Cross Validation of the Monoclonal Antibody Das-1 in Identification of High-Risk Mucinous Pancreatic Cystic Lesions.

BACKGROUND & AIMS: Although pancreatic cystic lesions (PCLs) are frequently and incidentally detected, it is a challenge to determine their risk of malignancy. In immunohistochemical and enzyme-linked immunosorbent assay (ELISA) analyses of tissue and cyst fluid from pancreatic intraductal papillary mucinous neoplasms, the monoclonal antibody Das-1 identifies those at risk for malignancy with high levels of specificity and sensitivity. We aimed to validate the ability of Das-1 to identify high-risk PCLs in comparison to clinical guidelines and clinical features, using samples from a multicenter cohort. METHODS: We obtained cyst fluid samples of 169 PCLs (90 intraductal papillary mucinous neoplasms, 43 mucinous cystic neoplasms, and 36 non-mucinous cysts) from patients undergoing surgery at 4 tertiary referral centers (January 2010 through June 2017). Histology findings from surgical samples, analyzed independently and centrally re-reviewed in a blinded manner, were used as the reference standard. High-risk PCLs were those with invasive carcinomas, high-grade dysplasia, or intestinal-type intraductal papillary mucinous neoplasms with intermediate-grade dysplasia. An ELISA with Das-1 was performed in parallel using banked cyst fluid samples. We evaluated the biomarker's performance, generated area under the curve values, and conducted multivariate logistic regression using clinical and pathology features. RESULTS: The ELISA for Das-1 identified high-risk PCLs with 88% sensitivity, 99% specificity, and 95% accuracy, at a cutoff optical density value of 0.104. In 10-fold cross-validation analysis with 100 replications, Das-1 identified high-risk PCLs with 88% sensitivity and 98% specificity. The Sendai, Fukuoka, and American Gastroenterological Association guideline criteria identified high-risk PCLs with 46%, 52%, and 74% accuracy (P for comparison to Das-1 ELISA <.001). When we controlled for Das-1 in multivariate regression, main pancreatic duct dilation >5 mm (odds ratio, 14.98; 95% confidence interval, 2.63-108; P < .0012), main pancreatic duct dilation ≥1 cm (odds ratio, 47.9; 95% confidence interval, 6.39-490; P < .0001), and jaundice (odds ratio, 6.16; 95% confidence interval, 1.08-36.7; P = .0397) were significantly associated with high-risk PCLs. CONCLUSIONS: We validated the ability of an ELISA with the monoclonal antibody Das-1 to detect PCLs at risk for malignancy with high levels of sensitivity and specificity. This biomarker might be used in conjunction with clinical guidelines to identify patients at risk for malignancy.

Effect of Long-Term Mesalamine Therapy on Cancer-Associated Gene Expression in Colonic Mucosa of Patients with Ulcerative Colitis.

BACKGROUND: The role of 5-aminosalicylic acid (5-ASA or mesalamine) in the prevention of colorectal cancer in ulcerative colitis (UC) patients was reported, but the effect on molecular targets in UC colon mucosa is unknown. AIM: This observational study evaluates gene expression levels of 5-ASA targets using serial colon biopsy specimens from UC patients undergoing long-term 5-ASA therapy. METHODS: Transcript levels were compared between colonoscopic biopsy specimens collected from 62 patients at initial and final follow-up colonoscopy at 2-6 years. All patients had mild-to-moderate UC and were undergoing long-term 5-ASA maintenance. Stepwise multiple linear regression analyses were performed to correlate changes in transcript levels with therapeutic response (Mayo clinical score endoscopy and DAI and/or Nancy histopathology score) and nonclinical variables. RESULTS: The transcript levels of colorectal carcinogenesis-associated known 5-ASA target genes were significantly reduced after prolonged 5-ASA therapy (P < 0.005-0.03). Multiple linear regression models predicted significant association between transcript levels of Ki-67, NF-kB (p65), PPARγ, COX-2 and IL-8, CDC25A, and CXCL10 with duration of drug (5-ASA) exposure (P ≤ 0.05). Ki-67, NF-kB (p65), and CXCL10 transcripts were also correlated with reduced endoscopy sub-score (P ≤ 0.05). COX-2, IL-8, CDC25A, and TNF transcripts strongly correlated with DAI sub-scores (P ≤ 0.05). Only COX-2 and IL-8 transcript levels correlated (P ≤ 0.05) with Nancy histological score. CONCLUSION: This study provides molecular evidence of changes in carcinogenesis-related targets/pathways in colon tissue during long-term 5-ASA maintenance therapy that may contribute to the observed chemopreventive effects of 5-ASA in UC patients.

