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Su1329 Long-Term Outcome of Pancreatic Function in Patients With Autoimmune Pancreatitis
the development of exocrine and endocrine pancreatic insufficiency is a very common finding during long-term follow-up. Evaluation of pancreatic function in AIP patients is recommended, as impaired pancreatic function is associated with serious complications and treatment options are readily available. Table 1. Characteristics of AIP patients in which pancreatic function is evaluated
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Background & Aim: Whole exome sequenceing (WES) focusing on only the coding regions of the genome, has become in a few years the choice strategy to identify a coding allelic variant for human monogenic disorder. The human exome, made of ~180,000 exons for a size of ~30 Mbp, is 1.5% of the total humane genome. Thereby, not only targeted selection strategy reduces the cost but also accelerates the discovery of genetic variants that cause genetic diseases. Previous genetic studies have revealed an association between chronic pancreatitis and mutations in the cationic trypsinogen gene (PRSS1), the serine protease inhibitor Kazal type 1 gene (SPINK1), cystic fibrosis transmembrane conductance regulator gene (CFTR), the chymotrypsin C gene (CTRC), and copy number mutation of the trypsinogen locus. However, some patients do not carry any mutations in these genes, suggesting that unidentified defects might be involved in the pathogenesis of the disease. We here examined to identify a gene responsible for chronic pancreatitis using WES of patients without known mutations. Methods: This study was approved by the Ethics Committee of Tohoku University School of Medicine. Genomic DNA was prepared from 7 patients from 3 families (1 family with hereditary pancreatitis and 2 families with familial pancreatitis). All families carried no mutations in PRSS1, SPINK1, CTRC, and no copy number mutations of trypsinogen locus. DNA libraries were constructed and sequenced using paired-end protocol with 101-base reads on Illumina HiSeq2000. Results: This resulted in each samples having greater than 138 million reads. Over 70% of all protein coding bases were covered at 50x or more. Mean depth was over 109x. There were about 2,060,000 variants in total of the 7 samples. After removing known common polymorphisms in dbSNP135 and 1000 Genomes, there were 2,856 novel and exonic variants. Of these, there was a new nonsynonymous variant in gene coding pancreatic enzyme in three patients of one family. This gene was most recently presented as new candidate gene of pancreatitis in western populations. Additionally, there were some other mutated genes that includes 2 genes highly expressed in pancreas, 2 genes related to calcium channel activity, and 2 genes related to ubiquitin mediated proteolysis. Conclusion: Whole exome sequenecing might become the new strategy to identify unknown mutations for pancreatitis.
AIP = autoimmune pancreatitis; EPI = exocrine pancreatic insufficiency; † Fisher's Exact Test; * Mann-Whitney Test Su1330 Whole Exome Sequenecing Might Become the New Strategy to Identify Unknown Mutations for Pancreatitis Kiyoshi Kume, Atsushi Masamune, Tooru Shimosegawa
Value of Faecal Elastase Estimation in Patients With Obscure Diarrhoea Rahul Shah, Ajay Varma, Sam Thomson, Natalie Direkze The faecal elastase test measures the concentration of the elastase-3B enzyme found in faecal matter with an enzyme-linked immunosorbent assay (ELISA). It is a good indicator of exocrine pancreatic status, and is less invasive and expensive than the secretin-cholecystokinin test, the current gold standard. Levels of fecal elastase lower than 200 μg/g of stool indicate an exocrine pancreatic insufficiency (EPI). Aim: Faecal elastase is a marker for EPI particularly in chronic pancreatitis and pancreatic malignancy. Our aim was to outline the value of faecal elastase in patients with obscure diarrhoea. Methods: We retrospectively collected data of patients who had a fecal elastase test from June 2010 to 2012. We correlated the abnormal results with symptoms, findings on imaging and response to treatment. We also stratified these findings in patients with ultra low faecal elastase to assess whether the diagnostic yield was different. Paediatric patients were excluded from the study. Results: There were a total of 72 abnormal results out of 523 in this 2 year study of which 33 (45%) patients had large volume diarrhoea. Of these, 26 (78%) patients had no therapeutic response to pancreatic enzyme supplements (PES) and had normal imaging, 4 had a response and in 3 we could not establish whether PES was trialed. Of the patients who responded to treatment, 2 had imaging suggestive of chronic pancreatitis. 