Laura Rubbia-Brandt

Hepatocyte steatosis is a cytopathic effect of hepatitis C virus genotype 3.

BACKGROUND/AIMS Patients infected with the hepatitis C virus (HCV) often have liver steatosis, suggesting the possibility of a viral cytopathic effect. The aim of this study was to correlate the occurrence and severity of liver steatosis with HCV RNA type, level and sequence of the core-encoding region. METHODS We scored the liver steatosis in 101 HCV-infected individuals carefully selected to exclude other risk factors of a fatty liver. Results were compared with HCV RNA genotype and level in serum and liver. In selected patients, we assessed the effect of antiviral therapy on steatosis and the relationship between nucleocapsid sequence heterogeneity and fat infiltration. RESULTS Steatosis was found in 41 (40.6%) patients, irrespective of sex, age or route of infection. HCV genotype 3 was associated with higher steatosis scores than other genotypes. A significant correlation between steatosis score and titer of intrahepatic HCV RNA was found in patients infected with genotype 3, but not in those infected with genotype 1. In selected patients, response to alpha-interferon was associated with the disappearance of steatosis. Analysis of the nucleocapsid of 14 HCV isolates failed to identify a sequence specifically associated with the development of steatosis. CONCLUSIONS We provide virological and clinical evidence that the steatosis of the liver is the morphological expression of a viral cytopathic effect in patients infected with HCV genotype 3. At variance with published evidence from experimental models, the HCV nucleocapsid protein does not seem to fully explain the lipid accumulation in these patients.

Neoadjuvant chemotherapy and resection of advanced synchronous liver metastases before treatment of the colorectal primary

In many patients with advanced synchronous liver metastases from colorectal tumours, the metastases progress during treatment of the primary, precluding curative treatment. The authors have investigated a management strategy that involves high‐impact chemotherapy first, resection of liver metastases second and finally removal of the primary tumour in patients with adverse prognostic factors.

The oncosurgery approach to managing liver metastases from colorectal cancer: a multidisciplinary international consensus

An international panel of multidisciplinary experts convened to develop recommendations for the management of patients with liver metastases from colorectal cancer (CRC). The aim was to address the main issues facing the CRC hepatobiliary multidisciplinary team (MDT) when managing such patients and to standardize the treatment patients receive in different centers. Based on current evidence, the group agreed on a number of issues including the following: (a) the primary aim of treatment is achieving a long disease-free survival (DFS) interval following resection; (b) assessment of resectability should be performed with high-quality cross-sectional imaging, staging the liver with magnetic resonance imaging and/or abdominal computed tomography (CT), depending on local expertise, staging extrahepatic disease with thoracic and pelvic CT, and, in selected cases, fluorodeoxyglucose positron emission tomography with ultrasound (preferably contrast-enhanced ultrasound) for intraoperative staging; (c) optimal first-line chemotherapy-doublet or triplet chemotherapy regimens combined with targeted therapy-is advisable in potentially resectable patients; (d) in this situation, at least four courses of first-line chemotherapy should be given, with assessment of tumor response every 2 months; (e) response assessed by the Response Evaluation Criteria in Solid Tumors (conventional chemotherapy) or nonsize-based morphological changes (antiangiogenic agents) is clearly correlated with outcome; no imaging technique is currently able to accurately diagnose complete pathological response but high-quality imaging is crucial for patient management; (f) the duration of chemotherapy should be as short as possible and resection achieved as soon as technically possible in the absence of tumor progression; (g) the number of metastases or patient age should not be an absolute contraindication to surgery combined with chemotherapy; (h) for synchronous metastases, it is not advisable to undertake major hepatic surgery during surgery for removal of the primary CRC; the reverse surgical approach (liver first) produces as good an outcome as the conventional approach in selected cases; (i) for patients with resectable liver metastases from CRC, perioperative chemotherapy may be associated with a modestly better DFS outcome; and (j) whether initially resectable or unresectable, cure or at least a long survival duration is possible after complete resection of the metastases, and MDT treatment is essential for improving clinical and survival outcomes. The group proposed a new system to classify initial unresectability based on technical and oncological contraindications.

