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The Performance of Diagnostic Tests for Adult-Type Hypolactasia
444
Serum Intestinal Fatty Acid Binding Protein (I-FABP) is Useful for Diagnosing Celiac Disease and Evaluating the Recovery of Mucosal Damage in Patients on a Gluten-Free Diet Marlou Adriaanse, Greetje J. Tack, Wim A. Buurman, Kim van Wijck, Marco W. Schreurs, Chris J. Mulder, Anita Vreugdenhil
Identification of the Gene Underlying Congenital Short Bowel Syndrome, Pointing to Its Major Role in Intestinal Development Christine S. van der Werf, Tara D. Wabbersen, Nai-Hua Hsiao, Joana Paredes, Heather C. Etchevers, Peter M. Kroisel, Dick Tibboel, Richard A. Schreiber, Edward J. Hoffenberg, Sirkka L. Zeder, Isabella Ceccherini, Stanislas Lyonnet, Ana S. Ribeiro, Raquel Seruca, Gerard J. te Meerman, Sven C. van IJzendoorn, Iain T. Shepherd, Joke B. Verheij, Robert M. Hofstra
Introduction: Non-invasive tools for evaluation of intestinal damage in celiac disease (CD) are needed for diagnosis and especially for follow-up. Celiac antibodies are well established markers for screening patients who need a biopsy, but are due to their long half life not accurate enough for monitoring the effect of gluten-free diet (GFD). Intestinal fatty acid binding protein (I-FABP), a sensitive marker for intestinal mucosal damage, is potentially useful since this small cytosolic enterocyte protein is released rapidly into the systemic circulation after intestinal damage. Recently we found that elevated I-FABP levels accurately predict villous atrophy in children with positive CD screening and recover rapidly in response to GFD in children. This study aimed to assess the usefulness of I-FABP for diagnosing celiac disease in adults and monitoring mucosal healing in patients on GFD. Methods: Serum I-FABP levels were analysed retrospectively at the time of initial biopsy in 58 adults (median age 46 years, range 21-83 years) with increased levels of tissue transglutaminase (IgA-tTG) and/or endomysium antibodies (IgA-EMA) and biopsy proven CD. In addition, I-FABP levels were measured in 53 patients on GFD (mean duration 26 months, range 3-59 months) at the time of normal antibody titers. The control group consisted of 125 healthy adults (mean age 30 years). Results: Initial I-FABP levels in adult CD patients (median 755 pg/ml, range 52-2,362 pg/ml) were significantly elevated compared to controls (median 250 pg/ml, range 32-2,024 pg/ml, P<0.001). I-FABP levels significantly decreased on GFD (median 391 pg/ ml, range 30-2,136 pg/ml) compared to the untreated CD patients (P<0.001). In 20/53 patients on GFD I-FABP levels remained increased despite normal antibody titers. Biopsies were available in 12 patients; 25% showed Marsh 0, 25% Marsh 1 and in 50% Marsh 23A was found. In biopsies of 23 patients on GFD with normalised I-FABP levels we observed Marsh 0 in 78%, Marsh 1 in 17% and Marsh 3A in 4% of patients. Conclusion: Serum IFABP levels predict villous atrophy in adults with positive CD screening and might be a useful additional marker in diagnosing CD in adults. Most important, the results suggest that I- FABP is more sensitive for ongoing intestinal damage at follow-up than celiac antibodies. Further studies are required to evaluate the usefulness of I-FABP for monitoring mucosal healing and to assess whether increased I-FABP levels in patients with positive CD antibody tests justify a diagnosis of celiac disease without intestinal biopsy.