9 of the patients who were investigated for steatorrhoea were on statins but had normal faecal elastase, normal cross sectional imaging and good response to treatment with PES 41 patients had ultra low faecal elastase levels (,50μg/g), of these 32(78%) patients had significant pancreatic pathology whilst only 9(22%) had watery diarrhoea. Conclusions 1- A normal fecal elastase does not exclude EPI - as the 9 patients who were on statins had normal fecal elastase and pancreatic imaging and a dramatic response to PES. Other drugs like azathioprine, steroids causing EPI needs further investigation. 2- An ultra-low fecal elastase level ( ,50μg/g), is more likely to be related to significant pancreatic pathology with a response to treatment. Patients with watery diarrhoea are less likely to have a level this low. In these patients stool lyophilising or concentration should be performed before faecal elastase estimation. 3- In our patient group conditions like diabetes, coeliac disease, Addisons disease, gastrointestinal fistulas, short bowel syndrome, microscopic colitis, bile salt malabsorption and previous radiation all lead to falsely low levels without clinical correlation or response to treatment.Faecal elastase in this sub group should be interpreted with caution. References: The role of fecal elastase-1 in detecting exocrine pancreatic disease John S. Leeds, Kofi Oppong & David S. Sanders
Su1331 Mutational Analysis of the Chymotrypsin C (CTRC) and Interferon Regulatory Factor 2 (IRF2) Genes in Japanese Patients With Chronic Pancreatitis Eriko Nakano, Atsushi Masamune, Kiyoshi Kume, Yoichi Kakuta, Tooru Shimosegawa Background: It has been reported that loss-of-function variants in the chymotrypsin C (CTRC) gene are associated with CP in Europe and India. Recent studies using knockout mice have suggested a protective role of interferon regulatory factor 2 (IRF2) against pancreatitis. We conducted mutational analysis of the CTRC and IRF2 genes in patients with chronic pancreatitis (CP) in Japan. Methods: All of the eight exons in the CTRC gene and nine exons in the IRF2 genes were directly sequenced in 506 patients with CP (244 alcoholic, 206 idiopathic, 35 hereditary, and 21 familial) and 274 healthy controls. Results: We identified 5 missense CTRC variants in patients with CP and one in controls (Table 1). Four variants were located in exon 7, 1 in exon 2, and 1 in exon 6. Five of these six variants were novel ones. The c.86G.A (p.R29Q) and c.716C.G (p.S239C) variants were found in patients with alcoholic CP, whereas the c.715T.G (p.S239A) was found in a patient with idiopathic CP. The c.739A.G (p.K247E) variant was found in a patient with alcoholic CP and two patients with idiopathic CP. The combined frequency of the missense CTRC variants was not statistically different between patients with CP (7/506) and control (1/274) (p=0.27, Fisher's exact test). The common variants in Europe (p.K247_R254del and p.R254W) and India (p.A73T and p.V251I) were very rare in Japanese subjects and only one patient with idiopathic CP had the p.R254W variant. No exonic missense mutation in the IRF2 gene was identified in both CP patients and controls. Conclusions: The spectrum and distribution of the CTRC variants in Japanese subjects with CP were different from those reported from Europe and India. Mutations in the IRF2 gene are not associated with CP in Japan. Table 1. CTRC variants in the exons identified in this study
Su1329 Long-Term Outcome of Pancreatic Function in Patients With Autoimmune Pancreatitis Jorie Buijs, Marianne J. Van Heerde, Ernst J. Kuipers, Henk R. van Buuren, Marco J. Bruno Introduction: Autoimmune pancreatitis (AIP) represents the pancreatic manifestation of IgG4-related disease (IgG4-RD), a systemic fibroinflammatory disorder. Inflammation of the pancreas during an extended period can result in substantial fibrosis of the pancreas and permanent loss of pancreatic acinar and islet cells. This frequently results in endocrine and/ or exocrine pancreatic insufficiency. The prevalence of endocrine and exocrine pancreatic insufficiency in patients with long-term AIP is still unclear. The aim of this study was to evaluate pancreatic function in patients who had been diagnosed with AIP for .2 years. Methods: Between July 2012 and November 2012 pancreatic function was evaluated in 70 AIP patients with a disease history of 2 years or longer. Exocrine function was assessed by means of fecal elastase and endocrine function by fasting blood glucose (FBG) and glycated hemoglobin. Exocrine insufficiency was defined as fecal elastase level , 200 μg/g of feces; patients were considered to have endocrine insufficiency if they received or required treatment for glycaemic control (FBG. 6.7 mmol/L). Additional data were collected regarding diagnostic delay, mortality, disease treatment and relapse. Results: In a single cohort of 70 patients (61 males; median age 72 years; IQR 64-78) with a median follow-up of 94 months (IQR: 49-144), 11 patients (16%) had insufficient follow-up and 16 (23%) had died prior to current assessment. In the remaining 43 patients exocrine insufficiency was present in 35/ 43 patients (83%) and endocrine insufficiency in 31/43 patients (72%). Median diagnostic delay was 12 months (IQR: 3-72). Ten patients (23%) had undergone pancreatic resection, 33 (77%) received steroid therapy and all responded favourably. In patients with exocrine insufficiency, follow-up period and diagnostic delay were somewhat longer than in patients with normal exocrine function, but not significantly (Table 1). Conclusions: In AIP patients,
