An accidental finding of a giant intra-abdominal mass.

INTRODUCTION: Mesenteric cysts are rare intra-abdominal tumours often found incidentally on imaging studies or during surgery. The clinical presentation is various with most subjects being asymptomatic, but complications can occur such as torsion, rupture, hemorrhage or obstruction of nearby structures. The etiology of mesenteric cysts remains uncertain. Complete surgical resection is preferred, although there are no specific guidelines concerning optimal treatment strategy. CASE REPORT: We present a 61-year-old male with type 2 diabetes mellitus who underwent a routine abdominal ultrasound examination which accidentally uncovered a large mass. The patient had no complaints nor any physical discomfort. Magnetic resonance imaging and computed tomography revealed a giant thin-walled cyst with multiple septa spanning 24 × 24 cm2 originating from the mesentery. The primary differential diagnosis included a mesenteric cyst, a hydatid cyst due to echinococcus or malignancy. After multidisciplinary team approach, open surgical exploration was preferred. Surgical drainage and cyst sac resection were performed without any peri- or postoperative complications. Histopathology confirmed the presence of a large mesenteric cyst, probably caused post-traumatically. The patient has made a full recovery. CONCLUSION: Mesenteric cysts can develop asymptomatically and reach enormous proportions. They are often found accidentally. Imaging studies aid in the differential diagnosis, but histopathology remains the diagnostic gold standard. Surgical resection prevails compared to a conservative approach due to the risk of complications. The choice between open or laparoscopic surgery should be determined based on the perioperative risk.

Muscle fat content is strongly associated with NASH: A longitudinal study in patients with morbid obesity.

BACKGROUND & AIMS: Studies exploring the relationship between muscle fat content and non-alcoholic fatty liver disease (NAFLD) are scarce. Herein, we aimed to evaluate the association of muscle mass and fatty infiltration with biopsy-assessed NAFLD in patients with obesity. METHODS: At inclusion (n = 184) and 12 months after a dietary intervention (n = 15) or bariatric surgery (n = 24), we evaluated NAFLD by liver biopsy, and skeletal muscle mass index (SMI) by CT (CT-SMI) or bioelectrical impedance analysis (BIA-SMI). We developed an index to evaluate absolute fat content in muscle (skeletal muscle fat index [SMFI]) from CT-based psoas muscle density (SMFIPsoas). RESULTS: Muscle mass was higher in patients with NAFLD than in those without (CT-SMI 56.8 ± 9.9 vs. 47.4 ± 6.5 cm2/m2, p <0.0001). There was no association between sarcopenia and non-alcoholic steatohepatitis (NASH). SMFIPsoas was higher in NASH ≥F2 and early NASH F0-1 than in NAFL (78.5 ± 23.6 and 73.1 ± 15.6 vs. 61.2 ± 12.6, p <0.001). A 1-point change in the score for any of the individual cardinal NASH features (i.e. steatosis, inflammation or ballooning) was associated with an increase in SMFIPsoas (all p <0.05). The association between SMFIPsoas and NASH was highly significant even after adjustment for multiple confounders (all p <0.025). After intervention (n = 39), NASH improvement, defined by NAFLD activity score <3 or a 2-point score reduction, was achieved in more than 75% of patients (n = 25 or n = 27, respectively) that had pre-established NASH at inclusion (n = 32) and was associated with a significant decrease in SMFIPsoas (p <0.001). Strikingly, all patients who had ≥11% reduction in SMFIPsoas achieved NASH improvement (14/14, p <0.05). CONCLUSIONS: Muscle fat content, but not muscle mass, is strongly and independently associated with NASH. All individuals who achieved a ≥11% decrease in SMFIPsoas after intervention improved their NASH. These data indicate that muscle fatty infiltration could be a potential marker for (and perhaps a pathophysiological contributor to) NASH. LAY SUMMARY: The fat content in skeletal muscles is highly reflective of the severity of non-alcoholic fatty liver disease (NAFLD) in patients with morbid obesity. In particular, muscle fat content is strongly associated with non-alcoholic steatohepatitis (NASH) and decreases upon NASH improvement. These data indicate that muscle fatty infiltration could be a marker and possible pathophysiological contributor to NASH.

