P051. Relationship between histological activity of inflammatory bowel disease (IBD) and angiogenic and lymphangiogenic factors (ALF)
A. Algaba1, P.M. Linares2, M.E. Fernández-Contreras2, A. Ordoñez3, J. Trápaga3, I. Guerra1, M. Chaparro2, J.L. Rodríguez-Agulló1, J.P. Gisbert2, F. Bermejo1
1Hospital Universitario de Fuenlabrada, Gastroenterology, Fuenlabrada, Spain; 2Hospital Universitario de La Princesa-IP, Gastroenterology and CIBERHED, Madrid, Spain; 3Hospital Universitario de Fuenlabrada, Laboratory, Fuenlabrada, Spain
Background: To correlate the levels of the main ALF in serum and colonic mucosa biopsy cultures supernatant (MCS) with the histological activity in patients with IBD.
Methods: Prospective study in patients with IBD that underwent a colonoscopy because of medical criteria. Three different samples were obtained per patient: a blood sample for ALF serum determination, several samples of colonic tissue for MCS determination of ALF, and other biopsies for histological analyses. In patients where activity was observed during colonoscopy, samples from affected and non-affected mucosa were also taken. Patients were classified into four groups based on endoscopic activity (endoscopic Mayo subscore for ulcerative colitis and SES-CD for Crohn's disease): non-activity, mild, moderate and severe activity. Considering histological findings, patients were also classified into four groups: Quiescent IBD, mild, moderate and severe lesion. VEGFA, VEGFC, VEGFD, VEGFR1, VEGFR2, VEGFR3, PlGF, Ang1, Ang2 and Tie2 concentrations both in serum and MCS were determined by ELISA.
Results: 72 patients with IBD (35 Crohn's disease, 37 ulcerative colitis) were included. 52% of the patients did not have endoscopic activity, 30% had moderate, 13% mild and 5% severe activity. There were significant (p < 0.05) differences in the concentrations of all ALF (except VEGFR3) in MCS depending on endoscopic activity. These concentrations were higher when the endoscopic activity was moderate or severe. According to histology, 38% of the patients had quiescent IBD, 34% had moderate lesions, 20% mild and 8% severe lesions. Levels of all the studied proteins in MCS were also significantly (p < 0.01) different based on histological activity. These concentrations were modified in parallel with the severity of histological lesions. Levels of Tie2 were significantly higher (p < 0.05) in the affected than in the non-affected mucosa. Ang1 serum levels were significantly higher (p < 0.05) in patients with endoscopic activity. The area under the Receiver Operator Characteristic (ROC) curve for the diagnosis of histological activity was 0.68 for Ang1 (cut-off at 51.2 ng/ml: 64% sensitivity and 64% specificity).
Conclusions: The levels of angio and lymphangiogenic factors and their receptors in MSC correlate with the histologic activity of IBD. The determination of Ang1 levels in serum may be useful as a non invasive method to assess histologic activity, although the correlation with this serum marker is only moderate.