Background: little is known about inflammatory mediators (IM); like cytokines, chemokines and receptors; in respiratory secretion as possible indicators of the severity of respiratory syncytial virus (RSV) disease. Nor have systematic studies been published on the ratios between IM as such indicators.
Objective: to define the role of IM ratios as possible indicators of the severity of RSV disease.
Study design: about 46 infants aged 0-9 months with acute RSV infections were studied. Prematurity (PM) and/or underlying disease (UD) were present in 11 of them. The concentrations of seven different IM were measured by ELISA in samples of nasopharyngeal secretions (NPS), four cytokines; IL-1, IL-6, IL-10 and TNF-alpha; the cytokine receptor TNF-R1 and the chemokines; IL-8 and RANTES. 21 IM ratios were calculated from these concentrations. The patients were assigned a clinical score (CS) ranging from 0 to 3 according to the severity of disease.
Results: when 25 patients with severe disease (CS 2-3) and 21 patients with mild disease (CS 0-1) were compared with respect to different IM ratios, three ratios were related to severity of disease: IL-1/RANTES, IL-8/RANTES and TNF-R1/RANTES. When 12 patients with mild disease were compared with 16 patients with severe disease, omitting patients more than 5 months of age and patients with PM and/or UD, the following IM ratios were related to severity of disease: TNF-R1/RANTES, IL-8/RANTES and RANTES/IL-10.
Conclusion: of 21 IM ratios studied, TNF-R1/RANTES was related to severity of disease with greatest consistency.