- Email: [email protected]
Improving the Quality of Inpatient Ulcerative Colitis Management: Promoting Evidence-Based Practice and Reducing Care Variation
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development. Methods. After 3 week intestinal colonization by the mouse nematode, Heligmosomoides polygyrus bakeri (Hpb), we explored the impact of STAT6 to helminth-induced TGFβ generation by T cells in wild-type (WT) and various engineered strains of mice. We tested the role of STAT6 in helminth-induced and TGFβ-dependent regulation of colitis in a model of acute graft-versus-host disease (GVHD). Results. Hpb colonization stimulated pro-TGFβ expression and active C terminal TGFβ secretion by WT and not by STAT6-/mesenteric lymph node (MLN) T cells. Constitutive STAT6 activity in T cells was sufficient to augment the expression pro-TGFβ protein but not the secretion of active TGFβ cytokine, as analyzed in cells purified from uninfected STAT6 VT mice. STAT6 VT is engineered as a constitutively active form of STAT6 by converting valine and threonine in the SH2 domain to alanines. T lymphocytes of STAT6 VT mice express STAT6 VT; this expression is driven by a CD2 promoter. Hpb infection was required for enhanced secretion of cleaved and active TGFβ from STAT6 VT T cells and - as observed in mice whose T cells are deficient for the endopeptidase, furin - furin was required for Hpb-induced secretion of cleaved and active TGFβ. Furin was not required for the expression of pro-TGFβ by T cells from uninfected or Hpb-infected mice. Hpb infection did not suppress acute GVHD in STAT6-/- bone marrow transplant (BMT) recipients, although it suppressed GVHD in TGFβ-dependent manner and promoted long-term survival (>70 days) in WT BMT mice. TGFβ-dependent expansion of GVHD-regulating Tregs was evident in WT and not in STAT6-/- BMT recipients, indicating the critical role of STAT6-dependent TGFβ generation in helminthic immune regulation. Conclusions. STAT6 is necessary and sufficient for pro-TGFβ expression in T cells, as well as in helminth-induced and TGFβ-dependent suppression of colitis. Moreover, the endopeptidase furin is required to generate active TGFβ from pro-TGFβ by proteolytic cleavage. Thus, we propose a two-step model where STAT6 and furin are successive steps on the developmental pathway to TGFβ-generating Th3 cells. Funded by NIAID and the Department of Veterans Affairs
AGA Abstracts
IL-28-DEPENDENT ACTIVATION OF EPITHELIAL STAT1 DRIVES EPITHELIAL WOUND HEALING IN INFLAMMATORY BOWEL DISEASE Mircea Chiriac, Claudia Günther, Christoph Becker, Jürgen Siebler, Markus Neurath Introduction Inflammatory bowel diseases (IBD) represent a heterogeneous group of chronic, relapsing disorders in which the intestinal homeostasis has been compromised by aberrant immune responses against microbial and environmental factors in genetically predisposed individuals. IL-28 has recently emerged as an important cytokine controlling immune responses at mucosal interfaces including the lung and the skin. We investigated the role of IL-28 signaling in intestinal epithelial cells in the context of IBD and intestinal mucosal healing. Methods Dextran sodium sulfate colitis was induced in wild-type mice and mice with defects in the IL-28 signaling pathway. To assess disease development we used highresolution mini-endoscopy and in vivo imaging. Furthermore, epithelial barrier function assays, histology, Western blotting and immunofluorescence were employed. To address the direct effects of IL-28 on primary intestinal epithelial cells we used three-dimensional organoid cultures, RNA-Seq and gene ontology analysis. We investigated the role of IL-28 for mucosal restitution in vivo using a wound healing mouse model. The results were validated using primary intestinal epithelial cells and biopsies from IBD patients. Results We found increased IL-28 production and IL-28R expression levels in both IBD patients and colitis susceptible mice compared to controls. The IL-28-induced phosphorylation of STAT1 in primary murine and human intestinal epithelial cells was time- and dose-dependent. Interestingly, Il28ra-/-, Irf3-/- and Irf3-/-Irf7-/- mice as well as newly generated conditional knockout mice with a specific deletion of STAT1 in intestinal epithelial cells were highly susceptible to experimental colitis and demonstrated impaired epithelial restitution after injury in vivo. IL-28-dependent phosphorylation of STAT1 induced proliferation of epithelial cells in organoid culture in vitro as well as in experimental DSS colitis and the mucosal wound healing model in vivo. Our RNA-Seq and gene ontology analysis revealed that IL28 signals induced sets of genes implicated in antimicrobial defence and, importantly, the wound healing response. Conclusions IL-28-dependent STAT1 signaling represents an important homeostatic regulator of the gut epithelium and a promoter of epithelial cell proliferation and mucosal wound healing. These results emphasize for the first time a potential use for IL-28 as a therapeutic agent in IBD.
