Frequency and prognostic role of mucosal healing in patients with Crohn's disease and ulcerative colitis after one-year of biological therapy

AIM: To assess the endoscopic activity before and after a one-year period of biological therapy and to evaluate the frequency of relapses and need for retreatment after stopping the biologicals in patients with Crohn’s disease (CD) and ulcerative colitis (UC).

Colorectal cancer in inflammatory bowel disease:What is the real magnitude of the risk?

The association between inflammatory bowel disease(IBD) and colorectal cancer(CRC) has been recognised since 1925 and still accounts for 10%-15% of deaths in IBD.IBD-associated CRC(IBD-CRC) affects patients at a younger age than sporadic CRC.The prognosis for sporadic CRC and IBD-CRC is similar,with a 5-year survival of approximately 50%.Identifying at risk patients and implementing appropriate surveillance for these patients is central to managing the CRC risk in IBD.The increased risk of colorectal cancer in association with IBD is thought to be due to genetic and acquired factors.The link between inflammation and cancer is well recognised but the molecular biology,immune pathobiology and genetics of IBD-CRC are areas of much ongoing research.This review examines the literature relating to IBD-CRC,focusing on the incidence of IBD-CRC and examining potential risk factors including age at diagnosis,gender,duration and extent of colitis,severity of inflammation,family history of sporadic CRC and co-existent primary sclerosing cholangitis(PSC).Confirmed risk factors for IBD-CRC are duration,severity and extent of colitis,the presence of co-existent PSC and a family history of CRC.There is insufficient evidence currently to support an increased frequency of surveillance for patients diagnosed with IBD at a younger age.Evidence-based guidelines advise surveillance colonoscopy for patients with colitis 8 to 10 years after diagnosis,with the interval for further surveillance guided by risk factors(extent of disease,family history of CRC,post-inflammatory polyps,concomitant PSC,personal history of colonic dysplasia,colonic strictures).There is a move away from using random colonic biopsies towards targeted biopsies aimed at abnormal areas identified by newer colonoscopic techniques(narrow band imaging,chromoendoscopy,confocal microendoscopy).

Therapy with stem cells in inflammatory bowel disease

Inflammatory bowel disease (IBD) affects a part of the young population and has a strong impact upon quality of life. The underlying etiology is not known, and the existing treatments are not curative. Furthermore, a significant percentage of patients are refractory to therapy. In recent years there have been great advances in our knowledge of stem cells and their therapeutic applications. In this context, autologous hematopoietic stem cell transplantation (HSCT) has been used in application to severe refractory Crohn’s disease (CD), with encouraging results. Allogenic HSCT would correct the genetic defects of the immune system, but is currently not accepted for the treatment of IBD because of its considerable risks. Mesenchymal stem cells (MSCs) have immune regulatory and regenerative properties, and low immunogenicity (both autologous and allogenic MSCs). Based on these properties, MSCs have been used via the systemic route in IBD with promising results, though it is still too soon to draw firm conclusions. Their local administration in perianal CD is the field where most progress has been made in recent years, with encouraging results. The next few years will be decisive for defining the role of such therapy in the management of IBD.

Multipotent role of platelets in inflammatory bowel diseases:A clinical approach

There is evidence that inflammatory bowel diseases (IBD) combine both inflammation and coagulation in their pathogenesis and clinical manifestations. Although platelets (PLT) are well known for their role in hemostasis, there are a rising number of studies supporting their considerable role as inflammatory amplifiers in chronic inflammatory conditions. IBD are associated with several alterations of PLT, including number, shape, and function, and these abnormalities are mainly attributed to the highly activated state of circulating PLT in IBD patients. When PLT activate, they increase in size, release a great variety of bio-active inflammatory and procoagulant molecules/particles, and express a variety of inflammatory receptors. These inflammatory products may represent a part of the missing link between coagulation and inflammation, and can be considered as possible IBD pathogenesis instigators. In clinical practice, thrombocytosis is associated both with disease activity and iron deficiency anemia. Controlling inflammation and iron replacement in anemic patients usually leads to a normalization of PLT count. The aim of this review is to update the role of PLT in IBD and present recent data revealing the possible therapeutic implications of anti-PLT agents in future IBD remedies.

