying patients into three categories: no cirrhosis; significant fibrosis; and cirrhosis.

FibroMeters: a family of blood tests for liver fibrosis.

FibroMeters are blood tests for liver fibrosis with several specificities: two main diagnostic targets (fibrosis stage and area of fibrosis); adaptation to specific causes; and results confirmed by an expert system. Thus, FibroMeters comprise six different tests: one for staging and one for quantitation of liver fibrosis in each of the three main causes of chronic liver disease-chronic viral hepatitis, alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD). FibroMeters display a high overall diagnostic accuracy and are the only tests to correctly classify 100% of HCV patients without fibrosis or with cirrhosis. They have 90% predictive values in a higher proportion of patients than with other usual blood tests. A 90% correct classification is available in 100% of HCV patients with the following reliable diagnostic intervals: F0/1, F1/2, F2+/-1, F3+/-1. In real-life conditions, the reproducibility of FibroMeters is higher than that of liver biopsy or ultrasonographic elastometry. FibroMeters are robust tests with the most stable diagnostic performance across different centers. Optional tests are also available, such as a specific one for cirrhosis, which has a diagnostic accuracy of 93.0% (AUROC: 0.92) and a 100% positive predictive value for diagnosis of HCV cirrhosis. Determination by FibroMeters of the area of fibrosis - the only direct, non-invasive, quantitative measurement of liver fibrosis - are especially useful for following-up cirrhosis as it correlates well with clinical events. FibroMeters are also very accurate in HVB or HIV-HCV co-infected patients. The tests specific for ALD and NAFLD also have a high diagnostic accuracy (AUROCs: 0.96 and 0.94, respectively, for significant fibrosis).

Screening for therapeutic trials and treatment indication in clinical practice: MACK-3, a new blood test for the diagnosis of fibrotic NASH.

BACKGROUND: The composite histological endpoint comprising nonalcoholic steatohepatitis (NASH) and NAFLD activity score ≥4 and advanced fibrosis (F ≥ 2) ("fibrotic NASH") is becoming an important diagnostic target in NAFLD: it is currently used to select patients for inclusion in phase III therapeutic trials and will ultimately be used to indicate treatment in clinical practice once the new drugs are approved. AIM: To develop a new blood test specifically dedicated for this new diagnostic target of interest. METHODS: Eight Hundred and forty-six biopsy-proven NAFLD patients from three centres (Angers, Nice, Antwerp) were randomised into derivation and validation sets. RESULTS: The blood fibrosis tests BARD, NFS and FIB4 had poor accuracy for fibrotic NASH with respective AUROC: 0.566 ± 0.023, 0.654 ± 0.023, 0.732 ± 0.021. In the derivation set, fibrotic NASH was independently predicted by AST, HOMA and CK18; all three were combined in the new blood test MACK-3 (hoMa, Ast, CK18) for which 90% sensitivity and 95% specificity cut-offs were calculated. In the validation set, MACK-3 had a significantly higher AUROC (0.847 ± 0.030, P ≤ 0.002) than blood fibrosis tests. Using liver biopsy in the grey zone between the two cut-offs (36.0% of the patients), MACK-3 provided excellent accuracy for the diagnosis of fibrotic NASH with 93.3% well-classified patients, sensitivity: 90.0%, specificity: 94.2%, positive predictive value: 81.8% and negative predictive value: 97.0%. CONCLUSION: The new blood test MACK-3 accurately diagnoses fibrotic NASH. This new test will facilitate patient screening and inclusion in NAFLD therapeutic trials and will enable the identification of patients who will benefit from the treatments once approved.

Liver fibrosis, cirrhosis, and cirrhosis-related nodules: Imaging diagnosis and surveillance.

Although biological scores and elastography continue to yield the best results, imaging retains a crucial role in the diagnosis of liver fibrosis and cirrhosis. First, digestive symptoms or biological liver test abnormalities often lead the referring physician to request an abdominal ultrasound, and with an experienced operator, accuracy of ultrasound can reach 85% for the diagnosis of severe fibrosis or cirrhosis. Second, imaging could lead to discovery of nonsymptomatic fibrosis or cirrhosis, with an estimated prevalence of 0.5-2.8% in the population. After diagnosis, imaging is central in the follow-up of cirrhosis. It is used to detect worsening of portal hypertension and hepatocellular carcinoma (HCC). Because many nodules are present in a cirrhotic liver, familiarity with the features of HCC can facilitate noninvasive diagnosis and early and accurate treatment.

Liver fibrosis diagnosis by blood test and elastography in chronic hepatitis C: agreement or combination?

