Safety and Efficacy of High-dose Leukocytapheresis Using a Large Filter in Patients With Refractory Asthma

Extracorporeal leukocytapheresis (LCAP) or granulocytapheresis (GCAP) has been used in the treatment of patients with rheumatoid arthritis and ulcerative colitis and has shown promising safety and efficacy. LCAP and GCAP seem to be effective for steroid-resistant inflammation. The investigators have already reported safety and efficacy of GCAP in refractory asthma and expect the beneficial effect of LCAP in refractory asthma. In this study, in order to improve the therapeutic effect of LCAP by increasing the quantity of leukocytes that were removed, the investigators conducted a clinical study to investigate safety and efficacy of high-dose LCAP performed using a larger filter and an increased dose of the blood volume per body weight treated, as an possible therapy for refractory asthma.