Barrett's metaplasia develops from cellular reprograming of esophageal squamous epithelium due to gastroesophageal reflux.

Gastroesophageal reflux disease (GERD) clinically predisposes to columnar Barrett's metaplasia (BM) in the distal esophagus. We demonstrate evidence supporting the cellular origin of BM from reprograming or transcommitment of resident normal esophageal squamous (NES) epithelial cells in response to acid and bile (A + B) exposure using an in vitro cell culture model. The hTERT-immortalized NES cell line NES-B10T was exposed 5 min/day to an A + B mixture for 30 wk. Morphological changes, mRNA, and protein expression levels for the inflammatory marker cyclooxygenase-2; the lineage-determining transcription factors TAp63 (squamous), CDX2, and SOX9 (both columnar); and the columnar lineage markers Villin, Muc-2, CK8, and mAb Das-1 (incomplete phenotype of intestinal metaplasia) were assessed every 10 wk. Markers of columnar lineage and inflammation increased progressively, while squamous lineage-determining transcriptional factors were significantly decreased both at the mRNA and/or protein level in the NES-B10T cells at/after A + B treatment for 30 wk. Distinct modifications in morphological features were only observed at/after 30 wk of A + B exposure. These changes acquired by the NES-B10T 30-wk cells were retained even after cessation of A + B exposure for at least 3 wk. This study provides evidence that chronic exposure to the physiological components of gastric refluxate leads to repression of the discernable squamous transcriptional factors and activation of latent columnar transcriptional factors. This reflects the alteration in lineage commitment of the precursor-like biphenotypic, NES-B10T cells in response to A + B exposure as the possible origin of BM from the resident NES cells.NEW & NOTEWORTHY This study provides evidence of the origins of Barrett's metaplasia from lineage transcommitment of resident esophageal cells after chronic exposure to gastroesophageal refluxate. The preterminal progenitor-like squamous cells alter their differentiation and develop biphenotypic characteristics, expressing markers of incomplete-type columnar metaplasia. Development of these biphenotypic precursors in vitro is a unique model to study pathogenesis of Barrett's metaplasia and esophageal adenocarcinoma.

Effects of Helicobacter pylori eradication on the development of metachronous gastric cancer after endoscopic treatment: analysis of molecular alterations by a randomised controlled trial.

BACKGROUND: Whether Helicobacter pylori eradication actually suppresses the development of metachronous gastric cancer (MGC) after endoscopic resection (ER) remains controversial. The aims of this study were to clarify (1) the molecular markers related to carcinogenesis in intestinal metaplasia (IM) by a cross-sectional study, and (2) the changes of those markers by an open-label, randomised controlled trial (RCT) of H. pylori treatment. METHODS: First, we evaluated microsatellite instability (MSI), the methylation status at hMLH1, CDKN2A and APC genes, and immunoreactivity using the monoclonal antibody (mAb) Das-1 in IM in the background mucosa of 131 patients who underwent ER for gastric neoplasia and 22 chronic gastritis cases (control). Next, we performed an RCT to evaluate the changes of MSI between the H. pylori-eradicated (n=19) and non-eradicated patients (n=17) at 1 year among the H. pylori-positive patients. RESULTS: Microsatellite instability and mAb Das-1 reactivity showed significantly higher incidences in both the H. pylori-positive and -negative patients compared with the control group, thus suggesting that MSI and mAb Das-1 reactivity are associated with gastric neoplasia (OR=5.06 for MSI; OR=2.51 for mAb Das-1 reactivity). The RCT showed that H. pylori eradication did not provide significant reversals of any molecular alterations including MSI (the primary end point) and other methylation statuses and mAb Das-1 reactivity (secondary end points). CONCLUSIONS: H. pylori eradication did not produce significant changes in the molecular alterations related to carcinogenesis, suggesting that H. pylori treatment may not prevent the development of MGC in background mucosa with IM.

