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Su2045 Gut Permeability in IBS is Site Specific, Subtype Dependent and Affected by Confounding Factors
Results, not adjusted for confounders, presented as: median [interquartile range (IQR) 25 ; 75 percentile]. Differences, relative to HC, tested with linear regression. Skewed variables were LN transformed prior to analysis. * p < 0.05, ** p < 0.01 vs. HC. Linear regression analysis of gastroduodenal and small intestinal permeability based on respectively natural logarithmic (LN) transformed urinary sucrose concentration and L/R ratio for IBS-TOTAL patients vs. HC and patients with IBS-D, IBS-C and IBS-M vs. HC.
Beta = regression coefficient, representing change of 1 LN transformed sucrose concentration or L/R ratio of IBS-TOTAL and IBS subtypes compared to HC. 95% confidence intervals (CI) and p-values are shown. Crude analysis adjusted for demographical characteristics (i.e. age, sex and BMI), psychological symptoms (i.e. anxiety and depression HADS scores > 8), lifestyle parameters (i.e. positive smoking history and alcohol intake >15 units/week), use of medication 2 weeks prior to participation (i.e. PPI, NSAID, SSRI, medication that positively and negatively affect motility). Su2045 Su2046 Gut Permeability in IBS is Site Specific, Subtype Dependent and Affected by Confounding Factors Zlatan Mujagic, Samefko Ludidi, Daniel Keszthelyi, Martine Hesselink, Joanna Kruimel, Kaatje Lenaerts, Nordin Hanssen, José M. Conchillo, Daisy Jonkers, Ad Masclee
High Sensitive C - Reactive Protein as a Marker for Inflammation in Irritable Bowel Syndrome Keren Hod, Tamar Ringel-Kulka, Christopher F. Martin, Nitsan Maharshak, Yehuda Ringel Introduction: Irritable Bowel Syndrome (IBS) is a common disorder affecting 8-23% of the adult population. The pathogenesis of IBS is not clear. A few recent studies have demonstrated subtle alterations in the intestinal immune function and low-grade inflammation in some patients with IBS. However, the reported studies in this area are relatively small and do not enable examining these factors by IBS subtypes and the possible confounding effects of commonly reported IBS co-morbidities that can be associated with inflammatory responses. Objectives: To investigate the association between an inflammatory biomarker, high sensitive C - reactive protein (hs-CRP), and the diagnosis of IBS, IBS-subtypes, symptoms severity and IBS-associated pain and psychological co-morbidities in a large cohort of IBS patients and healthy controls (HC). Methods: Clinical data and blood samples were collected through a large single site, case control study. IBS diagnosis was determined by Rome III criteria, negative screening blood tests and a recent (<1y) colonoscopy. IBS severity was assessed by Functional Bowel Disorder Severity Index (FBDSI). All subjects were evaluated for associated pain and psychological co-morbidities including pain syndromes (e.g., fibromyalgia, migraine headache, pelvic pain), anxiety and depression (Hospital Anxiety and Depression Scores; HADS), and somatization (Patient Health Questionnaire; PHQ-15). hs-CRP levels were measured in all subjects. T-test/ANOVAs were used for between groups comparisons and Pearson and Spearman correlations for testing associations between hs-CRP and clinical and psychological factors. Multiple linear regressions were performed to test for covariates. Results: A total of 242 IBS cases and 244 controls were studied. Mean hs-CRP levels in the IBS group was significantly higher than in HC (3.7±5.1mg/ vs. 2.8±4.3mg/l p<0.006). Levels were highest in IBS-D patients with greater disease severity. hs-CRP levels correlated with symptoms severity (r=0.128, p=0.047); this correlation was stronger for the IBS-D patients (r=0.21, p=0.037). IBS was a significant and independent predictor (p=0.025) for higher hs-CRP levels by a linear regression model, whereas other pain and psychological comorbidities were not. Conclusion: We found an association between a biomarker of systemic inflammation and IBS. We demonstrated that the level of hs-CRP is associated with a specific subtype of IBS (IBS-D), correlate with symptoms severity and is not explained by other pain and psychological co-morbidities. Our findings suggest a possible role for low-grade inflammation in the pathogenesis and/or clinical presentation of IBS.
