Growth hormone in inflammatory bowel disease.

Crohn's disease and ulcerative colitis are inflammatory diseases of the gastrointestinal tract characterized by chronic relapsing inflammation and catabolism. Growth hormone/insulin-like growth factor-I axis is important in inflammatory bowel disease, because of the effects on epithelial cell kinetics, collagen deposition and immunomodulation. The potential of growth hormone as a therapeutic option in inflammatory bowel disease has been proven in various clinical settings. Acquired growth hormone resistance in inflammatory bowel disease seems to be mediated by a combination of undernutrition and active inflammation. In particular, proinflammatory cytokines, such as TNF-a and interleukin-6, have been implicated as potential mediators of growth hormone resistance. The introduction of anti-TNF-alpha monoclonal antibodies has proven very efficacious in patients with inflammatory bowel disease. By reducing cytokines levels in inflammatory cells of intestinal mucosa, infliximab could interfere with cytokine-induced growth hormone resistance. Recent in vivo data have shown that acquired growth hormone resistance in patients with inflammatory bowel disease may be reversed after the administration of anti-TNF-alpha therapy.