Congenital Short Bowel Syndrome is characterized by substantial shortening of the small intestine and by intestinal malrotation. Sixty percent of the cases are familial. Because both boys and girls are affected and as in twenty-five percent of the cases the parents are consanguineous, an autosomal recessive pattern of inheritance has been suggested. Homozygosity mapping was performed using 610K SNP arrays of Illumina on five patients of four different families, including one consanguineous family with two affected siblings and one unaffected child. We found an overlapping homozygous region in four of the five patients. In this region a homozygous deletion concerning one exon of a gene encoding a tightjunction protein, was detected in one of the patients. Furthermore, a homozygous deletion in the first intron was detected in the affected siblings of the consanguineous family, this deletion co-segregates with the disease phenotype in this family. Sequencing of the gene in three other patients resulted in the identification of additional mutations: one patient proved to have a heterozygous frameshift mutation and a heterozygous splice site mutation, whereas two other patients were homozygous for a nonsense mutation and a missense mutation, respectively. The gene is expressed in the intestine of human embryos throughout development. The missense mutation abrogated the normal localization of the encoded protein at the cell membrane. Knock-down experiments in zebrafish resulted in general developmental defects, including shortening of the intestine and absence of goblet cells, which are characteristic for the mid-intestine. Therefore, loss-of-function of the identified gene leads to Congenital Short Bowel Syndrome, likely by interfering with tight-junction formation, with intestinal development and with gut length determination. Note: we will mention the gene name in our presentation. 445 Co-Occurrence of IBS, Depression and Anxiety, Among Norwegian Twins, is Influenced by Both Heredity and Intrauterine Growth May-Bente Bengtson, Jennifer R. Harris, Morten H. Vatn
443
Background and aims: Environmental and genetic factors contribute to variation in IBS, depression and anxiety. Comorbidity between these disorders is high. A previous investigation of our population-based twin cohort revealed that low birth weight increased the risk for development of IBS, with environmental influences in utero as the most relevant contributing factor. We hypothesise that both intrauterine and genetic factors influence the co-occurrence of IBS and psychiatric characteristics. Methods: A postal questionnaire, sent in 1998, to 12700 Norwegian twins born between 1967 and 1979, based on the Norwegian national birth registry, established in 1967, included a checklist of 31 illnesses and symptoms, including IBS, 2 items on anxiety and 3 items on depression. This short form questionnaire of psychometric characteristics has been shown to correlate 0.85 with the full scale checklist of Hopkins (HSCL-25) anxiety and depression score. The co-occurrence of IBS and symptoms of anxiety and depression were tested in the full sample and adjusted for sex. The results from this analysis were then compared to those based on monozygotic (MZ) twin pairs discordant for IBS (297 pairs) to control for genetic factors. Furthermore, to explore whether the co-occurrence of IBS with symptoms of anxiety and depression could be caused by common intrauterine environmental factors analyses were conducted based on stratifying the data from IBS discordant MZ pairs into two birth weight groups, below and above 2500 g. Paired t-tests were performed using data from MZ pairs discordant for anxiety (109 pairs) and depression (155 pairs), respectively, to analyse the influence of restricted birth weight on the development of these symptoms. Results: The analysis of the full sample revealed that IBS was significantly associated with depression (OR = 2.5. 95 % CI: 1.9, 3.3) and anxiety (OR = 2.8, 95 % CI: 2.0, 3.8). Analyses of MZ pairs discordant for IBS indicated significant associations between IBS and depression (OR = 4.0, 95 % CI: 1.2, 13.7), and between IBS and anxiety (OR = 6.6, 95 % CI: 1.3, 32.8) only in the birth weight group below 2500 g. The t-test results indicated that among the MZ twins with birth weight below 2500 g the twins with depression (193.9 g, p < 0.001) and anxiety (178.4 g, p = 0.006) were significantly lighter than their control co-twins. Conclusion: This study suggests that genetic factors could partly explain the association between the disorders IBS, anxiety and depression, in normal range of birth weight (> 2500 g). In the low range of birth weight scale (< 2500 g), restricted fetal growth seems to be a common contributing factor to the development of these disorders as well as to the co-occurrence between them. .
