Characteristics of inflammatory bowel diseases in patients with concurrent immune-mediated inflammatory diseases

Patients with inflammatory bowel disease (IBD) are more likely to have concurrent immune-mediated inflammatory diseases (IMIDs) than those without IBD. IMIDs have been observed to alter the phenotype and outcomes of IBD in recent studies. Several studies have found that IBD patients with concurrent IMIDs may have more extensive or severe disease phenotypes, and are considered to be at increased risk of requiring biologics and IBD-related surgeries, suggesting that having multiple IMIDs is a poor prognostic factor for IBD. Furthermore, IBD patients with primary sclerosing cholangitis and Takayasu arteritis are reported to have unique endoscopic phenotypes, suggesting concurrent IMIDs can influence IBD phenotype with specific intestinal inflammatory distributions. In this review, we discuss the pathogenesis, disease phenotypes, and clinical outcomes in IBD patients with concomitant IMIDs.     

Epidemiology and inflammatory bowel diseases

The role of alcohol in causing or aggravating the pathogenesis of inflammatory bowel disease is unclear.For finding a conclusive answer for this valuable question we conducted this review.Only two studies were identified that successfully fulfilled our inclusive criteria.Usual consumption of alcohol reduced the risk compared with less frequent use(odds ratio = 0.57,95%CI:0.37-0.86).Light alcoholic drinking has protective effects against development of ulcerative colitis.But this inverse association disappeared when smoking was included.     

The use of thiopurines for the treatment of inflammatory bowel diseases in clinical practice

BACKGROUND: Thiopurines are the most commonly used immunomodulatory drugs in inflammatory bowel diseases. AIM: To evaluate the use, the therapeutic and safety profiles of thiopurines in a large sample of IBD patients. METHODS: We reviewed 3641 case histories of IBD patients. Thiopurines were prescribed in 582 patients (16.0%); the analysis was performed on the 553 (267 ulcerative colitis, 286 Crohn's disease) with exhaustive clinical data. RESULTS: The main indications for treatment were steroid-dependence (328/553, 59.3%) and steroid-resistance (113/553, 20.7%). Thiopurines were started when CD were younger than UC patients (p<0.001) but earlier from diagnosis in UC than in CD patients (p=0.003). Efficacy was defined as optimal (258/553, 46.6%), partial (108/553, 19.5%), absent (85/553, 15.4%) and not assessable (102/553, 18.4%). Efficacy was independent of disease type, location/extension or duration and age at starting. Side effects were observed in 151/553 (27.3%) patients, leading to drug discontinuation in 101 (18.3%). 15 out of the 130 (11.5%) patients who took thiopurines for more than 4 years relapsed, more frequently in CD than in UC (OR=3.67 95% C.I. 0.98-13.69; p=0.053). CONCLUSIONS: Thiopurines confirm their clinical usefulness and acceptable safety profile in managing complicated IBD patients. The majority of patients treated for longer than 4 years maintain response. No clinical and demographic predictive factors for efficacy and side effects were identified.     

Gut-lung crosstalk in pulmonary involvement with inflammatory bowel diseases

Pulmonary abnormalities,dysfunction or hyper-reactivity occurs in association with inflammatory bowel disease(IBD) more frequently than previously recognized.Emerging evidence suggests that subtle inflammation exists in the airways among IBD patients even in the absence of any bronchopulmonary symptoms,and with normal pulmonary functions. The pulmonary impairment is more pronounced in IBD patients with active disease than in those in remission. A growing number of case reports show that the IBD patients develop rapidly progressive respiratory symptoms after colectomy,with failure to isolate bacterial pathogens on repeated sputum culture,and often request oral corticosteroid therapy. All the above evidence indicates that the inflammatory changes in both the intestine and lung during IBD. Clinical or subclinical pulmonary inflammation accompanies the main inflammation of the bowel.Although there are clinical and epidemiological reports of chronic inflammation of the pulmonary and intestinal mucosa in IBD,the detailed mechanisms of pulmonaryintestinal crosstalk remain unknown. The lung has no anatomical connection with the main inflammatory site of the bowel. Why does the inflammatory process shift from the gastrointestinal tract to the airways? The clinical and subclinical pulmonary abnormalities,dysfunction,or hyper-reactivity among IBD patients need further evaluation. Here,we give an overview of the concordance between chronic inflammatory reactions in the airways and the gastrointestinal tract. A better understanding of the possible mechanism of the crosstalk among the distant organs will be beneficial in identifying therapeutic strategies for mucosal inflammatory diseases such as IBD and allergy.     