Rationale: Altered intestinal barrier function is one of the assumed pathophysiological mechanisms of irritable bowel syndrome (IBS). Intestinal permeability has previously been studied in small IBS populations, but findings were contrasting. Objectives of the present study were 1) to assess intestinal permeability at different sites of the GI tract, in a large group well characterised IBS patients and healthy controls (HC) and investigate differences between subtypes, and 2) to assess potential confounding effects of multiple patient-related factors. Methods and materials: IBS patients and HC of a large IBS cohort underwent a validated multi-sugar test to assess intestinal permeability on four sites of the GI tract. Sucrose excretion and the lactulose/rhamnose (L/R) ratio in 0-5 h urine indicated gastroduodenal and small intestinal permeability, respectively. Sucralose/ erythritol (S/E) ratio in 0-24 and 5-24 h urine was used as indicators of whole gut and colon permeability, respectively. Linear regression analysis was used to assess the association between IBS subtypes and intestinal permeability and to adjust for possible confounding factors, i.e. demographics (age, sex, BMI), psychological symptoms (anxiety or depression), lifestyle factors (smoking history, (defined as current or previous smoker) and alcohol intake >15 units/week), and use of medication in the 2 weeks prior to inclusion (non-steroidal anti-inflammatory drugs, proton pump inhibitors, selective serotonin reuptake inhibitors and medication that affects motility). Results: 91 IBS patients, i.e. 37% diarrhoea predominant (IBS-D), 23% constipation predominant (IBS-C), 33% with mixed (IBS-M) and 7% with unspecified stool pattern (IBS-U), and 94 HC were enrolled. Urinary sucrose excretion was significantly increased in the total IBS group versus HC (median [Q1 ; Q3] in μmol: 5.26 [1.82 ; 11.03] vs. 2.44 [0.91 ; 5.85], p<0.05), as well as in IBS-C and IBS-D versus HC. However, the differences attenuated when adjusting for confounders. Factors with significant confounding effects were higher BMI, positive smoking history and use of drugs that positively affect motility. Furthermore, the L/R ratio was increased in IBS-D patients compared to HC (0.023 [0.013 ; 0.038] vs. 0.014 [0.008 ; 0.025], p<0.05), which remained significant after adjustment for confounders. There was no significant difference between groups in 0-24 and 5-24 hour S/E ratio. Conclusion: Small intestinal, but not gastroduodenal, colon and whole gut permeability is increased in patients with diarrhea predominant IBS when compared to healthy controls, irrespective of possible confounding factors. Adjustment for possible confounders is necessary when studying intestinal permeability, especially in a heterogeneous disorder as IBS. Permeability test: sugar excretion and ratios of excreted sugars as measured in urine (in 05, 5-24 and 0-24 hours fraction), for HC, IBS-TOTAL, IBS-D, IBS-C and IBS-M.
S-531
AGA Abstracts
AGA Abstracts
CXCL9, CXCL10 and CXCL11. CXCR3 exists as 2 functional variants, CXCR3-A and CXCR3B. Previous work from this group has demonstrated increased production of CXCL9 and CXCL10 from IBS biopsies when stimulated with anti-CD3/CD28 compared with controls. Aim: The aim of this study was to investigate the expression of CXCR3-A and CXCR3-B in colonic mucosa and the levels of CXCR3 chemokines in plasma of IBS patients Methods: A cohort of IBS patients fulfilling the ROME III criteria completed the ROME III questionnaire on 3 separate times, 3 months apart. Control patients were required to provide a negative bowel questionnaire. Plasma samples from IBS and controls (n=18) were analysed by MSD assays for levels of CXCL10 and CXCL11. In a separate cohort of patients, colonic mucosal biopsies from IBS (n=5) and controls (n=5) were fixed and detection of CXCL10 and CXCR3 was performed by immunohistochemistry. In the same patients, IBS (n=36) and controls (n=34), total RNA was extracted and analysed by RT-qPCR for expression of CXCR3-A and CXCR3-B and the CXCR3 chemokines, CXCL9, CXCL10, CXCL11. The 2_ΔΔCt method was used to calculate relative changes in gene expression, pooled IBS and control biopsy cDNA were used as the calibrator control for analysis of differential gene expression. Results: RT-qPCR analysis of CXCR3-A and CXCR3-B in IBS and controls revealed expression of both CXCR3 transcripts in the mucosa of all IBS patients (n=36) examined while controls did not express CXCR3-A and only 4 control patients (n=34) expressed CXCR3-B. In addition, CXCR3 protein was strongly expressed in the epithelia of IBS patients while being absent from controls. RT-qPCR analysis of CXCL9, CXCL10 and CXCL11 revealed significant reductions in the expression of CXCL9 (p<0.05) and CXCL10 (p<0.01) in biopsies from IBS patients. However, the levels of CXCL10 and CXCL11 were significantly increased periodically in the plasma of IBS patients compared to controls (p<0.05). The levels of plasma CXCL10 (p<0.05, R2 0.3) (and CXCL11, p<0.01, R2 0.3) correlated significantly with the amount of times in the past 3 months that patients had loose or watery stools. Conclusions: Collectively, these data implicate the CXCR3 chemokine system in the pathogenesis of IBS.
