The present status and the recent development of the treatment for inflammatory bowel diseases: desirable effect of extracorporeal immunomodulation.

The immunological and genetic pathogeneses of inflammatory bowel disease (IBD) have been well elucidated in the recent years. The pharmacologic treatment of IBDs accordingly becomes to focus upon the individual pathologic step (targeting therapy), whereas the therapeutic action is not yet a pinpoint one. It has been known recently that new drugs such as biological immunomodulating agents and anti-inflammatory cytokines have better short-term effects in some respects than the conventional drugs, and they might alter the treatment strategy of IBDs in the near future. The limitation of pharmacologic treatments mainly results from adverse effects of the drugs, i.e. infection susceptibility, oncogenesis, teratogenesis and so forth. The extracorporeal therapy such as leukocytapheresis and photopheresis is reportedly effective for IBDs probably through immunomodulation such as decrease in circulating activated T-lymphocytes and activated granulocytes that play a central role in the pathogenesis of IBD. It can be said that these extracorporeal treatment methods have advantage of rapid action and lack of serious adverse effects to drug therapy.