IMPORTANCE Treatment of Crohn disease is rapidly evolving, with the induction of novel biologic therapies and newer, often more intensive treatment approaches. Knowing how to treat individual ...patients in this quickly changing milieu can be a challenge. OBJECTIVE To review the diagnosis and management of moderate to severe Crohn disease, with a focus on newer treatments and goals of care. EVIDENCE REVIEW MEDLINE was searched from 2000 to 2011. Additional citations were procured from references of select research and review articles. Evidence was graded using the American Heart Association level-of-evidence guidelines. RESULTS Although mesalamines are still often used to treat Crohn disease, the evidence for their efficacy is lacking. Corticosteroids can be effectively used to induce remission in moderate to severe Crohn disease, but they do not maintain remission. The mainstays of treatment are immunomodulators and biologics, particularly anti–tumor necrosis factor. CONCLUSION AND RELEVANCE Immunomodulators and biologics are now the preferred treatment options for Crohn disease.
This paper is the first in a series of two publications relating to the European Crohn's and Colitis Organisation ECCO evidence-based consensus on the diagnosis and management of Crohn's disease and ...concerns the methodology of the consensus process, and the classification, diagnosis and medical management of active and quiescent Crohn's disease. Surgical management as well as special situations including management of perianal Crohn's disease of this ECCO Consensus are covered in a subsequent second paper Gionchetti et al JCC 2016.
Summary Crohn's disease is a chronic inflammatory disease of the gastrointestinal tract, with increasing incidence worldwide. Crohn's disease might result from a complex interplay between genetic ...susceptibility, environmental factors, and altered gut microbiota, leading to dysregulated innate and adaptive immune responses. The typical clinical scenario is a young patient presenting with abdominal pain, chronic diarrhoea, weight loss, and fatigue. Assessment of disease extent and of prognostic factors for complications is paramount to guide therapeutic decisions. Current strategies aim for deep and long-lasting remission, with the goal of preventing complications, such as surgery, and blocking disease progression. Central to these strategies is the introduction of early immunosuppression or combination therapy with biologicals in high-risk patients, combined with a tight and frequent control of inflammation, and adjustment of therapy on the basis of that assessment (treat to target strategy). The therapeutic armamentarium for Crohn's disease is expanding, and therefore the need to develop biomarkers that can predict response to therapies will become increasingly important for personalised medicine decisions in the near future. In this Seminar, we provide a physician-oriented overview of Crohn's disease in adults, ranging from epidemiology and cause to clinical diagnosis, natural history, patient stratification and clinical management, and ending with an overview of emerging therapies and future directions for research.
Crohn's disease is an idiopathic inflammatory disorder of unknown etiology with genetic, immunologic, and environmental influences. The incidence of Crohn's disease has steadily increased over the ...past several decades. The diagnosis and treatment of patients with Crohn's disease has evolved since the last practice guideline was published. These guidelines represent the official practice recommendations of the American College of Gastroenterology and were developed under the auspices of the Practice Parameters Committee for the management of adult patients with Crohn's disease. These guidelines are established for clinical practice with the intent of suggesting preferable approaches to particular medical problems as established by interpretation and collation of scientifically valid research, derived from extensive review of published literature. When exercising clinical judgment, health-care providers should incorporate this guideline along with patient's needs, desires, and their values in order to fully and appropriately care for patients with Crohn's disease. This guideline is intended to be flexible, not necessarily indicating the only acceptable approach, and should be distinguished from standards of care that are inflexible and rarely violated. To evaluate the level of evidence and strength of recommendations, we used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The Committee reviews guidelines in depth, with participation from experienced clinicians and others in related fields. The final recommendations are based on the data available at the time of the production of the document and may be updated with pertinent scientific developments at a later time.
