[Show abstract][Hide abstract] ABSTRACT: Most colorectal polyps are readily classified, but a subset of tubulovillous adenomas (TVA) with prominent serrated architecture cause diagnostic confusion. We aimed to 1) identify histological features that separate serrated TVAs from both conventional TVAs and traditional serrated adenomas (TSA) and 2) perform a clinicopathological and molecular analysis to determine if the serrated TVA has unique features.
We collected 48 serrated TVAs, 50 conventional TVAs and 66 BRAF wild-type TSAs for analysis. For each polyp we performed a clinicopathological assessment, BRAF and KRAS mutation profiling, CpG island methylator phenotype status, MGMT methylation and immunohistochemical assessment of seven markers (MLH1, p16, p53, β-catenin, Ki67, CK7 and CK20).
We found that serrated TVAs can be reliably diagnosed and have features distinct from both conventional TVAs and TSAs. Compared to conventional TVAs, serrated TVAs are larger, more often proximal, more histologically advanced, show more CpG island methylation and more frequent KRAS mutation. Compared to TSAs, they are more often proximal, show less CpG island methylation, more frequent MGMT methylation and more frequent nuclear staining for β-catenin.
The serrated TVA can be reliably diagnosed and has unique features. It represents a precursor of KRAS mutated, microsatellite stable colorectal carcinoma. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Current tools for risk stratification of chronic liver disease subjects are limited. We aimed to determine whether the serum-based ELF (Enhanced Liver Fibrosis) test predicted liver-related clinical outcomes, or progression to advanced liver disease, and to compare the performance of ELF to liver biopsy and non-invasive algorithms.
300 patients with ELF scores assayed at the time of liver biopsy were followed up (median 6.1 years) for liver-related clinical outcomes (n=16) and evidence of progression to advanced fibrosis (n=18), by review of medical records and clinical data.
Fourteen of 73 (19.2%) patients with ELF score indicative of advanced fibrosis (≥9.8, the manufacturer's cut-off) had a liver-related clinical outcome, compared to only 2 of 227 (<1%) patients with ELF score <9.8. By contrast, the simple scores APRI and FIB-4 would only have predicted subsequent decompensation in 6 and 4 patients, respectively. A unit increase in ELF score was associated with a 2.53-fold increased risk of a liver-related event (adjusted for age and stage of fibrosis). In patients without advanced fibrosis on biopsy at recruitment, 61% (11/18) with an ELF score ≥9.8 showed evidence of progression to advanced fibrosis (after an average 6 years), whereas only 13.5% of those with an ELF score <9.8 (28/207) progressed (average 14 years). In these subjects, a unit increase in ELF score was associated with a 4.34-fold increased risk of progression. Conclusions The ELF score is a valuable tool for risk stratification of patients with chronic liver disease. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
Liver international: official journal of the International Association for the Study of the Liver 06/2015; DOI:10.1111/liv.12896 · 4.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hepatocyte clone size was measured in liver samples of 21 patients in various stages of chronic hepatitis B virus (HBV) infection and from 21 to 76 years of age. Hepatocyte clones containing unique virus–cell DNA junctions formed by the integration of HBV DNA were detected using inverse nested PCR. The maximum hepatocyte clone size tended to increase with age, although there was considerable patient-to-patient variation in each age group. There was an upward trend in maximum clone size with increasing fibrosis, inflammatory activity and with seroconversion from HBV e-antigen (HBeAg)-positive to HBeAg-negative, but these differences did not reach statistical significance. Maximum hepatocyte clone size did not differ between patients with and without a coexisting hepatocellular carcinoma. Thus, large hepatocyte clones containing integrated HBV DNA were detected during all stages of chronic HBV infection. Using laser microdissection, no significant difference in clone size was observed between foci of HBV surface antigen (HBsAg)-positive and HBsAg-negative hepatocytes, suggesting that expression of HBsAg is not a significant factor in clonal expansion. Laser microdissection also revealed that hepatocytes with normal-appearing histology make up a major fraction of the cells undergoing clonal expansion. Thus, preneoplasia does not appear to be a factor in the clonal expansion detected in our assays. Computer simulations suggest that the large hepatocyte clones are not produced by random hepatocyte turnover but have an as-yet-unknown selective advantage that drives increased clonal expansion in the HBV-infected liver.
[Show abstract][Hide abstract] ABSTRACT: Barrett's esophagus (BE), a common condition, is the only known precursor to esophageal adenocarcinoma (EAC). There is uncertainty about the best way to manage BE, since most people with BE never develop EAC and most patients diagnosed with EAC have no preceding diagnosis of BE. Moreover, there have been recent advances in knowledge and practice about the management of BE and early EAC. To aid clinical decision-making in this rapidly moving field, Cancer Council Australia convened an expert working party to identify pertinent clinical questions. The questions covered a wide range of topics including endoscopic and histologic definitions of BE and early EAC; prevalence, incidence, natural history and risk factors for BE; and methods for managing BE and early EAC. The latter considered modification of lifestyle factors; screening and surveillance strategies; and medical, endoscopic and surgical interventions. To answer each question, the working party systematically reviewed the literature and developed a set of recommendations through consensus. Evidence underpinning each recommendation was rated according to quality and applicability.