Beta = regression coefficient, representing change of 1 LN transformed sucrose concentration or L/R ratio of IBS-TOTAL and IBS subtypes compared to HC. 95% confidence intervals (CI) and p-values are shown. Crude analysis adjusted for demographical characteristics (i.e. age, sex and BMI), psychological symptoms (i.e. anxiety and depression HADS scores > 8), lifestyle parameters (i.e. positive smoking history and alcohol intake >15 units/week), use of medication 2 weeks prior to participation (i.e. PPI, NSAID, SSRI, medication that positively and negatively affect motility). Su2045 Su2046 Gut Permeability in IBS is Site Specific, Subtype Dependent and Affected by Confounding Factors Zlatan Mujagic, Samefko Ludidi, Daniel Keszthelyi, Martine Hesselink, Joanna Kruimel, Kaatje Lenaerts, Nordin Hanssen, José M. Conchillo, Daisy Jonkers, Ad Masclee
High Sensitive C - Reactive Protein as a Marker for Inflammation in Irritable Bowel Syndrome Keren Hod, Tamar Ringel-Kulka, Christopher F. Martin, Nitsan Maharshak, Yehuda Ringel Introduction: Irritable Bowel Syndrome (IBS) is a common disorder affecting 8-23% of the adult population. The pathogenesis of IBS is not clear. A few recent studies have demonstrated subtle alterations in the intestinal immune function and low-grade inflammation in some patients with IBS. However, the reported studies in this area are relatively small and do not enable examining these factors by IBS subtypes and the possible confounding effects of commonly reported IBS co-morbidities that can be associated with inflammatory responses. Objectives: To investigate the association between an inflammatory biomarker, high sensitive C - reactive protein (hs-CRP), and the diagnosis of IBS, IBS-subtypes, symptoms severity and IBS-associated pain and psychological co-morbidities in a large cohort of IBS patients and healthy controls (HC). Methods: Clinical data and blood samples were collected through a large single site, case control study. IBS diagnosis was determined by Rome III criteria, negative screening blood tests and a recent (<1y) colonoscopy. IBS severity was assessed by Functional Bowel Disorder Severity Index (FBDSI). All subjects were evaluated for associated pain and psychological co-morbidities including pain syndromes (e.g., fibromyalgia, migraine headache, pelvic pain), anxiety and depression (Hospital Anxiety and Depression Scores; HADS), and somatization (Patient Health Questionnaire; PHQ-15). hs-CRP levels were measured in all subjects. T-test/ANOVAs were used for between groups comparisons and Pearson and Spearman correlations for testing associations between hs-CRP and clinical and psychological factors. Multiple linear regressions were performed to test for covariates. Results: A total of 242 IBS cases and 244 controls were studied. Mean hs-CRP levels in the IBS group was significantly higher than in HC (3.7±5.1mg/ vs. 2.8±4.3mg/l p<0.006). Levels were highest in IBS-D patients with greater disease severity. hs-CRP levels correlated with symptoms severity (r=0.128, p=0.047); this correlation was stronger for the IBS-D patients (r=0.21, p=0.037). IBS was a significant and independent predictor (p=0.025) for higher hs-CRP levels by a linear regression model, whereas other pain and psychological comorbidities were not. Conclusion: We found an association between a biomarker of systemic inflammation and IBS. We demonstrated that the level of hs-CRP is associated with a specific subtype of IBS (IBS-D), correlate with symptoms severity and is not explained by other pain and psychological co-morbidities. Our findings suggest a possible role for low-grade inflammation in the pathogenesis and/or clinical presentation of IBS.
