- Email: [email protected]
M1098 The Serum Metabolome in Inflammatory Bowel Disease
showed an accuracy of 87,3%, sensitivity of 90,2% and specificity of 83,6% for active disease. The pathological signs of the disease showed strong correlation with the CDAI score in MREG (r =0.69). Conclusion: It has been observed that the MRI technique with oral contrast administration is an accurate tool in detecting inflammatory activity. The relatively safe contrast medium and a negligible radiation exposure are the main reasons why MREG should be used as a preferred method for monitoring of patients with Crohn's disease.
M1097
Background: Some patients with mildly to moderately active ulcerative colitis (UC) fail to respond to first line therapy with aminosalicylates. In addition to disease behavior and severity, both transit time and lumenal pH have been proposed as mechanisms limiting the delivery of drug. Previous studies of the pH in patients with UC have been limited by available technology, small sample sizes and heterogeneous patient types. In order to explore physiologic explanation for therapeutic non-response, we used a new device (Smartpill pH.pTM, Buffalo, NY) to measure pH and transit time in patients with mildly to moderately active UC. Methods: Patients diagnosed clinically, endoscopically and histologically with UC who had mildly or moderately active disease by the ACG Practice Guidelines were recruited. These patients consumed a standardized breakfast before swallowing the Smartpill pH.pTM capsule. pH, temperature, pressure, and transit time of the GI tract were recorded. Location in the GI tract was determined by previously validated changes in the pH, motility and temperature. Simple summative statistics were performed. Results: Ten UC patients were recruited (9 male, median disease duration 6 y: range 1-32 y). Four patients had extensive colitis, 6 patients had distal colitis. UC activity was mild in five and moderate in five. pH and transit times for the portions of the GI tract are in Table 1. All patients achieved a lumenal pH of ≥6.0 for a minimum of 120 minutes. However, one patient never achieved a pH of 7.0 and six patients did not maintain a pH of ≥7.0 for longer than 120 minutes. Patients with distal colitis had a combined small and large bowel transit time of mean 1211 min (SD +/-722 min) while patients with extensive colitis had a mean small/large bowel transit of 705 min (SD +/- 998 min) (p=NS). There were no complications with this device. Conclusions: We have demonstrated the utility of the Smartpill pH.pTM capsule to measure pH and transit time in patients with mildly to moderately active UC, and demonstrated that six of ten patients failed to achieve a sustained pH level needed for dissolution of some delayed-release 5-ASA preparations. This device and these observations provide opportunities for future assessment and individualized therapies. pH and Transit Time in 10 patients with active UC
M1095 Is Ileoanal Pouch Surveillance Necessary to Detect Neoplasia After Restorative Proctocolectomy for Ulcerative Colitis? Frank J. van den Broek, Malaika S. Vlug, Kristien M. Tytgat, Susanne van Eeden, Cyriel Ponsioen, Pieter Stokkers, Paul Fockens, Willem Bemelman, Evelien Dekker Introduction: Patients with ulcerative colitis (UC) have an increased risk of developing colorectal cancer, especially in case premalignant neoplasia is present. Restorative proctocolectomy (RPC) is recommended in these cases. A recent systematic review of observational studies suggested that UC patients with an ileoanal pouch anastomosis still had a risk of neoplasia, either inside the ileoanal pouch or in the rectal cuff. The aim of this prospective study was to assess the prevalence of neoplasia in UC patients who have undergone RPC. Methods: Patients with UC who underwent RPC from 1988-2008 are being invited for surveillance endoscopy of their ileoanal pouch. The afferent and blind ileal loop, ileoanal pouch and rectal cuff are examined by both standard endoscopy and methylene blue (0.1%) chromoendoscopy. Mucosal abnormalities are being sampled and 4 random biopsies are taken from the afferent and blind ileal loop, pouch and rectal cuff each. Results: Thus far, 25 patients (12 male, mean 47 yrs) have undergone surveillance endoscopy of their ileoanal pouch. The mean time between RPC and pouch surveillance was 7.9 (median 5.3; range 1-20) yrs; including 6 patients with an interval of >10 yrs. The RPC resection specimen contained indefinite neoplasia in 11 (44%) cases, low grade neoplasia in 9 (36%), high grade neoplasia in 4 (16%) and invasive cancer in 1 (4%). The endoscopic protocol led to targeted biopsies of 14 abnormalities in the afferent ileal loop, 1 in the blind ileal loop, 4 in the pouch and 6 in the rectal cuff. In addition, a total of 392 random biopsies were taken. Only in one patient (4%) low grade neoplasia was detected in several adenoma-like lesions in the rectal cuff which were detected by targeted biopsies during standard endoscopy. In this single patient (male; 53 yrs of age) the previous RPC resection specimen contained indefinite neoplasia, there was no history of pouchitis, and the surveillance endoscopy was performed 4.7 years after the RPC. Conclusion: The interim results of this study demonstrate that the yield of endoscopic surveillance for the detection of neoplasia in the ileoanal pouch after RPC is 0%, and in the rectal cuff this is 4%. As the time interval between the RPC and surveillance endoscopy of our study population is relatively long, it appears that a surveillance endoscopy once-only within 5 yrs of the RPC in patients with (at least indefinite) neoplasia of the resection specimen would be sufficient to detect possible neoplasia.