This article is protected by copyright. All rights reserved.
Journal of Gastroenterology and Hepatology 01/2015; 30(5). DOI:10.1111/jgh.12913 · 3.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To develop a model of stress-induced senescence to study the hepatocyte senescence associated secretory phenotype (SASP).
Hydrogen peroxide treatment was used to induce senescence in the human HepG2 hepatocyte cell line. Senescence was confirmed by cytochemical staining for a panel of markers including Ki67, p21, heterochromatin protein 1β, and senescence-associated-β-galactosidase activity. Senescent hepatocytes were characterised by gene expression arrays and quantitative polymerase chain reaction (qPCR), and conditioned media was used in proteomic analyses, a human chemokine protein array, and cell migration assays to characterise the composition and function of the hepatocyte SASP.
Senescent hepatocytes induced classical markers of senescence (p21, heterochromatin protein 1β, and senescence-associated-β-galactosidase activity); and downregulated the proliferation marker, Ki67. Hepatocyte senescence induced a 4.6-fold increase in total secreted protein (P = 0.06) without major alterations in the protein profile. Senescence-induced genes were identified by microarray (Benjamini Hochberg-corrected P < 0.05); and, consistent with the increase in secreted protein, gene ontology analysis revealed a significant enrichment of secreted proteins among inducible genes. The hepatocyte SASP included characteristic factors such as interleukin (IL)-8 and IL-6, as well as novel components such as SAA4, IL-32 and Fibrinogen, which were validated by qPCR and/or chemokine protein array. Senescent hepatocyte-conditioned medium elicited migration of inflammatory (granulocyte-macrophage colony stimulating factor, GM-CSF-derived), but not non-inflammatory (CSF-1-derived) human macrophages (P = 0.022), which could contribute to a pro-inflammatory microenvironment in vivo, or facilitate the clearance of senescent cells.
Our novel model of hepatocyte senescence provides insights into mechanisms by which senescent hepatocytes may promote chronic liver disease pathogenesis.
[Show abstract][Hide abstract] ABSTRACT: Background and AimsThere is increasing need to identify individuals with advanced liver fibrosis, who are at risk of complications such as hepatocellular carcinoma. The commercially available Enhanced Liver Fibrosis (ELF) test provides a non-invasive assessment of fibrosis severity. This study was designed to determine the diagnostic accuracy of the manufacturer's cut-off value (≥9.8) in identifying advanced fibrosis.Methods
The relationship between ELF score and fibrosis was examined using serum collected at time of liver biopsy for investigation of liver disease, particularly viral hepatitis. Fibrosis was staged using a modified METAVIR score. If available, liver tissue was recut and stained with Sirius red to determine collagen proportional area and subsinusoidal fibrosis.ResultsELF score ≥9.8 had a sensitivity of 74.4% and specificity 92.4% for detecting advanced fibrosis. In the whole cohort (n=329), ELF score was more likely to incorrectly classify individuals if age was ≥45 years and METAVIR inflammatory grade was 2 or 3 (adjusted OR 3.71 and 2.62 respectively). In contrast, ELF score was less likely to misclassify individuals in the presence of steatosis (OR 0.37). Neither subsinusoidal fibrosis nor collagen proportional area explained the discordance in ELF score for patients with or without advanced fibrosis.Conclusion
Although ELF score ≥9.8 reliably identifies advanced fibrosis in patients with chronic liver disease, both age and inflammatory activity need to be considered when interpreting the result. Importantly, ELF score performed well in the presence of steatosis and could thus be helpful in the assessment of fatty liver disease.This article is protected by copyright. All rights reserved.
