Production of interleukin-10 by combining a granulocyte and monocyte adsorption carrier with ulinastatin.

Interleukin (IL)-10 is an anti-inflammatory cytokine mainly produced by monocytes and is essential for the induction of anti-inflammatory intestinal macrophages with macrophage colony-stimulating factor (M-CSF). Thus, IL-10- and M-CSF-rich conditions in colonic tissues seem to contribute to the improvement of pathological conditions in patients with inflammatory bowel diseases (IBD). We have already reported that ulinastatin, a serine protease inhibitor, increases M-CSF production during granulocyte/monocyte (GM) adsorption to cellulose acetate (CA) beads (carriers for Adacolumn therapy). However, the effects of ulinastatin on IL-10 production have not been clarified. The aim of the present study was to clarify the effects of ulinastatin on IL-10 production during GM adsorption by in vitro experiments. Peripheral blood was divided into four groups: (Control) no ulinastatin added, no contact with CA beads; (1) no ulinastatin added, contact with CA beads; (2) ulinastatin added, no contact with CA beads; and (3) ulinastatin added, contact with CA beads. After incubation, IL-10 in the plasma was measured. Compared with the level in the Control group, plasma IL-10 was significantly higher only in group 3, in which ulinastatin was added in the presence of CA beads, but did not increase in the absence of CA beads. These results suggest that ulinastatin synergistically increases IL-10 production with monocyte adsorption stimuli. By increasing not only M-CSF but also IL-10, a combination of ulinastatin and Adacolumn therapy may improve clinical efficacy for the treatment of IBD in terms of the induction of anti-inflammatory intestinal macrophages.