The Performance of Diagnostic Tests for Adult-Type Hypolactasia Marcis Leja, Houssam Abu Meri, Iveta Vaivade, Aigars Vanags, Ilze Kikuste, Una Kojalo, Janis Klovins INTRODUCTION/OBJECTIVES: Adult-type hypolactasia is a genetically determined condition characterized by decreased ability to digest lactose, and may clinically manifest as lactose intolerance; single nucleotide C/T(-13910) variant rs4988235, located 13,9 kb upstream of the lactase gene (LCT) in intron 13 of the adjacent minichromosome maintenance 6 (MCM6) is responsible for the condition. The C/C genotype is characteristic to hypolactasia; C/T and T/T genotypes - to lactase persistence. Traditionally, lactose breath test (LBT) based on hydrogen (or in combination with methane) detection in exhaled air as well as the recently proposed quick lactase biopsy test (QLBT) is used for diagnosing hypolactasia. The objective of the current study was to evaluate the performance LBT and QLBT against the genetic test (GT) results. PATIENTS & METHODS: Patients (pts) with complains on bloating as a possible symptom of lactose intolerance were enrolled in the study; celiac pts with Marsh III or above were excluded to avoid secondary hypolactasia. To access the hypolactasia status GT, LBT and QLBT were performed. For LCT 13910 C/T rs4988235 genotyping TaqMan allele specific probes were used; reactions were carried out on Real Time PCR System 7500 (Applied Biosystems, USA). For LBT samples were collected before and within 3 hours following the ingestion of 25 g lactose in 200 ml water. Hydrogen and methane were measured in the exhaled air; the values were corrected against the level of carbon dioxide by using the Breathtracker SC (QuinTron Instrument Company, USA). Results with hydrogen increase exceeding 20 ppm, or 12 ppm for methane, or 15 ppm for the combination of the both in the exhaled air were considered characteristic for hypolactasia. Quick Lactase Test (BIOHIT, Plc., Finland) was used to detect hypolactasia in the biopsy samples; distal duodenal biopsies placed in the test-system and read at 3 min. after sampling were used for the purpose. RESULTS: Altogether 76 pts were enrolled, 5 were diagnosed or suspected celiac disease; duodenal biopsies were available from all, Marsh III duodenal lesion was diagnosed in one patient that was excluded accordingly; therefore 75 pts were available for analysis. Out of these 54 were women, 21 - men; median age was 40 (range 19 - 74). C/C genotype was detected in 33 pts, C/T - in 30 pts, but T/T - in 12 pts. Hypolactasia was detected in 24 pts by LBT, but was absent in 51 cases; correspondingly hypolactasia was present in 43, but absent in 32 cases by QLBT. The performance characteristics of LBT and QLBT when compared to the GT are given in the table below. CONCLUSIONS: The overall accuracy of LBT and BT were similar for detecting adult-type hypolactasia, whereas BT demonstrated higher sensitivity, but LBT - higher specificity when compared to the GT. The performance of LBT and QLBT for diagnosing hypolactasia
446 Congenital Sucrase-Isomaltase Deficiency (CSID) Reduces Starch Digestion Bruno P. Chumpitazi, Claudia C. Robayo-Torres, Maricela Diaz-Sotomayor, Roberto Quezada-Calvillo, Antone R. Opekun, Buford L. Nichols, Mark A. Gilger We have reported that the sucrase-isomaltase (SI) enzyme complex accounts for 80% of In Vitro mucosal starch digesting activity (2007). It is unknown whether the dominant role of SI on maltose digestion is clinically and nutritionally important. Because it is believed that some CSID patients have starch as well as sucrose intolerance we investigated 11 children with CSID previously documented by duodenal biopsy assays and sucrose BT (2009). Hypothesis: Deficiency of sucrase activity will reduce the efficiency of starch digestion. Methods: UL 13C-glucose, 13C-sucrose, and 13C-starch (20mg, Isotec, Miamisburg, OH) were given orally. After the 13C-load, breath samples were collected every 15 min for 120 min. Breath 13CO2 enrichments were measured with a infrared spectrophotometer (POCone, Otsuka Electronics, Tokyo, Japan) and expressed as % coefficient of DOB 13CO2 of M 3090 min sucrose or starch / glucose oxidation (CGO %). Control subjects (6) had normal duodenal enzyme activities. Results: Sucrase activity of controls was 44.8 ± 11.4 vs. CSID
