New insights into the pathogenesis of Crohn's disease: are they relevant for therapeutic options?

During the last few years significant advances have been achieved in the understanding of the pathogenesis of inflammatory bowel disease (IBD). A genetic susceptibility to Crohn's disease has been proven by identification of variations as risk factor NOD2/CARD15. Functional data on NOD2/CARD15 and NF-kappaB activation indicate that an inflammatory reaction of the intestinal mucosa, as an immediate response of the innate immune system, may be necessary for the maintenance of gut homeostasis. Crohn's disease is now also discussed as an impaired and inadequate immune reaction and no longer only as a hyper-responsiveness of the mucosal immune system. Data on NOD2/CARD15 expression suggest that macrophages and epithelial cells could be the locus of the primary pathophysiological defect and that T-cell activation might just be a secondary effect inducing chronification of the inflammation, perhaps as backup mechanism to insufficient innate immunity. In addition to NOD2/CARD15 there are more "innate" pathways by which commensal and pathogenic bacteria can directly be hindered to invade the human body (such as interaction with Toll like receptors, TLRs and defensins). The "germ-concept" and the "genetic concept" of IBD pathophysiology are converging. However, more time is needed until these important insights in IBD pathogenesis will make their way into routine diagnostic procedures and treatment of patients with IBD

Serum protein electrophoresis : an underused but very useful test

Serum protein electrophoresis is used in clinical practice to identify patients with multiple myeloma and other serum protein disorders. It is an inexpensive and easy-to-perform screening procedure. Electrophoresis separates serum proteins based on their physical properties and identifies morphologic patterns in response to acute and chronic inflammation, various malignancies, liver or renal failure, and hereditary protein disorders. For gastroenterologists, the use of serum protein electrophoresis may be helpful in the diagnosis of both common diseases with unusual presentations and rare disorders with typical presentations. Therefore, it represents an ideal screening tool

High altitude journeys, flights and hypoxia: any role for disease flares in IBD patients?

The importance of environmental factors in the pathogenesis including their disease-modifying potential are increasingly recognized in inflammatory bowel disease (IBD) patients, largely driven by the perception that the prevalence and incidence of IBD are on the rise within the last few years, especially in non-western countries. One of those factors is believed to be hypoxia. The role of hypoxia as a modifying or even causative factor in the genesis and maintenance of inflammation has been increasingly elucidated in recent years. Hypoxia is believed to be a main inducing factor of inflammation. This has been studied in different animal experiments as well as in humans exposed to hypoxia. In several studies - mainly in mice - animals exposed to short-term hypoxia accumulated inflammatory cells in multiple organs and showed elevated cytokines in the blood. Comparable studies were performed in humans, mainly in healthy mountaineers. Recently, we reported on the association between IBD flare-up episodes and antecedent journeys to high-altitude region and aircraft travels. According to these findings, we concluded that flights and stays at high altitudes of >2,000 mg are a risk factor for increased disease activity in IBD. To evaluate the potential influence of hypoxia on the course of IBD on a biomolecular level and to test the effects of hypoxia under standardized conditions, we initiated a prospective and controlled investigation in both healthy controls and IBD patients in stable remission. The study participants underwent a 3-hour exposure to hypoxic conditions simulating an altitude of 4,000 m above sea level in a hyperbaric pressure chamber and clinical parameters as well as blood and stool samples were collected at several time points. The first results of this study are expected in the near future

Expression patterns of TNFα, MAdCAM1 and STAT3 in intestinal and skin manifestations of inflammatory bowel disease

Background: Pathogenesis of cutaneous extraintestinal manifestations (EIM) in inflammatory bowel disease (IBD) remains elusive. Efficacy of anti-TNF agents suggests TNF-dependent mechanisms. The role of other biologics such as anti-integrins or JAK-inhibitors is not yet clear. Methods: We performed immunohistochemistry for TNFα, NFκB, STAT1/STAT3, MAdCAM1, CD20/68, caspase 3/9, IFNγ, Hsp-27/70 on 240 intestinal (55 controls, 185 IBD) and 64 skin biopsies (11 controls, 18 Erythema nodosum (EN), 13 Pyoderma gangenosum (PG), 22 psoriasis). A semiquantitative score (0-100%) was used for evaluation. Results: TNFα was upregulated in intestinal biopsies from active Crohn`s disease (CD) vs. controls (36.2 vs. 12.1, p<0.001), but not ulcerative colitis (UC: 17.9). NFκB however was upregulated in intestinal biopsies from both active CD and UC (43.2 and 34.5 vs. 21.8, p<0.001 and p=0.017). TNFα and NFκB were overexpressed in skin biopsies from EN, PG and psoriasis. No MAdCAM1 overexpression was seen in skin tissues, while it was upregulated in active UC vs. controls (57.5 vs. 35.4, p=0.003). STAT3 was overexpressed in the intestinal mucosa of active and non-active IBD, while a similar upregulation was seen in skin biopsies from EN (84.7 vs. 22.3, p<0.001) and PG (60.5 vs. 22.3, p=0.011), but not in psoriasis. Caspase 3 and CD68 overexpression in skin biopsies distinguished EN/PG from psoriasis and controls. Conclusions: Upregulation of TNFα/NFκB in EN and PG is compatible with the efficacy of anti-TNF in EIM management. Data on overexpressed STAT3, but not MAdCAM1 support a rationale for JAK-inhibitors in EN and PG, while questioning the role of vedolizumab