Several large-scale genome-wide association studies genetically linked IRGM to Crohn’s disease and other inflammatory disorders in which the IRGM appears to have a protective function. However, the ...mechanism by which IRGM accomplishes this anti-inflammatory role remains unclear. Here, we reveal that IRGM/Irgm1 is a negative regulator of the NLRP3 inflammasome activation. We show that IRGM expression, which is increased by PAMPs, DAMPs, and microbes, can suppress the pro-inflammatory responses provoked by the same stimuli. IRGM/Irgm1 negatively regulates IL-1β maturation by suppressing the activation of the NLRP3 inflammasome. Mechanistically, we show that IRGM interacts with NLRP3 and ASC and hinders inflammasome assembly by blocking their oligomerization. Further, IRGM mediates selective autophagic degradation of NLRP3 and ASC. By suppressing inflammasome activation, IRGM/Irgm1 protects from pyroptosis and gut inflammation in a Crohn’s disease experimental mouse model. This study for the first time identifies the mechanism by which IRGM is protective against inflammatory disorders.
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•IRGM negatively regulates NLRP3/ASC inflammasome activation•IRGM obstructs NLRP3/ASC inflammasome assembly•IRGM mediates selective autophagic degradation of NLRP3/ASC inflammasome•Irgm1 by suppressing Nlrp3 inflammasome prevents gut inflammation in an IBD mouse model
The IRGM is an established genetic risk factor for Crohn’s diseases and several other inflammatory disorders. Mehto et al. show that IRGM inhibits NLRP3 inflammasome activation to keep the inflammation under check. This study provides a basis for the protective function of IRGM in inflammatory diseases.
Background
Inflammatory bowel disease (IBD), comprised of Crohn's disease (CD) and ulcerative colitis (UC), is characterized by chronic mucosal inflammation, frequent hospitalizations, adverse health ...economics, and compromised quality of life. Diet has been hypothesised to influence IBD activity.
Objectives
To evaluate the efficacy and safety of dietary interventions on IBD outcomes.
Search methods
We searched the Cochrane IBD Group Specialized Register, CENTRAL, MEDLINE, Embase, Web of Science, Clinicaltrials.gov and the WHO ICTRP from inception to 31 January 2019. We also scanned reference lists of included studies, relevant reviews and guidelines.
Selection criteria
We included randomized controlled trials (RCTs) that compared the effects of dietary manipulations to other diets in participants with IBD. Studies that exclusively focused on enteral nutrition, oral nutrient supplementation, medical foods, probiotics, and parenteral nutrition were excluded.
Data collection and analysis
Two review authors independently performed study selection, extracted data and assessed bias using the risk of bias tool. We conducted meta‐analyses where possible using a random‐effects model and calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for dichotomous outcomes. We assessed the certainty of evidence using GRADE.
Main results
The review included 18 RCTs with 1878 participants. The studies assessed different dietary interventions for active CD (six studies), inactive CD (seven studies), active UC (one study) and inactive UC (four studies). Dietary interventions involved either the consumption of low amounts or complete exclusion of one or more food groups known to trigger IBD symptoms. There was limited scope for data pooling as the interventions and control diets were diverse. The studies were mostly inadequately powered. Fourteen studies were rated as high risk of bias. The other studies were rated as unclear risk of bias.
The effect of high fiber, low refined carbohydrates, low microparticle diet, low calcium diet, symptoms‐guided diet and highly restricted organic diet on clinical remission in active CD is uncertain. At 4 weeks, remission was induced in: 100% (4/4) of participants in the low refined carbohydrates diet group compared to 0% (0/3) of participants in the control group (RR 7.20, 95% CI 0.53 to 97.83; 7 participants; 1 study; very low certainty evidence). At 16 weeks, 44% (23/52) of participants in the low microparticle diet achieved clinical remission compared to 25% (13/51) of control‐group participants (RR 3.13, 95% CI 0.22 to 43.84; 103 participants; 2 studies; I² = 73%; very low certainty evidence). Fifty per cent (16/32) of participants in the symptoms‐guided diet group achieved clinical remission compared to 0% (0/19) of control group participants (RR 20.00, 95% CI 1.27 to 315.40; 51 participants ; 1 study; very low certainty evidence) (follow‐up unclear). At 24 weeks, 50% (4/8) of participants in the highly restricted organic diet achieved clinical remission compared to 50% (5/10) of participants in the control group (RR 1.00, 95% CI 0.39 to 2.53; 18 participants; 1 study; very low certainty evidence). At 16 weeks, 37% (16/43) participants following a low calcium diet achieved clinical remission compared to 30% (12/40) in the control group (RR 1.24, 95% CI 0.67 to 2.29; 83 participants; 1 study; very low certainty evidence).