374 MITOCHONDRIAL DNA IS A DAMAGE-ASSOCIATED MOLECULAR PATTERN (DAMP) RELEASED DURING ACTIVE IBD PROMOTING TLR9MEDIATED INFLAMMATION Ray K. Boyapati, David Dorward, Arina Tamborska, Rahul Kalla, Nicholas Ventham, Adriano G. Rossi, Jack Satsangi, Gwo-tzer Ho
372
Background: Due to common evolutionary origins, mitochondrial DNA (mtDNA) shares many similarities with immunogenic bacterial DNA, and is recognised as a damage-associated molecular pattern (DAMP) that activates pro-inflammatory TLR9 signalling pathway. We hypothesised that mtDNA-TLR9 mediated inflammation is important in IBD, and mtDNA is released during active disease serving as a key pro-inflammatory trigger. Methods: Between 2015-2016, we collected plasma separated within 2 hours of sampling from 128 prospectively recruited IBD patients comprising 98 ulcerative colitis (UC) and 30 Crohn's disease (CD), and 39 non-IBD controls, with 210 sample points. We assessed plasma mtDNA levels by qPCR using primers amplifying mitochondrial specific ND2 and COXIII genes. In parallel, we investigated plasma mtDNA in vivo, in acute DSS- and chronic spontaneous mdr1adeficient colitis models; in human IBD: faecal mtDNA levels (n=12 UC vs. 12 healthy controls), electron microscopy (EM) of inflamed colonic mucosa (6 UC vs. 6 healthy controls; intestinal TLR9 protein expression (10 UC, 10 CD and 20 age-matched controls); and acute DSS-colitis in tlr9-deficient mice. Results: Increased cell-free plasma mtDNA was detected in UC (p<0.0001) and CD (p<0.003), as well as acute DSS- and chronic mdr1a-deficient colitis (both p<0.05). MtDNA levels were higher in active disease compared to those in remission in UC (p<0.001) as measured by the Simple Clinical Colitis Activity Index (SCCAI), and mtDNA levels correlated positively with C-reactive protein (r=0.33, p<0.0001) and negatively with albumin (r=-0.32, p<0.0001). MtDNA levels also correlated with severity of DSS-colitis. MtDNA is significantly higher in faecal samples during active UC vs. controls (>20 fold, p=0.005) indicative of local gut release and supported by the presence of intestinal sub-and epithelial deposits of mitochondrial debris by EM. TLR9 expression is higher in intestinal human IBD epithelium suggesting that a downstream pathway is present. Finally, tlr9-gene deletion in mice resulted in significant attenuation of acute-DSS colitis (colitis score, weight loss, and histological severity) confirming the importance of TLR9 pro-inflammatory signalling in colitis. Conclusion: For the first time, we show that significant levels of mtDNA are found systemically and locally in human IBD and in mouse models of acute and chronic colitis. These levels are associated with disease severity. TLR9, the target of mtDNA, is highly expressed in the gut and tlr9-deletion is protective in colitis. Collectively, our data suggest that mtDNA-TL9 signalling is important and a targetable pathway, and mtDNA itself represents an attractive functional potential biomarker in IBD.
TARGETING THE NUCLEAR RECEPTOR LRH-1 TO TREAT INFLAMMATORY BOWEL DISEASE IN MICE Hongtao Wang, Jae M. Lee, Ying Zhou, David D. Moore Background: Inflammatory bowel diseases (IBD) affect approximately 1.5 million patients in the US. It is a complex and chronic autoimmune disease group of unknown causes and without a cure. Murine models of colitis are intensely used in IBD research to identify its pathogenesis or novel therapeutic targets. Nuclear receptor Liver receptor homolog-1 (LRH1) has been proposed to inhibit intestinal and colonic inflammation by inducing epithelial glucocorticoid synthesis in response to inflammatory signals. We have previously identified DLPC (dilauroyl phosphatidylcholine; C12:0-12:0 PC) as an extrinsic agonist ligand for LRH-1. The aim of this study was to test whether DLPC treatment can impact on the inflammatory response in murine models of colitis. Material/Methods: Acute IBD model: 2.5% Dextran sodium sulfate (DSS) was added to the autoclaved drinking water of intestinal epithelial cell-specific LRH-1 knockout (LRH-1IEC-KO) mice and control littermates for 5 days. Chronic IBD model: Wild type splenic naïve CD4+ T cells were intraperitoneally (ip) injected to LRH-1IEC-KORag2-/- mice, human LRH-1 transgenic (hLRH-1IEC-Tg)Rag2-/- mice, and control Rag2-/- mice to induce a chronic immune modified enterocolitis (T cell transfer or Tct model). DLPC (30mg/kg body weight) was ip injected daily for 5 days in DSS fed mice after stopping DSS and for 7 days for Tct mice at the 8-9th week after T cell transfer. Results: In the DSS model, DLPC treatment decreased indirect colitis severity scores (diarrhea, hematochezia, weight loss, and sick appearance) and histological severity. DLPC induced steroidogenic enzymes Cyp11A1 and Cyp11B1 and anti-inflammatory cytokines (IL-10), while suppressing pro-inflammatory cytokines (TNF-alpha and IL-1beta). These anti-inflammatory effects of DLPC were blunted in LRH-1IEC-KO mice. In the Tct model, LRH-1IEC-KO mice showed higher disease activities, hLRH-1IEC-Tg mice showed lower disease activities than those of controls respectively. Similar to the DSS model, DLPC treatment suppressed pro-inflammatory cytokines, reduced colonic damage and disease activities in the Tct model. In both models, treatment with a control PC Dipalmitoyl PC (DPPC), or vehicle, did not reveal any significant effects. Conclusion: LRH-1 activation was beneficial in suppressing colonic inflammation in both acute and chronic IBD models in mice, whereas its suppression may contribute to developing chronic colitis. These findings indicate the protective role of LRH-1 in mammalian colitis by triggering local corticosteroid production in response to injury and autoimmunity. LRH-1 activation might serve as a therapeutic intervention to treat human IBD patients in the future. This work is supported by NIH NIDDK grant, NIH T32 training grant, NIH supported digestive disease center (DDC), NIH supported cytometry & cell sorting core.
