Presence of spondyloarthritis associated to higher disease activity and HLA-B27 positivity in patients with early Crohn's disease: Clinical and MRI results from a prospective inception cohort.

OBJECTIVE: To determine the SpA prevalence and identify its associated factors in Crohn's disease (CD) patients receiving a systematically rheumatological and imaging assessment, including magnetic resonance imaging (MRI) of the sacroiliac joints and spine. METHODS: CD patients either naive to biologics or without them for three months prior enrollment were recruited in a subgroup of the German Spondyloarthritis Inception Cohort (GESPIC-Crohn). A structured assessment of SpA manifestations was performed by a rheumatologist, including MRI of sacroiliac joints and spine. Demographic and clinical parameters including disease activity in CD (Harvey Bradshaw Index-HBI) and SpA (C-reactive protein - CRP, Bath Ankylosing Spondylitis Disease Activity Index, and Ankylosing Spondylitis Disease Activity Score) were collected. Univariable and multivariable logistic regression analyses were performed to identify factors associated with the presence of SpA. RESULTS: A total of 103 patients with CD were included in the cohort. The mean CD disease duration was 1.3±2.4years and 95.1% were naïve to biologics. The most frequent musculoskeletal manifestation was back pain (65.0%), followed by chronic back pain (50.5%), and arthralgia (43.7%). Prevalence of SpA was 19.4% with slightly higher proportion of axial SpA than peripheral SpA, and higher proportion of radiographic axial SpA (7.4%) than non-radiographic axial SpA (2.8%). Changes in MRI compatible with axial SpA were found in 15 (14.7%) patients, of which 9 (81.1%) patients had the clinical diagnosis of axial SpA. HLA-B27 positivity (OR 9.02, CI 95% 2.29-35.55) and higher disease activity of CD as reflected by the HBI (OR 1.14, 95%CI 1.01-1.30) were significant and independently associated with the presence of SpA. CONCLUSION: SpA was present in nearly one out of five patients with CD and it was associated with the expression of HLA-B27 and a higher clinical activity of CD. Our findings raise awareness to rheumatologists and gastroenterologists on the high concomitance between both diseases and may help to reduce the delay in SpA diagnosis.

T-cell Composition in Ileal and Colonic Creeping Fat - Separating Ileal from Colonic Crohn's Disease.

BACKGROUND AND AIMS: Creeping fat [CF] is a hyperplasia of adipose tissue adjacent to inflamed intestine in Crohn's disease [CD]. Data from genome-wide association studies [GWAS] distinguished Crohn's colitis from ileal CD and ulcerative colitis [UC]. This study analysed the T-cell compartments of ileal and colonic mesenteric fat and corresponding mucosa to provide cellular proof for the suggested GWAS classification. METHODS: Samples were obtained from 34 CD or UC patients. Cells were analysed by immunohistochemistry and flow cytometry, and tissue cytokine release was assessed by cytometric bead array. RESULTS: Only ileal CF revealed the distinct adipocyte hyperplasia combined with dense T-cell infiltration and fibrosis; colonic fat from CD and UC patients lacked these findings. T-cell subpopulations differed between mesenteric fat in ileal CD, colonic CD and UC: ileal CF had nearly 10 times more T-cells than colonic fat. The proportions of regulatory and central memory T-cells were significantly higher in ileal CF compared with colonic fat in CD and UC. In all groups, the mucosal T-cell compartment was distinct from the mesenteric fat. Remarkably, correlation between disease activity and proportion of pro- and anti-inflammatory T-cell subpopulations was inverse, comparing ileal and colonic fat in CD. CONCLUSIONS: This first in-depth analysis of the T-cell compartment in ileal and colonic mesenteric adipose tissue in CD and UC identifies a unique T-cell niche in the ileal mesenteric fat tissue in CD. From a clinical point of view, our findings underscore the novel concept of colonic and ileal CD as distinct IBD entities.

Accuracy of diagnostic tests and a new algorithm for diagnosing cytomegalovirus colitis in inflammatory bowel diseases: a diagnostic study.

PURPOSE: The optimal method for detecting CMV colitis in patients with inflammatory bowel disease (IBD) has not been established. We wanted to investigate which diagnostic test would be most accurate when defining CMV colitis rather by the further clinical course than by using another diagnostic modality. METHODS: All consecutive patients with moderately or severely active IBD who had been tested for CMV by PCR, histology, or antigenemia assay at the two campuses CBF and CCM of the Charité - Universitätsmedizin Berlin between September 2006 and September 2009 were included in this retrospective study. During that time, in patients with a positive CMV test, immunosuppressive treatment of any kind was immediately reduced and antiviral treatment was started. This allowed identifying patients who responded to antiviral treatment and those who only responded to later escalation of immunosuppressive therapy. RESULTS: One hundred and nine patients were identified, out of whom nine were considered to have clinically relevant CMV colitis. Sensitivity and specificity were 1 and 0.94 for CMV PCR and 0.5 and 1 for pp65 antigen immunofluorescence assay from peripheral blood, 0.67 and 0.98 for immunohistochemistry, and 0.17 and 0.98 for hematoxylin-eosin staining. When using absence of leukocytosis, splenomegaly, and steroid refractory disease as clinical parameters to test for CMV colitis, blood CMV PCR and immunohistochemistry were able to exclude CMV colitis in negative patients with a 75% likelihood of positive patients to have clinically relevant CMV colitis. CONCLUSIONS: Blood-based CMV PCR together with simple clinical parameters can exclude clinically relevant CMV colitis at a high specificity.