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AGA Abstracts
AGA Abstracts
pancreatic exocrine insufficiency (PEI) as measured by fecal elastase-1 (Fel-1) in subjects with diarrhea dominated IBS, reporting a prevalence of 6%. Aim To investigate the prevalence of PEI in a cohort of patients fulfilling Rome III criteria for IBS. Method Consecutive patients referred for a suspicion of IBS to the gastroenterology unit at Sahlgrenska University Hospital, Gothenburg, Sweden, were eligible for the study. Inclusion criteria were age between 18 and 65 years and IBS according to Rome III criteria. Exclusion criteria included concomitant known gastrointestinal disease and other severe disease. Bowel habits were registered during 2 weeks using the Bristol Stool Form Scale. Stool samples for Fel-1 analysis were obtained at two separate occasions, 2 weeks apart. Fel-1 levels ,200 μg/g stool were considered as pathological. Results A total of 111 patients with IBS (42 (37.9%) male, mean age 34 years, mean BMI 22.9) were included in the study. Patients reported a median of 1.5 stools per day (range 0.4-5.8) and loose stools in a median of 21 percent of all bowel movements. Stool samples were available from one occasion in 65 patients and two occasions in 46 patients. Low levels of Fel-1 were detected on at least one occasion in seven patients (6.3%). One patient had a single sample that was pathological, three patients had one pathological and one normal sample and three patients had two pathological samples. Only one out of the seven patients with pathological Fel-1 reported a clearly higher frequency of loose stools (63% of all stools) and higher number of stools per day (mean 4.1 stools per day) compared to the rest of the cohort. Conclusion Low Fel-1 can be demonstrated in a small subset of patients fulfilling Rome III criteria for IBS. Reported bowel habit were a poor predictor of a pathological Fel-1. Further investigation into exocrine pancreatic function seems warranted in patients with low Fel-1 considering the low intra-individual reproducibility of the test.
Su1328
Background & Aim: Whole exome sequenceing (WES) focusing on only the coding regions of the genome, has become in a few years the choice strategy to identify a coding allelic variant for human monogenic disorder. The human exome, made of ~180,000 exons for a size of ~30 Mbp, is 1.5% of the total humane genome. Thereby, not only targeted selection strategy reduces the cost but also accelerates the discovery of genetic variants that cause genetic diseases. Previous genetic studies have revealed an association between chronic pancreatitis and mutations in the cationic trypsinogen gene (PRSS1), the serine protease inhibitor Kazal type 1 gene (SPINK1), cystic fibrosis transmembrane conductance regulator gene (CFTR), the chymotrypsin C gene (CTRC), and copy number mutation of the trypsinogen locus. However, some patients do not carry any mutations in these genes, suggesting that unidentified defects might be involved in the pathogenesis of the disease. We here examined to identify a gene responsible for chronic pancreatitis using WES of patients without known mutations. Methods: This study was approved by the Ethics Committee of Tohoku University School of Medicine. Genomic DNA was prepared from 7 patients from 3 families (1 family with hereditary pancreatitis and 2 families with familial pancreatitis). All families carried no mutations in PRSS1, SPINK1, CTRC, and no copy number mutations of trypsinogen locus. DNA libraries were constructed and sequenced using paired-end protocol with 101-base reads on Illumina HiSeq2000. Results: This resulted in each samples having greater than 138 million reads. Over 70% of all protein coding bases were covered at 50x or more. Mean depth was over 109x. There were about 2,060,000 variants in total of the 7 samples. After removing known common polymorphisms in dbSNP135 and 1000 Genomes, there were 2,856 novel and exonic variants. Of these, there was a new nonsynonymous variant in gene coding pancreatic enzyme in three patients of one family. This gene was most recently presented as new candidate gene of pancreatitis in western populations. Additionally, there were some other mutated genes that includes 2 genes highly expressed in pancreas, 2 genes related to calcium channel activity, and 2 genes related to ubiquitin mediated proteolysis. Conclusion: Whole exome sequenecing might become the new strategy to identify unknown mutations for pancreatitis.