Intestinal barrier in inflammatory bowel disease

A complex mucosal barrier protects as the first line of defense the surface of the healthy intestinal tract from adhesion and invasion by luminal microorganisms. In this review, we provide an overview about the major components of this protective system as for example an intact epithelium, the synthesis of various antimicrobial peptides (AMPs) and the formation of the mucus layer. We highlight the crucial importance of their correct functioning for the maintenance of a proper intestinal function and the prevention of dysbiosis and disease. Barrier disturbances including a defective production of AMPs, alterations in thickness or composition of the intestinal mucus layer, alterations of pattern-recognition receptors, defects in the process of autophagy as well as unresolved endoplasmic reticulum stress result in an inadequate host protection and are thought to play a crucial role in the pathogenesis of the inflammatory bowel diseases Crohn’s disease and ulcerative colitis.

Restoring the gut microbiome for the treatment of inflammatory bowel diseases

Fecal microbiota transplantation (FMT) is considered to be a highly successful therapy for recurrent and refractory Clostridium difficile infection (CDI) based on recent clinical trials. The pathogenesis of inflammatory bowel diseases (IBD) is thought to be due in part to perturbations in the gut microflora that disrupt homeostasis. FMT restores essential components of the microflora which could reverse the inflammatory processes observed in IBD. Case reports and series for the treatment of IBD by FMT have shown promise with regards to treatment success and safety despite the limitations of the reporting. Future studies will determine the optimal delivery and preparation of stool as well as the conditions under which the recipient will derive maximal benefit. The long term consequences of FMT with regards to infection, cancer, auto-immune, and metabolic diseases are not known and will require continued regulation and study. Despite these limitations, FMT may be beneficial for the treatment of ulcerative colitis and Crohn’s disease, particularly those with concurrent CDI or with pouchitis.

Role of the gut microbiota in inflammatory bowel disease pathogenesis: What have we learnt in the past 10 years?

Our understanding of the microbial involvement in inflammatory bowel disease (IBD) pathogenesis has increased exponentially over the past decade. The development of newer molecular tools for the global assessment of the gut microbiome and the identification of nucleotide-binding oligomerization domain-containing protein 2 in 2001 and other susceptibility genes for Crohn’s disease in particular has led to better understanding of the aetiopathogenesis of IBD. The microbial studies have elaborated the normal composition of the gut microbiome and its perturbations in the setting of IBD. This altered microbiome or “dysbiosis” is a key player in the protracted course of inflammation in IBD. Numerous genome-wide association studies have identified further genes involved in gastrointestinal innate immunity (including polymorphisms in genes involved in autophagy: ATG16L1 and IGRM), which have helped elucidate the relationship of the local innate immunity with the adjacent luminal bacteria. These developments have also spurred the search for specific pathogens which may have a role in the metamorphosis of the gut microbiome from a symbiotic entity to a putative pathogenic one. Here we review advances in our understanding of microbial involvement in IBD pathogenesis over the past 10 years and offer insight into how this will shape our therapeutic management of the disease in the coming years.

Crucial steps in the natural history of inflammatory bowel disease

Inflammatory bowel diseases(IBD),including ulcerative colitis(UC) and Crohn's disease(CD),are chronic,progressive and disabling disorders.Over the last few decades,new therapeutic approaches have been introduced which have led not only to a reduction in the mortality rate but also offered the possibility of a favorable modification in the natural history of IBD.The identification of clinical,genetic and serological prognostic factors has permitted a better stratification of the disease,thus allowing the opportunity to indicate the most appropriate therapy.Early treatment with immunosuppressive drugs and biologics has offered the opportunity to change,at least in the short term,the course of the disease by reducing,in a subset of patients with IBD,hospitalization and the need for surgery.In this review,the crucial steps in the natural history of both UC and CD will be discussed,as well as the factors that may change their clinical course.The methodological requirements for high quality studies on the course and prognosis of IBD,the true impact of environmental and dietary factors on the clinical course of IBD,the clinical,serological and genetic predictors of the IBD course(in particular,which of these are rel-evant and appropriate for use in clinical practice),the impact of the various forms of medical treatment on the IBD complication rate,the role of surgery for IBD in the biologic era,the true magnitude of risk of colorectal cancer associated with IBD,as well as the mortality rate related to IBD will be stressed;all topics that are extensively discussed in separate reviews included in this issue of World Journal of Gastroenterology.