Pulmonary involvement in inflammatory bowel disease

AIM:To determine the relationship of pulmonary abnormalities and bowel disease activity in inflammatory bowel disease(IBD).METHODS:Thirty ulcerative colitis(UC)and nine Crohn’s disease patients,and 20 control subjects were enrolled in this prospective study.Detailed clinical information was obtained.Extent and activity of the bowel disease were established endoscopically.Each patient underwent pulmonary function tests and high-resolution computed tomography(HRCT).Blood samples for measurement of C-reactive protein(CRP),erythrocyte sedimentation rate(ESR),angiotensin converting enzyme and total IgE were delivered by the patients.RESULTS:Ten(25.6%)patients had respiratory symptoms.A pulmonary function abnormality was present in 22 of 39 patients.Among all patients,the most prevalent abnormalities in lung functions were a decrease in forced expiratory volume in 1 s(FEV1),FEV1/forced vital capacity(FVC),forced expiratory flow(FEF)25%-75%,transfer coefficient for carbon monoxide(DLCO),DLCO/alveolar volume.Increased respiratory symptoms score was associated with high endoscopic activity index in UC patients.Endoscopic and clinical activities in UC patients were correlated with FEV1,FEV1/FVC,and FEF 25%-75%.Smoking status,duration of disease and medication were not correlated with pulmonary physiological test results,HRCT abnormalities,clinical/endoscopic disease activity,CRP,ESR or total IgE level or body mass index.CONCLUSION:It is important that respiratory manifestations are recognized and treated early in IBD.Otherwise,they can lead to destructive and irreversible changes in the airway wall.     

Extraintestinal manifestations and complications in inflammatory bowel diseases

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory bowel diseases (IBD) that often involve organs other than those of the gastrointestinal tract. These nonintestinal affections are termed extraintestinal symptoms. Differentiating the true extraintestinal manifestations of inflammatory bowel diseases from secondary extraintestinal complications, caused by malnutrition, chronic inflammation or side effects of therapy, may be difficult. This review concentrates on frequency, clinical presentation and therapeutic implications of extraintestinal symptoms in inflammatory bowel diseases. If possible, extraintestinal manifestations are differentiated from extraintestinal complications. Special attention is given to the more recently described sites of involvement; i.e. thromboembolic events, osteoporosis, pulmonary involvement and affection of the central nervous system.     

Innate and adaptive immunity in inflammatory bowel disease

Inflammatory bowel diseases are the consequence of a dysregulated mucosal immune system. The mucosal immune system consists of two arms, innate and adaptive immunity, that have been studied separately for a long time. Functional studies from in vivo models of intestinal inflammation as well as results from genome-wide association studies strongly suggest a crossregulation of both arms. The present review will illustrate this interaction by selecting examples from innate immunity and adaptive immunity, and their direct impact on each other. Broadening our view by focusing on the cross-regulated areas of the mucosal immune system will not only facilitate our understanding of disease, but furthermore will allow identification of future therapeutic targets.     

Crohnology： A tale of time and times and inflammatory bowel diseases

Time, times and timing are key words in inflammatory bowel diseases （IBD）. The leifmotif of this issue or World Journal of Gastroenterology is time. We have asked experts to review on the epidemiology of these diseases over time, the changes in innate immunity that could be present in the first time, and then the timing of key treatments. The correct time of using azathioprine, mercaptopurine, infliximab, cyclosporine and surgery are reviewed. We have chosen experts with not only great clinical expertise but also personal interest in clinical and basic investigation. Our goal in this monograph is to get an idea not only of the present but of the immediate future in some of the key management issues in IBD. To this end, we think that the authors are the most adequate.     