M1098 The Serum Metabolome in Inflammatory Bowel Disease Garrett C. Zella, Danny C. Alexander, Jeffrey Shuster, Bruce E. Sands, Joshua R. Korzenik
M1096
Background: Metabolomic analysis is the global, non-targeted profiling of small molecules found in biological tissues and fluids. Metabolomics serves as a valuable discovery platform to uncover new biomarkers relevant to disease, therapeutic response, and genetic variation. Small molecules from the serum metabolome potentially represent an early and non-invasive source of biomarkers for the diagnosis of various aspects of inflammatory bowel disease (IBD). We aimed to discover potential biomarkers in serum which distinguish Crohn's disease (CD) from ulcerative colitis (UC) and differentiate active from inactive disease. Methods: A total of 174 serum samples were assayed. Samples were obtained as part of the Prospective Registry in IBD Study at Massachusetts General Hospital (PRISM). Each patient was phenotyped and a disease activity score was assessed using the Harvey Bradshaw Index in CD or the Simple Clinical Colitis Activity Index in UC. The samples represented patients with active CD (n = 50), inactive CD (n = 51), active UC (n = 36), or inactive UC (n = 37). A subset of each disease group included matched sample pairs from individual patients taken during active and inactive disease states. All serum samples were subjected to metabolomic analysis on three mass spectrometry platforms, GC-MS, LC-MS-POS, and LC-MS-NEG. Compounds were identified, categorized by metabolic pathway, and their integrated ion peak values determined in each sample. Data were statistically analyzed using Welsh's two-sample t-test and Random Forest classification. Results: A total of 438 compounds were detected, of which 211 could be identified by comparison to a library entry based on an authentic purified standard. Compounds from most major biochemical pathways were represented in the dataset. Analysis of data revealed significant statistical differences between the CD and UC metabolomes, many of which were informative even in patients with inactive disease. Several biomarkers were able to classify CD sub-types related to ileal involvement, while other classes of compounds statistically distinguished inactive from active disease, especially for CD. Conclusion: The serum metabolome of patients with CD and UC differ significantly and may yield small-molecule biomarkers, singly or in combination, which are diagnostic of IBD types and sub-types and which may distinguish between active and inactive disease non-invasively.
Proteomic Analysis of Colonic Submucosa Differentiates Crohn's and Ulcerative Colitis Amosy E. M'Koma, Erin H. Seeley, Paul E. Wise, Mary K. Washington, David A. Schwartz, Alan J. Herline, Roberta L. Muldoon, Richard M. Caprioli PURPOSE: Since treatment approaches for Crohn's (CC) and Ulcerative colitis (UC) differ, accurate diagnosis is of paramount importance, but this cannot be made accurately in up to 30% of inflammatory bowel disease (IBD) patients because their histological and clinical features often overlap. Understanding the molecular differences that underlie these features may help diagnostic accuracy as well as clarify the etiology of IBD. Our aim was to clarify proteomic differences between the colonic tissue layers in UC and CC through pilot analyses. METHODS: Fresh frozen colon resection specimens were retrieved. Colitis diagnoses were reconfirmed by a blinded gastrointestinal pathologist. Three sample subtype groups were examined as follows: inflamed mucosa (CC [n=18] vs. UC [n=24]); inflamed submucosa (CC [n=20] vs. UC [n=22]), and uninflamed submucosa (CC [n=17] vs. UC [n=21]). Matrix assisted laser desorption/ionization mass spectrometry (MALDI MS) was used to profile the proteome of the individual colonic tissue layer compartments. Frozen tissues were sectioned at ~10-15μm for mounting onto target plates. Histology of a serial section was used to guide matrix placement on the tissue section. Sinapinic acid was used to give the best combination of uniform crystal coverage and signal quality for direct tissue protein analysis. After preprocessing to remove background noise, subtype tissue spectra were averaged from multiple analyses from various sites in the designated layers of each individual specimen's mucosa and submucosa. Pair-wise comparisons of the subsets were performed using Leave One Out Cross-Validation (LOOCV) and Weighted-Flexible Compound Covariate (WFCC) statistical methods. RESULTS: Several mass-to-charge ratio (m/z) values discriminated CC vs. UC (p< 0.0001). Analyses of inflamed and uninflamed submucosa yielded 2 and 3 discrete m/z values, respectively, with the best results in cross-validation tests with error