RETURNYonago Acta medica 1992;35:9–22
Increased Production of Interleukin-1 β (IL-1β) in the Low-Density Monocytes from Patients with Bronchial Asthma
Katsuyuki Tomita, Kouji Fukutani and Yutaka Hitsuda
Third Department of Internal Medicine, Faculty of Medicine, Tottori University, Yonago 683, Japan
The role of peripheral blood monocytes in the pathogenesis of asthma has not yet been clearly established. We investigated the density distribution of monocytes in the peripheral blood of asymptomatic asthmatic patients and difference in the secretion of interleukin-1 β (IL-1β) in the subpopulations. Monocytes from 7 normal subjects and 7 asthmatics were separated by discontinuous density gradient centrifugation using bovine serum albumin. Following incubation of the monocyte subsets in the presence of lipopolysaccharide, the supernatants and cell-lysates were assayed for IL-1β by a specific enzyme-linked immunosorbent assay. Low-density monocytes [1.062 kg/L ≥ specific gravity (SG)] of the asthmatic patients appeared to be a higher rate than that of normal subjects. The low-density cells appeared to be with larger amounts of intracellular IL-1β (iIL-1β) production and extracellular IL-1β (eIL-1β) release than high-density cells (1.062 < SG ≤ 1.068 kg/L) or pellets (SG > 1.068 kg/L). As the rate of the amounts of eIL-lβ to total amounts of IL-lβ, the sum of eIL-1β and iIL-lβ, was regarded as the normal process of release, the augmentation of iIL-lβ production in the low-density monocytes from asthmatic patients could be observed. These findings suggest that the low-density monocytes may play an important role in the immune response of asthma.
Key words: asthma; heterogeneity; interleukin-1 β; monocyte