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* = Presenting author

P043 Immunohistochemical expression of angio and lymphangiogenic factors in colonic mucosa of patients with inflammatory bowel disease.

P.M. Linares1, M. Chaparro1, A. Algaba2, I. Guerra2, F. Bermejo2, J.P. Gisbert*1

1Hospital Universitario de La Princesa, IIS-IP and CIBERehd, Gastroenterology Unit, Madrid, Spain, 2Hospital Universitario de Fuenlabrada, Gastroenterology Unit, Madrid, Spain

Background

To evaluate the possible differences between inflammatory bowel disease (IBD) and non-IBD, and between ulcerative colitis (UC) and Crohn's disease (CD), in the expression of VEGFA, -C, -D, VEGFR1, -R2, -R3, PlGF, Ang1, Ang2 and Tie2 in colonic mucosa

Methods

Biopsies from patients with and without IBD that underwent to a colonoscopy by medical criteria were prospectively included and their mucosal samples studied by immunohistochemistry. VEGFA, -C, -D, -R1, -R2, -R3 and PlGF expression Results were graded as follows: (++) over 50% of the tissue cells were stained, (+) below 50%, and (-) completely negative. Ang1, Ang2 and Tie2 were assessed as the average density of five hot spots at a magnification of x40. Endoscopic activity was assessed by endoscopic Mayo Subscore (UC) and SES-CD (CD) indexes. Patients were classified in accordance with the Montreal classification. In cases with active disease, biopsies were taken from both endoscopically affected and non-affected mucosa

Results

101 biopsies from 58 patients with IBD (36 UC and 22 CD) and 19 controls were included; 56% patients were male and 20% smokers. 64% of the patients did not have endoscopic activity, 16% had moderate, 14% mild and 6% severe activity. Expression and mean count of Ang1, Ang2, VEGFR2 (p<0.01), and VEGFC, -R1 and Tie2 were higher in samples from patients with UC compared to CD (p<0.05). In patients with CD, Ang1 mean count, and expression of VEGFC, -D, -R2, PlGF, and VEGFR3, were higher (p<0.05), and the rest of factors were lower, than in controls. Expression of Ang2 (p<0.05) and of all the studied factors were higher in active samples than in non-active CD; on the opposite, VEGFD and -R3 were lower. Expression of VEGFR1 and Tie2 were higher in patients under anti-TNF treatment than in those who were not (p<0.05). VEGFR1 and -R2 expressions were higher in patients with extraintestinal manifestations (p<0.05). In UC, expression of all factors were higher in patients with UC than in controls (p<0.05). Mean count and expression of Ang1, Ang2 were higher, and VEGFD was lower (p<0,05) in samples with active disease. Patients with smoking habit had a lower expression of VEGFR2 (p<0.05). Patients under 5-ASA treatment had a lower expression of VEGFD (p<0.05), and those under thiopurine treatment had a higher expression of VEGFA and PLGF (p<0.05) compared to untreated ones. VEGFR2 expression was higher in patients with left-sided colitis (p<0.05)

Conclusion

Angiogenic factors are differentially expressed at mucosal level in patients with CD and UC. Our findings might support a role of angiogenic factors in disease activity and behaviour of IBD. Expression of these factors in colonic mucosa of IBD patients may be modulated by immunosuppressive and anti-TNF treatment