Gastrointestinal motility disorders in inflammatory bowel diseases

The relationship between motility and inflammatory gastrointestinal disorders is at the same time complex and intriguing since these conditions might share some genetic,environmental,immunological and microbial predisposing factors.In addition,significant symptom overlapping may occur,muddling the waters within the clinical context.Although on one hand this represents a challenge for the clinician for a potential under-or over-treatment and diagnostic delay,on the other hand it possibly represents an opportunity for the researcher to better disclose the intimate relationship between chronic(often low-grade)inflammation,motor disorders and deranged sensory function.The best example is probably represented by Crohn’s disease and ulcerative colitis.In fact,a number of gastrointestinal motor disorders have been described in association with these diseases,disorders which span from the esophagus to the anorectum,and which will be extensively covered in this review.It is conceivable that at least part of this derangement is strictly related to inflammatory cytokine trafficking and neuromuscular changes;however,given the high prevalence of functional gastrointestinal disorders in the general population,this overlap might also be serendipitous.However,it is worth noting that literature data on this topic are relatively scarce,sometimes quite outdated,and mostly focused on the interplay between irritable bowel syndrome and inflammatory bowel disease.Nevertheless,both researchers and clinicians must be aware that symptoms related to gastrointestinal motility disorders may be highly prevalent in both active and inactive inflammatory bowel disease,correlate with greater psychological comorbidity and poorer quality of life,and may negatively influence the therapeutic approaches.     

Rheumatic manifestations of inflammatory bowel disease

This article reviews the literature concerning rheumatic manifestations of inflammatory bowel disease(IBD), including common immune-mediated pathways,frequency, clinical course and therapy. Musculoskeletal complications are frequent and well-recognized manifestations in IBD, and affect up to 33% of patients with IBD. The strong link between the bowel and the osteo-articular system is suggested by many clinical and experimental observations, notably in HLA-B27 transgenic rats. The autoimmune pathogenic mechanisms shared by IBD and spondyloarthropathies include genetic susceptibility to abnormal antigen presentation,aberrant recognition of self, the presence of autoantibodies against specific antigens shared by the colon and other extra-colonic tissues, and increased intestinal permeability. The response against microorganisms may have an important role through molecular mimicry and other mechanisms. Rheumatic manifestations of IBD have been divided into peripheral arthritis, and axial involvement, including sacroiliitis,with or without spondylitis, similar to idiopathic ankylosing spondylitis. Other periarticular features can occur,including enthesopathy, tendonitis, clubbing, periostitis,and granulomatous lesions of joints and bones.Osteoporosis and osteomalacia secondary to IBD and iatrogenic complications can also occur. The management of the rheumatic manifestations of IBD consists of physical therapy in combination with local injection of corticosteroids and nonsteroidal anti-inflammatory drugs; caution is in order however, because of their possible harmful effects on intestinal integrity, permeability,and even on gut inflammation. Sulfasalazine,methotrexate, azathioprine, cyclosporine and leflunomide should be used for selected indications. In some cases, tumor necrosis factor-α blocking agents should be considered as first-line therapy.     

Hematological malignancies in chronic inflammatory bowel diseases: report of five cases and review of the literature

Several forms of primary and secondary hematological malignancies were rarely observed during the clinical course of inflammatory bowel diseases (IBD). Patients needing a prolonged treatment with immunosuppressants, such as azathioprine or methotrexate, with familiarity and genetic predisposition seem to be at a higher risk of leukemia. On the other hand, asthenia, thickness, and fever may be the symptoms of the onset of each kind of hematological malignancy. The finding of anemia, alteration of leukocyte count and large undetermined cells may suggest increased probability of abnormal proliferation of a single white blood cell line. In this report, the occurrence of hematological malignancies is described in five patients affected by IBD (three with ulcerative colitis and two with Crohn’s disease) attending our Gastroenterology Unit.     

Pulmonary involvement and allergic disorders in inflammatory bowel disease

Inflammatory bowel disease (IBD) has been associated with either clinical or subclinical airway and parenchymal lung involvement and interstitial lung complications. Several studies have reported that atopy has a high prevalence in IBD patients. Overlapping allergic disorders seem to be present in both the respiratory and gastrointestinal systems. The purpose of this review is to update clinicians on recent available literature and to discuss the need for a highly suspicious approach by clinicians.     

