Valérie Paradis

Assessment of hepatic steatosis by expert pathologists: the end of a gold standard

Background:The presence of fat in the liver is considered a major risk for postoperative complication after liver surgery and transplantation. The current standard of quantification of hepatic steatosis is microscopic evaluation by pathologists, although consistency in such assessment remains unclear. Computerized image analysis is an alternative method for objective assessment of the degree of hepatic steatosis. Methods:High resolution images of hematoxylin and eosin stained liver sections from 46 consecutive patients, initially diagnosed with liver steatosis, were blindly assessed by 4 established expert pathologists from different institutions. Computerized analysis was carried out simultaneously on the same sections. Interobserver agreement and correlation between the pathologists’ and computerized assessment were evaluated using intraclass correlation coefficients (ICC), Spearman rank correlation coefficients, or descriptive statistics. Results:Poor agreement among pathologists (ICC: 0.57) was found regarding the assessment of total steatosis, (ICC >0.7 indicates acceptable agreement). Pathologists’ estimation of micro- and macrosteatosis disclosed also poor correlation (ICC: 0.22, 0.55, respectively). Inconsistent assessment of histological features of steatohepatitis (lobular inflammation, portal inflammation, hepatocyte ballooning, and Mallory hyaline) was documented. Poor conformity was also shown between the computerized quantification and ratings of 3 pathologists (Spearman rank correlation coefficients: 0.22, 0.82, 0.28, and 0.38). Conclusion:Quantification of hepatic steatosis in histological sections is strongly observer-dependent, not reproducible, and does not correlate with the computerized estimation. Current standards of assessment, previously published data and the clinical relevance of hepatic steatosis for liver surgery and transplantation must be challenged.

Genomic profiling of hepatocellular adenomas reveals recurrent FRK-activating mutations and the mechanisms of malignant transformation.

Hepatocellular adenomas (HCA) are benign liver tumors predominantly developed in women using oral contraceptives. Here, exome sequencing identified recurrent somatic FRK mutations that induce constitutive kinase activity, STAT3 activation, and cell proliferation sensitive to Src inhibitors. We also found uncommon recurrent mutations activating JAK1, gp130, or β-catenin. Chromosome copy number and methylation profiling revealed patterns that correlated with specific gene mutations and tumor phenotypes. Finally, integrative analysis of HCAs transformed to hepatocellular carcinoma revealed β-catenin mutation as an early alteration and TERT promoter mutations as associated with the last step of the adenoma-carcinoma transition. In conclusion, we identified the genomic diversity in benign hepatocyte proliferation, several therapeutic targets, and the key genomic determinants of the adenoma-carcinoma transformation sequence.

Accuracy and disagreement of computed tomography and magnetic resonance imaging for the diagnosis of small hepatocellular carcinoma and dysplastic nodules: Role of biopsy

Liver macronodules, ranging from benign to low‐grade or high‐grade dysplastic nodules (LGDNs/HGDNs) and hepatocellular carcinoma (HCC), may develop during chronic liver diseases (CLDs). Current guidelines were recently updated and the noninvasive criteria for the diagnosis of small HCC are based on a single typical radiological pattern and nonconclusive coincidental findings with two techniques. This study aimed to assess the accuracy and disagreements of noninvasive multiphasic examinations for the diagnosis of HCC and dysplastic nodules (DNs) and the role of biopsy. Seventy‐four consecutive patients with CLD with ultrasound‐detected 1‐2‐cm nodules underwent, within 1 month, multiphasic computed tomography (CT), magnetic resonance imaging (MRI), and biopsy of the nodule. Median age was 60 years; 33 patients (45%) had hepatitis C virus, 20 (27%) had hepatitis B virus, and 13 (18%) patients had no cirrhosis. Biopsy revealed 47 HCCs, 6 HGDNs, 1 LGDNs, 1 cholangiocarcinoma, and 1 epithelioid hemangioendothelioma. There were no tumors in the other 18 patients. All patients (31 of 31; 100%) who had conclusive coincidental findings (i.e., arterial enhancement and washout) on both examinations had HCC or HGDN (sensitivity, 57%; specificity, 100%). All patients (51 of 51; 100%) who had conclusive findings on at least one of the two examinations had HCC or HGDN (sensitivity, 96%; specificity, 100%). There was a disagreement regarding imaging findings between CT and MRI in 21 of 74 (28%) patients and no washout on both examinations in 23 of 74 patients (31%). In these 44 patients, liver biopsy provided an initial accurate diagnosis. Conclusion: The noninvasive diagnosis of HCC or HGDN can be obtained if arterial enhancement and washout are found in a single dynamic imaging examination. These findings are frequently discordant on both CT and MRI, supporting the place of biopsy for the diagnosis of small HCCs. (HEPATOLOGY 2011)