LBT - lactose breath test QLBT - quick lactase biopsy test
S-89
AGA Abstracts
AGA Abstracts
442
Serum Intestinal Fatty Acid Binding Protein (I-FABP) is Useful for Diagnosing Celiac Disease and Evaluating the Recovery of Mucosal Damage in Patients on a Gluten-Free Diet Marlou Adriaanse, Greetje J. Tack, Wim A. Buurman, Kim van Wijck, Marco W. Schreurs, Chris J. Mulder, Anita Vreugdenhil
Identification of the Gene Underlying Congenital Short Bowel Syndrome, Pointing to Its Major Role in Intestinal Development Christine S. van der Werf, Tara D. Wabbersen, Nai-Hua Hsiao, Joana Paredes, Heather C. Etchevers, Peter M. Kroisel, Dick Tibboel, Richard A. Schreiber, Edward J. Hoffenberg, Sirkka L. Zeder, Isabella Ceccherini, Stanislas Lyonnet, Ana S. Ribeiro, Raquel Seruca, Gerard J. te Meerman, Sven C. van IJzendoorn, Iain T. Shepherd, Joke B. Verheij, Robert M. Hofstra
Introduction: Non-invasive tools for evaluation of intestinal damage in celiac disease (CD) are needed for diagnosis and especially for follow-up. Celiac antibodies are well established markers for screening patients who need a biopsy, but are due to their long half life not accurate enough for monitoring the effect of gluten-free diet (GFD). Intestinal fatty acid binding protein (I-FABP), a sensitive marker for intestinal mucosal damage, is potentially useful since this small cytosolic enterocyte protein is released rapidly into the systemic circulation after intestinal damage. Recently we found that elevated I-FABP levels accurately predict villous atrophy in children with positive CD screening and recover rapidly in response to GFD in children. This study aimed to assess the usefulness of I-FABP for diagnosing celiac disease in adults and monitoring mucosal healing in patients on GFD. Methods: Serum I-FABP levels were analysed retrospectively at the time of initial biopsy in 58 adults (median age 46 years, range 21-83 years) with increased levels of tissue transglutaminase (IgA-tTG) and/or endomysium antibodies (IgA-EMA) and biopsy proven CD. In addition, I-FABP levels were measured in 53 patients on GFD (mean duration 26 months, range 3-59 months) at the time of normal antibody titers. The control group consisted of 125 healthy adults (mean age 30 years). Results: Initial I-FABP levels in adult CD patients (median 755 pg/ml, range 52-2,362 pg/ml) were significantly elevated compared to controls (median 250 pg/ml, range 32-2,024 pg/ml, P<0.001). I-FABP levels significantly decreased on GFD (median 391 pg/ ml, range 30-2,136 pg/ml) compared to the untreated CD patients (P<0.001). In 20/53 patients on GFD I-FABP levels remained increased despite normal antibody titers. Biopsies were available in 12 patients; 25% showed Marsh 0, 25% Marsh 1 and in 50% Marsh 23A was found. In biopsies of 23 patients on GFD with normalised I-FABP levels we observed Marsh 0 in 78%, Marsh 1 in 17% and Marsh 3A in 4% of patients. Conclusion: Serum IFABP levels predict villous atrophy in adults with positive CD screening and might be a useful additional marker in diagnosing CD in adults. Most important, the results suggest that I- FABP is more sensitive for ongoing intestinal damage at follow-up than celiac antibodies. Further studies are required to evaluate the usefulness of I-FABP for monitoring mucosal healing and to assess whether increased I-FABP levels in patients with positive CD antibody tests justify a diagnosis of celiac disease without intestinal biopsy.