Risk of Development of More-advanced Lesions in Patients With Inflammatory Bowel Diseases and Dysplasia.

BACKGROUND & AIMS: Patients with inflammatory bowel diseases (IBD) have increased risks of dysplasia and colitis-associated cancer (CAC). We evaluated the risk of development of high-grade dysplasia (HGD) or CAC after diagnosis of dysplasia using data from a national cohort of patients with IBD. METHODS: We performed a multicenter retrospective analysis of data collected from 7 tertiary referral regional or academic centers in Belgium. In searches of IBD pathology databases, we identified 813 lesions (616 low-grade dysplasias [LGDs], 64 high-grade dysplasias [HGDs], and 133 CACs) in 410 patients with IBD: 299 had dysplasia (73%) and 111 had CAC (27%). The primary aim was to determine the risk of more-advanced lesions after diagnosis of LGD or HGD. RESULTS: Of the 287 patients with LGD, 21 (7%) developed more-advanced lesions (HGD or CAC) after a median time period of 86 months (interquartile range, 34-214). Of the 28 patients with HGD, 4 (14%) developed CAC after a median time period of 180 months (interquartile range, 23-444). The overall cumulative incidence of CAC at 10 years after an initial diagnosis of HGD was 24.3% and after an initial diagnosis of LGD was 8.5% (P < .05). Metachronous lesions, non-polypoid lesions, and colonic stricture were associated with risk of occurrence of more-advanced lesions after LGD (P < .05). Of the 630 dysplastic lesions identified during endoscopy, 545 (86%) were removed during the same procedure or during a follow-up endoscopy or by surgery. Of 111 patients with CAC, 95 (86%) did not have prior detection of dysplasia and 64 of these 95 patients (67%) developed CAC outside of the screening or surveillance period recommended by the European Crohn's and Colitis Organisation. CONCLUSIONS: In an analysis of pathology data from 7 medical centers in Belgium, we found a low rate of detection of more-advanced lesions following detection of LGD or HGD-taking into account that most of the lesions were removed. Main risk factors for development of more-advanced lesions after LGD were metachronous lesions, non-polypoid lesions, and colon strictures.

Severe steatosis induces portal hypertension by systemic arterial hyporeactivity and hepatic vasoconstrictor hyperreactivity in rats.

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease. The presence of portal hypertension has been demonstrated in NAFLD prior to development of inflammation or fibrosis, and is a result of extrahepatic and intrahepatic factors, principally driven by vascular dysfunction. An increased intrahepatic vascular resistance potentially contributes to progression of NAFLD via intralobular hypoxia. However, the exact mechanisms underlying vascular dysfunction in NAFLD remain unknown. This study investigates systemic hemodynamics and both aortic and intrahepatic vascular reactivity in a rat model of severe steatosis. Wistar rats were fed a methionine-choline-deficient diet, inducing steatosis, or control diet for 4 weeks. In vivo hemodynamic measurements, aortic contractility studies, and in situ liver perfusion experiments were performed. The mean arterial blood pressure was lower and portal blood pressure was higher in steatosis compared to controls. The maximal contraction force in aortic rings from steatotic rats was markedly reduced compared to controls. While blockade of nitric oxide (NO) production did not reveal any differences, cyclooxygenase (COX) blockade reduced aortic reactivity in both controls and steatosis, whereas effects were more pronounced in controls. Effects could be attributed to COX-2 iso-enzyme activity. In in situ liver perfusion experiments, exogenous NO donation or endogenous NO stimulation reduced the transhepatic pressure gradient (THPG), whereas NO synthase blockade increased the THPG only in steatosis, but not in controls. Alpha-1-adrenergic stimulation and endothelin-1 induced a significantly more pronounced increase in THPG in steatosis compared to controls. Our results demonstrate that severe steatosis, without inflammation or fibrosis, induces portal hypertension and signs of a hyperdynamic circulation, accompanied by extrahepatic arterial hyporeactivity and intrahepatic vascular hyperreactivity. The arterial hyporeactivity seems to be NO-independent, but appears to be mediated by specific COX-2-related mechanisms. Besides, the increased intrahepatic vascular resistance in steatosis appears not to be NO-related but rather to vasoconstrictor hyperreactivity.