Experience With Anti-TNF-α Biologic Agents in Succession in Patients With Crohn's Disease: A Retrospective Analysis of a Single Center.

GOALS: Our aim was to identify and compare the effectiveness of antitumor necrosis factor biologics when used as initial agents and when used in succession for the treatment of moderate to severe Crohn's disease (CD). BACKGROUND: Studies directly comparing the efficacy of biologics are lacking. When one biologic loses efficacy, patients are often treated with an alternate biologic. The effectiveness of this strategy has not been thoroughly investigated. STUDY: This is a retrospective cohort study from a database of 153 patients with CD treated with infliximab, adalimumab, or certolizumab pegol. Response rates determined by physician global assessment were compared between biologics when given as initial agents and after failure of 1 or 2 prior biologics. RESULTS: There were no significant differences in response between infliximab (64.5%), adalimumab (60.0%), and certolizumab pegol (66.7%) when given as initial biologics. As second-line or third-line agents after prior biologic failure, there was a trend toward increased response with infliximab (83.3%) versus adalimumab (52.7%) and certolizumab pegol (59.4%); however, this did not meet statistical significance. After failure or loss of response of 2 previous biologics, use of a third biologic was still effective with a response rate of 54.2%. CONCLUSIONS: All 3 biologics have similar efficacy in the treatment of CD when given as initial agents. Infliximab has a trend toward increased response after prior biologic failure; however, this did not meet statistical significance. Even after loss of response or failure of 2 previous biologics, trial of a third alternate biologic is an effective strategy.

mAb Das-1 is specific for high-risk and malignant intraductal papillary mucinous neoplasm (IPMN).

OBJECTIVE: Intraductal papillary mucinous neoplasm (IPMN) consists of four epithelial subtypes that correlate with histological grades and risks for malignant transformation. mAb Das-1 is a monoclonal antibody against a colonic epithelial phenotype that is reactive to premalignant conditions of the upper GI tract. We sought to assess the ability of mAb Das-1 to identify IPMN with high risk of malignant transformation. DESIGN: mAb Das-1 reactivity was evaluated in 94 patients with IPMNs by immunohistochemistry. Lesional fluid from 38 separate patients with IPMN (n=27), low-grade non-mucinous cystic neoplasms (n=7) and pseudocysts (n=4) was analysed by ELISA and western blot. RESULTS: Immunohistochemistry-Normal pancreatic ducts were non-reactive and low-grade gastric-type IPMN (IPMN-G) (1/17) and intermediate-grade IPMN-G (1/23) were minimally reactive with mAb Das-1. In contrast, mAb Das-1 reactivity was significantly higher in high-risk/malignant lesions (p<0.0001) including: intestinal-type IPMN with intermediate-grade dysplasia (9/10); high-grade dysplasia of gastric (4/7), intestinal (12/12), oncocytic (2/2) and pancreatobiliary types (2/2); and invasive tubular (8/12), colloid (7/7) and oncocytic (2/2) carcinoma. The sensitivity and specificity of mAb Das-1 for high-risk/malignant IPMNs were 85% and 95%, respectively. Lesional fluid-Samples from low- and intermediate-grade IPMN-G (n=9), and other low-grade/benign non-mucinous lesions demonstrated little reactivity with mAb Das-1. Conversely, cyst fluid from high-risk/malignant IPMNs (n=18) expressed significantly higher reactivity (p<0.0001). The sensitivity and specificity of mAbDas-1 in detecting high-risk/malignant IPMNs were 89% and 100%, respectively. CONCLUSIONS: mAb Das-1 reacts with high specificity to tissue and cyst fluid from high-risk/malignant IPMNs and thus may help in preoperative clinical risk stratification.

Musculoskeletal manifestations in inflammatory bowel disease: a revisit in search of immunopathophysiological mechanisms.