393 IMPROVING THE QUALITY OF INPATIENT ULCERATIVE COLITIS MANAGEMENT: PROMOTING EVIDENCE-BASED PRACTICE AND REDUCING CARE VARIATION Ryan A. McConnell, Roshan Patel, Suzanne R. Sharpton, Fernando Velayos, Uma Mahadevan
373 Background: Up to 25% of patients with ulcerative colitis (UC) will require hospitalization for severe disease, resulting in over 36,000 annual UC-related hospitalizations in the U.S. Hospitalization is a high-stakes, vulnerable event in a patient's disease course. Disease severity of this magnitude increases risk of colectomy and venous thromboembolism, and usually commits the patient to both a corticosteroid course and biologic therapy with the associated side effects and risks. Although inpatient quality measures and evidence-based management recommendations exist, there is variation in care delivery at our institution (Table 1). Care coordination and standardization are vital to ensure that appropriate diagnostic tests and therapies are applied at the optimal times. Aim: To develop and implement a quality improvement intervention for inpatient UC management that standardizes gastroenterology (GI) consultant recommendations, improves the delivery of evidence-based care, reduces patient risk exposure, and minimizes length of stay. Intervention: There are 5 components to the intervention: (1) Standardized text inserted into the initial GI consultation note communicating 8 categories of evidence-based recommendations (Table 2). (2) A checklist
A TWO-STEP MODEL - INVOLVING TRANSCRIPTION FACTOR STAT6 AND THE ENDOPEPTIDASE FURIN - FOR THE DEVELOPMENT OF TGFÎ'GENERATING T HELPER 3 (TH3) CELLS AND REGULATION OF COLITIS Weiren Liu, Xiaoqun Guan, John W. Creemers, Marko Pesu, Joseph F. Urban, Mark Kaplan, David E. Elliott, Bruce R. Blazar, Mirac N. Ince Introduction. Peripheral T lymphocytes that produce TGFβ are called T helper 3 (Th3) cells and they play a nonredundant role in suppressing colitis - associated with inflammatory bowel disease (IBD) or other immune-mediated disorders. TGFβ is expressed as a propeptide (pro-TGFβ) where the C terminal cytokine (TGFβ) is activated by proteolytic cleavage of pro-TGFβ. Molecular pathways that lead to Th3 development are unknown. Because intestinal helminths suppress colitis by stimulating peripheral development of Th2 and Th3 cells, we investigated the role of Th2 pathway-associated transcription factor, STAT6 in Th3
AGA Abstracts
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Table 1. New Standard Sedation Classification System
AGA Abstracts
for organizing and documenting completion of patient care items, to be used in subsequent daily GI progress notes. (3) A bundled electronic order set to ease order entry. (4) Stakeholder education for GI fellows, internal medicine residents, and hospitalists. (5) Narcotics awareness campaign, including analgesia information handout for patients and data summary for providers. Study Design: Three-year, single-center, observational study comparing UC management and outcomes over the 2 years pre-intervention (n=42 patients) and 1 year postintervention (n=16 patients to date). The intervention was implemented on July 1, 2016 and enrollment is ongoing. All hospitalized patients with a diagnosis of UC who receive systemic corticosteroids are eligible for study inclusion. Planned Analysis: Process Measures: Fidelity to the intervention, sustainability of the intervention Outcome Measures: The primary outcome is a composite of evidence-based care (C. difficile testing performed, venous thromboembolism prophylaxis ordered, and opiates avoided). Secondary outcomes include the individual components of the composite outcome, time to rescue therapy administration, mean cumulative corticosteroid dose per hospitalization, mean morphine equivalents per day, inpatient and 90-day colectomy rates, length of stay, vaccination rates, and total hospital charges. Preliminary analysis demonstrates improving performance across multiple care components (Table 1). Conclusion: Evidence-based inpatient management of moderatesevere UC may be enhanced with standardized algorithms that reinforce core principles and reduce unnecessary care variation.
GAVE: Gastric antral vascular ectasia; HCV: hepatitis C virus; HIV: human immunodeficiency virus; MAC: monitored anesthesia care; MS: moderate sedation. Table 2. Clinical Data
Table 1. Pre- and post-intervention adherence to inpatient ulcerative colitis evidence-based care principles and ideal performance targets.
Table 2. Categories and example content of the standardized evidence-based recommendations inserted into initial gastroenterology consultation note.