Spatial Systems Lipidomics Reveals Nonalcoholic Fatty Liver Disease Heterogeneity.

Hepatocellular lipid accumulation characterizes nonalcoholic fatty liver disease (NAFLD). However, the types of lipids associated with disease progression are debated, as is the impact of their localization. Traditional lipidomics analysis using liver homogenates or plasma dilutes and averages lipid concentrations, and does not provide spatial information about lipid distribution. We aimed to characterize the distribution of specific lipid species related to NAFLD severity by performing label-free molecular analysis by mass spectrometry imaging (MSI). Fresh frozen liver biopsies from obese subjects undergoing bariatric surgery ( n = 23) with various degrees of NAFLD were cryosectioned and analyzed by matrix-assisted laser desorption/ionization (MALDI)-MSI. Molecular identification was verified by tandem MS. Tissue sections were histopathologically stained, annotated according to the Kleiner classification, and coregistered with the MSI data set. Lipid pathway analysis was performed and linked to local proteome networks. Spatially resolved lipid profiles showed pronounced differences between nonsteatotic and steatotic tissues. Lipid identification and network analyses revealed phosphatidylinositols and arachidonic acid metabolism in nonsteatotic regions, whereas low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) metabolism was associated with steatotic tissue. Supervised and unsupervised discriminant analysis using lipid based classifiers outperformed simulated analysis of liver tissue homogenates in predicting steatosis severity. We conclude that lipid composition of steatotic and nonsteatotic tissue is highly distinct, implying that spatial context is important for understanding the mechanisms of lipid accumulation in NAFLD. MSI combined with principal component-linear discriminant analysis linking lipid and protein pathways represents a novel tool enabling detailed, comprehensive studies of the heterogeneity of NAFLD.

Blocking CD40-TRAF6 signaling is a therapeutic target in obesity-associated insulin resistance.

The immune system plays an instrumental role in obesity and insulin resistance. Here, we unravel the role of the costimulatory molecule CD40 and its signaling intermediates, TNF receptor-associated factors (TRAFs), in diet-induced obesity (DIO). Although not exhibiting increased weight gain, male CD40(-/-) mice in DIO displayed worsened insulin resistance, compared with wild-type mice. This worsening was associated with excessive inflammation of adipose tissue (AT), characterized by increased accumulation of CD8(+) T cells and M1 macrophages, and enhanced hepatosteatosis. Mice with deficient CD40-TRAF2/3/5 signaling in MHCII(+) cells exhibited a similar phenotype in DIO as CD40(-/-) mice. In contrast, mice with deficient CD40-TRAF6 signaling in MHCII(+) cells displayed no insulin resistance and showed a reduction in both AT inflammation and hepatosteatosis in DIO. To prove the therapeutic potential of inhibition of CD40-TRAF6 in obesity, DIO mice were treated with a small-molecule inhibitor that we designed to specifically block CD40-TRAF6 interactions; this compound improved insulin sensitivity, reduced AT inflammation, and decreased hepatosteatosis. Our study reveals that the CD40-TRAF2/3/5 signaling pathway in MHCII(+) cells protects against AT inflammation and metabolic complications associated with obesity whereas CD40-TRAF6 interactions in MHCII(+) cells aggravate these complications. Inhibition of CD40-TRAF6 signaling by our compound may provide a therapeutic option in obesity-associated insulin resistance.

Hepatocellular autophagy modulates the unfolded protein response and fasting-induced steatosis in mice.