Overview of cytokines and nitric oxide involvement in immuno-pathogenesis of inflammatory bowel diseases

Inflammatory bowel diseases(IBDs), including Crohn's disease and ulcerative colitis are complex disorders with undetermined etiology. Several hypotheses suggest that IBDs result from an abnormal immune response against endogenous flora and luminal antigens in genetically susceptible individuals. The dysfunction of the mucosal immune response is implicated in the pathogenesis of IBD. The balance between pro-inflammatory cytokines [tumor necrosis factor(TNF)-α, interleukin(IL)-1b, IL-8, and IL-17A], anti-inflammatory cytokines(IL-4 and IL-13), and immunoregulatory cytokines(IL-10 and transforming growth factors b) is disturbed. Moreover, evidence from animal and clinical studies demonstrate a positive correlation between an increased concentration of nitric oxide(NO) and the severity of the disease. Interestingly, proinflammatory cytokines are involved in the up-regulation of inducible oxide synthase(iN OS) expression in IBD. However, anti-inflammatory and immunoregulatory cytokines are responsible for the negative regulation of iN OS. A positive correlation between NO production and increased pro-inflammatory cytokine levels(TNF-α, IL-6, IL-17, IL-12, and interferon-γ) were reported in patients with IBD. This review focuses on the role of cytokines in intestinal inflammation and their relationship with NO in IBD.     

Visceral hypersensitivity in inflammatory bowel diseases and irritable bowel syndrome: The role of proteases

Proteases, enzymes catalyzing the hydrolysis of peptide bonds, are present at high concentrations in the gastrointestinal tract. Besides their well-known role in the digestive process, they also function as signaling molecules through the activation of protease-activated receptors(PARs). Based on their chemical mechanism for catalysis, proteases can be classified into several classes: serine, cysteine, aspartic, metallo- and threonine proteases represent the mammalian protease families. In particular, the class of serine proteases will play a significant role in this review. In the last decades, proteases have been suggested to play a key role in the pathogenesis of visceral hypersensitivity, which is a major factor contributing to abdominal pain in patients with inflammatory bowel diseases and/or irritable bowel syndrome. So far, only a few preclinical animal studies have investigated the effect of protease inhibitors specifically on visceral sensitivity while their effect on inflammation is described in more detail. In our accompanying review we describe their effect on gastrointestinal permeability. On account of their promising results in the field of visceral hypersensitivity, further research is warranted. The aim of this review is to give an overview on the concept of visceral hypersensitivity as well as on the physiological and pathophysiological functions of proteases herein.     

Role of Smad7 in inflammatory bowel diseases

Crohn''s disease and ulcerative colitis, the major forms of inflammatory bowel diseases (IBD) in man, are complex diseases in which genetic and environmental factors interact to promote an excessive mucosal immune response directed against normal components of the bacterial microflora. There is also evidence that the pathologic process is due to defects in counter-regulatory mechanisms, such as those involving the immunosuppressive cytokine transforming growth factor (TGF)-β1. Indeed, studies in human IBD tissues and murine models of colitis have documented a disruption of TGF-β1 signalling marked by a block in the phosphorylation of Smad3, a signalling molecule associated with the activated TGF-β receptor, due to up-regulation of Smad7, an intracellular inhibitor of Smad3 phosphorylation. Knock-down of Smad7 with a specific antisense oligonucleotide restores TGF-β1/Smad3 signalling, thus resulting in a marked suppression of inflammatory cytokine production and attenuation of murine colitis. These findings together with the demonstration that Smad7 antisense oligonucleotide is not toxic when administered in mice have paved the way for the development of a Smad7 antisense oligonucleotide-based pharmaceutical compound that is now ready to enter the clinics. In this article we review the available data supporting the pathogenic role of Smad7 in IBD and discuss whether and how Smad7 antisense therapy could help dampen the ongoing inflammation in IBD.     

Pregnancy and inflammatory bowel diseases: Current perspectives,risks and patient management

Inflammatory bowel diseases(IBD) are chronic idiopathic inflammatory conditions characterized by relapsing and remitting episodes of inflammation which can affect several different regions of the gastrointestinal tract, but also shows extra-intestinal manifestations. IBD is most frequently diagnosed during peak female reproductive years, with 25% of women with IBD conceiving after their diagnosis. While IBD therapy has improved dramatically with enhanced surveillance and more abundant and powerful treatment options, IBD disease can have important effects on pregnancy and presents several challenges for maintaining optimal outcomes for mothers with IBD and the developing fetus/neonate. Women with IBD, the medical team treating them(both gastroenterologists and obstetricians/gynecologists) must often make highly complicated choices regarding conception, pregnancy, and post-natal care(particularly breastfeeding) related to their choice of treatment options at different phases of pregnancy as well as post-partum. This current review discusses current concerns and recommendations for pregnancy duringIBD and is intended for gastroenterologists, general practitioners and IBD patients intending to become,(or already) pregnant, and their families. We have addressed patterns of IBD inheritance, effects of IBD on fertility and conception(in both men and women), the effects of IBD disease activity on maintenance of pregnancy and outcomes, risks of diagnostic procedures during pregnancy and potential risks and complications associated with different classes of IBD therapeutics. We also have evaluated the clinical experience using "top-down" care with biologics, which is currently the standard care at our institution. Post-partum care and breastfeeding recommendations are also addressed.     