Obesity and Fatty Pancreatic Infiltration Are Risk Factors for Pancreatic Precancerous Lesions (PanIN)

Purpose: The roles of intravisceral and subcutaneous fat are unknown, and the prevalence of precancerous lesions in obese patients was never evaluated. This study aims to assess the frequency and severity of pancreatic intraepithelial neoplasia (PanIN) and to correlate pathologic findings with metabolic abnormalities, type of fat, and fatty pancreatic infiltration. Experimental Design: Normal pancreatic tissue from surgical specimens was analyzed. Fatty infiltration and fibrosis in intra- and extralobular locations and PanIN lesions were assessed. General characteristics were collected: body mass index (BMI), diabetes, and tobacco intake. Liver steatosis and subcutaneous and intravisceral fat were assessed by CT scan (ImageJ software). Results: Of note, 110 patients were included [median age, 53.8 (17–85) years]. Arterial hypertension, diabetes, and tobacco intake were found in 19%, 9%, and 23%, respectively. Median BMI was 24 (16–37; BMI < 25: 45%, 25 ≤ 30: 24%, ≥30: 11%). Overall, PanIN lesions were found in 65% (type I, II, and III PanIN in 62%, 38%, and 1%, respectively). Fibrosis and fatty pancreas (intra- and extralobular locations) were found in 1% and 24% and in 30% and 51%, respectively. A correlation was observed between PanIN lesions and fatty pancreas [extralobular (0.01) and intralobular (<0.0001)], intralobular fibrosis (0.003), high BMI (P = 0.02), and subcutaneous (P = 0.02) and intravisceral fat (P = 0.02). The number of PanIN lesions was correlated with intravisceral fat (r = 0.22, P = 0.04), but not with subcutaneous fat (r = 0.14, P = 0.22). In multivariate analysis, PanIN lesions were associated with intralobular fibrosis [OR, 5.61; 95% confidence interval (CI), 1.18–42.99] and intralobular fat (OR, 17.86; 95% CI, 4.935–88.12). Conclusions: Obesity (especially android obesity) and pancreatic fatty infiltration are risk factors for pancreatic precancerous lesions. Clin Cancer Res; 21(15); 3522–8. ©2015 AACR. See related commentary by Wang et al., p. 3369

Performance of PIVKA-II for early hepatocellular carcinoma diagnosis and prediction of microvascular invasion

BACKGROUND & AIMSnProthrombin induced by vitamin K absence-II (PIVKA-II) is a diagnostic and surveillance marker for HCC mainly used in Asia, and has also been shown to be a predictor of microvascular invasion (MVI), a major prognostic factor in HCC. However, experience with PIVKA-II in Europe remains limited.nnnMETHODSnIn a French cohort, we conducted a case-control study to compare the performances of α-fetoprotein (AFP) and PIVKA-II serum levels for diagnosis of early stage HCC, and we determined the value of PIVKA-II serum and tissue expression in pre-operative detection of MVI. 43 cirrhotic control patients and 85 HCC cases were included, of which 54 (63.5%) had early stage HCC (n=22 very early, n=32 early). PIVKA-II tissue expression was assessed by immunohistochemistry in HCC surgical samples.nnnRESULTSnFor the diagnosis of early HCC, PIVKA-II had a sensitivity of 77% and a specificity of 82% at a cut-off of 42 mAU/ml, vs. 61% and 50% for AFP at a cut-off of 5.5 ng/ml (AUC 0.81 vs. 0.58, respectively). A PIVKA-II level >90 mAU/ml was an independent predictor of MVI (HR 3.5; 95% CI 1.08-11.8; p=0.043). High PIVKA-II tissue expression was significantly associated with the presence of MVI (p=0.001). When combining PIVKA-II immunostaining with the PIVKA-II serum level, sensitivity and specificity for the diagnosis of MVI increased from 70% to 87% and 63% to 90%, respectively.nnnCONCLUSIONSnPIVKA-II was more efficient than AFP for the diagnosis of early HCC, and could be used as a predictive biomarker of MVI.