Inflammatory bowel diseases are chronic inflammatory disorders of multiple organ systems, primarily involving the gut, with chronic relapsing and remitting course. Musculoskeletal involvement is the most common extraintestinal manifestation. Distinct cell-mediated and humoral immunopathophysiological mechanisms have been identified underlying gut and joint inflammation in patients with inflammatory bowel disease and arthritis. Genetic polymorphisms in genes coding for NOD2 and IL12/IL23 complex lead to impaired antigenic handling in the gut and local immune dysregulation. The gut-synovial axis hypothesis implicates both environmental and host factors acting as triggers to initiate inflammation in genetically predisposed individuals, leading to priming of Th1 and Th17 lymphocytes in the gut and subsequent homing to the synovial tissue. Similar to gut, antibody-dependent cell-mediated cytotoxicity and complement-mediated cell lysis may also contribute to the joint damage. Involvement of peripheral joints occurs in 2 distinct manners, one being oligoarticular asymmetric arthritis associated with active disease and the other being polyarticular symmetric involvement of small joints. The axial involvement may include asymptomatic sacroiliitis, inflammatory back pain, and ankylosing spondylitis, running an independent clinical course. Noninflammatory involvement of the musculoskeletal system may present as osteopenia, osteonecrosis, fibromyalgia, or myopathies, leading to significant impact on quality of life.

High resolution integrative analysis reveals widespread genetic and epigenetic changes after chronic in-vitro acid and bile exposure in Barrett's epithelium cells.

Barrett's epithelium (BE) is a premalignant condition resulting from chronic gastroesophageal reflux that may progress to esophageal adenocarcinoma (EAC). Early intervention holds promise in preventing BE progression. However, identification of high-risk BE patients remains challenging due to inadequate biomarkers for early diagnosis. We investigated the effect of prolonged chronic acid and bile exposure on transcriptome, methylome, and mutatome of cells in an in-vitro BE carcinogenesis (BEC) model. Twenty weeks acid and bile exposed cells from the BEC model (BEC20w) were compared with their naïve predecessors HiSeq Illumina based RNA sequencing was performed on RNA from both the cells for gene expression and mutational analysis. HELP Tagging Assay was performed for DNA methylation analysis. Ingenuity pathway, Gene Ontology, and KEGG PATHWAY analyses were then performed on datasets. Widespread aberrant genetic and epigenetic changes were observed in the BEC20w cells. Combinatorial analyses revealed 433 from a total of 863 downregulated genes had accompanying hypermethylation of promoters. Simultaneously, 690 genes from a total of 1,492 were upregulated with accompanying promoter hypomethylation. In addition, 763 mutations were identified on 637 genes. Ingenuity pathway analysis, Gene Ontology, and KEGG PATHWAY analyses associated the genetic and epigenetic changes in BEC20w cells with cellular and biological functions. Integration of high resolution comparative analyses of naïve BAR-T and BEC20w cells revealed striking genetic and epigenetic changes induced by chronic acid and bile exposure that may disrupt normal cellular functions and promote carcinogenesis. This novel study reveals several potential targets for future biomarkers and therapeutic development.

Biomarkers predicting development of metachronous gastric cancer after endoscopic resection: an analysis of molecular pathology of Helicobacter pylori eradication.

Metachronous gastric cancer (MGC) after endoscopic resection (ER) of gastric cancer still occurs to some degree even after Helicobacter pylori (H. pylori) treatment. We evaluated whether two biomarkers related to carcinogenesis expressed in intestinal metaplasia (IM) become predictors for MGC development after eradication. We performed a hospital-based, case-control study of 75 patients, including 50 mucosal cancer patients who had undergone ER (Group DYS), and 25 age- and sex-matched chronic gastritis patients for whom H. pylori had been successfully eradicated (control). Additionally, Group DYS patients were divided into two groups: 25 successfully H. pylori-eradicated (eradicated group) and 25 un-eradicated patients (persistent group). All patients were followed for 1 year. We analyzed microsatellite instability (MSI) and immunoperoxidase assays using a monoclonal antibody for the colonic phenotype (Das-1). Both MSI and Das-1 reactivity in IM were significantly higher in Group DYS than in the control (p < 0.05 and p < 0.01, respectively). MSI and Das-1 reactivity were strong and independent predictors for gastric cancer (OR = 7.09, 95% CI 1.27-39.6, p = 0.03 for MSI and OR = 4.96, 95% CI 1.64-15.0, p = 0.005 for Das-1 reactivity). The incidence of MSI tended to decrease in the eradicated group (p = 0.07), but not in the persistent group. The Das-1 immunoreactivity in IM also declined in both the eradicated group and the control. Interestingly, all MGCs after ER were positive for MSI or Das-1 reactivity. MSI or Das-1 reactivity in IM strongly predicts the development of MGC. Patients in whom these biomarkers persist after eradication may therefore have a high risk of developing MGC.