Interleukin and interleukin receptor gene polymorphisms in inflammatory bowel diseases susceptibility

Inflammatory bowel disease (IBD), which includes Crohn’s disease (CD) and ulcerative colitis (UC), represents a group of chronic inflammatory disorders caused by dysregulated immune responses in genetically predisposed individuals. Genetic markers are associated with disease phenotype and long-term evolution, but their value in everyday clinical practice is limited at the moment. IBD has a clear immunological background and interleukins play key role in the process. Almost 130 original papers were revised including meta-analysis. It is clear these data are very important for understanding the base of the disease, especially in terms of clinical utility and validity, but text often do not available for the doctors use these in the clinical practice nowadays. We conducted a systematic review of the current literature on interleukin and interleukin receptor gene polymorphisms associated with IBD, performing an electronic search of PubMed Database from publications of the last 10 years, and used the following medical subject heading terms and/or text words: IBD, CD, UC, interleukins and polymorphisms.

Magnetic resonance imaging in children and adolescents with chronic inflammatory bowel disease

Inflammatory bowel diseases(IBD) represent challenges, both from a diagnostic, and therapeutic point of view. Deep-seated anatomic structures are difficult to assess by ultrasound technique alone. As radiation-free alternative cross-sectional imaging method, magnetic resonance imaging of the intestinal structures is costly and time-consuming. Examination of pediatric patients imply additional considerations: reduction of body motions in younger children and consideration of the most appropriate preparation, and examination technique. The demanding Sellink technique is the only means for appropriately distending the lesser intestine in order to detect small bowel strictures. Oral intake of contrast medium(CM) alone shows its limitations regarding distensibility. The need for intravenous contrast media application needs to be considered, too. Active inflammation of both intestinal wall, and mesentery can be demonstrated accurately. Nevertheless, viable alternatives to CM application is desirable, considering non-negligible adverse reactions. Recent data suggest diffusion weighted imaging might fill this diagnostic gap. Irrespective of sequence technique chosen, bowel movement remains a major obstacle. Antispasmolytics in their function as smooth muscle relaxants help in improving image quality, however, their use in children might be off-label. Optimal preparation for the examination and appropriate imaging technique allow for diagnosing typical patterns of changes in IBD, such as bowel wall thickening, ulcers, mural stratification, strictures, creeping fat, and comb sign, and lymphadenopathy. The article gives a detailed overview of current significance of magnetic resonance imaging pediatric patients suffering from IBD, considering indications, limitations, and safety aspects.

Clinical,serological and genetic predictors of inflammatory bowel disease course

Patients with extensive or complicated Crohn's disease(CD) at diagnosis should be treated straightaway with immunosuppressive therapy according to the most recent guidelines.In patients with localized and uncomplicated CD at diagnosis,early use of immunosuppressive therapy is debated for preventing disease progression and limiting the disabling clinical impact.In this context,there is a need for predictors of benign or unfavourable subsequent clinical course,in order to avoid over-treating with risky drugs those patients who would have experienced spontaneous mid-term asymptomatic disease without progression towards irreversible intestinal lesions.At diagnosis,an age below 40 years,the presence of perianal lesions and the need for treating the first flare with steroids have been consistently associated with an unfavourable subsequent 5-year or 10-year clinical course.The positive predictive value of unfavourable course in patients with 2 or 3 predictors ranges between 0.75 and 0.95 in population-based and referral centre cohorts.Consequently,the use of these predictors can be integrated into the elements that influence individual decisions.In the CD postoperative context,keeping smoking and history of prior resection are the stron-gest predictors of disease symptomatic recurrence.However,these clinical predictors alone are not as reliable as severity of early postoperative endoscopic recurrence in clinical practice.In ulcerative colitis(UC),extensive colitis at diagnosis is associated with unfavourable clinical course in the first 5 to 10 years of the disease,and also with long-term colectomy and colorectal inflammation-associated colorectal cancer.In patients with extensive UC at diagnosis,a rapid step-up strategy aiming to achieve sustained deep remission should therefore be considered.At the moment,no reliable serological or genetic predictor of inflammatory bowel disease clinical course has been identified.