Hepatocellular nodules expressing markers of hepatocellular adenomas in Budd-Chiari syndrome and other rare hepatic vascular disorders

BACKGROUND & AIMSnA broad range of hepatocellular nodules has been reported in hepatic vascular disorders. It is not clear whether hepatocellular adenoma (HCA) in this context share the same characteristics as conventional HCA. The aim of this study was to carry out a retrospective multicenter survey of hepatocellular nodules associated with hepatic vascular disorders.nnnMETHODSnForty-five cases were reviewed, including 32 Budd-Chiari syndrome (BCS). Benign nodules were subtyped using the HCA immunohistochemical panel.nnnRESULTSnNodules with a HCA morphology were observed in 11 cases. Six originated in BCS: two were liver fatty acid binding protein (LFABP) negative (one with malignant transformation); two expressed glutamine synthetase (GS) and nuclear b-catenin, two expressed C reactive protein (CRP). Among three cases with portal vein agenesis, one nodule was LFABP negative, two expressed GS and nuclear b-catenin, both with malignant transformation. In a Fallot tetralogy case, there were multiple LFABP negative nodules with borderline features and in a hepatoportal sclerosis case, the nodule looked like an inflammatory HCA. Two additional cases had nodules expressing CRP, without typical characteristics of inflammatory HCA.nnnCONCLUSIONnHCA of different immunohistochemical phenotype can develop in hepatic vascular disorders; they may have a different behavior compared to conventional HCA and be more at risk of malignant transformation.

Vasopressin and hydration play a major role in the development of glucose intolerance and hepatic steatosis in obese rats.

Aims/hypothesisHigh plasma copeptin, a marker of vasopressin (VP) secretion, has been shown to be associated with the metabolic syndrome and development of type 2 diabetes in humans. The present study was designed to determine the long-term influence of plasma VP concentration in a rodent model prone to metabolic dysfunction.MethodsObese Zucker rats and their lean counterparts were submitted for 4xa0weeks to one of three protocols inducing different levels of VP. Circulating VP was either reduced by increasing the daily water intake (low-VP), or increased by a chronic i.p. infusion of VP (high-VP). The control rats had normal VP levels that depended on their own regulation of water intake and VP secretion.ResultsCompared with controls with normal VP, lean rats with high-VP had a higher fasting glycaemia after 4xa0weeks. In obese rats, high-VP promoted hyperinsulinaemia, glucose intolerance, assessed by glucose and insulin tolerance tests, and an impaired response to a pyruvate challenge. Conversely, treatment with a selective arginine vasopressin receptor 1A (V1aR) antagonist reduced glucose intolerance. Low-VP obese rats had unchanged glucose tolerance but exhibited a drastic decrease in liver steatosis compared with control obese rats, associated with low hepatic triacylglycerol and cholesterol content, and reduced expression of hepatic lipogenic genes. These effects were independent of changes in body adiposity, and plasma sodium and osmolality did not differ among groups.Conclusion/interpretationThese findings show a causal relationship between the VP–hydration axis and the metabolic risk. Therapeutic perspectives include diet recommendations regarding hydration, but also potential pharmacological interventions targeting the VP V1aR.

Fat deposition decreases diffusion parameters at MRI: a study in phantoms and patients with liver steatosis

AbstractPurposeAssess the effect of fat deposition on the MRI diffusion coefficients in lipid emulsion-based phantoms and patients with proven isolated liver steatosis.Materials and methodsDiffusion-weighted MRI with 11 b values from 0–500xa0s/mm2 was performed in phantoms (fat fractions 0–18xa0%) with and without fat suppression and in 19 patients with normal liver (nu2009=u200914) or isolated liver steatosis (nu2009=u20095) proven by histopathology. The apparent, pure and perfusion-related diffusion coefficients and the perfusion fraction were measured. Spearman correlation coefficient and Mann–Whitney U test were used for comparisons.ResultsA strong correlation between the apparent and pure diffusion coefficients and fat fractions was seen in phantoms. The pure diffusion coefficient decreased significantly in patients with liver steatosis (0.96u2009±u20090.16u2009×u200910-3xa0mm2/s versus 1.18u2009±u20090.09u2009×u200910-3xa0mm2/s in normal liver, Pu2009=u20090.005), whereas the decrease in apparent diffusion coefficient did not reach statistical significance (1.26u2009±u20090.25u2009×u200910-3xa0mm2/s versus 1.41u2009±u20090.14u2009×u200910-3xa0mm2/s in normal liver, Pu2009=u20090.298).ConclusionsFat deposition decreases the apparent and pure diffusion coefficients in lipid emulsion-based phantoms and patients with isolated liver steatosis proven by histopathology.Key Points• Magnetic resonance imaging is increasingly used to quantify hepatic fibrosis.n • Lipid phantoms show inverse correlations between diffusion coefficients and fat fractions.n • The pure diffusion coefficient decreases in patients with isolated liver steatosis.n • Steatosis may be a confounding factor when measuring the liver diffusion parameters.