α-Smooth muscle actin is expressed in a subpopulation of cultured and cloned fibroblasts and is modulated by γ-interferon

Clinical and experimental investigations have shown that, during wound healing and fibrocontractive diseases, fibroblasts acquire, more or less permanently according to the situation, morphological and biochemical features of smooth muscle (SM) cells including the expression of alpha-SM actin. Primary and passaged cultures of rat and human fibroblasts contain a subpopulation of cells expressing alpha-SM actin. These cells could derive from SM cells and/or pericytes present in the tissue from which cultures have been produced or represent bona fide fibroblasts. We have investigated the presence of alpha-SM actin in fibroblast cultures, clones, and subclones. In all cases the fibroblastic populations studied showed a proportion of alpha-SM actin expressing cells. Even after cloning, we never obtained populations negative for alpha-SM actin. We conclude that alpha-SM actin expression in fibroblastic cultures is not due to contaminant cells but is a feature of fibroblasts themselves. Our results support the view that fibroblastic cells are a heterogeneous population. It has been previously shown that gamma-interferon (gamma-IFN) decreases alpha-SM actin expression in SM cells. In rat and human fibroblasts, gamma-IFN decreases alpha-SM actin protein and mRNA expression as well as proliferation. The properties of this cytokine make it a good candidate for exerting an anti-fibrotic activity in vivo.

Sinusoidal obstruction syndrome and nodular regenerative hyperplasia are frequent oxaliplatin-associated liver lesions and partially prevented by bevacizumab in patients with hepatic colorectal metastasis

Rubbia‐Brandt L, Lauwers G Y, Wang H, Majno P E, Tanabe K, Zhu A X, Brezault C, Soubrane O, Abdalla E K, Vauthey J‐N, Mentha G & Terris B
(2010) Histopathology56, 430–439
Sinusoidal obstruction syndrome and nodular regenerative hyperplasia are frequent oxaliplatin‐associated liver lesions and partially prevented by bevacizumab in patients with hepatic colorectal metastasis

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.

Combination of steroids with infliximab or placebo in severe alcoholic hepatitis: a randomized controlled pilot study☆

BACKGROUND/AIMS The aim of this study is to evaluate the tolerance and effects of infliximab combined with steroids in severe alcoholic hepatitis (AH). METHODS Twenty patients with biopsy-proven severe AH (Maddreys score>32) received prednisone 40 mg/day for 28 days and either infliximab 5mg/kg IV (group A) or placebo (group B) at day 0. Histology, plasma interleukin-6 (IL-6) and interleukin-8 (IL-8) were measured at baseline and at day 10. RESULTS Infliximab was well tolerated. Histology showed no significant changes. At day 28, Maddreys score significantly improved in group A (39 (32-53) to 12 (7-52), P<0.05 vs. baseline) but not in group B (44 (33-50) to 22 (2-59), P=NS). At day 10, IL-6 and IL-8 decreased in group A (25 pg/ml (10-85 pg/ml) to 4.5 pg/ml (2-25 pg/ml); 301 pg/ml (107-1207 pg/ml) to 14 6 pg/ml (25-252 pg/ml), P<0.01, P<0.05 vs. baseline, respectively). In group B, changes were not significant (38 pg/ml (13-116 pg/ml) to 16 pg/ml (4-128); 315 pg/ml (26-1698 pg/ml) to 110 pg/ml (27-492 pg/ml)). CONCLUSIONS In severe AH, infliximab was well tolerated and associated with significant improvement in Maddreys score at day 28. Although the size of this study does not allow comparison between groups, these promising results should encourage larger trials assessing the effects of this therapy on survival.

Expression of NOX1, a superoxide-generating NADPH oxidase, in colon cancer and inflammatory bowel disease

