Wheezy bronchitis in infants and small children

During acute infections of the respiratory tract, infants and small children often experience episodes of wheezing, which for some of them represent the onset of bronchial asthma. Activated eosinophiles play a central part in asthmatic inflammation in children. The objective of this research was to establish whether infants and small children show evidence of eosinophil activation already during the first episode of wheezy bronchitis (WB), and to estimate if the eosinophil cationic protein (ECP), as the marker of eosinophil activation, as well as total IgE, can be considered as predictors for later development of asthma, and finally, to analyze which are the most frequently occurring pathogenic microorganisms linked with WB in our patients. In a prospective trial, measurements were made of the total eosinophil count, ECP and total IgE in serum of 44 infants and small children hospitalized during their first WB episode. The results showed that 15 (34%) patients had total eosinophiles above the upper normal limit, 34 (77%) patients had increased total IgE, while 12 (27%) patients registered ECP above 20 mg/L. Acute infection of the respiratory tract had a viral origin in 22 (50%) patients, bacteria were isolated from upper respiratory tract in 12 (27%) patients, while 4 (9%) patients had a mixed bacterial and viral infection. Pathogenic cause was not isolated in 6 (14%) patients. During the 1-year follow-up period, 9 (20%) of the patients experienced subsequent episodes of wheezing and in all of these cases serum ECP was significantly higher in relation to children without exacerbation (p < 0.001). Eosinophil activation measured as serum ECP is already present in the first WB episode, and is significantly higher in those young patients who are prone to exacerbation of wheezing and bronchial obstruction during acute infections of the upper respiratory tract and which are predisposed to develop of asthma.