Innovative Imaging Helps Detect Angiogenesis in Inflammatory Bowel Disease Patients

Narrow-band imaging (NBI) could visualize angiogenesis in chronic inflammatory disorders, and may represent the first step in developing a therapeutic approach to blocking it.

Researchers at the Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Instituto Clinico Humanitas (Milan, Italy) conducted a pilot study to investigate whether NBI could serve as a useful tool for the in vivo detection of angiogenesis in 14 inflammatory bowel disease (IBD) patients (8 with ulcerative colitis and 6 with Crohn's disease) who underwent both conventional and NBI colonoscopy to examine their colonic inflammation. Biopsy samples were taken, cluster definition 31 (CD31)--also called platelet endothelial cell adhesion molecule (PECAM-1)--expression was assayed immunohistochemically, and microvascular density was assessed by vessel count.

The researchers found that in areas that were endoscopically normal but positive on NBI, there was a significant increase in angiogenesis, compared with areas negative on NBI. In addition, in areas that were inflamed on white light endoscopy and positive on NBI, there was a significant increase in vessel density compared with NBI-negative areas. The researchers claim the findings suggest that NBI could be a novel tool for the in vivo assessment of mucosal angiogenesis; however, they caution, larger studies are needed to define the exact role of NBI in IBD patient follow-up. The study was published in the May 21, 2010, issue of the World Journal of Gastroenterology.

"Narrow-band imaging is a new endoscopic technology that highlights mucosal surface structures and microcapillaries. NBI could be used to visualize areas of abnormal microvascular changes that could not be observed with white light colonoscopy,” concluded lead author Silvio Danese, M.D., Ph.D., and colleagues of the division of gastroenterology. "The findings suggest that NBI could be a novel tool for the in vivo assessment of mucosal angiogenesis.”

Blocking angiogenesis is an attractive strategy to inhibit tumor growth, invasion, and metastasis, and could be beneficial in patients with chronic inflammation. Some drugs, such as tumor necrosis factor-α inhibitors, have demonstrated potent antiangiogenic activity in the treatment of IBD. Another promising candidate is a cyclic peptide derived from vascular endothelial growth factor (VEGF).

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IRCCS Instituto Clinico Humanitas