rate ~20% (considered a good classifier). These proteomic peaks, therefore, provided ~80% accuracy. Each individual sample displayed these different submucosal values as well. The inflamed mucosa provided 3 discriminating m/z peaks between CC and UC with an average accuracy but did not reach statistical significance. CONCLUSION: Significant discriminatory m/z values were identified in these pilot proteomic analyses of both inflamed and uninflamed submucosa from UC vs. CC colonic specimens, while the inflamed mucosa showed no significant differentiating values. As the submucosa is uninvolved in UC further analyses and protein identification may provide differentiating biomarkers that would aid in diagnosis and treatment for UC/CC
M1099 The Role of MR Enterography for Detection of Enteral Fistulas in Crohn's Disease; Correlation with Radiological and Surgical Findings Dorota Mankowska-Wierzbicka, Katarzyna Katulska, Wlodzimierz Paprzycki, Marcin Kucharski, Ludwika Jakubowska-Burek, Krzysztof Linke, Agnieszka DobrowolskaZachwieja Purpose: Crohn's disease (CD) is a lifelong disease arising from an interaction between genetic and environmental factors. Crohn's disease pathogenesis is characterized by two main mechanisms, causing transmural lesions of the bowel wall and an excessive fibrogenic response . CD is a chronic inflammatory disease of the gastrointestinal tract characterized by aphthous ulceration, cobblestoning, strictures, and fistula formation. CD is accompanied by fistulas in 40-50% of the patients during the course of illness. The aim of this study is
A-349
AGA Abstracts
AGA Abstracts
Measurement of Lumenal pH in Patients with Mildly to Moderately Active UC: A Pilot Study Using SmartPill pH.Ptm David T. Rubin, Alana P. Bunnag, Bonnie L. Surma, Adam Mikolajczyk
M1097
Background: Some patients with mildly to moderately active ulcerative colitis (UC) fail to respond to first line therapy with aminosalicylates. In addition to disease behavior and severity, both transit time and lumenal pH have been proposed as mechanisms limiting the delivery of drug. Previous studies of the pH in patients with UC have been limited by available technology, small sample sizes and heterogeneous patient types. In order to explore physiologic explanation for therapeutic non-response, we used a new device (Smartpill pH.pTM, Buffalo, NY) to measure pH and transit time in patients with mildly to moderately active UC. Methods: Patients diagnosed clinically, endoscopically and histologically with UC who had mildly or moderately active disease by the ACG Practice Guidelines were recruited. These patients consumed a standardized breakfast before swallowing the Smartpill pH.pTM capsule. pH, temperature, pressure, and transit time of the GI tract were recorded. Location in the GI tract was determined by previously validated changes in the pH, motility and temperature. Simple summative statistics were performed. Results: Ten UC patients were recruited (9 male, median disease duration 6 y: range 1-32 y). Four patients had extensive colitis, 6 patients had distal colitis. UC activity was mild in five and moderate in five. pH and transit times for the portions of the GI tract are in Table 1. All patients achieved a lumenal pH of ≥6.0 for a minimum of 120 minutes. However, one patient never achieved a pH of 7.0 and six patients did not maintain a pH of ≥7.0 for longer than 120 minutes. Patients with distal colitis had a combined small and large bowel transit time of mean 1211 min (SD +/-722 min) while patients with extensive colitis had a mean small/large bowel transit of 705 min (SD +/- 998 min) (p=NS). There were no complications with this device. Conclusions: We have demonstrated the utility of the Smartpill pH.pTM capsule to measure pH and transit time in patients with mildly to moderately active UC, and demonstrated that six of ten patients failed to achieve a sustained pH level needed for dissolution of some delayed-release 5-ASA preparations. This device and these observations provide opportunities for future assessment and individualized therapies. pH and Transit Time in 10 patients with active UC