The effect of low refined carbohydrate diets, symptoms‐guided diets and low red processed meat diets on relapse in inactive CD is uncertain. At 12 to 24 months, 67% (176/264) of participants in low refined carbohydrate diet relapsed compared to 64% (193/303) in the control group (RR 1.04, 95% CI 0.87 to 1.25; 567 participants; 3 studies; I² = 35%; low certainty evidence). At 6 to 24 months, 48% (24/50) of participants in the symptoms‐guided diet group relapsed compared to 83% (40/48) participants in the control diet (RR 0.53, 95% CI 0.28 to 1.01; 98 participants ; 2 studies; I² = 54%; low certainty evidence). At 48 weeks, 66% (63/96) of participants in the low red and processed meat diet group relapsed compared to 63% (75/118) of the control group (RR 1.03, 95% CI 0.85 to 1.26; 214 participants; 1 study; low certainty evidence). At 12 months, 0% (0/16) of participants on an exclusion diet comprised of low disaccharides / grains / saturated fats / red and processed meat experienced clinical relapse compared to 26% (10/38) of participants on a control group (RR 0.11, 95% CI 0.01 to 1.76; 54 participants; 1 study; very low certainty evidence).
The effect of a symptoms‐guided diet on clinical remission in active UC is uncertain. At six weeks, 36% (4/11) of symptoms‐guided diet participants achieved remission compared to 0% (0/10) of usual diet participants (RR 8.25, 95% CI 0.50 to 136.33; 21 participants; 1 study; very low certainty evidence).
The effect of the Alberta‐based anti‐inflammatory diet, the Carrageenan‐free diet or milk‐free diet on relapse rates in inactive UC is uncertain. At 6 months, 36% (5/14) of participants in the Alberta‐based anti‐inflammatory diet group relapsed compared to 29% (4/14) of participants in the control group (RR 1.25, 95% CI 0.42 to 3.70; 28 participants; 1 study; very low certainty evidence). Thirty per cent (3/10) of participants following the carrageenan‐free diet for 12 months relapsed compared to 60% (3/5) of the participants in the control group (RR 0.50, 95% CI 0.15 to 1.64; 15 participants; 1 study; very low certainty evidence). At 12 months, 59% (23/39) of milk free diet participants relapsed compared to 68% (26/38) of control diet participants (RR 0.83, 95% CI 0.60 to 1.15; 77 participants; 2 studies; I² = 0%; low certainty evidence).
None of the included studies reported on diet‐related adverse events.
Authors' conclusions
The effects of dietary interventions on CD and UC are uncertain. Thus no firm conclusions regarding the benefits and harms of dietary interventions in CD and UC can be drawn. There is need for consensus on the composition of dietary interventions in IBD and more RCTs are required to evaluate these interventions. Currently, there are at least five ongoing studies (estimated enrollment of 498 participants). This review will be updated when the results of these studies are available.
Vitamin D exerts a regulatory role over mucosal immunity via the vitamin D receptor (VDR). Although Paneth cells and their products are known to regulate the commensal and pathogenic microbiota, the ...role that VDRs in Paneth cells play in these responses is unknown.
We identified the decreased intestinal VDR significantly correlated with reduction of an inflammatory bowel disease risk gene ATG16L1 and Paneth cell lysozymes in patients with Crohn’s disease. We generated Paneth cell–specific VDR knockout (VDRΔPC) mice to investigate the molecular mechanisms.