Guideline recommendations for treatment of patients with inflammatory bowel diseases are not implemented in clinical practice-results of a non-representative survey.

PURPOSE: There is a growing evidence for over-, under-, or misuse of health care in patients with inflammatory bowel disease. Most studies looked at treatment variability or used quality measures, which mostly capture supportive interventions rather than treatment of IBD in itself. We aimed to evaluate if current recommendations in clinical practice guidelines regarding the medical treatment of patients with inflammatory bowel diseases are being followed in Germany. METHODS: A questionnaire was sent to 1901 patients insured with two large German statutory sickness funds and an ICD 10 diagnosis of Crohn's disease (CD) or ulcerative colitis (UC). The questionnaire asked about drug treatment, indications for drug treatment, provision of surveillance endoscopies in ulcerative colitis patients, and smoking status in Crohn's disease patients. RESULTS: Out of 460 evaluable patients, 62.4% of UC patients and 53.9% of CD patients were treated with mesalamine according to guidelines, 91.3% of all patients were treated with glucocorticoids according to guideline recommendations, while only 75.6% received recommended immunosuppressive treatment. Of UC patients, 94.5% had surveillance colonoscopies at the recommended interval and 58.8% of CD patients were non-smokers. No predictor for overall treatment according to guidelines could be found while being of age older than 60 or being treated outside of a dedicated IBD clinic was associated with less immunosuppressive treatment. CONCLUSIONS: A large proportion of patients with IBD do not receive drug treatment in accordance with clinical practice guidelines. Quality improvement measures are much needed.

Role of visceral fat in colonic inflammation: from Crohn's disease to diverticulitis.

PURPOSE OF REVIEW: The composition of activated adipose tissue with adipocytes secreting a broad spectrum of immune-modulatory adipokines next to adipose tissue-derived stromal cells and professional immune effector cells in the visceral fat creates a complex network of inflammatory processes shaping local immune responses in the adjacent inflamed intestinal mucosa. RECENT FINDINGS: In Crohn's disease a particular phenomenon called 'creeping fat' can be observed. Here the hyperplastic mesenteric fat tissue not only grows around inflamed small intestinal segments but also furthermore affects the regulation of the mucosal immune system. Diverticular disease is highly prevalent in the western world but the knowledge about its immunopathology remains incomplete. Interestingly, adipose tissue also frequently covers the basolateral site of inflamed diverticula, hence locally reflecting the phenomenon seen in Crohn's disease. SUMMARY: This review aims to summarize the current knowledge in which measures this intraabdominal fat participates in the regulation of intestinal inflammation with a particular focus on differences and possible parallels in Crohn's disease and diverticulitis. The available data allow for suggesting that each inflamed diverticula mechanistically reflects Crohn's disease on a miniature scale.

Diversity of Intestinal Macrophages in Inflammatory Bowel Diseases.

Macrophages as innate immune cells and fast responders to antigens play a central role in protecting the body from the luminal content at a huge interface. Chronic inflammation in inflammatory bowel diseases massively alters the number and the subset diversity of intestinal macrophages. We here address the diversity within the human intestinal macrophage compartment at the level of similarities and differences between homeostasis and chronic intestinal inflammation as well as between UC and CD, including the potential role of macrophage subsets for intestinal fibrosis. Hallmark of macrophages is their enormous plasticity, i.e., their capacity to integrate signals from their environment thereby changing their phenotype and functions. Tissue-resident macrophages located directly beneath the surface epithelium in gut homeostasis are mostly tolerogenic. The total number of macrophages increases with luminal contents entering the mucosa through a broken intestinal barrier in ulcerative colitis (UC) as well as in Crohn's disease (CD). Although not fully understood, the resulting mixtures of tissue-resident and tissue-infiltrating macrophages in both entities are diverse with respect to their phenotypes and their distribution. Macrophages in UC mainly act within the intestinal mucosa. In CD, macrophages can also be found in the muscularis and the mesenteric fat tissue compartment. Taken together, the present knowledge on human intestinal macrophages so far provides a good starting point to dig deeper into the similarities and differences of functional subsets and to finally use their phenotypical diversity as markers for complex local milieus in health and disease.

Adipose-tissue and intestinal inflammation - visceral obesity and creeping fat.

Obesity has become one of the main threats to health worldwide and therefore gained increasing clinical and economic significance as well as scientific attention. General adipose-tissue accumulation in obesity is associated with systemically increased pro-inflammatory mediators and humoral and cellular changes within this compartment. These adipose-tissue changes and their systemic consequences led to the concept of obesity as a chronic inflammatory state. A pathognomonic feature of Crohn's disease (CD) is creeping fat (CF), a locally restricted hyperplasia of the mesenteric fat adjacent to the inflamed segments of the intestine. The precise role of this adipose-tissue and its mediators remains controversial, and ongoing work will have to define whether this compartment is protecting from or contributing to disease activity. This review aims to outline specific cellular changes within the adipose-tissue, occurring in either obesity or CF. Hence the potential impact of adipocytes and resident immune cells from the innate and adaptive immune system will be discussed for both diseases. The second part focuses on the impact of generalized adipose-tissue accumulation in obesity, respectively on the locally restricted form in CD, on intestinal inflammation and on the closely related integrity of the mucosal barrier.