Autophagy and the unfolded protein response (UPR) are key cellular homeostatic mechanisms and are both involved in liver diseases, including nonalcoholic fatty liver disease (NAFLD). Although increasing but conflicting results link these mechanisms to lipid metabolism, their role and potential cross talk herein have been poorly investigated. Therefore, we assessed the effects of hepatocyte-specific autophagy deficiency on liver parenchyma, the UPR, and lipid metabolism. Adult hepatocellular-specific autophagy-deficient mice (Atg7F/FAlb-Cre+) were compared with their autophagy-competent littermates (Atg7+/+Alb-Cre+). Livers were analyzed by electron microscopy, histology, real-time qPCR, and Western blotting. Atg7F/FAlb-Cre+ mice developed hepatomegaly with significant parenchymal injury, as shown by inflammatory infiltrates, hepatocellular apoptosis, pericellular fibrosis, and a pronounced ductular reaction. Surprisingly, the UPR exhibited a pathway-selective pattern upon autophagy deficiency. The activity of the adaptive activating transcription factor 6 (ATF6) pathway was abolished, whereas the proapoptotic protein kinase RNA-like ER kinase pathway was increased compared with Atg7+/+Alb-Cre+ mice. The inositol-requiring enzyme-1α signal was unaltered. Fasting-induced steatosis was absent in Atg7F/FAlb-Cre+ mice. Remarkably, some isolated islands of fat-containing and autophagy-competent cells were observed in these livers. Hepatocellular autophagy is essential for parenchymal integrity in mice. Moreover, in the case of autophagy deficiency, the three different UPR branches are pathway selectively modulated. Attenuation of the ATF6 pathway might explain the observed impairment of fasting-induced steatosis. Finally, autophagy and lipid droplets are directly linked to each other.

Adult suprapatellar pleiomorphic rhabdomyosarcoma with jejunal metastasis causing intussusception: a case report.

Jejuno-jejunal intussusception is rarely encountered in adults. Management depends on the viability of the involved bowel. Exploration is favored because in adults generally an underlying 'lead point' is found to be present. Pleimorphic rhabdomyosarcoma (pRMS) arises from striated muscle cells. They are usually diagnosed during childhood and can occur virtually all over the body, controversially in places were few striated cells are found. In adults, these tumors are rare and are mostly encountered in the head-and-neck region. We present the case of a 48-year-old woman with a jejunal metastasis from a suprapatellar pRMS diagnosed 2.5 years earlier resulting in a jejuno-jejunal intussusception.

Future remnant liver function estimated by combining liver volumetry on magnetic resonance imaging with total liver function on (99m)Tc-mebrofenin hepatobiliary scintigraphy: can this tool predict post-hepatectomy liver failure?

INTRODUCTION: Posthepatectomy liver failure (PHLF) is a major complication after hepatectomy with a high mortality rate and is likely to happen in insufficient liver remnant. We hypothesize that assessment of the estimated future liver remnant function (eFLRF), combining future remnant liver volume (FLRV) with total liver function (TLF), is an accurate formula for prediction of PHLF. METHODS: 88 patients undergoing hepatectomy were included. The ratio of the future liver remnant volume (FLRV%) was measured on MRI. TLF was estimated by liver clearance of (99m)Technetium (Tc)-mebrofenin on hepatobiliary scintigraphy (HBS). eFLRF was calculated by multiplying FLRV% by TLF. Cut-off values of FLRV% and eFLRF predicting PHLF, were defined by receiver-operating-characteristic (ROC) analysis. RESULTS: PHLF occurred in 12 patients (13%). Perioperative mortality was 5/12 (41%). Multivariate analysis showed that FLRV% cut off at 40% was not an independent predictive factor. eFLRF cut off at 2.3%/min/m(2) was the only independent predictive factor for PHLF. For FLRV% vs. eFLRF, positive predictive value was 41% vs. 92% and Odds Ratio 26 vs. 836. CONCLUSION: FRLF measured by combining FLRV% and TLF is a more valuable tool to predict PHLF than FLRV% alone. The cutoff of eFLRF can be used in clinical decision making.