394 IMPLEMENTATION OF A STANDARDIZED SEDATION CLASSIFICATION SYSTEM TO IMPROVE ENDOSCOPY UNIT EFFICIENCY: A QUALITY IMPROVEMENT PROJECT Ricardo Badillo, Bader A. Alajlan, Chien-Huan Chen, Dayna S. Early
395 TRAINEE COLONOSCOPY WITHDRAWAL TIME IS INFLUENCED BY THE INDEPENDENT PERFORMANCE CHARACTERISTICS OF SUPERVISING PHYSICIANS SriHari Mahadev, Richard M. Rosenberg, Benjamin Lebwohl, Daniel E. Freedberg
Background As the patient population becomes more complex, our inpatient endoscopy unit (GIU) has increased its dependence on the anesthesia (ANES) department to assist with monitored anesthesia care (MAC) sedation. However, ANES staff availability is limited and can result in delays in procedure start times or cancellations of non-urgent cases at our busy academic center. Formerly, our sedation planning (FS) relied on attending preference and experience, and was affected by ANES availability. Therefore, we introduced a standardized sedation classification system (SS) to more adequately identify cases able to be performed with moderate sedation (MS) and decrease reliance on ANES support. Aim To assess the efficacy of a new sedation classification system implemented to assist endoscopists in identifying cases for MS using number of cases performed as the primary end point. Methods We performed a retrospective analysis of patients referred for inpatient endoscopy to a single center (June-Dec 2015). ProVation inquiry identified cases scheduled. Prior to September 2015, patient sedation needs were based on attending preference and experience. The SS system was then introduced (Table 1). Clinical data was obtained during the old FS (JuneAug 2015) and new SS guidelines (Oct-Dec 2015). September was excluded for transition. Data collected included endoscopy records, sedation method, GIU schedules, and procedural complications. Cases performed in the intensive care unit, emergency department, or operating rooms were excluded. Results 1,431 cases were scheduled during the study period. 113 cases were excluded and 320 cancellations were reported. 998 total cases (mean age 59 ± 16, 449 females) were performed. The mean number of cases performed daily were similar in both groups (8.01 FS vs 7.45 SS; p=0.27). After SS implementation, the number of MAC cases and cancellations of non-urgent cases significantly decreased, while MS cases increased (Table 2). Overall complication rates were not statistically different in both groups (p=0.42). 2 patients in the FS cohort required intubation, one for hypoxia (started with MAC) and one for food impaction retrieval (MS). 6 patients in the SS cohort (all MAC) were intubated for respiratory distress, laryngospasms, or bleeding. After SS, mean GIU start time improved by 36 minutes (min); and, on the days of least anesthesia availability (Wednesdays), the GIU started 1 hour 28 min earlier. The last MAC case of the day started a mean 46 min earlier. Conclusion A quality improvement project to improve endoscopy unit efficacy by implementing a new sedation classification system saw an increase in MS cases performed and decrease in cancellations while not affecting the number of cases performed daily or rates of complications. The new system also resulted in earlier start times, especially on days of limited anesthesia availability.
Background: Adenoma detection rate (ADR) and withdrawal time (WT) are important measures used to evaluate the quality of screening colonoscopy. Trainee quality measures have been shown to correlate with performance in independent practice, but the factors that determine quality during fellowship are poorly understood. We sought to determine if the performance characteristics of supervising physicians can influence the quality of the screening colonoscopies performed by trainees under their supervision. Methods: In this retrospective cohort study we reviewed colonoscopies performed at a single endoscopy unit affiliated with a teaching hospital. Screening colonoscopies performed from March 2006 to October 2015 on average-risk outpatients ≥50 years were eligible for inclusion. Patient and procedure characteristics were obtained electronically from endoscopy reports. Adenomas were identified from a linked pathology database and WT was determined for a subset of exams in which no maneuver was performed. Supervisor characteristics (ADR and WT) were calculated from procedures performed independently (without a fellow). Supervisors were dichotomized into above- and below-average performers, based on median ADR and WT for supervisors during this time span. The ADR and WT was then compared for cases performed by fellows under the supervision of above- versus below-average performers. Multivariable regression was used to determine independent predictors of fellow WT and ADR. Results: 13,690 average-risk screening colonoscopies were performed by 39 attending physicians, with a further 2,528 colonoscopies performed by one of 64 trainees (gastroenterology fellows) under their supervision. Sex and mean age were similar for attending and fellow cases (Table 1). Fellow cases were more likely to have suboptimal prep (31% vs 23%, p < 0.001). Overall ADR was higher for fellow cases (28.6% vs 24.9%, p < 0.001), while WT was longer (12.7 vs 8.8 min, p < 0.001). Fellow rates of adenoma detection did not differ significantly for exams supervised by high-ADR vs low-ADR physicians (29.6 vs 28.0, p = 0.386). Fellow WT was prolonged, however, for cases supervised by high-WT vs low-WT physicians (13.1 vs 11.2 min, p = 0.001). After adjusting for sex, age, and suboptimal preparation, fellow WT increased an average of 0.5 minutes for every 1 minute increase in a supervising physician WT (b-coeff 0.50, 95% CI 0.14-0.86, p = 0.006, Table 2). Conclusions: Trainee endoscopists seem to emulate the behavior of supervising physicians, taking longer to examine the colon when supervised by physicians who also do so. Further study on the impact of supervisor traits on trainee performance is warranted.
