[Vascular development in inflammatory bowel disease]

There are 4 major concepts in vascular development: vasculogenesis (formation of blood vessels from angioblasts), angiogenesis (formation of vascular sprouts from preexisting vessels), arteriogenesis (thickening and development of vessels) and lymphangiogenesis (formation of lymphatic vessels). In the last decade, these concepts, especially angiogenesis and lymphangiogenesis, have acquired major importance due to their role in tumoral growth and metastatic dissemination. Moreover, the activity of various diseases that involve chronic inflammation, such as asthma, psoriasis and rheumatoid arthritis, has been associated with vascular development. Several growth factors and cytokines are involved in this process and consequently investigation into these elements, both in peripheral blood and their expression in affected tissues, could elucidate the role of vascular development in diseases whose pathogenesis involves chronic inflammation, such as inflammatory bowel disease. The presence of distinct molecules involved in vascular development processes, such as vascular endothelial growth factor (VEGF), basic fibroblastic growth factor and placental growth factor, among others, has been studied in both ulcerative colitis and Crohn's disease, although not extensively. It has been suggested that the phenomena of vasculogenesis, angiogenesis and lymphangiogenesis play a critical, although not exclusive, role in the inflammation that characterizes inflammatory bowel disease. In general, the results obtained to date suggest that new vascular formation is involved in the pathogenesis of these diseases.