Biallelic inactivation of protoporphyrinogen oxidase and hydroxymethylbilane synthase is associated with liver cancer in acute porphyrias.

Variegate porphyria (VP) and acute intermittent porphyria (AIP), the two most common types of acute porphyrias (AHPs), result from a partial deficiency of protoporphyrinogen oxidase (PPOX) and hydroxymethylbilane synthase (HMBS), respectively. A rare but serious complication in the AHPs is hepatocellular carcinoma (HCC). However, the underlying pathomechanisms are yet unknown. We performed DNA sequence analysis in cancerous and non-cancerous liver tissue of a VP and an AIP patient, both with HCC. In samples of both cancerous and non-cancerous liver tissues from the patients, we identified the underlying PPOX and HMBS germline mutations, c.1082dupC and p.G111R, respectively. Additionally, we detected a second somatic mutation, only in the cancer tissue i.e., p.L416X in the PPOX gene of the VP patient and p.L220X in the HMBS gene of the AIP patient, both located in trans to the respective germline mutations. Both somatic mutations were not detected in 10 non-porphyria-associated HCCs. Our data demonstrate that in the hepatic cancer tissue of AHP patients, somatic second-hit mutations result in nearly complete inactivation of the enzymes catalyzing major steps in the heme biosynthetic pathway. Both PPOX and HMBS, which might act as tumor suppressors, play a crucial role in the development of HCC in these individuals.

Endoscopic characterization of sessile serrated adenomas/polyps with and without dysplasia.

BACKGROUND AND STUDY AIMS: Sessile serrated adenomas/polyps (SSA/Ps) are precursors of colorectal cancer (CRC), but their endoscopic detection can be difficult. We therefore examined the endoscopic characteristics of SSA/Ps with and without dysplasia in a cross-sectional study. PATIENTS AND METHODS: We reviewed clinical, endoscopic, and histopathologic data from patients undergoing colonoscopy between February 2008 and February 2012. We categorized colorectal polyps according to anatomic site, size, and shape, and classified serrated polyps using the World Health Organization (WHO) classification. Multiple logistic regression analyses examined potential differences regarding site, size, and shape between SSA/Ps and colorectal adenomas (overall and advanced only). RESULTS: We examined 7433 patients (mean age 59 years, 45.9 % men) with 5968 colorectal polyps. In total, we found 170 SSA/Ps (170/5968, 2.9 %), including 63 SSA/Ps with dysplasia (1.1 %) and 107 SSA/Ps without dysplasia (1.8 %). Compared with SSA/Ps with dysplasia, SSA/Ps without dysplasia were more often proximally located (odds ratio [OR] 3.3, 95 % confidence interval [95 %CI] 1.7 - 6.4), but less often < 6 mm in size (OR 0.6, 95 %CI 0.3 - 1.1). No significant differences were found regarding location between SSA/Ps with dysplasia and advanced adenomas (proximal colon, 47.6 % vs. 40.1 %). However, SSA/Ps with dysplasia were more often < 6 mm in size than advanced adenomas (OR 0.3, 95 %CI 0.2 - 0.5). Of the 63 dysplastic SSA/Ps, 6 (9.5 %) contained high grade dysplasia, but none invasive carcinoma. CONCLUSIONS: SSA/Ps with dysplasia are frequently < 6 mm in size, located throughout the colon and 9.5 % of them contain high grade dysplasia. These findings underscore the importance of high quality colonoscopic examination to maximize protection against CRC.

Vegetable, fruit and nitrate intake in relation to the risk of Barrett's oesophagus in a large Dutch cohort.

