Association of interleukin-1 and and respiratory syncytial virus infection: a possible role in the pathogenesis of bronchial asthma in children

ABSTRACT

Bronchial asthma is considered an ongoing inflammatory process. Respiratory syncytial virus infection early in life may be the cause of the airway hyperresponsiveness. Many factors take part in the pathogenesis. The proinflammatory Interleukin-[1] alpha [IL-[1]alpha] seems to have a critical initiating role. The aim of this study was to assess the IL-[1]alpha level and R. S. V. antigen in the nasopharyngeal secretion of respiratory tract infected [wheezing and non-wheezing] children and the possible associations among several factors leading to the development of bronchial asthma. The present work is a cross-sectional cohort study on one hundred children attending Allergy Outpatient Clinic of New Children Hospital, Cairo University. All children were subjected to full routine investigations as well as to some immunological parameters. They were divided into 3 groups. Group [I] was formed of 50 children who suffered from acute respiratory infections with wheezes [asthmatics], most probably due to respiratory syncytial virus, [R.S.V.]; group [II] comprised 30 children, they were chronic asthmatic who came for follow up and were apparently free from any infections or wheezes and finally group [III] was formed of 20 children, they were not asthmatic but were suffering from viral respiratory infection with no wheezes. The 3 groups were examined for antigen detection of R.S.V. and Interlukin-[1]alpha was assessed by solid phase enzyme immunoassay in nasopharyngeal secretions in a trial to find out any association [correlation] in order to evaluate the pathophysiological events occurring in the microenvironment of the infected airway epithelium. The results were as such - In group [I] R.S.V. was significantly positively correlated with Interleukin-[1]alpha level [[54.7 +/- 64.3] pg/ml], [r = 0.486]. Also it was significantly positively correlated with the presence of infection [clinically] [r = 0.611, P < 0.001]. The graded level of Interleukin-[1]alpha was positively correlated with clinically diagnosed infection and also with the presence of R.S.V. [r = 0.673, P < 0.001] In group [II] There was no correlation between R.S.V. and the severity of asthma, IL-[1]alpha level [mean level of IL-[1]alpha = [3.9 +/- 4.4] pg/ml] or clinically diagnosed infection. There was no correlation between IL-[1]alpha and total leucocytic count [TLC], Ig[E] level, Ig[G] level and mean absolute eosinophilic count. In group [III] There was no correlation between R. S. V. and the severity of asthma, Interleukin-[1]alpha level [[41.2 +/- 57.5]pg/ml], or clinically infection. Also there was no correlation between IL-[1]alpha level and mean T.L.C, mean absolute eosinophilic count, Ig[G] level and Ig[E] level