M1095 Is Ileoanal Pouch Surveillance Necessary to Detect Neoplasia After Restorative Proctocolectomy for Ulcerative Colitis? Frank J. van den Broek, Malaika S. Vlug, Kristien M. Tytgat, Susanne van Eeden, Cyriel Ponsioen, Pieter Stokkers, Paul Fockens, Willem Bemelman, Evelien Dekker Introduction: Patients with ulcerative colitis (UC) have an increased risk of developing colorectal cancer, especially in case premalignant neoplasia is present. Restorative proctocolectomy (RPC) is recommended in these cases. A recent systematic review of observational studies suggested that UC patients with an ileoanal pouch anastomosis still had a risk of neoplasia, either inside the ileoanal pouch or in the rectal cuff. The aim of this prospective study was to assess the prevalence of neoplasia in UC patients who have undergone RPC. Methods: Patients with UC who underwent RPC from 1988-2008 are being invited for surveillance endoscopy of their ileoanal pouch. The afferent and blind ileal loop, ileoanal pouch and rectal cuff are examined by both standard endoscopy and methylene blue (0.1%) chromoendoscopy. Mucosal abnormalities are being sampled and 4 random biopsies are taken from the afferent and blind ileal loop, pouch and rectal cuff each. Results: Thus far, 25 patients (12 male, mean 47 yrs) have undergone surveillance endoscopy of their ileoanal pouch. The mean time between RPC and pouch surveillance was 7.9 (median 5.3; range 1-20) yrs; including 6 patients with an interval of >10 yrs. The RPC resection specimen contained indefinite neoplasia in 11 (44%) cases, low grade neoplasia in 9 (36%), high grade neoplasia in 4 (16%) and invasive cancer in 1 (4%). The endoscopic protocol led to targeted biopsies of 14 abnormalities in the afferent ileal loop, 1 in the blind ileal loop, 4 in the pouch and 6 in the rectal cuff. In addition, a total of 392 random biopsies were taken. Only in one patient (4%) low grade neoplasia was detected in several adenoma-like lesions in the rectal cuff which were detected by targeted biopsies during standard endoscopy. In this single patient (male; 53 yrs of age) the previous RPC resection specimen contained indefinite neoplasia, there was no history of pouchitis, and the surveillance endoscopy was performed 4.7 years after the RPC. Conclusion: The interim results of this study demonstrate that the yield of endoscopic surveillance for the detection of neoplasia in the ileoanal pouch after RPC is 0%, and in the rectal cuff this is 4%. As the time interval between the RPC and surveillance endoscopy of our study population is relatively long, it appears that a surveillance endoscopy once-only within 5 yrs of the RPC in patients with (at least indefinite) neoplasia of the resection specimen would be sufficient to detect possible neoplasia.
M1098 The Serum Metabolome in Inflammatory Bowel Disease Garrett C. Zella, Danny C. Alexander, Jeffrey Shuster, Bruce E. Sands, Joshua R. Korzenik
M1096
Background: Metabolomic analysis is the global, non-targeted profiling of small molecules found in biological tissues and fluids. Metabolomics serves as a valuable discovery platform to uncover new biomarkers relevant to disease, therapeutic response, and genetic variation. Small molecules from the serum metabolome potentially represent an early and non-invasive source of biomarkers for the diagnosis of various aspects of inflammatory bowel disease (IBD). We aimed to discover potential biomarkers in serum which distinguish Crohn's disease (CD) from ulcerative colitis (UC) and differentiate active from inactive disease. Methods: A total of 174 serum samples were assayed. Samples were obtained as part of the Prospective Registry in IBD Study at Massachusetts General Hospital (PRISM). Each patient was phenotyped and a disease activity score was assessed using the Harvey Bradshaw Index in CD or the Simple Clinical Colitis Activity Index in UC. The samples represented patients with active CD (n = 50), inactive CD (n = 51), active UC (n = 36), or inactive UC (n = 37). A subset of each disease group included matched sample pairs from individual patients taken during active and inactive disease states. All serum samples were subjected to metabolomic analysis on three mass spectrometry platforms, GC-MS, LC-MS-POS, and LC-MS-NEG. Compounds were identified, categorized by metabolic pathway, and their integrated ion peak values determined in each sample. Data were statistically analyzed using Welsh's two-sample t-test and Random Forest classification. Results: A total of 438 compounds were detected, of which 211 could be identified by comparison to a library entry based on an authentic purified standard. Compounds from most major biochemical pathways were represented in the dataset. Analysis of data revealed significant statistical differences between the CD and UC metabolomes, many of which were informative even in patients with inactive disease. Several biomarkers were able to classify CD sub-types related to ileal involvement, while other classes of compounds statistically distinguished inactive from active disease, especially for CD. Conclusion: The serum metabolome of patients with CD and UC differ significantly and may yield small-molecule biomarkers, singly or in combination, which are diagnostic of IBD types and sub-types and which may distinguish between active and inactive disease non-invasively.