Immunopathology of inflammatory bowel disease

Inflammatory bowel disease (IBD) results from a complex series of interactions between susceptibility genes, the environment, and the immune system. The host microbiome, as well as viruses and fungi, play important roles in the development of IBD either by causing inflammation directly or indirectly through an altered immune system. New technologies have allowed researchers to be able to quantify the various components of the microbiome, which will allow for future developments in the etiology of IBD. Various components of the mucosal immune system are implicated in the pathogenesis of IBD and include intestinal epithelial cells, innate lymphoid cells, cells of the innate (macrophages/monocytes, neutrophils, and dendritic cells) and adaptive (T-cells and B-cells) immune system, and their secreted mediators (cytokines and chemokines). Either a mucosal susceptibility or defect in sampling of gut luminal antigen, possibly through the process of autophagy, leads to activation of innate immune response that may be mediated by enhanced toll-like receptor activity. The antigen presenting cells then mediate the differentiation of naïve T-cells into effector T helper (Th) cells, including Th1, Th2, and Th17, which alter gut homeostasis and lead to IBD. In this review, the effects of these components in the immunopathogenesis of IBD will be discussed.

Immunosuppressive therapies for inflammatory bowel disease

Inflammatory bowel disease (IBD) is comprised of Crohn’s disease and ulcerative colitis, both chronic inflammatory intestinal disorders of unknown etiology characterized by a waxing and waning clinical course. For many years, the drug therapy was limited to sulfasalazine and related aminosalicylates, corticosteroids and antibiotics. Studies suggesting that the pathophysiology of these disorders relates to a disregulated, over-active immune response to indigenous bacteria have led to the increasing importance of immunosuppressive drugs for the therapy of IBD. This review details the mechanisms of action, clinical efficacy, and adverse effects of these agents.

Utility of faecal calprotectin analysis in adult inflammatory bowel disease

The inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis, are chronic relapsing, remitting disorders. Diagnosis, along with assessment of disease activity and prognosis present challenges to managing clinicians. Faecal biomarkers, such as faecal calprotectin, are a non-invasive method which can be used to aid these decisions. Calprotectin is a calcium and zinc binding protein found in the cytosol of human neutrophils and macrophages. It is released extracellularly in times of cell stress or damage and can be detected within faeces and thus can be used as a sensitive marker of intestinal inflammation. Faecal calprotectin has been shown to be useful in the diagnosis of IBD, correlates with mucosal disease activity and can help to predict response to treatment or relapse. With growing evidence supporting its use, over the last decade this faecal biomarker has significantly changed the way IBD is managed.

Oral manifestation in inflammatory bowel disease:A review

Inflammatory bowel diseases (IBDs), including Crohn’s disease (CD) and ulcerative colitis, not only affect the intestinal tract but also have an extraintestinal involvement within the oral cavity. These oral manifestations may assist in the diagnosis and the monitoring of disease activity, whilst ignoring them may lead to an inaccurate diagnosis and useless and expensive workups. Indurated tag-like lesions, cobblestoning, and mucogingivitis are the most common specific oral findings encountered in CD cases. Aphthous stomatitis and pyostomatitis vegetans are among non-specific oral manifestations of IBD. In differential diagnosis, side effects of drugs, infections, nutritional deficiencies, and other inflammatory conditions should also be considered. Treatment usually involves managing the underlying intestinal disease. In severe cases with local symptoms, topical and/or systemic steroids and immunosuppressive drugs might be used.