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AGA Abstracts
development. Methods. After 3 week intestinal colonization by the mouse nematode, Heligmosomoides polygyrus bakeri (Hpb), we explored the impact of STAT6 to helminth-induced TGFβ generation by T cells in wild-type (WT) and various engineered strains of mice. We tested the role of STAT6 in helminth-induced and TGFβ-dependent regulation of colitis in a model of acute graft-versus-host disease (GVHD). Results. Hpb colonization stimulated pro-TGFβ expression and active C terminal TGFβ secretion by WT and not by STAT6-/mesenteric lymph node (MLN) T cells. Constitutive STAT6 activity in T cells was sufficient to augment the expression pro-TGFβ protein but not the secretion of active TGFβ cytokine, as analyzed in cells purified from uninfected STAT6 VT mice. STAT6 VT is engineered as a constitutively active form of STAT6 by converting valine and threonine in the SH2 domain to alanines. T lymphocytes of STAT6 VT mice express STAT6 VT; this expression is driven by a CD2 promoter. Hpb infection was required for enhanced secretion of cleaved and active TGFβ from STAT6 VT T cells and - as observed in mice whose T cells are deficient for the endopeptidase, furin - furin was required for Hpb-induced secretion of cleaved and active TGFβ. Furin was not required for the expression of pro-TGFβ by T cells from uninfected or Hpb-infected mice. Hpb infection did not suppress acute GVHD in STAT6-/- bone marrow transplant (BMT) recipients, although it suppressed GVHD in TGFβ-dependent manner and promoted long-term survival (>70 days) in WT BMT mice. TGFβ-dependent expansion of GVHD-regulating Tregs was evident in WT and not in STAT6-/- BMT recipients, indicating the critical role of STAT6-dependent TGFβ generation in helminthic immune regulation. Conclusions. STAT6 is necessary and sufficient for pro-TGFβ expression in T cells, as well as in helminth-induced and TGFβ-dependent suppression of colitis. Moreover, the endopeptidase furin is required to generate active TGFβ from pro-TGFβ by proteolytic cleavage. Thus, we propose a two-step model where STAT6 and furin are successive steps on the developmental pathway to TGFβ-generating Th3 cells. Funded by NIAID and the Department of Veterans Affairs
AGA Abstracts
IL-28-DEPENDENT ACTIVATION OF EPITHELIAL STAT1 DRIVES EPITHELIAL WOUND HEALING IN INFLAMMATORY BOWEL DISEASE Mircea Chiriac, Claudia Günther, Christoph Becker, Jürgen Siebler, Markus Neurath Introduction Inflammatory bowel diseases (IBD) represent a heterogeneous group of chronic, relapsing disorders in which the intestinal homeostasis has been compromised by aberrant immune responses against microbial and environmental factors in genetically predisposed individuals. IL-28 has recently emerged as an important cytokine controlling immune responses at mucosal interfaces including the lung and the skin. We investigated the role of IL-28 signaling in intestinal epithelial cells in the context of IBD and intestinal mucosal healing. Methods Dextran sodium sulfate colitis was induced in wild-type mice and mice with defects in the IL-28 signaling pathway. To assess disease development we used highresolution mini-endoscopy and in vivo imaging. Furthermore, epithelial barrier function assays, histology, Western blotting and immunofluorescence were employed. To address the direct effects of IL-28 on primary intestinal epithelial cells we used three-dimensional organoid cultures, RNA-Seq and gene ontology analysis. We investigated the role of IL-28 for mucosal restitution in vivo using a wound healing mouse model. The results were validated using primary intestinal epithelial cells and biopsies from IBD patients. Results We found increased IL-28 production and IL-28R expression levels in both IBD patients and colitis susceptible mice compared to controls. The IL-28-induced phosphorylation of STAT1 in primary murine and human intestinal epithelial cells was time- and dose-dependent. Interestingly, Il28ra-/-, Irf3-/- and Irf3-/-Irf7-/- mice as well as newly generated conditional knockout mice with a specific deletion of STAT1 in intestinal epithelial cells were highly susceptible to experimental colitis and demonstrated impaired epithelial restitution after injury in vivo. IL-28-dependent phosphorylation of STAT1 induced proliferation of epithelial cells in organoid culture in vitro as well as in experimental DSS colitis and the mucosal wound healing model in vivo. Our RNA-Seq and gene ontology analysis revealed that IL28 signals induced sets of genes implicated in antimicrobial defence and, importantly, the wound healing response. Conclusions IL-28-dependent STAT1 signaling represents an important homeostatic regulator of the gut epithelium and a promoter of epithelial cell proliferation and mucosal wound healing. These results emphasize for the first time a potential use for IL-28 as a therapeutic agent in IBD.