Evaluation of a U.S. National Cohort to Determine Utilization in Colectomy Rates for Ulcerative Colitis Among Ethnicities.

BACKGROUND: Colectomy is the curative management for ulcerative colitis (UC). Multiple studies have reported racial disparities for colectomy before the advent of anti-TNF alpha agents. The aim of this study was to describe racial and geographic differences in colectomy rates among hospitalized patients with UC after anti-TNF therapy was introduced. METHODS: We examined all patients discharged from the hospital between 2010 and 2014 with a primary diagnosis of UC or of complications of UC. The data were evaluated for race and colectomy rates among the hospitalized patients with UC. RESULTS: The unadjusted national colectomy rate among hospitalized patients with UC between 2010 and 2014 was 3.90 per 1000 hospitalization days (95% confidence interval, 3.72-4.08). The undajusted colectomy rates in African American (2.33 vs 4.35; P < 0.001) and Hispanic patients (3.99 vs 4.35; P ≤ 0.009) were considerably lower than those for White patients. After adjustment for confounders, the incidence rate ratio for African American as compared to White patients was 0.43 (95% confidence interval, 0.32-0.58; P < 0.001). Geographic region of the United States also showed significant variation in colectomy rates, with western regions having the highest rate (4.76 vs 3.20; P < 0.001). CONCLUSIONS: Racial and geographical disparities persist for the rate of colectomy among hospitalized patients with UC. The national database analysis reveals that colectomy rates for hospitalized African American and Hispanic patients were lower than those for White patients. Further studies are important to determine the social and biologic foundations of these disparities.

Transformation of benign Barrett's epithelium by repeated acid and bile exposure over 65 weeks: a novel in vitro model.

The mechanism by which gastroesophageal reflux promotes metaplasia→dysplasia→carcinoma is unknown. The aim of the study is to determine if repeated exposure to acid and bile confers a tumorigenic phenotype in a telomerase (hTERT)-immortalized benign Barrett's cell line (BAR-T). BAR-T cells were exposed to acid (pH 4) (A) and bile salt (200 µM glycochenodeoxycholic acid) (B) daily for 5 min up to 65+ weeks. The control cells were grown in parallel without any A or B treatment. Cell morphology, proliferation, transformation, and molecular changes in the gene expression for COX-2, TC22, p53 and p53 target genes were analyzed at 8-12 weeks intervals. At 46 weeks BAR-T cells exposed to (A+B) showed distinct phenotypic changes: forming clusters and acini, and at 65 weeks displayed foci in monolayer, and formed distinct colonies in soft agar. Untreated cells did not show any such changes. In A+B-treated BAR-T cells, COX-2 mRNA increased 10- to 20-fold, TC22 mRNA increased by 2- to 3-fold at 22-65 weeks, p53, MDM2, PERP, and p21mRNA increased 2.5-, 6.4-, 4-, and 2.6-fold respectively when compared to untreated cells at 34 weeks. However, at 58 weeks onward, there was a sharp decline of p53 and its target genes to the baseline level. At 65 weeks A+B-treated BAR-T cells formed tumor in nude mice whereas untreated cells did not. We demonstrate a novel in vitro model of transformation of a benign Barrett's cell line following repeated exposure to A+B over the course of 65 weeks.

mAb Das-1 recognizes 3'-Sulfated Lewis A/C, which is aberrantly expressed during metaplastic and oncogenic transformation of several gastrointestinal Epithelia.

