Attenuated production of intracellular IL-10 and IL-12 in monocytes from patients with severe asthma.

Abstract Interleukin (IL)-10 and IL-12 production is decreased in peripheral blood mononuclear cells of patients with mild asthma. Using whole blood culture and flow cytometry we examined whether monocyte heterogeneity influenced IL-10 and IL-12 production in subjects with severe asthma. We demonstrated that IL-10 release in LPS-stimulated whole blood culture was decreased in patients with severe persistent asthma compared to those with mild asthma and controls ( P = 0.04 and P + CD16 + cells was higher than that from normal subjects ( P = 0.04). Severe asthmatics showed significantly less positive staining for IL-10 and IL-12 ( P P = 0.02, respectively) after stimulation in monocytes, compared to mild asthmatics and controls in both CD14 + CD16 + and CD14 + CD16 − cells. These results suggest that IL-10 synthesis is attenuated in severe persistent asthma compared to mild asthma and that this cannot be explained by the increase in the CD14 + CD16 + monocytes in asthma.