Cytomegalovirus disease in inflammatory bowel disease: epidemiology and disease characteristics in a large single-centre experience

BACKGROUND Patients with inflammatory bowel disease (IBD) show an increased risk of developing cytomegalovirus (CMV) disease because of immunosuppressive medication and malnutrition. Here, we aimed to investigate the prevalence and clinical characteristics of CMV disease in our cohort of IBD patients. PATIENTS AND METHODS We carried out a retrospective analysis of 1023 IBD patients treated at our IBD clinic at the University Hospital Zurich between 2007 and 2014. CMV disease was defined as a positive immunohistochemistry for CMV and 14 patients were identified. RESULTS The prevalence of CMV disease in our IBD cohort was 1.37%. Twelve patients had ulcerative colitis and two had Crohn's disease with colonic involvement. All patients who developed CMV disease received immunosuppressive medication or, as in one case, had HIV infection. The most used immunosuppressive medications were steroids and azathioprine. The most common therapeutic strategy was the consecutive use of ganciclovir and valganciclovir. Ten patients recovered and two were treatment refractory; among these, one required colectomy and two had a relapse. CONCLUSION CMV disease may influence the clinical course of IBD. There is probably an association between CMV disease and IBD-specific medication. Risk factors, epidemiology and therapeutic strategy need to be further investigated

Effect of distance to specialist care for the diagnosis and disease outcome of inflammatory bowel disease in the Swiss inflammatory bowel disease cohort study

Background: Inflammatory bowel disease (IBD) needs early interventions and an individual specialist-patient relationship. Distance from a tertiary IBD center might affect patient's disease course and outcome. We investigated whether the patient-to-specialist distance has an impact on the disease course using the well-defined patient collective of the Swiss Inflammatory Bowel Disease Cohort Study (SIBDCS). Methods: Patient's home address at diagnosis (postal zip code) was extracted from the SIBDCS database. Distance between each zip code and the nearest located IBD specialist center was calculated and classified into the following three sections based on proximity: 35 km (group 3). Results: Our study included in total 408 IBD patients [234 Crohn's disease (CD), 154 ulcerative colitis (UC), 20 IBD unclassified (IBDU)]. Median age was lowest in group 2 at diagnosis (G1: 28 years; G2: 21 years, G3: 26 years, p < 0.01). The diagnostic delay did not differ between groups. CD patients in group 1 were treated more often with anti-tumor necrosis factor (TNF) agents (72% versus 56%, p = 0.04) and 5-aminosalicylates (44% versus 28%, p = 0.04) than in group 3. UC/IBDU patients in group 1 were treated more often with corticosteroids than patients in group 3 (83% versus 58%, p < 0.01). The occurrence of IBD-related surgeries did not differ between groups. Conclusions: Patient-to-specialist distance might affect drug treatment. However, disease course and the need for IBD-related surgery does not seem to be associated with a longer distance to specialist care in Switzerland

