A study of total eosinophil count, total IgE concentration and sensitization of house dust mite allergens as atopic parameters in recurrent wheezing infants

Kim, Bong Seong; Shim, Jung Yeon; Hong, Soo Jong

Abstract

BACKGROUND: Recurrent wheezing is probably related to airway hyperresponsiveness. Many young infants wheeze during viral lower respiratory tract infections, but the pathogenesis of these episodes and their relation to the development of asthma or other allergic disease later in life are not well understood. Whether environmental allergen exposure affects the inception of asthma remains to be determined.
OBJECTIVE
We performed this study to determine whether recurrent wheezing in infancy is related to atopy and if so, when infantile asthmatics become sensitized to house dust mite allergens.
METHODS
In a cross-sectional study, we investigated the factors related to recurrent wheezing before the age of three. A total of 119 infants were selected for this study and they were divided into two groups : 88 infants who experienced wheezing episodes more than three times before the age of two as infantile asthmatics, and 31 infants who had never experienced wheezing before visiting our hospital between January 1998 and July 1999. For these subjects, we performed assessments including measurement of peripheral total eosinophil counts, serum total IgE levels, specific IgE levels (Dermatophagoides pteronyssinus, Dermatophagoides farinae and food allergens) and questionnaires were completed by the children's parents.
RESULTS
The group who experienced recurrent wheezing showed significantly higher total eosinophil counts, serum concentrations of total IgE, D.p- and D.f-specific IgE than controls (p<0.05). There were no significant differences in the history of respiratory disease, familial history of allergic disease and environmental factors(domestic animals, bed cloth, carpet, smoking etc) between the group with recurrent wheezing and controls. The group who experienced recurrent wheezing showed significantly higher total eosinophil counts among those over 12 months old, and serum concentration of total IgE among those under 12 months old than controls(p<0.05). The concentration of D.p-specific IgE, but not D.f-specific IgE, in the recurrent wheezing group was higher than controls who were aged over 24 months(p<0.05).
CONCLUSION
The infants with recurrent wheezing are strongly related to a predisposition to atopy. Eosinophilia is one of the important markers of recurrent wheezing. The period of sen- sitization of inhalant allergens like a D.p occurs as early as 24 months old. These findings suggest that early recognition of atopy and environmental controls are important to manage re- current wheezing in infants.