Current status and future perspectives of leukocytapheresis for inflammatory bowel disease.

Ulcerative colitis (UC) and Crohn's disease (CD) comprise the idiopathic inflammatory bowel diseases (IBD) of the gut. The etiology of IBD is poorly understood, but an autoimmune disturbance has been suggested to play an important role in this incurable disease. Extracorporeal leukocytapheresis (CAP) is an additional adjunct for IBD patients refractory to other conventional therapies, including steroids. The primary aim of CAP should be to suppress such unwanted immunological response by removing circulating inflammatory cells from the blood stream. The first decade has been passed since CAP was approved by Japanese social health insurance policy. It is therefore now an appropriate opportunity to upgrade and summarize our current understandings and/or future perspectives of this unique non-pharmacological and non-surgical strategy for IBD patients. According to several clinical and basic research reports, an early introduction of CAP should produce higher efficacy as compared with CAP applied sometime after a clinical relapse. Likewise, CAP therapy adjusted to patients' body-weight as well as two treatment sessions per week (intensive regimen) should benefit the efficacy rate. The etiology of IBD is not fully elucidated yet. As a result, the major therapeutic strategies in the Western world have been immunosuppressive therapy, including biologics. CAP is an unusual treatment modality for IBD because it seems to have both effectiveness and safety, which should generally be balanced in this type of illness. We now have to develop future strategies with and without combining biologics to improve the quality of life of IBD patients.