Elevation of serum soluble tumour necrosis factor (TNF) receptor and IL-1 receptor antagonist levels in bronchial asthma

The specific inhibitor for TNF-α activity, soluble form of the 55-kD TNF receptor (sTNF-RI) and soluble form of the 75-kD receptor (sTNF-RII), and the specific inhibitor for IL-1 activity, IL-1 receptor antagonist (IL-1Ra), have been identified. It has been shown that the levels of these inhibitors are elevated in plasma/serum and biological fluids in several diseases, and the protective and inhibitory effect of these inhibitors exist in several inflammatory diseases. In the present study, we measured serum levels of sTNF-RI, STNF-RII and IL-1Ra by ELISA in 36 patients with bronchial asthma (16 atopic and 20 non-atopic) during asthma attacks and in stable conditions in order to assess the state of these inhibitors in allergic inflammation. The levels of sTNF-RI, sTNF-RII and IL-1Ra in sera obtained during bronchial asthma attacks were higher than those in sera obtained in stable conditions. These findings were obtained regardless of atopic status. These results suggest that higher levels of serum sTNF-RI, sTNF-RII and IL-1Ra may reflect up-regulation of TNF-R expression and IL-1Ra production in allergic inflammation, and sTNF-RI, sTNF-RII and IL-1Ra may contribute to regulating TNF-α- and IL-1-mediated production and development of allergic inflammation.