374 MITOCHONDRIAL DNA IS A DAMAGE-ASSOCIATED MOLECULAR PATTERN (DAMP) RELEASED DURING ACTIVE IBD PROMOTING TLR9MEDIATED INFLAMMATION Ray K. Boyapati, David Dorward, Arina Tamborska, Rahul Kalla, Nicholas Ventham, Adriano G. Rossi, Jack Satsangi, Gwo-tzer Ho
372
Background: Due to common evolutionary origins, mitochondrial DNA (mtDNA) shares many similarities with immunogenic bacterial DNA, and is recognised as a damage-associated molecular pattern (DAMP) that activates pro-inflammatory TLR9 signalling pathway. We hypothesised that mtDNA-TLR9 mediated inflammation is important in IBD, and mtDNA is released during active disease serving as a key pro-inflammatory trigger. Methods: Between 2015-2016, we collected plasma separated within 2 hours of sampling from 128 prospectively recruited IBD patients comprising 98 ulcerative colitis (UC) and 30 Crohn's disease (CD), and 39 non-IBD controls, with 210 sample points. We assessed plasma mtDNA levels by qPCR using primers amplifying mitochondrial specific ND2 and COXIII genes. In parallel, we investigated plasma mtDNA in vivo, in acute DSS- and chronic spontaneous mdr1adeficient colitis models; in human IBD: faecal mtDNA levels (n=12 UC vs. 12 healthy controls), electron microscopy (EM) of inflamed colonic mucosa (6 UC vs. 6 healthy controls; intestinal TLR9 protein expression (10 UC, 10 CD and 20 age-matched controls); and acute DSS-colitis in tlr9-deficient mice. Results: Increased cell-free plasma mtDNA was detected in UC (p<0.0001) and CD (p<0.003), as well as acute DSS- and chronic mdr1a-deficient colitis (both p<0.05). MtDNA levels were higher in active disease compared to those in remission in UC (p<0.001) as measured by the Simple Clinical Colitis Activity Index (SCCAI), and mtDNA levels correlated positively with C-reactive protein (r=0.33, p<0.0001) and negatively with albumin (r=-0.32, p<0.0001). MtDNA levels also correlated with severity of DSS-colitis. MtDNA is significantly higher in faecal samples during active UC vs. controls (>20 fold, p=0.005) indicative of local gut release and supported by the presence of intestinal sub-and epithelial deposits of mitochondrial debris by EM. TLR9 expression is higher in intestinal human IBD epithelium suggesting that a downstream pathway is present. Finally, tlr9-gene deletion in mice resulted in significant attenuation of acute-DSS colitis (colitis score, weight loss, and histological severity) confirming the importance of TLR9 pro-inflammatory signalling in colitis. Conclusion: For the first time, we show that significant levels of mtDNA are found systemically and locally in human IBD and in mouse models of acute and chronic colitis. These levels are associated with disease severity. TLR9, the target of mtDNA, is highly expressed in the gut and tlr9-deletion is protective in colitis. Collectively, our data suggest that mtDNA-TL9 signalling is important and a targetable pathway, and mtDNA itself represents an attractive functional potential biomarker in IBD.
TARGETING THE NUCLEAR RECEPTOR LRH-1 TO TREAT INFLAMMATORY BOWEL DISEASE IN MICE Hongtao Wang, Jae M. Lee, Ying Zhou, David D. Moore Background: Inflammatory bowel diseases (IBD) affect approximately 1.5 million patients in the US. It is a complex and chronic autoimmune disease group of unknown causes and without a cure. Murine models of colitis are intensely used in IBD research to identify its pathogenesis or novel therapeutic targets. Nuclear receptor Liver receptor homolog-1 (LRH1) has been proposed to inhibit intestinal and colonic inflammation by inducing epithelial glucocorticoid synthesis in response to inflammatory signals. We have previously identified DLPC (dilauroyl phosphatidylcholine; C12:0-12:0 PC) as an extrinsic agonist ligand for LRH-1. The aim of this study was to test whether DLPC treatment can impact on the inflammatory response in murine models of colitis. Material/Methods: Acute IBD model: 2.5% Dextran sodium sulfate (DSS) was added to the autoclaved drinking water of intestinal epithelial cell-specific LRH-1 knockout (LRH-1IEC-KO) mice and control littermates for 5 days. Chronic IBD model: Wild type splenic naïve CD4+ T cells were intraperitoneally (ip) injected to LRH-1IEC-KORag2-/- mice, human LRH-1 transgenic (hLRH-1IEC-Tg)Rag2-/- mice, and control Rag2-/- mice to induce a chronic immune modified enterocolitis (T cell transfer or Tct model). DLPC (30mg/kg body weight) was ip injected daily for 5 days in DSS fed mice after stopping DSS and for 7 days for Tct mice at the 8-9th week after T cell transfer. Results: In the DSS model, DLPC treatment decreased indirect colitis severity scores (diarrhea, hematochezia, weight loss, and sick appearance) and histological severity. DLPC induced steroidogenic enzymes Cyp11A1 and Cyp11B1 and anti-inflammatory cytokines (IL-10), while suppressing pro-inflammatory cytokines (TNF-alpha and IL-1beta). These anti-inflammatory effects of DLPC were blunted in LRH-1IEC-KO mice. In the Tct model, LRH-1IEC-KO mice showed higher disease activities, hLRH-1IEC-Tg mice showed lower disease activities than those of controls respectively. Similar to the DSS model, DLPC treatment suppressed pro-inflammatory cytokines, reduced colonic damage and disease activities in the Tct model. In both models, treatment with a control PC Dipalmitoyl PC (DPPC), or vehicle, did not reveal any significant effects. Conclusion: LRH-1 activation was beneficial in suppressing colonic inflammation in both acute and chronic IBD models in mice, whereas its suppression may contribute to developing chronic colitis. These findings indicate the protective role of LRH-1 in mammalian colitis by triggering local corticosteroid production in response to injury and autoimmunity. LRH-1 activation might serve as a therapeutic intervention to treat human IBD patients in the future. This work is supported by NIH NIDDK grant, NIH T32 training grant, NIH supported digestive disease center (DDC), NIH supported cytometry & cell sorting core.