Rationale: Altered intestinal barrier function is one of the assumed pathophysiological mechanisms of irritable bowel syndrome (IBS). Intestinal permeability has previously been studied in small IBS populations, but findings were contrasting. Objectives of the present study were 1) to assess intestinal permeability at different sites of the GI tract, in a large group well characterised IBS patients and healthy controls (HC) and investigate differences between subtypes, and 2) to assess potential confounding effects of multiple patient-related factors. Methods and materials: IBS patients and HC of a large IBS cohort underwent a validated multi-sugar test to assess intestinal permeability on four sites of the GI tract. Sucrose excretion and the lactulose/rhamnose (L/R) ratio in 0-5 h urine indicated gastroduodenal and small intestinal permeability, respectively. Sucralose/ erythritol (S/E) ratio in 0-24 and 5-24 h urine was used as indicators of whole gut and colon permeability, respectively. Linear regression analysis was used to assess the association between IBS subtypes and intestinal permeability and to adjust for possible confounding factors, i.e. demographics (age, sex, BMI), psychological symptoms (anxiety or depression), lifestyle factors (smoking history, (defined as current or previous smoker) and alcohol intake >15 units/week), and use of medication in the 2 weeks prior to inclusion (non-steroidal anti-inflammatory drugs, proton pump inhibitors, selective serotonin reuptake inhibitors and medication that affects motility). Results: 91 IBS patients, i.e. 37% diarrhoea predominant (IBS-D), 23% constipation predominant (IBS-C), 33% with mixed (IBS-M) and 7% with unspecified stool pattern (IBS-U), and 94 HC were enrolled. Urinary sucrose excretion was significantly increased in the total IBS group versus HC (median [Q1 ; Q3] in μmol: 5.26 [1.82 ; 11.03] vs. 2.44 [0.91 ; 5.85], p<0.05), as well as in IBS-C and IBS-D versus HC. However, the differences attenuated when adjusting for confounders. Factors with significant confounding effects were higher BMI, positive smoking history and use of drugs that positively affect motility. Furthermore, the L/R ratio was increased in IBS-D patients compared to HC (0.023 [0.013 ; 0.038] vs. 0.014 [0.008 ; 0.025], p<0.05), which remained significant after adjustment for confounders. There was no significant difference between groups in 0-24 and 5-24 hour S/E ratio. Conclusion: Small intestinal, but not gastroduodenal, colon and whole gut permeability is increased in patients with diarrhea predominant IBS when compared to healthy controls, irrespective of possible confounding factors. Adjustment for possible confounders is necessary when studying intestinal permeability, especially in a heterogeneous disorder as IBS. Permeability test: sugar excretion and ratios of excreted sugars as measured in urine (in 05, 5-24 and 0-24 hours fraction), for HC, IBS-TOTAL, IBS-D, IBS-C and IBS-M.
S-531
AGA Abstracts
AGA Abstracts
CXCL9, CXCL10 and CXCL11. CXCR3 exists as 2 functional variants, CXCR3-A and CXCR3B. Previous work from this group has demonstrated increased production of CXCL9 and CXCL10 from IBS biopsies when stimulated with anti-CD3/CD28 compared with controls. Aim: The aim of this study was to investigate the expression of CXCR3-A and CXCR3-B in colonic mucosa and the levels of CXCR3 chemokines in plasma of IBS patients Methods: A cohort of IBS patients fulfilling the ROME III criteria completed the ROME III questionnaire on 3 separate times, 3 months apart. Control patients were required to provide a negative bowel questionnaire. Plasma samples from IBS and controls (n=18) were analysed by MSD assays for levels of CXCL10 and CXCL11. In a separate cohort of patients, colonic mucosal biopsies from IBS (n=5) and controls (n=5) were fixed and detection of CXCL10 and CXCR3 was performed by immunohistochemistry. In the same patients, IBS (n=36) and controls (n=34), total RNA was extracted and analysed by RT-qPCR for expression of CXCR3-A and CXCR3-B and the CXCR3 chemokines, CXCL9, CXCL10, CXCL11. The 2_ΔΔCt method was used to calculate relative changes in gene expression, pooled IBS and control biopsy cDNA were used as the calibrator control for analysis of differential gene expression. Results: RT-qPCR analysis of CXCR3-A and CXCR3-B in IBS and controls revealed expression of both CXCR3 transcripts in the mucosa of all IBS patients (n=36) examined while controls did not express CXCR3-A and only 4 control patients (n=34) expressed CXCR3-B. In addition, CXCR3 protein was strongly expressed in the epithelia of IBS patients while being absent from controls. RT-qPCR analysis of CXCL9, CXCL10 and CXCL11 revealed significant reductions in the expression of CXCL9 (p<0.05) and CXCL10 (p<0.01) in biopsies from IBS patients. However, the levels of CXCL10 and CXCL11 were significantly increased periodically in the plasma of IBS patients compared to controls (p<0.05). The levels of plasma CXCL10 (p<0.05, R2 0.3) (and CXCL11, p<0.01, R2 0.3) correlated significantly with the amount of times in the past 3 months that patients had loose or watery stools. Conclusions: Collectively, these data implicate the CXCR3 chemokine system in the pathogenesis of IBS.