Impact of medical therapies on inflammatory bowel disease complication rate

Crohn's disease and ulcerative colitis are progressive diseases associated with a high risk of complications over time including strictures,fistulae,perianal complications,surgery,and colorectal cancer.Changing the natural history and avoiding evolution to a disabling disease should be the main goal of treatment.In recent studies,mucosal healing has been associated with longer-term remission and fewer complications.Conventional therapies with immunosuppressive drugs are able to induce mucosal healing in a minority of cases but their impact on disease progression appears modest.Higher rates of mucosal healing can be achieved with anti-tumor necrosis factor therapies that reduce the risk of relapse,surgery and hospitalization,and are associated with perianal fistulae closure.These drugs might be able to change the natural history of the disease mainly when introduced early in the course of the disease.Treatment strategy in inflammatory bowel diseases should thus be tailored according to the risk that each patient could develop disabling disease.

Epidemiological studies of migration and environmental risk factors in the inflammatory bowel diseases

Inflammatory bowel diseases(IBD)are idiopathic chronic diseases of the gastrointestinal tract well known to be associated with both genetic and environmental risk factors.Permissive genotypes may manifest into clinical phenotypes under certain environmental influences and these may be best studied from migratory studies.Exploring differences between first and second generation migrants may further highlight the contribution of environmental factors towards the development of IBD.There are few opportunities that have been offered so far.We aim to review the available migration studies on IBD,evaluate the known environmental factors associated with IBD,and explore modern migration patterns to identify new opportunities and candidate migrant groups in IBD migration research.

Update on nutritional status,body composition and growth in paediatric inflammatory bowel disease

Growth and nutritional status are important issues in paediatric inflammatory bowel disease(IBD).While linear growth is easy to assess,nutritional status is more complicated,with reports often compromised by the use of simple measures,such as weight and the body mass index,to assess nutritional status rather than more appropriate and sophisticated techniques to measure body composition.This review is an update on what is currently known about nutritional status as determined by body composition in paediatric IBD.Further,this review will focus on the impact of biologics on growth in paediatric IBD.Significant lean mass deficits have been reported in children with IBD compared with controls,and there is evidence these deficits persist over time.Furthermore,data imply that gender differences exist in body composition,both at diagnosis and in response to treatment.With respect to growth improvements following treatment with biologics,there are conflicting data.While some studies report enhancement of growth,others do not.The relationship between disease severity,impaired growth and the requirement for biologics needs to be considered when interpreting these data.However,key features associated with improvements in growth appear to be successful clinical response to treatment,patients in early stages of puberty,and the presence of growth failure at the onset of treatment.

Case-control study of factors that trigger inflammatory bowel disease flares

AIM: To explore the association between inflammatory bowel diseases (IBD) flares and potential triggers.

Risk of post-operative complications associated with anti-TNF therapy in inflammatory bowel disease

There have been increasing concerns regarding the safety of perioperative anti-tumour necrosis factor (anti-TNF) α agents. We performed a literature review to evaluate the post-operative complications associated with perioperative anti-TNF use in patients with inflammatory bowel disease. A comprehensive review was performed with a literature search utilizing Pub Med, Cochrane, OVID and EMBASE databases according to published guidelines. To date, there are only data for infliximab. There are three published studies which have assessed post-operative complications with perioperative infliximab use in patients with Crohn' s disease (CD), four studies in ulcerative colitis (UC) patients, and one study on both CD and UC patients. Two out of the three studies in CD patients showed no increased post-operative complications associated with perioperative infliximab. Two out of four studies in UC patients also did not show an increase in post-operative complications, and the combined study with CD and UC patients did not show an increased risk as well. Studyresults could not be combined secondary to significant differences in study designs, patient population and definition of their endpoints. There appears to be a risk of post-operative complications associated with TNF therapy in some patients. Based on these data, careful patient selection and prospective data collection should be performed.