393 IMPROVING THE QUALITY OF INPATIENT ULCERATIVE COLITIS MANAGEMENT: PROMOTING EVIDENCE-BASED PRACTICE AND REDUCING CARE VARIATION Ryan A. McConnell, Roshan Patel, Suzanne R. Sharpton, Fernando Velayos, Uma Mahadevan
373 Background: Up to 25% of patients with ulcerative colitis (UC) will require hospitalization for severe disease, resulting in over 36,000 annual UC-related hospitalizations in the U.S. Hospitalization is a high-stakes, vulnerable event in a patient's disease course. Disease severity of this magnitude increases risk of colectomy and venous thromboembolism, and usually commits the patient to both a corticosteroid course and biologic therapy with the associated side effects and risks. Although inpatient quality measures and evidence-based management recommendations exist, there is variation in care delivery at our institution (Table 1). Care coordination and standardization are vital to ensure that appropriate diagnostic tests and therapies are applied at the optimal times. Aim: To develop and implement a quality improvement intervention for inpatient UC management that standardizes gastroenterology (GI) consultant recommendations, improves the delivery of evidence-based care, reduces patient risk exposure, and minimizes length of stay. Intervention: There are 5 components to the intervention: (1) Standardized text inserted into the initial GI consultation note communicating 8 categories of evidence-based recommendations (Table 2). (2) A checklist
A TWO-STEP MODEL - INVOLVING TRANSCRIPTION FACTOR STAT6 AND THE ENDOPEPTIDASE FURIN - FOR THE DEVELOPMENT OF TGFÎ'GENERATING T HELPER 3 (TH3) CELLS AND REGULATION OF COLITIS Weiren Liu, Xiaoqun Guan, John W. Creemers, Marko Pesu, Joseph F. Urban, Mark Kaplan, David E. Elliott, Bruce R. Blazar, Mirac N. Ince Introduction. Peripheral T lymphocytes that produce TGFβ are called T helper 3 (Th3) cells and they play a nonredundant role in suppressing colitis - associated with inflammatory bowel disease (IBD) or other immune-mediated disorders. TGFβ is expressed as a propeptide (pro-TGFβ) where the C terminal cytokine (TGFβ) is activated by proteolytic cleavage of pro-TGFβ. Molecular pathways that lead to Th3 development are unknown. Because intestinal helminths suppress colitis by stimulating peripheral development of Th2 and Th3 cells, we investigated the role of Th2 pathway-associated transcription factor, STAT6 in Th3
AGA Abstracts
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Table 1. New Standard Sedation Classification System
AGA Abstracts
for organizing and documenting completion of patient care items, to be used in subsequent daily GI progress notes. (3) A bundled electronic order set to ease order entry. (4) Stakeholder education for GI fellows, internal medicine residents, and hospitalists. (5) Narcotics awareness campaign, including analgesia information handout for patients and data summary for providers. Study Design: Three-year, single-center, observational study comparing UC management and outcomes over the 2 years pre-intervention (n=42 patients) and 1 year postintervention (n=16 patients to date). The intervention was implemented on July 1, 2016 and enrollment is ongoing. All hospitalized patients with a diagnosis of UC who receive systemic corticosteroids are eligible for study inclusion. Planned Analysis: Process Measures: Fidelity to the intervention, sustainability of the intervention Outcome Measures: The primary outcome is a composite of evidence-based care (C. difficile testing performed, venous thromboembolism prophylaxis ordered, and opiates avoided). Secondary outcomes include the individual components of the composite outcome, time to rescue therapy administration, mean cumulative corticosteroid dose per hospitalization, mean morphine equivalents per day, inpatient and 90-day colectomy rates, length of stay, vaccination rates, and total hospital charges. Preliminary analysis demonstrates improving performance across multiple care components (Table 1). Conclusion: Evidence-based inpatient management of moderatesevere UC may be enhanced with standardized algorithms that reinforce core principles and reduce unnecessary care variation.
GAVE: Gastric antral vascular ectasia; HCV: hepatitis C virus; HIV: human immunodeficiency virus; MAC: monitored anesthesia care; MS: moderate sedation. Table 2. Clinical Data
Table 1. Pre- and post-intervention adherence to inpatient ulcerative colitis evidence-based care principles and ideal performance targets.
Table 2. Categories and example content of the standardized evidence-based recommendations inserted into initial gastroenterology consultation note.