There are few epidemiological data on the dietary risk factors of Barrett's oesophagus, a precursor of oesophageal adenocarcinoma. The present study investigated the association between vegetable, fruit and nitrate intake and Barrett's oesophagus risk in a large prospective cohort. The Netherlands Cohort Study recruited 120,852 individuals aged 55-69 years in 1986. Vegetable and fruit intake was assessed using a 150-item FFQ, and nitrate intake from dietary sources and drinking water was determined. After 16.3 years of follow-up, 433 cases (241 men and 192 women) of Barrett's oesophagus with specialised intestinal metaplasia and 3717 subcohort members were analysed in a case-cohort design using Cox proportional hazards models while adjusting for potential confounders. Men exhibited a lower risk of Barrett's oesophagus in the highest v. the lowest quintile of total (multivariable-adjusted hazard ratio (HR): 0.66, 95% CI 0.43, 1.01), raw (HR 0.63, 95% CI 0.40, 0.99), raw leafy (HR 0.55, 95% CI 0.36, 0.86) and Brassica (HR 0.64, 95% CI 0.41, 1.00) vegetable intake. No association was found for other vegetable groups and fruits. No significant associations were found between vegetable and fruit intake and Barrett's oesophagus risk among women. Total nitrate intake was inversely associated with Barrett's disease risk in men (HR 0.50, 95% CI 0.25, 0.99) and positively associated with it in women (HR 3.77, 95% CI 1.68, 8.45) (P for interaction = 0.04). These results suggest that vegetable intake may contribute to the prevention of Barrett's oesophagus. The possible differential effect in men and women should be evaluated further.

Definitions of Histological Abnormalities in Inflammatory Bowel Disease: an ECCO Position Paper.

Histological assessment of endoscopic biopsies in inflammatory bowel disease [IBD] plays an important role in clinical management, investigative studies, and clinical trials. Scoring schemes consisting of multiple histological items and offering considerable precision are widely available. However, definitions of histological abnormalities are often inconsistent. Furthermore, interobserver variability for their recognition and assessment may be high. The European Crohn's and Colitis Organisation [ECCO] formed an expert panel to explore definitions of histological abnormalities in IBD, with the aim of improving the quality of diagnosis and facilitating development of scoring schemes. The process confirmed that the current definitions often have no evidence base and vary between sources. Using available evidence and expert knowledge, the panel produced a series of ECCO consensus position statements on histological features in IBD.

An unbiased ranking of murine dietary models based on their proximity to human metabolic dysfunction-associated steatotic liver disease (MASLD).

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease, encompasses steatosis and metabolic dysfunction-associated steatohepatitis (MASH), leading to cirrhosis and hepatocellular carcinoma. Preclinical MASLD research is mainly performed in rodents; however, the model that best recapitulates human disease is yet to be defined. We conducted a wide-ranging retrospective review (metabolic phenotype, liver histopathology, transcriptome benchmarked against humans) of murine models (mostly male) and ranked them using an unbiased MASLD 'human proximity score' to define their metabolic relevance and ability to induce MASH-fibrosis. Here, we show that Western diets align closely with human MASH; high cholesterol content, extended study duration and/or genetic manipulation of disease-promoting pathways are required to intensify liver damage and accelerate significant (F2+) fibrosis development. Choline-deficient models rapidly induce MASH-fibrosis while showing relatively poor translatability. Our ranking of commonly used MASLD models, based on their proximity to human MASLD, helps with the selection of appropriate in vivo models to accelerate preclinical research.

Non-alcoholic steatohepatitis: a non-invasive diagnosis by analysis of exhaled breath.