Liver international: official journal of the International Association for the Study of the Liver 12/2014; 35(6). DOI:10.1111/liv.12760 · 4.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The traditional serrated adenoma is the least common colorectal serrated polyp. The clinicopathological features and molecular drivers of these polyps require further investigation. We have prospectively collected a cohort of 200 ordinary and advanced traditional serrated adenomas and performed BRAF and KRAS mutational profiling, CpG island methylator phenotype analysis, and immunohistochemistry for a panel of 7 antibodies (MLH1, β-catenin, p53, p16, Ki67, CK7, and CK20) on all cases. The mean age of the patients was 64 years and 50% were female. Of the polyps, 71% were distal. Advanced histology (overt dysplasia or carcinoma) was present in 19% of cases. BRAF mutation was present in 67% and KRAS mutation in 22%. BRAF mutant traditional serrated adenomas were more frequently proximal (39% versus 2%; P≤0.0001), were exclusively associated with a precursor polyp (57% versus 0%; P≤0.0001), and were more frequently CpG island methylator phenotype high (60% versus 16%; P≤0.0001) than KRAS mutant traditional serrated adenomas. Advanced traditional serrated adenomas retained MLH1 expression in 97%, showed strong p53 staining in 55%, and nuclear β-catenin staining in 40%. P16 staining was lost in the advanced areas of 55% of BRAF mutant traditional serrated adenomas compared with 10% of the advanced areas of KRAS mutant or BRAF/KRAS wild-type traditional serrated adenomas. BRAF and KRAS mutant traditional serrated adenomas are morphologically related but biologically disparate polyps with distinctive clinicopathological and molecular features. The overwhelming majority of traditional serrated adenomas retain mismatch repair enzyme function indicating a microsatellite-stable phenotype. Malignant progression occurs via TP53 mutation and Wnt pathway activation regardless of mutation status. However, CDKN2A (encoding the p16 protein) is silenced nearly exclusively in the advanced areas of the BRAF mutant traditional serrated adenomas. Thus, the BRAF mutant traditional serrated adenoma represents an important precursor of the aggressive BRAF mutant, microsatellite-stable subtype of colorectal carcinoma.Modern Pathology advance online publication, 12 September 2014; doi:10.1038/modpathol.2014.122.
Modern Pathology 09/2014; 28(3). DOI:10.1038/modpathol.2014.122 · 6.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background Celiac disease (CeD) is a common gluten-sensitive autoimmune enteropathy. A gluten-free diet is an effective treatment, but compliance is demanding; hence, new treatment strategies for CeD are required. Objective Parasitic helminths hold promise for treating inflammatory disorders, so we examined the influence of experimental hookworm infection on the predicted outcomes of escalating gluten challenges in CeD subjects. Methods A 52-week study was conducted involving 12 adults with diet-managed CeD. Subjects were inoculated with 20 Necator americanus larvae, and escalating gluten challenges consumed as pasta were subsequently administered: (1) 10 to 50 mg for 12 weeks (microchallenge); (2) 25 mg daily + 1 g twice weekly for 12 weeks (GC-1g); and (3) 3 g daily (60-75 straws of spaghetti) for 2 weeks (GC-3g). Symptomatic, serologic, and histological outcomes evaluated gluten toxicity. Regulatory and inflammatory T cell populations in blood and mucosa were examined. Results Two gluten-intolerant subjects were withdrawn after microchallenge. Ten completed GC-1g, 8 of whom enrolled in and completed GC-3g. Primary outcomes: median villous height-to-crypt depth ratios (2.60-2.63; P =.98) did not decrease as predicted after GC-1g, and the mean IgA-tissue transglutaminase titers declined, contrary to the predicted rise after GC-3g. Secondary outcomes: quality of life scores improved (46.3-40.6; P =.05); celiac symptom indices (24.3-24.3; P =.53), intra-epithelial lymphocyte percentages (32.5-35.0; P =.47), and Marsh scores were unchanged by gluten challenge. Intestinal T cells expressing IFNγ were reduced following hookworm infection (23.9%-11.5%; P =.04), with corresponding increases in CD4+ Foxp3+ regulatory T cells (0.19%-1.12%; P =.001). Conclusions Necator americanus and gluten microchallenge promoted tolerance and stabilized or improved all tested indices of gluten toxicity in CeD subjects.
Journal of Allergy and Clinical Immunology 08/2014; 135(2). DOI:10.1016/j.jaci.2014.07.022 · 11.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chronic GVHD (cGVHD) is the major cause of late, nonrelapse death following stem cell transplantation and characteristically develops in organs such as skin and lung. Here, we used multiple murine models of cGVHD to investigate the contribution of macrophage populations in the development of cGVHD. Using an established IL-17-dependent sclerodermatous cGVHD model, we confirmed that macrophages infiltrating the skin are derived from donor bone marrow (F4/80+CSF-1R+CD206+iNOS-). Cutaneous cGVHD developed in a CSF-1/CSF-1R-dependent manner, as treatment of recipients after transplantation with CSF-1 exacerbated macrophage infiltration and cutaneous pathology. Additionally, recipients of grafts from Csf1r-/- mice had substantially less macrophage infiltration and cutaneous pathology as compared with those receiving wild-type grafts. Neither CCL2/CCR2 nor GM-CSF/GM-CSFR signaling pathways were required for macrophage infiltration or development of cGVHD. In a different cGVHD model, in which bronchiolitis obliterans is a prominent manifestation, F4/80+ macrophage infiltration was similarly noted in the lungs of recipients after transplantation, and lung cGVHD was also IL-17 and CSF-1/CSF-1R dependent. Importantly, depletion of macrophages using an anti-CSF-1R mAb markedly reduced cutaneous and pulmonary cGVHD. Taken together, these data indicate that donor macrophages mediate the development of cGVHD and suggest that targeting CSF-1 signaling after transplantation may prevent and treat cGVHD.