Proteomic Analysis of Colonic Submucosa Differentiates Crohn's and Ulcerative Colitis Amosy E. M'Koma, Erin H. Seeley, Paul E. Wise, Mary K. Washington, David A. Schwartz, Alan J. Herline, Roberta L. Muldoon, Richard M. Caprioli PURPOSE: Since treatment approaches for Crohn's (CC) and Ulcerative colitis (UC) differ, accurate diagnosis is of paramount importance, but this cannot be made accurately in up to 30% of inflammatory bowel disease (IBD) patients because their histological and clinical features often overlap. Understanding the molecular differences that underlie these features may help diagnostic accuracy as well as clarify the etiology of IBD. Our aim was to clarify proteomic differences between the colonic tissue layers in UC and CC through pilot analyses. METHODS: Fresh frozen colon resection specimens were retrieved. Colitis diagnoses were reconfirmed by a blinded gastrointestinal pathologist. Three sample subtype groups were examined as follows: inflamed mucosa (CC [n=18] vs. UC [n=24]); inflamed submucosa (CC [n=20] vs. UC [n=22]), and uninflamed submucosa (CC [n=17] vs. UC [n=21]). Matrix assisted laser desorption/ionization mass spectrometry (MALDI MS) was used to profile the proteome of the individual colonic tissue layer compartments. Frozen tissues were sectioned at ~10-15μm for mounting onto target plates. Histology of a serial section was used to guide matrix placement on the tissue section. Sinapinic acid was used to give the best combination of uniform crystal coverage and signal quality for direct tissue protein analysis. After preprocessing to remove background noise, subtype tissue spectra were averaged from multiple analyses from various sites in the designated layers of each individual specimen's mucosa and submucosa. Pair-wise comparisons of the subsets were performed using Leave One Out Cross-Validation (LOOCV) and Weighted-Flexible Compound Covariate (WFCC) statistical methods. RESULTS: Several mass-to-charge ratio (m/z) values discriminated CC vs. UC (p< 0.0001). Analyses of inflamed and uninflamed submucosa yielded 2 and 3 discrete m/z values, respectively, with the best results in cross-validation tests with error rate ~20% (considered a good classifier). These proteomic peaks, therefore, provided ~80% accuracy. Each individual sample displayed these different submucosal values as well. The inflamed mucosa provided 3 discriminating m/z peaks between CC and UC with an average accuracy but did not reach statistical significance. CONCLUSION: Significant discriminatory m/z values were identified in these pilot proteomic analyses of both inflamed and uninflamed submucosa from UC vs. CC colonic specimens, while the inflamed mucosa showed no significant differentiating values. As the submucosa is uninvolved in UC further analyses and protein identification may provide differentiating biomarkers that would aid in diagnosis and treatment for UC/CC
M1099 The Role of MR Enterography for Detection of Enteral Fistulas in Crohn's Disease; Correlation with Radiological and Surgical Findings Dorota Mankowska-Wierzbicka, Katarzyna Katulska, Wlodzimierz Paprzycki, Marcin Kucharski, Ludwika Jakubowska-Burek, Krzysztof Linke, Agnieszka DobrowolskaZachwieja Purpose: Crohn's disease (CD) is a lifelong disease arising from an interaction between genetic and environmental factors. Crohn's disease pathogenesis is characterized by two main mechanisms, causing transmural lesions of the bowel wall and an excessive fibrogenic response . CD is a chronic inflammatory disease of the gastrointestinal tract characterized by aphthous ulceration, cobblestoning, strictures, and fistula formation. CD is accompanied by fistulas in 40-50% of the patients during the course of illness. The aim of this study is
A-349
AGA Abstracts
AGA Abstracts
Measurement of Lumenal pH in Patients with Mildly to Moderately Active UC: A Pilot Study Using SmartPill pH.Ptm David T. Rubin, Alana P. Bunnag, Bonnie L. Surma, Adam Mikolajczyk