BACKGROUND & AIMS: Histological evaluation of a liver biopsy is the current gold standard to diagnose non-alcoholic steatohepatitis (NASH), but the procedure to obtain biopsies is associated with morbidity and high costs. Hence, only subjects at high risk are biopsied, leading to underestimation of NASH prevalence, and undertreatment. Since analysis of volatile organic compounds in breath has been shown to accurately identify subjects with other chronic inflammatory diseases, we investigated its potential as a non-invasive tool to diagnose NASH. METHODS: Wedge-shaped liver biopsies from 65 subjects (BMI 24.8-64.3 kg/m(2)) were obtained during surgery and histologically evaluated. The profile of volatile organic compounds in pre-operative breath samples was analyzed by gas chromatography-mass spectrometry and related to liver histology scores and plasma parameters of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). RESULTS: Three exhaled compounds were sufficient to distinguish subjects with (n=39) and without NASH (n=26), with an area under the ROC curve of 0.77. The negative and positive predictive values were 82% and 81%. In contrast, elevated ALT levels or increased AST/ALT ratios both showed negative predictive values of 43%, and positive predictive values of 88% and 70%, respectively. The breath test reduced the hypothetical percentage of undiagnosed NASH patients from 67-79% to 10%, and of misdiagnosed subjects from 49-51% to 18%. CONCLUSIONS: Analysis of volatile organic compounds in exhaled air is a promising method to indicate NASH presence and absence. In comparison to plasma transaminase levels, the breath test significantly reduced the percentage of missed NASH patients and the number of unnecessarily biopsied subjects.

Hyaluronic acid as a marker of hepatic sinusoidal obstruction syndrome secondary to oxaliplatin-based chemotherapy in patients with colorectal liver metastases.

BACKGROUND: A considerable number of patients develop sinusoidal obstruction syndrome (SOS) after oxaliplatin-based chemotherapy for colorectal liver metastases (CLMs). SOS is associated with adverse outcomes after major hepatectomy. Hyaluronic acid (HA) is a marker of hepatic sinusoidal endothelial cell function and may serve as an accurate marker of SOS. This study aimed to assess the value of systemic HA levels and fractional extraction (FE) of HA by the splanchnic area and liver as markers of SOS after oxaliplatin-based chemotherapy for CLMs. METHODS: Forty patients were studied. The presence of SOS was assessed histopathologically. Blood samples from the radial artery and portal and hepatic veins were collected. HA levels were determined by ELISA and the FE of HA was estimated. RESULTS: SOS was present in 23 patients, 11 of whom demonstrated moderate or severe SOS. Preoperative HA levels were significantly higher in patients with moderate or severe SOS (group B, n = 11) compared to patients with no or mild SOS (group A, n = 29) (51.6 ± 10.2 ng/mL vs. 32.1 ± 3.5 ng/mL, p = 0.030). A cutoff HA level of 44.1 ng/mL yielded a sensitivity of 67 % and specificity of 83 % for detection of SOS. The positive predictive value was 50 % and the negative predictive value 91 %. Both groups exhibited a similar FE of HA by the splanchnic area (-7.9 ± 8.5 % in Group A vs. 7.3 ± 3.6 % in Group B, p = 0.422) and liver (-10.7 ± 6.2 % in Group A vs. 4.6 ± 2.3 % in Group B, p = 0.265). CONCLUSIONS: Systemic HA levels can be used to detect patients at risk of SOS after oxaliplatin-based chemotherapy for CLMs. Additional investigations into the presence of SOS are indicated in patients with elevated HA levels.

Zonated quantification of immunohistochemistry in normal and steatotic livers.

Immunohistochemical stains (IHC) reveal differences between liver lobule zones in health and disease, including nonalcoholic fatty liver disease (NAFLD). However, such differences are difficult to accurately quantify. In NAFLD, the presence of lipid vacuoles from macrovesicular steatosis further hampers interpretation by pathologists. To resolve this, we applied a zonal image analysis method to measure the distribution of hypoxia markers in the liver lobule of steatotic livers.The hypoxia marker pimonidazole was assessed with IHC in the livers of male C57BL/6 J mice on standard diet or choline-deficient L-amino acid-defined high-fat diet mimicking NAFLD. Another hypoxia marker, carbonic anhydrase IX, was evaluated by IHC in human liver tissue. Liver lobules were reconstructed in whole slide images, and staining positivity was quantified in different zones in hundreds of liver lobules. This method was able to quantify the physiological oxygen gradient along hepatic sinusoids in normal livers and panlobular spread of the hypoxia in NAFLD and to overcome the pronounced impact of macrovesicular steatosis on IHC. In a proof-of-concept study with an assessment of the parenchyma between centrilobular veins in human liver biopsies, carbonic anhydrase IX could be quantified correctly as well.The method of zonated quantification of IHC objectively quantifies the difference in zonal distribution of hypoxia markers (used as an example) between normal and NAFLD livers both in whole liver as well as in liver biopsy specimens. It constitutes a tool for liver pathologists to support visual interpretation and estimate the impact of steatosis on IHC results.