Medical management of inflammatory bowel disease among Canadian gastroenterologists

BACKGROUND:

Little is known about physician perceptions of and practices in using infliximab – a biological agent that was approved in Canada for the treatment of Crohn’s disease in 2001, and for ulcerative colitis in 2006.

OBJECTIVES:

To describe Canadian gastroenterologists’ use and perceptions of infliximab in the treatment of refractory inflammatory bowel disease (IBD), and to identify factors that may influence a gastroenterologist’s decision to initiate infliximab therapy.

METHODS:

A postal questionnaire was distributed to all practicing clinicians captured in the 2007 membership of the Canadian Association of Gastroenterology. Each physician was contacted up to a maximum of three times.

RESULTS:

Of 466 questionnaires mailed out, responses were received from 336 (72%), with 292 respondents (63%) returning fully completed surveys. For 80% of respondents, IBD patients comprised less than 30% of their clinical practice. Most prescribed infliximab at an initial dose of 5 mg/kg (97%), prescribed loading doses at 0, 2 and 6 weeks (88%), premedicated with corticosteroids (74%), administered maintenance infusions at eight-week intervals (89%), co-administered immunosuppressive agents (81%) and continued infliximab ‘indefinitely’ as long as it was effective and well tolerated (76%). Most gastroenterologists (>70%) identified lack of drug insurance coverage and provincial funding criteria as important barriers to prescribing infliximab.

CONCLUSIONS:

Most Canadian gastroenterologists exhibited similar practice patterns with respect to the use of infliximab for induction and maintenance therapy of IBD. Common barriers to the initiation of infliximab therapy were identified.     

Secondary causes of inflammatory bowel diseases

Inflammatory bowel diseases(IBD), conventionally consist of Crohn's disease(CD) and ulcerative colitis. They occur in individuals with high risk genotype for the disease in the setting of appropriate environmental factors. The pathogenesis of IBD involves a dysregulated autoimmune response to gut dysbiosis, which in turn is triggered due to exposure to various inciting environmental factors. But there is no clearly defined etiology of IBD and this type of disease is termed as "idiopathic IBD", "classic IBD", or "primary IBD". We reviewed the current medical literature and found that certain etiological factors may be responsible for the development of IBD or IBD-like conditions, and we consider this form of de novo IBD as "secondary IBD". Currently known factors that are potentially responsible for giving rise to secondary IBD are medications; bowel altering surgeries and transplantation of organs, stem cells or fecal microbiome. Medications associated with the development of secondary IBD include; immunomodulators, anti-tumor necrosis factor alpha agents, anti-interleukin agents, interferons, immune stimulating agents and checkpoint inhibitors. Colectomy can in some cases give rise to de novo CD, pouchitis of the ileal pouch, or postcolectomy enteritis syndrome. After solid organ transplantation or hematopoietic stem cell transplantation, the recipient may develop de novo IBD or IBD flare. Fecal microbiota transplantation has been widely used to treat patients suffering from recurrent Clostridium difficile infection but can also causes IBD flares.     

Confocal laser endomicroscopy in inflammatory bowel diseases:Dream or reality?

Confocal laser endomicroscopy(CLE)is a newly introduced procedure that provide real-time,high-resolution imaging of the gastrointestinal mucosa during endoscopy,allowing the visualization of the pathology of the mucosal epithelium with its cellular and subcellular structures.Recently,the use of CLE was reported in the study of colonic mucosa in patients with inflammatory bowel diseases and in particular in patients affected by ulcerative colitis.CLE has the potential to have an important role in management of inflammatory bowel diseases(IBD)patients as it can be used to assess the grading of colitis and in detection of microscopic colitis in endoscopically silent segments.Moreover,CLE can be used in surveillance programs especially in highrisk patients.Finally,CLE has been effectively used in diagnosing a biliary dysplasia/neoplasia in patients with primary sclerosing cholangitis,a pathological condition frequently associated with IBD,with a coexisting bile duct stricture.