MR findings of steatotic focal nodular hyperplasia and comparison with other fatty tumours.

ObjectivesTo correlate MR findings with pathology in steatotic FNHs and to compare the MR findings with those of other fatty tumours developed on noncirrhotic liver in a consecutive series of resected lesions.MethodsOur population included resected FNH with intralesional steatosis (nu2009=u200925) and other resected fatty tumours selected as controls (hepatocellular adenomas and angiomyolipomas, nu2009=u200934). Lesions were classified into three groups: those with typical FNH without (group 1) or with (group 2) fat on MR and those with atypical lesions (group 3). In group 3, diagnostic criteria for other fatty tumours were applied.ResultsThere were 9 lesions in group 1 (15.3xa0%), 4 in group 2 (16.8xa0%) and 46 in group 3 (77.9xa0%). Group 3 contained 12 FNHs (26xa0%) and all the other fatty tumours. In group 3, the association of lesion homogeneity, signal intensity similar to or slightly different from adjacent liver on in-phase T1- and T2-weighted sequences, and strong arterial enhancement was observed in 7/12 (58xa0%) of steatotic FNHs and 3/34 (9xa0%) of other tumours.ConclusionOn MR, fat within a typical FNH should not reduce the diagnostic confidence. We recommend further investigations including liver biopsy if necessary when fatty tumours exhibit atypical MR findings.Key Points• MRI is increasingly used to assess hepatic lesions containing fat.• Nodules of focal nodular hyperplasia often contain foci of fat.• However, steatotic FNH does not always demonstrate typical fatty features on MRI.• The main mimickers of steatotic FNHs are telangiectatic/inflammatory hepatocellular adenomas.• We recommend liver biopsy when fatty tumours exhibit atypical MR findings.

Progression from cirrhosis to cancer is associated with early ubiquitin post-translational modifications: identification of new biomarkers of cirrhosis at risk of malignancy.

Cirrhosis is a lesion at risk of hepatocellular carcinoma (HCC). Identifying mechanisms associated with the transition from cirrhosis to HCC and characterizing biomarkers of cirrhosis at high risk of developing into cancer are crucial for improving early diagnosis and prognosis of HCC. We used MALDI imaging to compare mass spectra obtained from tissue sections of cirrhosis without HCC, cirrhosis with HCC, and HCC, and a top‐down proteomics approach to characterize differential biomarkers. We identified a truncated form of monomeric ubiquitin lacking the two C‐terminal glycine residues, Ubi(1‐74), the level of which increased progressively, from cirrhosis without HCC to cirrhosis with HCC to HCC. We showed that kallikrein‐related peptidase 6 (KLK6) catalysed the production of Ubi(1‐74) from monomeric ubiquitin. Furthermore, we demonstrated that KLK6 was induced de novo in cirrhosis and increased in HCC in parallel with accumulation of Ubi(1‐74). We investigated in vitro the possible consequences of Ubi(1‐74) accumulation and demonstrated that Ubi(1‐74) interferes with the normal ubiquitination machinery in what is likely to be a kinetic process. Our data suggest that de novo KLK6 expression during early liver carcinogenesis may induce production of Ubi(1‐74) by post‐translational modification of ubiquitin. Given the deleterious effect of Ubi(1‐74) on protein ubiquitination and the major role of ubiquitin machinery in maintenance of cell homeostasis, Ubi(1‐74) might severely impact a number of critical cellular functions during transition from cirrhosis to cancer. Ubi(1‐74) and KLK6 may serve as markers of cancer risk in patients with cirrhosis. Copyright