INTRODUCTION: Multiple previous studies have shown the monoclonal antibody Das-1 (formerly called 7E12H12) is specifically reactive towards metaplastic and carcinomatous lesions in multiple organs of the gastrointestinal system (e.g. Barrett's esophagus, intestinal-type metaplasia of the stomach, gastric adenocarcinoma, high-grade pancreatic intraepithelial neoplasm, and pancreatic ductal adenocarcinoma) as well as in other organs (bladder and lung carcinomas). Beyond being a useful biomarker in tissue, mAb Das-1 has recently proven to be more accurate than current paradigms for identifying cysts harboring advanced neoplasia. Though this antibody has been used extensively for clinical, basic science, and translational applications for decades, its epitope has remained elusive. METHODS: In this study, we chemically deglycosylated a standard source of antigen, which resulted in near complete loss of the signal as measured by western blot analysis. The epitope recognized by mAb Das-1 was determined by affinity to a comprehensive glycan array and validated by inhibition of a direct ELISA. RESULTS: The epitope recognized by mAb Das-1 is 3'-Sulfo-Lewis A/C (3'-Sulfo-LeA/C). 3'-Sulfo-LeA/C is broadly reexpressed across numerous GI epithelia and elsewhere during metaplastic and carcinomatous transformation. DISCUSSION: 3'-Sulfo-LeA/C is a clinically important antigen that can be detected both intracellularly in tissue using immunohistochemistry and extracellularly in cyst fluid and serum by ELISA. The results open new avenues for tumorigenic risk stratification of various gastrointestinal lesions.

Recurring Translocations in Barrett's Esophageal Adenocarcinoma.

Barrett's esophagus (BE) is a premalignant metaplasia in patients with chronic gastroesophageal reflux disease (GERD). BE can progress to esophageal adenocarcinoma (EA) with less than 15% 5-year survival. Chromosomal aneuploidy, deletions, and duplication are early events in BE progression to EA, but reliable diagnostic assays to detect chromosomal markers in premalignant stages of EA arising from BE are lacking. Previously, we investigated chromosomal changes in an in vitro model of acid and bile exposure-induced Barrett's epithelial carcinogenesis (BEC). In addition to detecting changes already known to occur in BE and EA, we also reported a novel recurring chromosomal translocation t(10:16) in the BE cells at an earlier time point before they undergo malignant transformation. In this study, we refine the chromosomal event with the help of fluorescence microscopy techniques as a three-way translocation between chromosomes 2, 10, and 16, t(2:10;16) (p22;q22;q22). We also designed an exclusive fluorescent in situ hybridization for esophageal adenocarcinoma (FISH-EA) assay that detects these chromosomal breakpoints and fusions. We validate the feasibility of the FISH-EA assay to objectively detect these chromosome events in primary tissues by confirming the presence of one of the fusions in paraffin-embedded formalin-fixed human EA tumors. Clinical validation in a larger cohort of BE progressors and non-progressors will confirm the specificity and sensitivity of the FISH-EA assay in identifying malignant potential in the early stages of EA.

mAb Das-1 identifies pancreatic ductal adenocarcinoma and high-grade pancreatic intraepithelial neoplasia with high accuracy.

Pancreatic intraepithelial neoplasia (PanIN) is a microscopic precursor lesion to pancreatic ductal adenocarcinoma (PDAC); however, there are few biomarkers that segregate high-grade PanIN/PDAC from low-grade PanIN lesions. mAb Das-1 is a monoclonal antibody against a colonic epithelial antigen that is reactive to premalignant conditions of the upper gastrointestinal tract including Barrett's esophagus, incomplete-type gastric intestinal metaplasia, and intraductal papillary mucinous neoplasm of the pancreas at high risk of malignancy. We sought to examine a role for Das-1 expression in differentiating high-grade PanIN/PDAC from low-grade PanIN lesions. We examined surgical specimens from 86 patients and 2 autopsied pancreata (74 with and 14 without PDAC) with 107 distinct PanIN lesions, 74 PDAC cases, and 32 associated lymph node metastases, with internal controls of normal pancreatic ducts observed in 56 cases. All of the normal pancreatic duct controls (0/56) and low-grade PanIN (0/95) lesions were nonreactive to Das-1. Das-1 expression among high-grade PanIN (7/12, 58%), PDAC (55/74, 74%), and lymph node metastasis (21/32, 66%) cases was significantly higher (p < 0.0001). Clinicopathologically, Das-1 reactivity was significantly correlated with nodal metastasis (p = 0.021). Overall, the sensitivity, specificity, and accuracy of Das-1 in segregating high-grade PanIN/PDAC from low-grade PanIN lesions and normal ducts were 72%, 100%, and 90%, respectively. Thus, mAb Das-1 reacts with high specificity with high-grade PanIN and PDAC and may help in preoperative diagnosis and/or clinical risk stratification.