Nutrition in Inflammatory Bowel Disease

BACKGROUND Westernization, above all associated changes in diet, has been postulated to be one of the most important factors contributing to the increasing incidence in inflammatory bowel disease (IBD), consisting mainly of Crohn's disease and ulcerative colitis. SUMMARY Diet represents a crucially important and intuitively relevant topic for IBD patients. Although a substantial number of patients are prone to follow dietary advice from a variety of sources, including the lay press, there is intriguingly little scientific evidence for such an incitement. This may result in physicians being insufficiently informed about various aspects of nutrition, precluding adequate guidance of their patients with IBD. Importantly, IBD patients are at risk to develop deficiencies in iron, vitamin B12, folic acid, and several micronutrients, which may even be more pronounced in patients with active disease and those following a restrictive diet. This review aims to summarize the latest data from clinical and epidemiological studies investigating diet and its effect on the course of the disease and to outline the most important nutrient deficiencies in IBD patients. Key Messages: A western diet with an imbalance between omega-6 (n-6)/omega-3 (n-3) polyunsaturated fatty acids (PUFAs), in favor of n-6 PUFAs, may increase the risk of IBD, whereas a diet high in fruits and vegetables may decrease the risk of IBD. Many approaches to influence the course of IBD with dietary intervention exist. However, to induce or maintain remission in IBD with a change of diet is still in its infancy, and more dietary research is needed before we can apply it in daily practice. Patients with IBD, even in remission, have to be screened regularly for malnutrition

Close follow-up is associated with fewer stricture formation and results in earlier detection of histological relapse in the long-term management of eosinophilic esophagitis.

BACKGROUND AND AIMS No recommendations exist regarding optimal follow-up schedule in patients with eosinophilic esophagitis (EoE) under maintenance treatment. METHODS We retrospectively evaluated a long-term surveillance concept at the Swiss EoE clinic, where clinical, endoscopic and histological disease activity is assessed annually regardless of EoE symptoms. Data on 159 adult patients under maintenance steroid treatment with available follow-up were analyzed. Patients were classified as having close (duration between visits <18 months) or non-close follow-up (≥18 months). RESULTS We analyzed a total of 309 follow-up visits of 159 patients (123 males, age at diagnosis 38.9 ± 15.4 years). 157 (51%) visits were within a close follow-up schedule (median duration between visits of 1.0 years (interquartile range (IQR) 0.9-1.2)), while 152 visits (49%) were not (median duration between visits 2.9 years (IQR 2.0-4.1)). There was no difference regarding ongoing clinical, endoscopic, and histological disease activity, and adherence to prescribed steroid treatment between the two groups. However, stricture formation was significantly less frequently observed at visits within a close follow-up schedule (22.9 vs. 33.6%, p = 0.038). Absence of close follow-up was a significant risk factor for stricture development in a multivariate regression model. Patients who achieved histological remission and were followed within a close-follow-up schedule had significantly earlier detection of histological relapse compared to patients not within such close follow-up. CONCLUSION Close follow-up is associated with fewer stricture formation and appears to result in earlier detection of histological relapse in patients with eosinophilic esophagitis. We advocate for regular assessment of disease activity (every 12-18 months) in order to detect relapsing disease as early as possible, and therefore potentially minimize the risk for EoE complications

Impact of Diagnostic Delay on Disease Course in Pediatric- versus Adult-Onset Patients with Ulcerative Colitis: Data from the Swiss IBD Cohort

INTRODUCTION Given the lack of data, we aimed to assess the impact of the length of diagnostic delay on the natural history of ulcerative colitis (UC) in pediatric (diagnosed <18 years) and adult patients (diagnosed ≥18 years). METHODS Data from the Swiss Inflammatory Bowel Disease Cohort Study were analyzed. Diagnostic delay was defined as the interval between the first appearance of UC-related symptoms until diagnosis. Logistic regression modeling evaluated the appearance of the following complications in the long term according to the length of diagnostic delay: colonic dysplasia, colorectal cancer, UC-related hospitalization, colectomy, and extraintestinal manifestations (EIMs). RESULTS A total of 184 pediatric and 846 adult patients were included. The median diagnostic delay was 4 [IQR 2-7.5] months for the pediatric-onset group and 3 [IQR 2-10] months for the adult-onset group (p = 0.873). In both, pediatric- and adult-onset groups, the length of diagnostic delay at UC diagnosis was not associated with colectomy, UC-related hospitalization, colon dysplasia, and colorectal cancer. EIMs were significantly more prevalent at UC diagnosis in the adult-onset group with long diagnostic delay than in the adult-onset group with short diagnostic delay (p = 0.022). In the long term, the length of diagnostic delay was associated in the adult-onset group with colorectal dysplasia (p = 0.023), EIMs (p < 0.001), and more specifically arthritis/arthralgias (p < 0.001) and ankylosing spondylitis/sacroiliitis (p < 0.001). In the pediatric-onset UC group, the length of diagnostic delay in the long term was associated with arthritis/arthralgias (p = 0.017); however, it was not predictive for colectomy and UC-related hospitalization. CONCLUSIONS As colorectal cancer and EIMs are associated with considerable morbidity and costs, every effort should be made to reduce diagnostic delay in UC patients