394 IMPLEMENTATION OF A STANDARDIZED SEDATION CLASSIFICATION SYSTEM TO IMPROVE ENDOSCOPY UNIT EFFICIENCY: A QUALITY IMPROVEMENT PROJECT Ricardo Badillo, Bader A. Alajlan, Chien-Huan Chen, Dayna S. Early
395 TRAINEE COLONOSCOPY WITHDRAWAL TIME IS INFLUENCED BY THE INDEPENDENT PERFORMANCE CHARACTERISTICS OF SUPERVISING PHYSICIANS SriHari Mahadev, Richard M. Rosenberg, Benjamin Lebwohl, Daniel E. Freedberg
Background As the patient population becomes more complex, our inpatient endoscopy unit (GIU) has increased its dependence on the anesthesia (ANES) department to assist with monitored anesthesia care (MAC) sedation. However, ANES staff availability is limited and can result in delays in procedure start times or cancellations of non-urgent cases at our busy academic center. Formerly, our sedation planning (FS) relied on attending preference and experience, and was affected by ANES availability. Therefore, we introduced a standardized sedation classification system (SS) to more adequately identify cases able to be performed with moderate sedation (MS) and decrease reliance on ANES support. Aim To assess the efficacy of a new sedation classification system implemented to assist endoscopists in identifying cases for MS using number of cases performed as the primary end point. Methods We performed a retrospective analysis of patients referred for inpatient endoscopy to a single center (June-Dec 2015). ProVation inquiry identified cases scheduled. Prior to September 2015, patient sedation needs were based on attending preference and experience. The SS system was then introduced (Table 1). Clinical data was obtained during the old FS (JuneAug 2015) and new SS guidelines (Oct-Dec 2015). September was excluded for transition. Data collected included endoscopy records, sedation method, GIU schedules, and procedural complications. Cases performed in the intensive care unit, emergency department, or operating rooms were excluded. Results 1,431 cases were scheduled during the study period. 113 cases were excluded and 320 cancellations were reported. 998 total cases (mean age 59 ± 16, 449 females) were performed. The mean number of cases performed daily were similar in both groups (8.01 FS vs 7.45 SS; p=0.27). After SS implementation, the number of MAC cases and cancellations of non-urgent cases significantly decreased, while MS cases increased (Table 2). Overall complication rates were not statistically different in both groups (p=0.42). 2 patients in the FS cohort required intubation, one for hypoxia (started with MAC) and one for food impaction retrieval (MS). 6 patients in the SS cohort (all MAC) were intubated for respiratory distress, laryngospasms, or bleeding. After SS, mean GIU start time improved by 36 minutes (min); and, on the days of least anesthesia availability (Wednesdays), the GIU started 1 hour 28 min earlier. The last MAC case of the day started a mean 46 min earlier. Conclusion A quality improvement project to improve endoscopy unit efficacy by implementing a new sedation classification system saw an increase in MS cases performed and decrease in cancellations while not affecting the number of cases performed daily or rates of complications. The new system also resulted in earlier start times, especially on days of limited anesthesia availability.
Background: Adenoma detection rate (ADR) and withdrawal time (WT) are important measures used to evaluate the quality of screening colonoscopy. Trainee quality measures have been shown to correlate with performance in independent practice, but the factors that determine quality during fellowship are poorly understood. We sought to determine if the performance characteristics of supervising physicians can influence the quality of the screening colonoscopies performed by trainees under their supervision. Methods: In this retrospective cohort study we reviewed colonoscopies performed at a single endoscopy unit affiliated with a teaching hospital. Screening colonoscopies performed from March 2006 to October 2015 on average-risk outpatients ≥50 years were eligible for inclusion. Patient and procedure characteristics were obtained electronically from endoscopy reports. Adenomas were identified from a linked pathology database and WT was determined for a subset of exams in which no maneuver was performed. Supervisor characteristics (ADR and WT) were calculated from procedures performed independently (without a fellow). Supervisors were dichotomized into above- and below-average performers, based on median ADR and WT for supervisors during this time span. The ADR and WT was then compared for cases performed by fellows under the supervision of above- versus below-average performers. Multivariable regression was used to determine independent predictors of fellow WT and ADR. Results: 13,690 average-risk screening colonoscopies were performed by 39 attending physicians, with a further 2,528 colonoscopies performed by one of 64 trainees (gastroenterology fellows) under their supervision. Sex and mean age were similar for attending and fellow cases (Table 1). Fellow cases were more likely to have suboptimal prep (31% vs 23%, p < 0.001). Overall ADR was higher for fellow cases (28.6% vs 24.9%, p < 0.001), while WT was longer (12.7 vs 8.8 min, p < 0.001). Fellow rates of adenoma detection did not differ significantly for exams supervised by high-ADR vs low-ADR physicians (29.6 vs 28.0, p = 0.386). Fellow WT was prolonged, however, for cases supervised by high-WT vs low-WT physicians (13.1 vs 11.2 min, p = 0.001). After adjusting for sex, age, and suboptimal preparation, fellow WT increased an average of 0.5 minutes for every 1 minute increase in a supervising physician WT (b-coeff 0.50, 95% CI 0.14-0.86, p = 0.006, Table 2). Conclusions: Trainee endoscopists seem to emulate the behavior of supervising physicians, taking longer to examine the colon when supervised by physicians who also do so. Further study on the impact of supervisor traits on trainee performance is warranted.
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AGA Abstracts