Abstract: Apheresis has been recognized both economically and therapeuticallyas a novel approach for the treatment of inflammatory diseases,and certain others, which respond poorly to drug therapy. This reportis about Adacolumn, an adsorptive carrier based granulocyteand monocyte apheresis device with a volume of 335 mL,filled with about 220 g of cellulose acetate beads of 2 mmdiameter as the column adsorptive carriers. Pre- and post-columnleukocyte counts have shown that the carriers adsorb about 65% ofgranulocytes, 55% of monocytes and 2% of lymphocytesfrom the blood in the column. Additionally, after apheresis, thereis a marked decrease in inflammatory cytokines (TNF-α,IL-1β, IL-6 and IL-8) produced by blood leukocytes,together with down-modulation of l-selectinand the chemokine receptor CXCR3. Adacolumn has been used to treatpatients with rheumatoid arthritis, ulcerative colitis and HIV infection. Typicalapheresis sessions have been 4–10, at a frequency of oneor two sessions per week. Treatment of patients with Adacolumn hasbeen associated with very promising efficacy and safety data. Accordingly,in Japan, Adacolumn has been approved by the Ministry of Healthfor the treatment of ulcerative colitis. Furthermore, Adacolumnmet the required quality and safety standards for medical devices andreceived an EC certification (CE-mark) from TUV in 1999. However,although Adacolumn carriers are very efficient in depleting excessand activated granulocytes and monocytes/macrophages, theclinical efficacy associated with Adacolumn apheresis cannot befully explained on the basis of reducing granulocytes and monocytesper se. Hence, a long lasting effect on inflammatory cytokine generation,chemokine activities or immunomodulation is likely, but the precisemechanisms involved are not fully understood yet.