AIP = autoimmune pancreatitis; EPI = exocrine pancreatic insufficiency; † Fisher's Exact Test; * Mann-Whitney Test Su1330 Whole Exome Sequenecing Might Become the New Strategy to Identify Unknown Mutations for Pancreatitis Kiyoshi Kume, Atsushi Masamune, Tooru Shimosegawa
Value of Faecal Elastase Estimation in Patients With Obscure Diarrhoea Rahul Shah, Ajay Varma, Sam Thomson, Natalie Direkze The faecal elastase test measures the concentration of the elastase-3B enzyme found in faecal matter with an enzyme-linked immunosorbent assay (ELISA). It is a good indicator of exocrine pancreatic status, and is less invasive and expensive than the secretin-cholecystokinin test, the current gold standard. Levels of fecal elastase lower than 200 μg/g of stool indicate an exocrine pancreatic insufficiency (EPI). Aim: Faecal elastase is a marker for EPI particularly in chronic pancreatitis and pancreatic malignancy. Our aim was to outline the value of faecal elastase in patients with obscure diarrhoea. Methods: We retrospectively collected data of patients who had a fecal elastase test from June 2010 to 2012. We correlated the abnormal results with symptoms, findings on imaging and response to treatment. We also stratified these findings in patients with ultra low faecal elastase to assess whether the diagnostic yield was different. Paediatric patients were excluded from the study. Results: There were a total of 72 abnormal results out of 523 in this 2 year study of which 33 (45%) patients had large volume diarrhoea. Of these, 26 (78%) patients had no therapeutic response to pancreatic enzyme supplements (PES) and had normal imaging, 4 had a response and in 3 we could not establish whether PES was trialed. Of the patients who responded to treatment, 2 had imaging suggestive of chronic pancreatitis. 9 of the patients who were investigated for steatorrhoea were on statins but had normal faecal elastase, normal cross sectional imaging and good response to treatment with PES 41 patients had ultra low faecal elastase levels (,50μg/g), of these 32(78%) patients had significant pancreatic pathology whilst only 9(22%) had watery diarrhoea. Conclusions 1- A normal fecal elastase does not exclude EPI - as the 9 patients who were on statins had normal fecal elastase and pancreatic imaging and a dramatic response to PES. Other drugs like azathioprine, steroids causing EPI needs further investigation. 2- An ultra-low fecal elastase level ( ,50μg/g), is more likely to be related to significant pancreatic pathology with a response to treatment. Patients with watery diarrhoea are less likely to have a level this low. In these patients stool lyophilising or concentration should be performed before faecal elastase estimation. 3- In our patient group conditions like diabetes, coeliac disease, Addisons disease, gastrointestinal fistulas, short bowel syndrome, microscopic colitis, bile salt malabsorption and previous radiation all lead to falsely low levels without clinical correlation or response to treatment.Faecal elastase in this sub group should be interpreted with caution. References: The role of fecal elastase-1 in detecting exocrine pancreatic disease John S. Leeds, Kofi Oppong & David S. Sanders
Su1331 Mutational Analysis of the Chymotrypsin C (CTRC) and Interferon Regulatory Factor 2 (IRF2) Genes in Japanese Patients With Chronic Pancreatitis Eriko Nakano, Atsushi Masamune, Kiyoshi Kume, Yoichi Kakuta, Tooru Shimosegawa Background: It has been reported that loss-of-function variants in the chymotrypsin C (CTRC) gene are associated with CP in Europe and India. Recent studies using knockout mice have suggested a protective role of interferon regulatory factor 2 (IRF2) against pancreatitis. We conducted mutational analysis of the CTRC and IRF2 genes in patients with chronic pancreatitis (CP) in Japan. Methods: All of the eight exons in the CTRC gene and nine exons in the IRF2 genes were directly sequenced in 506 patients with CP (244 alcoholic, 206 idiopathic, 35 hereditary, and 21 familial) and 274 healthy controls. Results: We identified 5 missense CTRC variants in patients with CP and one in controls (Table 1). Four variants were located in exon 7, 1 in exon 2, and 1 in exon 6. Five of these six variants were novel ones. The c.86G.A (p.R29Q) and c.716C.G (p.S239C) variants were found in patients with alcoholic CP, whereas the c.715T.G (p.S239A) was found in a patient with idiopathic CP. The c.739A.G (p.K247E) variant was found in a patient with alcoholic CP and two patients with idiopathic CP. The combined frequency of the missense CTRC variants was not statistically different between patients with CP (7/506) and control (1/274) (p=0.27, Fisher's exact test). The common variants in Europe (p.K247_R254del and p.R254W) and India (p.A73T and p.V251I) were very rare in Japanese subjects and only one patient with idiopathic CP had the p.R254W variant. No exonic missense mutation in the IRF2 gene was identified in both CP patients and controls. Conclusions: The spectrum and distribution of the CTRC variants in Japanese subjects with CP were different from those reported from Europe and India. Mutations in the IRF2 gene are not associated with CP in Japan. Table 1. CTRC variants in the exons identified in this study
