Inflammation-driven angiogenesis contributes to the pathogenesis of inflammatory bowel disease (IBD). In line with this, the efficacy of inhibitors of angiogenesis has been demonstrated in ...experimental models of colitis. Currently, the ability of infliximab, an anti-tumor necrosis factor-α (TNF-α) agent that is highly beneficial in patients with IBD, to affect mucosal angiogenesis in patients with Crohn's disease (CD) and ulcerative colitis (UC) is unknown.
Patients with active CD (n=14) were treated with infliximab for 1 year, and peripheral blood and intestinal mucosa samples were collected before and after treatment. Mucosal angiogenesis was evaluated by CD31 and Ki-67 staining in endoscopic biopsies at baseline (week 0) and at week 54. The release of vascular endothelial growth factor-A (VEGF-A) by cultured mucosal extracts was measured by enzyme-linked immunosorbent assay (ELISA), before and after administration of infliximab, as well as in cultures of human intestinal fibroblasts (HIFs) stimulated with TNF-α in the presence or absence of infliximab. Migration of human intestinal microvascular endothelial cells (HIMECs) was investigated by migration assays.
Microvessel density was significantly higher in the mucosa from patients with CD compared with tissue from healthy control individuals. Of the 14 patients, 8 (57%) showed a clinical remission in response to infliximab, which was associated with a significant reduction of microvascular density. Morphometric vessel analysis further confirmed the significant reduction of the area of vascular section after administration of infliximab. Furthermore, the expression levels of the proliferation marker Ki-67 in endothelial cells were significantly reduced after treatment. The mucosal concentration of VEGF-A was also significantly decreased, whereas in vitro exposure of HIF to infliximab virtually abolished TNF-α-induced VEGF-A production. These phenomena did not occur in patients who showed no clinical response to infliximab.
Administration of infliximab downregulates mucosal angiogenesis in patients with CD and restrains production of VEGF-A by mucosal fibroblasts. It is proposed that this ameliorates inflammation-driven angiogenesis in the gut mucosa and contributes to the therapeutic efficacy of blockade of TNF-α.
Crohn's disease (CD) and ulcerative colitis (UC) are immune-mediated disorders characterized by a chronic inflammation, with intermittent exacerbations of symptoms and inflammation. In both diseases, ...medical treatment has made revolutionary steps forward. Nevertheless, surgery is still required in many cases due to inefficacy of multiple medical therapies. It is not clear whether surgery rates in inflammatory bowel diseases (IBD) are currently decreasing despite all improvements.
Multidisciplinary management is critical in surgical patients to improve long-term outcomes. Endoscopy plays a crucial role, both before and after surgery, in planning therapeutic strategies and stratifying risk of recurrence. Aim of this review is to provide a deeper insight into the central role of endoscopy in the postoperative management of IBD patients, focusing on recent research advances, future challenges and unresolved questions.
Both UC and CD surgical patients need endoscopy to define the correct therapeutic choice, predict subsequent disease course and adopt the correct surveillance strategy. In the next future, newer endoscopic techniques could be systematically applied in IBD patients after surgery, to assess early postoperative inflammation, response to treatment, or, regarding UC, to provide enhanced pouch surveillance, allowing for early detection of inflammation and dysplasia.
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