Serum levels of tumor necrosis factor alpha and soluble tumor necrosis factor-receptor I in asthmatic patients and patients with chronic respiratory tract infection

In order to investigate the role of tumor necrosis factor alpha (TNF-alpha) in bronchial asthma or chronic respiratory infection, we measured serum levels of TNF-alpha and serum soluble tumor necrosis factor-receptor I (sTNF-RI) in asthmatic patients (n = 11) and patients (n = 10) with chronic respiratory infection by Pseudomonas aeruginosa. We also measured serum levels of eosinophil cationic protein (ECP) in the asthmatic patients. The serum levels of TNF-alpha in the asthmatic patients, patients with chronic respiratory tract infection and control group were 2.864 +/- 0.719 g/ml, 2.564-1.384 pg/ml and 0.681 +/- 0.453 pg/ml respectively. The levels of the former two groups were higher than those of the control group (p < 0.05). The serum levels of sTNF-RI in the asthmatic patients, the patients with chronic respiratory tract infection, and the control group was 758 +/- 268 pg/ml, 999 +/- 242 pg/ml and 909 +/- 268 pg/ml respectively. The levels of the former two groups did not differ significantly from those of the control group. There were significant correlations between TNF-alpha and sTNF-RI in the control group and in the patients with chronic respiratory tract infection, but there was no significant correlation in the asthmatic patients. In the asthmatic patients. TNF-alpha/s TNF-RI correlated with %best of PEF (r = 0.691, n = 9, p 0.0373). The serum levels of ECP correlated significantly with TNF-alpha, but not with sTNF-RI in the asthmatic patients. It is suggested that TNF-alpha plays a significant role in the pathogenesis of bronchial asthma and chronic respiratory tract infection as a factor causing inflammation and that the increase of TNF-alpha/sTNF-RI reflects the activation of eosinophil functions in an asthmatic attack.