Inducing and maintaining remission in ulcerative colitis: role of high-dose, extended-release mesalamine.

In mild-to-moderate inflammatory bowel disease, particularly ulcerative colitis, 5-aminosalicylic acid (5-ASA) remains a cornerstone of therapy. Sulfasalazine, originally synthesized in 1940 as an arthritis treatment for Sweden's King Gustaf V, is an azo-linked compound between 5-ASA and sulfapyridine. This medication was soon discovered to be effective in treating ulcerative colitis. However, dose-related side effects of the sulfapyridine moiety led to considerable effort in developing medications to deliver 5-ASA to the desired parts of the intestine. The newest generation of 5-ASA medications allows high-dose medication delivery with decreased pill burden, thereby improving patient compliance. This review will describe the pharmacokinetics of various 5-ASA preparations, particularly focusing on high-dose formulations and their role in therapy; will examine current scientific literature; and will review clinical outcomes and safety profiles.

Comparison of Disease Phenotypes and Clinical Characteristics Among South Asian and White Patients with Inflammatory Bowel Disease at a Tertiary Referral Center.

BACKGROUND: The prevalence and clinical features of inflammatory bowel disease (IBD) vary among different racial and ethnic groups. The aim of this study was to compare the clinical and phenotypic features of Crohn's disease (CD) and ulcerative colitis (UC) in South Asian patients living in the United States with those of a white cohort. METHODS: The demographic, clinical, and phenotypic characteristics of 73 South Asian patients (31 CD and 42 UC) who presented initially to our tertiary referral center from 2012 to 2016 and had subsequent follow-up were retrospectively compared with those of 408 consecutive white patients (245 CD and 163 UC). RESULTS: South Asian IBD patients were significantly more likely to have UC (58.0% vs 40.0%; P = 0.005) than white patients. South Asians with CD were less likely to have a family history of IBD (9.7% vs 26.9%; P = 0.037) and required fewer CD-related surgeries (22.5% vs 46.1; P = 0.012). South Asians were also less likely to be active or former smokers in both the CD (P = 0.004) and UC (P = 0.020) groups. South Asians with UC had a higher incidence of Clostridium difficile infection compared with white patients (19.0% vs 8.6%; P = 0.050). CONCLUSIONS: A cohort of South Asian patients with IBD were more likely to have UC and had differing family and tobacco risk factors, requirements for surgery, and Clostridium difficile infection rates as compared with white patients.

Mesalamine suppresses the expression of TC22, a novel tropomyosin isoform associated with colonic neoplasia.

Although a protective role for mesalamine against colon cancer in ulcerative colitis has been shown epidemiologically, its molecular mechanism is unknown. We cloned and sequenced a novel human tropomyosin (hTM) isoform, TC22, which is an alternatively spliced variant of normal epithelial hTM isoform 5 (hTM5), identical apart from 25 C-terminal amino acids. TC22 is expressed in 100% of colorectal carcinoma but is not expressed in normal colon epithelial cells. To explore a molecular mechanism of chemoprevention, we examined the effect of mesalamine on TC22 expression using LS180 colon cancer cells. Expression of hTM5 and TC22 was investigated at the protein and gene levels by fluorescence-activated cell sorting and real-time reverse transcription-polymerase chain reaction. Small interference RNA (siRNA) against the TC22 variant were transfected into LS180 colon cancer cells, reducing protein and transcript levels by 45 to 50%. Mesalamine or sulfasalazine (2 mM), but not sulfapyridine, significantly (p < 0.02-0.006) reduced the expression of the TC22 transcript and significantly (p < 0.05 to <0.0002) reduced the expression of TC22 protein in a dose-dependent and reversible manner. Rosiglitazone, a specific peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist, similarly and significantly (p < 0.002) reduced TC22 protein expression. A polymerase chain reaction array of 84 cancer-related genes performed on TC22 siRNA-transfected cells demonstrated a significant (more than two times) change in targets involved in apoptosis, adhesion, angiogenesis, and tissue remodeling. We conclude that mesalamine, sulfasalazine, and rosiglitazone significantly reduced the cellular expression of TC22, implicating PPARgamma in this modulation. Similar suppression of TC22 by siRNA produced gene level changes on several critical carcinogenic pathways. These findings suggest a novel antineoplastic molecular effect of mesalamine.