Endogenous formation of Nε-(carboxymethyl)lysine is increased in fatty livers and induces inflammatory markers in an in vitro model of hepatic steatosis.

BACKGROUND & AIMS: Increased lipid peroxidation and inflammation are major factors in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). A lipoxidation product that could play a role in the induction of hepatic inflammation is N(ε)-(carboxymethyl)lysine (CML). The aim of the present study was to investigate the relationship between steatosis and CML and to study the role of CML in hepatic inflammation. METHODS: We included 74 obese individuals, which were categorized into 3 groups according to the grade of hepatic steatosis. CML accumulation in liver biopsies was assessed by immunohistochemistry and plasma CML levels were measured by mass spectrometry. Plasma CML levels were also determined in the hepatic artery, portal, and hepatic vein of 22 individuals, and CML fluxes across the liver were calculated. Hepatocyte cell lines were used to study CML formation during intracellular lipid accumulation and the effect of CML on pro-inflammatory cytokine expression. Gene expression levels of the inflammatory markers were determined in liver biopsies of the obese individuals. RESULTS: CML accumulation was significantly associated with the grade of hepatic steatosis, the grade of hepatic inflammation, and gene expression levels of inflammatory markers PAI-1, IL-8, and CRP. Analysis of CML fluxes showed no release/uptake of CML by the liver. Lipid accumulation in hepatocytes, induced by incubation with fatty acids, was associated with increased CML formation and expression of the receptor for advanced glycation endproducts (RAGE), PAI-1, IL-8, IL-6, and CRP. Pyridoxamine and aminoguanidine inhibited the endogenous CML formation and the increased RAGE, PAI-1, IL-8, IL-6, and CRP expression. Incubation of hepatocytes with CML-albumin increased the expression of RAGE, PAI-1, and IL-6, which was inhibited by an antibody against RAGE. CONCLUSIONS: Accumulation of CML and a CML-upregulated RAGE-dependent inflammatory response in steatotic livers may play an important role in hepatic steatosis and in the pathogenesis of NAFLD.

Hepatic sinusoidal obstruction syndrome (SOS) reduces the effect of oxaliplatin in colorectal liver metastases.

AIMS: Oxaliplatin is an important chemotherapeutic agent used to reduce hepatic colorectal metastases, resulting in tumour reduction and permitting surgical resection. This treatment has significant side effects, as oxaliplatin can induce sinusoidal obstruction syndrome (SOS) in the non-tumour-bearing liver, resulting in increased morbidity. We hypothesized that SOS might impede hepatic perfusion, thereby interfering with the tumour environment and attenuate the response to the chemotherapy. METHODS AND RESULTS: From the prospective database of the Maastricht University Medical Centre we collected 50 patients with hepatic colorectal carcinoma metastases. All patients received neo-adjuvant oxaliplatin followed by partial hepatectomy. Metastases and non-tumour-bearing liver were studied histopathologically. Thirty-two of 50 (64%) patients showed SOS lesions, classified as mild (26%) and moderate-severe (38%). The response to treatment, as expressed in the tumour regression grade (TRG), was grade 1 (10%); grade 2 (14%); grade 3 (28%); grade 4 (32%) and grade 5 (16%). Statistical analysis showed that a higher grade of SOS was associated with a higher grade of TRG (P = 0.016). CONCLUSION: Developing SOS is associated with a lower tumour response to neo-adjuvant oxaliplatin treatment. Hepatic hypoperfusion due to sinusoidal obstruction syndrome might induce hepatic hypoxia, diminishing the response to chemotherapy.