Su1329 Long-Term Outcome of Pancreatic Function in Patients With Autoimmune Pancreatitis Jorie Buijs, Marianne J. Van Heerde, Ernst J. Kuipers, Henk R. van Buuren, Marco J. Bruno Introduction: Autoimmune pancreatitis (AIP) represents the pancreatic manifestation of IgG4-related disease (IgG4-RD), a systemic fibroinflammatory disorder. Inflammation of the pancreas during an extended period can result in substantial fibrosis of the pancreas and permanent loss of pancreatic acinar and islet cells. This frequently results in endocrine and/ or exocrine pancreatic insufficiency. The prevalence of endocrine and exocrine pancreatic insufficiency in patients with long-term AIP is still unclear. The aim of this study was to evaluate pancreatic function in patients who had been diagnosed with AIP for .2 years. Methods: Between July 2012 and November 2012 pancreatic function was evaluated in 70 AIP patients with a disease history of 2 years or longer. Exocrine function was assessed by means of fecal elastase and endocrine function by fasting blood glucose (FBG) and glycated hemoglobin. Exocrine insufficiency was defined as fecal elastase level , 200 μg/g of feces; patients were considered to have endocrine insufficiency if they received or required treatment for glycaemic control (FBG. 6.7 mmol/L). Additional data were collected regarding diagnostic delay, mortality, disease treatment and relapse. Results: In a single cohort of 70 patients (61 males; median age 72 years; IQR 64-78) with a median follow-up of 94 months (IQR: 49-144), 11 patients (16%) had insufficient follow-up and 16 (23%) had died prior to current assessment. In the remaining 43 patients exocrine insufficiency was present in 35/ 43 patients (83%) and endocrine insufficiency in 31/43 patients (72%). Median diagnostic delay was 12 months (IQR: 3-72). Ten patients (23%) had undergone pancreatic resection, 33 (77%) received steroid therapy and all responded favourably. In patients with exocrine insufficiency, follow-up period and diagnostic delay were somewhat longer than in patients with normal exocrine function, but not significantly (Table 1). Conclusions: In AIP patients,
S-459
AGA Abstracts
AGA Abstracts
pancreatic exocrine insufficiency (PEI) as measured by fecal elastase-1 (Fel-1) in subjects with diarrhea dominated IBS, reporting a prevalence of 6%. Aim To investigate the prevalence of PEI in a cohort of patients fulfilling Rome III criteria for IBS. Method Consecutive patients referred for a suspicion of IBS to the gastroenterology unit at Sahlgrenska University Hospital, Gothenburg, Sweden, were eligible for the study. Inclusion criteria were age between 18 and 65 years and IBS according to Rome III criteria. Exclusion criteria included concomitant known gastrointestinal disease and other severe disease. Bowel habits were registered during 2 weeks using the Bristol Stool Form Scale. Stool samples for Fel-1 analysis were obtained at two separate occasions, 2 weeks apart. Fel-1 levels ,200 μg/g stool were considered as pathological. Results A total of 111 patients with IBS (42 (37.9%) male, mean age 34 years, mean BMI 22.9) were included in the study. Patients reported a median of 1.5 stools per day (range 0.4-5.8) and loose stools in a median of 21 percent of all bowel movements. Stool samples were available from one occasion in 65 patients and two occasions in 46 patients. Low levels of Fel-1 were detected on at least one occasion in seven patients (6.3%). One patient had a single sample that was pathological, three patients had one pathological and one normal sample and three patients had two pathological samples. Only one out of the seven patients with pathological Fel-1 reported a clearly higher frequency of loose stools (63% of all stools) and higher number of stools per day (mean 4.1 stools per day) compared to the rest of the cohort. Conclusion Low Fel-1 can be demonstrated in a small subset of patients fulfilling Rome III criteria for IBS. Reported bowel habit were a poor predictor of a pathological Fel-1. Further investigation into exocrine pancreatic function seems warranted in patients with low Fel-1 considering the low intra-individual reproducibility of the test.