Effects of Helicobacter pylori infection on genetic instability, the aberrant CpG island methylation status and the cellular phenotype in Barrett's esophagus in a Japanese population.

Genetic or epigenetic alterations in Barrett's esophagus (BE) with/without Helicobacter pylori (H. pylori) infection remain unclear. We examined the effects of H. pylori infection on genetic instability (GIN), the CpG island methylation status and a biomarker related to BE carcinogenesis. We analyzed 113 Japanese individuals with endoscopically suspected BE. The patients included, Group CLE (n = 25): no specialized intestinal metaplasia (SIM) in a columnar lined epithelium (control); Group BE (n = 88): all had SIM. Microsatellite instability and a loss of heterozygosity as GIN, the methylation status at hMLH1, E-cadherin, p16 and APC, and immunoreactivity using a monoclonal antibody (mAb) Das-1, which specifically reacts with BE, were evaluated. Nine additional patients with BE were prospectively followed up for 2 years after successful H. pylori eradication. The frequency of GIN, methylation at E-cadherin and APC, and mAb Das-1 reactivity in Group BE was significantly higher than that in Group CLE (p < 0.0001, p < 0.0001 and p < 0.005, and p < 0.0001, respectively). Furthermore, GIN, E-cadherin methylation and mAb Das-1 reactivity showed a significantly higher incidence in patients with H.pylori infection than in those without H. pylori infection (p < 0.01, p < 0.005, and p < 0.01, respectively). Interestingly, the patients from Group BE were observed to change to a stable state of molecular alterations in 60% for GIN, 42.9% for E-cadherin methylation and 55.6% for APC methylation, or a reduction of mAb Das-1 reactivity was noted in 25% following eradication. H. pylori infection may therefore affect these molecular alterations associated with the pathogenesis of BE, to some degree, in the Japanese population.

Antibody to tropomyosin isoform 5 and complement induce the lysis of colonocytes in ulcerative colitis.

OBJECTIVES: Tropomyosins (TMs) are cytoskeletal microfilament proteins present in all eukaryotic cells. Human TM isoform 5 (hTM5) is the predominant isoform in colonic epithelial cells. Antibodies against hTM5 are found both in the sera and in the mucosa of patients with ulcerative colitis (UC) but not Crohn's disease (CD). We investigated whether anti-hTM5 autoantibodies are pathogenic. METHODS: Normal-appearing colonic mucosal biopsy specimens were incubated with autologous serum. After 45 min, deposition of the complement component C3b was identified by indirect immunofluorescence assay (IFA). Additional specimens were incubated with autologous serum fixed in formalin, and their architecture was examined by hematoxylin and eosin (H&E) staining. RESULTS: For 79% of UC patients, autologous serum caused C3b staining along the colonic epithelium. Recombinant hTM5 or anti-hTM5 monoclonal antibody blocked serum-induced C3b deposition. Immunoglobulin G (IgG) antibody and affinity-purified anti-hTM5 IgG antibody from UC sera with complement caused C3b deposition, indicating specificity of hTM5 as an autoantigen. When analyzed by H&E staining, sera obtained from 71% of UC patients caused a significant loss of epithelium. This process was inhibited by Fc fragments, indicating that it is complement mediated. With medium, normal, or CD serum, there was no C3b deposition or morphological changes of the colonic epithelium, indicating disease specificity. The ileal mucosa was not affected by UC sera, suggesting specificity for the colon. In UC mucosa, expression of hTM5 increased. CONCLUSIONS: hTM5 acts as an autoantigen in UC. hTM5-specific IgG autoantibody in sera from UC patients induces C3b deposition and destruction of colonic epithelial cells, suggesting a direct pathogenic effect. If used as a diagnostic test to distinguish UC from CD, IFA would have 79% sensitivity and 100% specificity. Development of blocking antibodies may lead to novel therapies.