Eosinophil counts and urinary eosinophil protein X in children hospitalized for wheezing during the first year of life: prediction of recurrent wheezing.

UNLABELLED: Early identification of wheezing children with an increased risk of recurrent wheezing or subsequent asthma is important. The aim of the study was to determine the role of markers of eosinophil activation, along with other parameters, in the prediction of recurrent wheezing and allergic sensitization in children with early and severe wheezing. We examined 105 children without atopic dermatitis, hospitalized for wheezing during the first year of life. At a 20-mo follow-up, 101 of the children were assessed for the occurrence of recurrent wheezing (at least 3 episodes, including 1 in the previous 6 mo) and allergic sensitization (positive skin-prick test). By univariate analysis, levels of eosinophil counts at the time of hospitalization (p = 0.005, OR = 18.9), age in months (p < 0.0001, OR = 1.5), respiratory syncytial virus (RSV)-negative disease (p < 0.0001, OR = 8.8), parental atopy (p = 0.006, OR = 3.3) and male sex (0.02, OR = 2.7) were all predictive factors for recurrent wheezing at follow-up. With all parameters included in a multiple regression analysis, RSV-negative disease was not a predictive factor for recurrent wheezing. A simple model including eosinophil counts > or = 0.1 x 10(9)/L and age had a predictive accuracy of 79%, with only a 6% chance of a child being wrongly predicted as symptomatic. Urinary protein X (U-EPX) was not a predictive factor for recurrent wheezing. When included in a multiple logistic regression analysis, a level of U-EPX > or = 100 microg/mmol creatinine was the only parameter with a positive predictive value for allergic sensitization (p = 0.007, OR = 18.9), whereas age, parental allergy or parental asthma were not.
CONCLUSION: Children with severe wheezing during the first year of life and subsequent recurrent wheezing are characterized by a normal or high eosinophil count in response to viral infections.