NF-kB pathway is involved in microscopic colitis pathogenesis.

OBJECTIVE: To investigate the potential inflammatory pathways involved in the development of microscopic colitis (MC). METHODS: This prospective study analysed human intestinal tissue that was collected and classified as healthy controls (HC), microscopic colitis (MC) and ulcerative colitis (UC). An RT2 Profiler PCR Array for human inflammatory response and autoimmunity was used to evaluate the expression of 84 specific genes related to the inflammatory and autoimmunity pathways. Data were validated by means of real-time polymerase chain reaction on an independent group of MC intestinal tissue samples. RESULTS: This study measured the expression of inflammatory genes in HC (n = 10), in patients with MC (n = 8) and in patients with active UC (n = 10). Of the 84 genes included in the array, the expression of the C-C motif chemokine ligand 19, C-C motif chemokine ligand 21, lymphotoxin beta and complement C3 genes that are involved in the non-canonical nuclear transcription factor kappa B (NF-kB) pathway was increased by 2.96, 6.05, 5.96 and 5.93 times in MC compared with HC, respectively. These results were confirmed by real-time polymerase chain reaction. CONCLUSIONS: The findings suggest that an impairment of the non-canonical NF-kB pathway is involved in the development of MC.

Course of Disease in Patients with Microscopic Colitis: A European Prospective Incident Cohort Study.

BACKGROUND AND AIMS: The disease course of microscopic colitis [MC] is considered chronic but benign. However, this assumption is based on mainly retrospective studies, reporting on incomplete follow-up of selective cohorts. Systematic, prospective and unbiased data to inform patients and healthcare professionals on the expected course of the disease and real-life response to therapy are warranted. METHODS: A prospective, pan-European, multi-centre, web-based registry was established. Incident cases of MC were included. Data on patient characteristics, symptoms, treatment and quality of life were systematically registered at baseline and during real-time follow-up. Four disease course phenotypes were discriminated and described. RESULTS: Among 381 cases with complete 1-year follow-up, 49% had a chronic active or relapsing disease course, 40% achieved sustained remission after treatment and 11% had a quiescent course. In general, symptoms and quality of life improved after 3 months of follow-up. A relapsing or chronic active disease course was associated with significantly more symptoms and impaired quality of life after 1 year. CONCLUSIONS: A minority of MC patients follow a quiescent disease course with spontaneous clinical improvement, whereas the majority suffer a chronic active or relapsing disease course during the first year after diagnosis, with persisting symptoms accompanied by a significantly impaired quality of life.

In-vivo Axial-strain Sonoelastography Helps Distinguish Acutely-inflamed from Fibrotic Terminal Ileum Strictures in Patients with Crohn's Disease: Preliminary Results.

We tested real-time sonoelastography (RTS) in-vivo to differentiate fibrotic from inflammatory terminal ileum strictures in patients with Crohn's disease (CD), using magnetic resonance enterography (MRE) as a reference standard. Sixteen patients (13 male, 3 female; median [interquartile interval] age = 41 [31-48.5] y; median C-reactive protein (CRP) = 0.95 [0-2.23] mg/dL; median disease duration = 108.5 [35-213.75] mo; median Harvey-Bradshaw Index (HBI) = 3 [3-5.25]) with terminal ileum CD were prospectively included. Short-axis scans were performed; each cross-section was ideally sub-divided into eight circular sectors. Color map provided by RTS was translated into semi-quantitative scale (1 = red; 2 = green; 3 = blue). At MRE, inflammation was seen in nine patients and fibrosis in seven. Total median RTS score was significantly lower in patients with inflammatory stricture (16 [16-18]) than in patients with fibrosis (20 [17.5-22]; p = 0.003). The same happened when the four most superficial quadrants of the loop were considered (8 [7-9] vs. 10 [9-11.5]; p = 0.003). No significant correlation was seen between RTS and HBI (r = 0.467; p = 0.686), RTS and CRP (r = -0.750; p = 0.567) or RTS and disease duration (r = 0.238; p = 0.483). RTS of the terminal ileum in patients with CD is feasible in-vivo, potentially differentiating between fibrotic and inflammatory strictures.

Development of the Lémann index to assess digestive tract damage in patients with Crohn's disease.

BACKGROUND & AIMS: There is a need for a scoring system that provides a comprehensive assessment of structural bowel damage, including stricturing lesions, penetrating lesions, and surgical resection, for measuring disease progression. We developed the Lémann Index and assessed its ability to measure cumulative structural bowel damage in patients with Crohn's disease (CD). METHODS: We performed a prospective, multicenter, international, cross-sectional study of patients with CD evaluated at 24 centers in 15 countries. Inclusions were stratified based on CD location and duration. All patients underwent clinical examination and abdominal magnetic resonance imaging analyses. Upper endoscopy, colonoscopy, and pelvic magnetic resonance imaging analyses were performed according to suspected disease locations. The digestive tract was divided into 4 organs and subsequently into segments. For each segment, investigators collected information on previous operations, predefined strictures, and/or penetrating lesions of maximal severity (grades 1-3), and then provided damage evaluations ranging from 0.0 (no lesion) to 10.0 (complete resection). Overall level of organ damage was calculated from the average of segmental damage. Investigators provided a global damage evaluation (from 0.0 to 10.0) using calculated organ damage evaluations. Predicted organ indexes and Lémann Index were constructed using a multiple linear mixed model, showing the best fit with investigator organ and global damage evaluations, respectively. An internal cross-validation was performed using bootstrap methods. RESULTS: Data from 138 patients (24, 115, 92, and 59 with upper tract, small bowel, colon/rectum, and anus CD location, respectively) were analyzed. According to validation, the unbiased correlation coefficients between predicted indexes and investigator damage evaluations were 0.85, 0.98, 0.90, 0.82 for upper tract, small bowel, colon/rectum, anus, respectively, and 0.84 overall. CONCLUSIONS: In a cross-sectional study, we assessed the ability of the Lémann Index to measure cumulative structural bowel damage in patients with CD. Provided further successful validation and good sensitivity to change, the index should be used to evaluate progression of CD and efficacy of treatment.

Imaging of the small bowel in Crohn's disease: a review of old and new techniques.

The investigation of small bowel morphology is often mandatory in many patients with Crohn's disease. Traditional radiological techniques (small bowel enteroclysis and small bowel follow-through) have long been the only suitable methods for this purpose. In recent years, several alternative imaging techniques have been proposed. To review the most recent advances in imaging studies of the small bowel, with particular reference to their possible application in Crohn's disease, we conducted a complete review of the most important studies in which traditional and newer imaging methods were performed and compared in patients with Crohn's disease. Several radiological and endoscopic techniques are now available for the study of the small bowel; each of them is characterized by a distinct profile of favourable and unfavourable features. In some cases, they may also be used as complementary rather than alternative techniques. In everyday practice, the choice of the technique to be used stands upon its availability and a careful evaluation of diagnostic accuracy, clinical usefulness, safety and cost. The recent development of innovative imaging techniques has opened a new and exciting area in the exploration of the small bowel in Crohn's disease patients.