Congenital Short Bowel Syndrome is characterized by substantial shortening of the small intestine and by intestinal malrotation. Sixty percent of the cases are familial. Because both boys and girls are affected and as in twenty-five percent of the cases the parents are consanguineous, an autosomal recessive pattern of inheritance has been suggested. Homozygosity mapping was performed using 610K SNP arrays of Illumina on five patients of four different families, including one consanguineous family with two affected siblings and one unaffected child. We found an overlapping homozygous region in four of the five patients. In this region a homozygous deletion concerning one exon of a gene encoding a tightjunction protein, was detected in one of the patients. Furthermore, a homozygous deletion in the first intron was detected in the affected siblings of the consanguineous family, this deletion co-segregates with the disease phenotype in this family. Sequencing of the gene in three other patients resulted in the identification of additional mutations: one patient proved to have a heterozygous frameshift mutation and a heterozygous splice site mutation, whereas two other patients were homozygous for a nonsense mutation and a missense mutation, respectively. The gene is expressed in the intestine of human embryos throughout development. The missense mutation abrogated the normal localization of the encoded protein at the cell membrane. Knock-down experiments in zebrafish resulted in general developmental defects, including shortening of the intestine and absence of goblet cells, which are characteristic for the mid-intestine. Therefore, loss-of-function of the identified gene leads to Congenital Short Bowel Syndrome, likely by interfering with tight-junction formation, with intestinal development and with gut length determination. Note: we will mention the gene name in our presentation. 445 Co-Occurrence of IBS, Depression and Anxiety, Among Norwegian Twins, is Influenced by Both Heredity and Intrauterine Growth May-Bente Bengtson, Jennifer R. Harris, Morten H. Vatn
443
Background and aims: Environmental and genetic factors contribute to variation in IBS, depression and anxiety. Comorbidity between these disorders is high. A previous investigation of our population-based twin cohort revealed that low birth weight increased the risk for development of IBS, with environmental influences in utero as the most relevant contributing factor. We hypothesise that both intrauterine and genetic factors influence the co-occurrence of IBS and psychiatric characteristics. Methods: A postal questionnaire, sent in 1998, to 12700 Norwegian twins born between 1967 and 1979, based on the Norwegian national birth registry, established in 1967, included a checklist of 31 illnesses and symptoms, including IBS, 2 items on anxiety and 3 items on depression. This short form questionnaire of psychometric characteristics has been shown to correlate 0.85 with the full scale checklist of Hopkins (HSCL-25) anxiety and depression score. The co-occurrence of IBS and symptoms of anxiety and depression were tested in the full sample and adjusted for sex. The results from this analysis were then compared to those based on monozygotic (MZ) twin pairs discordant for IBS (297 pairs) to control for genetic factors. Furthermore, to explore whether the co-occurrence of IBS with symptoms of anxiety and depression could be caused by common intrauterine environmental factors analyses were conducted based on stratifying the data from IBS discordant MZ pairs into two birth weight groups, below and above 2500 g. Paired t-tests were performed using data from MZ pairs discordant for anxiety (109 pairs) and depression (155 pairs), respectively, to analyse the influence of restricted birth weight on the development of these symptoms. Results: The analysis of the full sample revealed that IBS was significantly associated with depression (OR = 2.5. 95 % CI: 1.9, 3.3) and anxiety (OR = 2.8, 95 % CI: 2.0, 3.8). Analyses of MZ pairs discordant for IBS indicated significant associations between IBS and depression (OR = 4.0, 95 % CI: 1.2, 13.7), and between IBS and anxiety (OR = 6.6, 95 % CI: 1.3, 32.8) only in the birth weight group below 2500 g. The t-test results indicated that among the MZ twins with birth weight below 2500 g the twins with depression (193.9 g, p < 0.001) and anxiety (178.4 g, p = 0.006) were significantly lighter than their control co-twins. Conclusion: This study suggests that genetic factors could partly explain the association between the disorders IBS, anxiety and depression, in normal range of birth weight (> 2500 g). In the low range of birth weight scale (< 2500 g), restricted fetal growth seems to be a common contributing factor to the development of these disorders as well as to the co-occurrence between them. .