BACKGROUND: In chronic hepatitis C, the European Association for the Study of the Liver and the Asociacion Latinoamericana para el Estudio del Higado recommend performing transient elastography plus a blood test to diagnose significant fibrosis; test concordance confirms the diagnosis. AIM: To validate this rule and improve it by combining a blood test, FibroMeter (virus second generation, Echosens, Paris, France) and transient elastography (constitutive tests) into a single combined test, as suggested by the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America. METHODS: A total of 1199 patients were included in an exploratory set (HCV, n = 679) or in two validation sets (HCV ± HIV, HBV, n = 520). Accuracy was mainly evaluated by correct diagnosis rate for severe fibrosis (pathological Metavir F ≥ 3, primary outcome) by classical test scores or a fibrosis classification, reflecting Metavir staging, as a function of test concordance. RESULTS: Score accuracy: there were no significant differences between the blood test (75.7%), elastography (79.1%) and the combined test (79.4%) (P = 0.066); the score accuracy of each test was significantly (P < 0.001) decreased in discordant vs. concordant tests. Classification accuracy: combined test accuracy (91.7%) was significantly (P < 0.001) increased vs. the blood test (84.1%) and elastography (88.2%); accuracy of each constitutive test was significantly (P < 0.001) decreased in discordant vs. concordant tests but not with combined test: 89.0 vs. 92.7% (P = 0.118). Multivariate analysis for accuracy showed an interaction between concordance and fibrosis level: in the 1% of patients with full classification discordance and severe fibrosis, non-invasive tests were unreliable. The advantage of combined test classification was confirmed in the validation sets. CONCLUSIONS: The concordance recommendation is validated. A combined test, expressed in classification instead of score, improves this rule and validates the recommendation of a combined test, avoiding 99% of biopsies, and offering precise staging.

[Coexistence of hepatocellular carcinoma and hepatic metastasis: advantages of positron emission tomography for liver tumors]. / Coexistence d'un carcinome hépato-cellulaire et d'une métastase hépatique: Intérêt de la tomodensitométrie par émission de positrons dans les tumeurs du foie.

We report the case of a cirrhotic patient with a hepatocellular carcinoma and a synchronous hepatic metastasis of a colorectal cancer, both visualized on a positron emission tomography (PET) and a CT scanner. We repeat the need for the arterial phase on CT scanner when a possibility of cirrhosis exists, even in the follow-up of a colorectal cancer. We detail the usual pattern of HCC and the present efficacy of the PET in the diagnosis of HCC.

Osteoprotegerin levels are associated with liver fat and liver markers in dysmetabolic adults.

AIM: This study aimed to determine the association between visceral adipose tissue (VAT), liver fat (LF) content, and other markers of the metabolic syndrome (MetS) and osteoprotegerin (OPG) in dysmetabolic adults. METHODS: Subjects from the NUMEVOX cohort were included if they fulfilled at least one MetS criterion. They then underwent a thorough metabolic and cardiovascular evaluation, including arterial stiffness, atherosclerotic plaques, homoeostasis model assessment for insulin resistance (HOMA-IR) indices and OPG. VAT and LF content were measured by magnetic resonance imaging (MRI). Ultrasound examination of arteries and arterial stiffness were recorded, and age- and gender-adjusted paired correlations calculated. RESULTS: Body mass index, waist circumference and MRI-derived VAT correlated with OPG, whereas abdominal subcutaneous fat did not. OPG levels were strongly correlated with LF content (r=0.25, P=0.003), liver markers such as alanine aminotransferase (r=0.39, P<0.001) and HOMA-IR index (r=0.39, P<0.0001). Plasma OPG also correlated with arterial stiffness and the number of atherosclerotic sites. CONCLUSION: Plasma OPG levels are positively associated with both liver markers and increased LF content, but not with subcutaneous fat in dysmetabolic men. These findings suggest that elevated OPG levels may play a role in the link between fatty liver disease and enhanced cardiovascular risk.

A soluble form of the human CD8 alpha chain expressed in the baculovirus system: biochemical characterization and binding to MHC class I.

We have generated a soluble form of the CD8 molecule consisting of the entire extracellular domains of the human alpha chain, by expressing a mutated CD8 alpha cDNA in SF9 cells infected with a recombinant baculovirus. The truncated molecule was secreted into the medium mostly as a disulfide-linked homodimer in which a single cysteine residue in the hinge-like region (Cys143) was sufficient to assure covalent bonding. Soluble CD8 purified to homogeneity appears to be monodisperse as assessed by gel filtration analysis and contains only O-linked carbohydrates. To determine whether recombinant CD8 can interact with MHC class I molecules, we developed an assay that measures binding of MHC class I-bearing cell lines to purified CD8 adsorbed to plastic plates. The level of binding of cells to immobilized CD8 depended on the amount of CD8 bound to the plate and correlated with the levels of cell surface MHC class I expression. The binding was specifically inhibited by monoclonal antibodies directed either against CD8 or MHC class I molecules. This assay therefore provides a way to measure CD8 binding to MHC class I independently of other cell-cell interactions and should allow direct structure-function studies.

MRI versus histological methods for time course monitoring of steatosis amount in a murine model of NAFLD.

