Vascular endothelial growth factor in inflammatory bowel disease

Abstract

Background and aims: Angiogenesis is an important component of tissue regeneration. As Inflammatory bowel disease (IBD) involves inflammation, ulceration, and regeneration of the intestinal mucosa, angiogenesis may be an integral part of IBD pathology. This study investigated the role of vascular endothelial growth factor in IBD.

Patients and methods: The VEGF plasma (pVEGF) and serum (sVEGF) levels were assessed in patients with ulcerative colitis (UC; n=50) or Crohn's disease (CD; n=44) and in healthy controls (n=23). The immunohistochemical expression of VEGF was also assessed in surgical material from 11 patients with active IBD.

Results: Overall the sVEGF levels ranged from 30-899 pg/ml (median 200 pg/ml) and were significantly higher than the pVEGF levels (range 20-80 pg/ml, median 30 pg/ml). pVEGF levels were significantly lower in patients with active and quiescent CD than in healthy controls. Despite the lower pVEGF levels noted also for patients with UC, the difference was not significant. sVEGF levels were also reduced in patients with IBD, but the difference was not significant. No association of pEGF/sVEGF with beta-thromboglobulin and platelet factor 4 levels (markers of platelet activation) was noted. On immunohistochemistry VEGF was not expressed in the inflammatory component (lymphocytes and macrophages), the fibroblasts, or the muscular layer of the intestinal wall. The intestinal epithelium was negative in CD, while a cytoplasmic reactivity was noted in UC and normal controls.

Conclusion: As VEGF is a vascular and epithelial cell survival factor, the defective VEGF response ability, confirmed here for patients with CD, may be a key element in the pathology of the disease. The pathology of UC, however, seems not to be VEGF dependent.