Reactive oxygen species (ROS) are at the centre of many physiological and pathological processes. NOX1, a ROS‐producing NADPH oxidase, is highly expressed in the colon but its function in colonic physiology or pathology is still poorly understood. It has been suggested to play a role in host defence, but also in cell growth and possibly malignant transformation. In this study we characterized NOX1 expression in human colon samples derived from healthy control subjects and patients with colon cancer or inflammatory bowel disease (IBD). NOX1 mRNA expression was assessed by dot‐blot hybridization, real‐time PCR and in situ hybridization, using samples derived from surgical specimens from patients undergoing colon resection. In normal tissues, NOX1 expression was low in the ileum, intermediate in the right colon, and high in the left colon (p = 0.0056 right vs. left colon). NOX1 mRNA levels were not influenced by factors linked to colon tumourigenesis, such as age or sex. Moreover, there was no statistical difference in NOX1 expression between samples derived from adenomas, well differentiated or poorly differentiated colon adenocarcinomas. At a cellular level, NOX1 was highly expressed in colon epithelial cells, both within the crypts and on the luminal surface. In addition, a population of lymphocytes, particularly in the appendix, showed NOX1 expression. Lymphocytes in lesions of Crohns disease and ulcerative colitis were also strongly positive for NOX1. In conclusion, NOX1 is an enzyme that is constitutively expressed in colon epithelium and is not associated with tumourigenesis. Its distribution in crypts and on the luminal surface, as well as its left‐to‐right gradient in the colon, suggests a role in host defence function. In addition to the known epithelial localization, we define lymphocytes as a novel site of NOX1 expression, where it may potentially be involved in the pathogenesis of inflammatory bowel diseases. Copyright

Unsaturated fatty acids inhibit the expression of tumor suppressor phosphatase and tensin homolog (PTEN) via microRNA-21 up-regulation in hepatocytes†‡

Phosphatase and tensin homolog (PTEN) is a regulator of phosphoinositide 3‐kinase signaling and an important tumor suppressor mutated/deleted in human cancers. PTEN deletion in the liver leads to insulin resistance, steatosis, inflammation, and cancer. We recently demonstrated that unsaturated fatty acids trigger steatosis by down‐regulating PTEN expression in hepatocytes via activation of a mammalian target of rapamycin (mTOR)/nuclear factor kappa B (NF‐κB) complex, but the molecular mechanisms implicated in this process are still unknown. Here, we investigated potential genetic and epigenetic mechanisms activated by fatty acids leading to PTEN down‐regulation. Our results indicate that unsaturated fatty acids down‐regulate PTEN messenger RNA expression in hepatocytes through mechanisms unrelated to methylation of the PTEN promoter, histone deacetylase activities, or repression of the PTEN promoter activity. In contrast, unsaturated fatty acids up‐regulate the expression of microRNA‐21, which binds to PTEN messenger RNA 3′‐untranslated region and induces its degradation. The promoter activity of microRNA‐21 was increased by mTOR/NF‐κB activation. Consistent with these data, microRNA‐21 expression was increased in the livers of rats fed high‐fat diets and in human liver biopsies of obese patients having diminished PTEN expression and steatosis. Conclusion: Unsaturated fatty acids inhibit PTEN expression in hepatocytes by up‐regulating microRNA‐21 synthesis via an mTOR/NF‐κB–dependent mechanism. Aberrant up‐regulation of microRNA‐21 expression by excessive circulating levels of fatty acids exemplify a novel regulatory mechanism by which fatty acids affect PTEN expression and trigger liver disorders. (HEPATOLOGY 2009.)

Locally applied GM-CSF induces the accumulation of α-smooth muscle act in containing myofibroblasts

SummaryWe have examined the histological and cytoskeletal changes in rat connective tissues induced by subcutaneous perfusion with cytokines. Granulocyte macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor-α (TNF-α), interleukin-1-α (IL-l-α), transforming growth factor-β (TGF-β) and platelet-derived growth factor (PDGF) produced a significant fibroblast accumulation, neovascular development and a weak to moderate leukocyte infiltration, while interleukin-2 (IL-2) and γ-interferon (γ-IFN) induced intense mononucleated leukocyte infiltration. Immunofluorescence staining showed that accumulated fibroblastic cells were positive for α-smooth muscle (SM) actin (but negative for the desmin and muscle myosin) only in GM-CSF-treated tissues. Electron microscopic examination established that a signifikant proportion of fibroblastic cell in GM-CSF-, IL-l-α- or TGF-β-treated animals were typical myofibroblasts. Only in GM-CSF-treated animals did microfilament bundles of myofibroblasts contain α-SM actin, when examined by immuno electron microscopy. Our results suggest that locally applied cytokines induce the formation of distinct granulation tissues. In particular, GM-CSF stimulates a-SM actin synthesis in myofibroblasts, illustrating an unexpected extra-hematopoietic in vivo effect of this factor.