PURPOSE: Hepatic steatosis is an increasingly frequent disease with potentially severe complications. A simple quantification method is required for pretherapeutic studies to allow steatosis monitoring. This study aimed at evaluating steatosis quantification via a standard 1.5T MRI machine in a murine model. MATERIALS AND METHODS: Eleven groups of two rats received a choline methionine deficient diet. MRI was performed at days 0, 2, 4, 5, 6, 7 and 8, and weeks 2, 3, 4 and 5. A phased array surface coil system was used to acquire a GE T1 in- and out-of-phase multi-echo sequence, with neither cardiac nor respiratory synchronization. Steatosis was calculated with the 3-echoes method. Histological quantifications were performed both by optical analysis (percentage of fatty hepatocytes) and by automated measurement of the area of steatosis (AOS). The reference was total intrahepatic triglycerides (TIT). Protocol was approved by the ethic committee. RESULTS: Steatosis without inflammation, increasing with diet duration, was obtained. MRI provided better agreement (intraclass correlation coefficient) with TIT (0.889, p<0.001) than did AOS (0.629, p=0.001) or optical analysis (0.280, p=0.098). MRI permitted closer monitoring of TIT over time than did AOS or optical analysis. By multivariate analysis, MRI was an independent predictor of TIT on first step and ALT on second step. A model combining these 2 variables provided excellent agreement with TIT (0.953, p<0.001) and permitted excellent monitoring of steatosis over time. CONCLUSION: MRI is reliable, easy, fast and superior to histological techniques for the assessment of hepatic steatosis in a murine model.

Combination of blood tests for significant fibrosis and cirrhosis improves the assessment of liver-prognosis in chronic hepatitis C.

BACKGROUND: Recent longitudinal studies have emphasised the prognostic value of noninvasive tests of liver fibrosis and cross-sectional studies have shown their combination significantly improves diagnostic accuracy. AIM: To compare the prognostic accuracy of six blood fibrosis tests and liver biopsy, and evaluate if test combination improves the liver-prognosis assessment in chronic hepatitis C (CHC). METHODS: A total of 373 patients with compensated CHC, liver biopsy (Metavir F) and blood tests targeting fibrosis (APRI, FIB4, Fibrotest, Hepascore, FibroMeter) or cirrhosis (CirrhoMeter) were included. Significant liver-related events (SLRE) and liver-related deaths were recorded during follow-up (started the day of biopsy). RESULTS: During the median follow-up of 9.5 years (3508 person-years), 47 patients had a SLRE and 23 patients died from liver-related causes. For the prediction of first SLRE, most blood tests allowed higher prognostication than Metavir F [Harrell C-index: 0.811 (95% CI: 0.751-0.868)] with a significant increase for FIB4: 0.879 [0.832-0.919] (P = 0.002), FibroMeter: 0.870 [0.812-0.922] (P = 0.005) and APRI: 0.861 [0.813-0.902] (P = 0.039). Multivariate analysis identified FibroMeter, CirrhoMeter and sustained viral response as independent predictors of first SLRE. CirrhoMeter was the only independent predictor of liver-related death. The combination of FibroMeter and CirrhoMeter classifications into a new FM/CM classification improved the liver-prognosis assessment compared to Metavir F staging or single tests by identifying five subgroups of patients with significantly different prognoses. CONCLUSIONS: Some blood fibrosis tests are more accurate than liver biopsy for determining liver prognosis in CHC. A new combination of two complementary blood tests, one targeted for fibrosis and the other for cirrhosis, optimises assessment of liver-prognosis.

MRI measurement of liver fat content predicts the metabolic syndrome.

BACKGROUND AND AIMS: The prevalence of non-alcoholic fatty liver disease among cardiometabolic patients is not completely known because liver biopsy cannot be routinely performed. However, as magnetic resonance imaging (MRI) allows accurate and safe measurement of the hepatic fat fraction (HFF), the aim of this study was to quantify liver fat content in a dysmetabolic adult population. METHODS: A total of 156 adults were included in this cross-sectional study. Liver and visceral fat were assessed by MRI in these subjects, who presented with zero to five metabolic components of the metabolic syndrome (MetS). Arterial stiffness was recorded by ultrasonography, and the maximum Youden index was used to set the optimal HFF cutoff value predictive of the presence of the MetS. RESULTS: Overall, 72% of participants displayed three or more MetS components. HFF ranged from 0.3% to 52% (mean 13.4%). Age- and gender-adjusted HFF was positively correlated with BMI (r=0.44), blood pressure (r=0.19), triglyceridaemia (r=0.22) and glycaemia (r=0.31). MRI-measured visceral adipose tissue did not influence the relationship of steatosis with glycaemia, HOMA-IR and carotid stiffness, but there was a dose-response relationship between the number of MetS components and mean HFF. The optimal HFF for predicting the MetS was found to be 5.2% according to the maximum Youden index point. CONCLUSION: This study highlighted the impact of liver steatosis on cardiometabolic abnormalities with an optimal cutoff value of 5.2% for defining increased metabolic risk.