Lysozymes in the Paneth cells were significantly decreased in the VDRΔPC mice. Isolated VDRΔPC Paneth cells exhibited weakened inhibition of pathogenic bacterial growth and displayed reduced autophagic responses. VDRΔPC mice had significantly higher inflammation after Salmonella infections. VDRΔPC mice also showed high susceptibility to small intestinal injury induced by indomethacin, a nonsteroidal anti-inflammatory drug. Co-housing of VDRΔPC and VDRlox mice made the VDRΔPC less vulnerable to dextran sulfate sodium colitis, suggesting the transmission of protective bacterial from the VDRlox mice. Thus, a lack of VDR in Paneth cells leads to impaired antibacterial activities and consequently increased inflammatory responses. Genetically and environmentally regulated VDRs in the Paneth cells may set the threshold for the development of chronic inflammation, as observed in inflammatory bowel diseases.
We provide new insights into the tissue-specific functions of VDRs in maintaining Paneth cell alertness to pathogens in intestinal disorders. Targeting the VDR affects multiple downstream events within Paneth cells that inhibit intestinal inflammation and establish host defense against enteropathogens.
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This paper is the second in a series of two publications relating to the European Crohn's and Colitis Organisation ECCO evidence-based consensus on the diagnosis and management of Crohn's disease CD ...and concerns the surgical management of CD as well as special situations including management of perianal CD and extraintestinal manifestations. Diagnostic approaches and medical management of CD of this ECCO Consensus are covered in the first paper Gomollon et al JCC 2016.
Crohn’s disease is a chronic inflammatory disease process involving different sites in the gastrointestinal tract.Occasionally,so-called metastatic disease occurs in extra-intestinal ...sites.Granulomatous inflammation may be detected in endoscopic biopsies or resected tissues.Genetic,epigenetic and environmental factors appear to play a role.Multiple susceptibility genes have been described in both familial and non-familial forms while the disease is phenotypically heterogeneous with a female predominance.The disorder occurs over a broad age spectrum,from early childhood to late adulthood.More than 80%are diagnosed before age 40 years usually with terminal ileal and colonic involvement.Pediatric-onset disease is more severe and more extensive,usually with a higher chance of upper gastrointestinal tract disease,compared to adult-onset disease.Long-term studies have shown that the disorder may evolve with time into more complex disease with stricture formation and penetrating disease complications(i.e.,fistula,abscess).Although prolonged remission may occur,discrete periods of symptomatic disease may re-appear over many decades suggesting recurrence or re-activation of this inflammatory process.Eventual development of a cure will likely depend on identification of an etiologic cause and a fundamental understanding of its pathogenesis.Until now,treatment has focused on removing risk factors,particularly cigarette smoking,and improving symptoms.In clinical trials,clinical remission is largely defined as improved numerical and endoscopic indices for"mucosal healing"."Deep remission"is a conceptual,more"extended"goal that may or may not alter the long-term natural history of the disease in selected patients,albeit at a significant risk for treatment complications,including serious and unusual opportunistic infections.
Crohn's disease Baumgart, Daniel C, Prof; Sandborn, William J, Prof
Lancet,
11/2012, Letnik:
380, Številka:
9853
Journal Article
Recenzirano
Odprti dostop
Summary Crohn's disease is a relapsing systemic inflammatory disease, mainly affecting the gastrointestinal tract with extraintestinal manifestations and associated immune disorders. Genome wide ...association studies identified susceptibility loci that—triggered by environmental factors—result in a disturbed innate (ie, disturbed intestinal barrier, Paneth cell dysfunction, endoplasmic reticulum stress, defective unfolded protein response and autophagy, impaired recognition of microbes by pattern recognition receptors, such as nucleotide binding domain and Toll like receptors on dendritic cells and macrophages) and adaptive (ie, imbalance of effector and regulatory T cells and cytokines, migration and retention of leukocytes) immune response towards a diminished diversity of commensal microbiota. We discuss the epidemiology, immunobiology, amd natural history of Crohn's disease; describe new treatment goals and risk stratification of patients; and provide an evidence based rational approach to diagnosis (ie, work-up algorithm, new imaging methods ie, enhanced endoscopy, ultrasound, MRI and CT and biomarkers), management, evolving therapeutic targets (ie, integrins, chemokine receptors, cell-based and stem-cell-based therapies), prevention, and surveillance.