The Performance of Diagnostic Tests for Adult-Type Hypolactasia Marcis Leja, Houssam Abu Meri, Iveta Vaivade, Aigars Vanags, Ilze Kikuste, Una Kojalo, Janis Klovins INTRODUCTION/OBJECTIVES: Adult-type hypolactasia is a genetically determined condition characterized by decreased ability to digest lactose, and may clinically manifest as lactose intolerance; single nucleotide C/T(-13910) variant rs4988235, located 13,9 kb upstream of the lactase gene (LCT) in intron 13 of the adjacent minichromosome maintenance 6 (MCM6) is responsible for the condition. The C/C genotype is characteristic to hypolactasia; C/T and T/T genotypes - to lactase persistence. Traditionally, lactose breath test (LBT) based on hydrogen (or in combination with methane) detection in exhaled air as well as the recently proposed quick lactase biopsy test (QLBT) is used for diagnosing hypolactasia. The objective of the current study was to evaluate the performance LBT and QLBT against the genetic test (GT) results. PATIENTS & METHODS: Patients (pts) with complains on bloating as a possible symptom of lactose intolerance were enrolled in the study; celiac pts with Marsh III or above were excluded to avoid secondary hypolactasia. To access the hypolactasia status GT, LBT and QLBT were performed. For LCT 13910 C/T rs4988235 genotyping TaqMan allele specific probes were used; reactions were carried out on Real Time PCR System 7500 (Applied Biosystems, USA). For LBT samples were collected before and within 3 hours following the ingestion of 25 g lactose in 200 ml water. Hydrogen and methane were measured in the exhaled air; the values were corrected against the level of carbon dioxide by using the Breathtracker SC (QuinTron Instrument Company, USA). Results with hydrogen increase exceeding 20 ppm, or 12 ppm for methane, or 15 ppm for the combination of the both in the exhaled air were considered characteristic for hypolactasia. Quick Lactase Test (BIOHIT, Plc., Finland) was used to detect hypolactasia in the biopsy samples; distal duodenal biopsies placed in the test-system and read at 3 min. after sampling were used for the purpose. RESULTS: Altogether 76 pts were enrolled, 5 were diagnosed or suspected celiac disease; duodenal biopsies were available from all, Marsh III duodenal lesion was diagnosed in one patient that was excluded accordingly; therefore 75 pts were available for analysis. Out of these 54 were women, 21 - men; median age was 40 (range 19 - 74). C/C genotype was detected in 33 pts, C/T - in 30 pts, but T/T - in 12 pts. Hypolactasia was detected in 24 pts by LBT, but was absent in 51 cases; correspondingly hypolactasia was present in 43, but absent in 32 cases by QLBT. The performance characteristics of LBT and QLBT when compared to the GT are given in the table below. CONCLUSIONS: The overall accuracy of LBT and BT were similar for detecting adult-type hypolactasia, whereas BT demonstrated higher sensitivity, but LBT - higher specificity when compared to the GT. The performance of LBT and QLBT for diagnosing hypolactasia
446 Congenital Sucrase-Isomaltase Deficiency (CSID) Reduces Starch Digestion Bruno P. Chumpitazi, Claudia C. Robayo-Torres, Maricela Diaz-Sotomayor, Roberto Quezada-Calvillo, Antone R. Opekun, Buford L. Nichols, Mark A. Gilger We have reported that the sucrase-isomaltase (SI) enzyme complex accounts for 80% of In Vitro mucosal starch digesting activity (2007). It is unknown whether the dominant role of SI on maltose digestion is clinically and nutritionally important. Because it is believed that some CSID patients have starch as well as sucrose intolerance we investigated 11 children with CSID previously documented by duodenal biopsy assays and sucrose BT (2009). Hypothesis: Deficiency of sucrase activity will reduce the efficiency of starch digestion. Methods: UL 13C-glucose, 13C-sucrose, and 13C-starch (20mg, Isotec, Miamisburg, OH) were given orally. After the 13C-load, breath samples were collected every 15 min for 120 min. Breath 13CO2 enrichments were measured with a infrared spectrophotometer (POCone, Otsuka Electronics, Tokyo, Japan) and expressed as % coefficient of DOB 13CO2 of M 3090 min sucrose or starch / glucose oxidation (CGO %). Control subjects (6) had normal duodenal enzyme activities. Results: Sucrase activity of controls was 44.8 ± 11.4 vs. CSID
LBT - lactose breath test QLBT - quick lactase biopsy test
S-89
AGA Abstracts
AGA Abstracts
442