Can Asia afford new and emerging therapies in inflammatory bowel disease?

摘要

Ulcerative colitis (UC) and Crohn's disease (CD) comprise a series of inflammatory bowel diseases (IBD) resulting from chronic up-regulation of the mucosal immune system. Although the pathogenesis of IBD remains elusive, it appears that there is chronic activation of the immune and inflammatory cascade in genetically susceptible individuals, which is directed by genetic, immunological, and environmental factors. Although the prevalence of IBD in Asian countries is still not so high compared to Western countries, the accumulated numbers of patients has increased over the years, especially in Japan. This tendency may be observed similarly in other Asian countries; however, accurate numbers do not seem to be available except for Japan and South Korea. Corticosteroids, aminosalicylic acid and antibiotics have represented the principal approaches in evidence-based drug therapy for IBD, and these drugs are able to suppress disease activity in most cases. However, there are cases that do not respond to conventional drug therapy, or which remain dependent on high doses of steroids associated with severe side-effects in the long run. Thus immunosuppressive agents (cyclosporin A/tacrolimus, 6-mercaptopurine/azathioprine) and biological agents (anti-TNF-alpha antibody) have been in general use recently in Japan. Furthermore cytapheresis therapy and oral administration of tacrolimus against UC, and anti-IL-6 receptor antibody against CD, which originated in Japan, have demonstrated clinical efficacy. In this chapter current advances in diagnosis and treatment of IBD in Japan are introduced.