IgE antibody quantification and the probability of wheeze in preschool children.
BACKGROUND
IgE-mediated sensitization is usually considered a dichotomous variable (either sensitized or not). Quantitative IgE antibody analysis may better predict the expression of wheeze.


OBJECTIVE
Within the context of a population-based birth cohort, we investigated the association among wheeze, lung function, and specific IgE antibody levels.


METHODS
Children (n = 521) were followed to age 5 years with repeated questionnaires, skin testing, and measurement of lung function (specific airway resistance) and specific serum IgE (ImmunoCAP).


RESULTS
Using specific IgE as a continuous variable, the risk of current wheeze increased significantly with increasing IgE to mite, cat, and dog (P < .0001). When IgE levels to these 3 allergens were summed, the probability of current wheeze increased 1.33-fold (95% CI, 1.21-1.47; P < .0001) per logarithmic unit increase, corresponding to an odds ratio of 3.1 at 10 and 4.25 at 30 kU(A)/L (kilo units of Allergen per liter). Similarly, increasing sum of mite-specific, cat-specific, and dog-specific IgE was associated with reduced lung function (P = .004). Among sensitized children (n = 184), the sum of mite, cat, and dog IgE was the strongest associate of current wheeze (odds ratio, 1.28; 95% CI, 1.13-1.46; P < .001), corresponding to an odds ratio of 2.56 at 10 and 3.32 at 30 kU(A)/L. There was no association between current wheeze and the size of skin test wheal. Furthermore, the sum of IgE to mite, cat, and dog at age 3 years increased the risk of persistent wheeze by age 5 years (2.15-fold/logarithmic unit increase in the specific IgE).


CONCLUSIONS
IgE-mediated sensitization is not an all or nothing phenomenon. The probability of wheeze and reduced lung function increases with increasing specific IgE antibody levels.
Simpson
Angela
A
North West Lung Centre, Wythenshawe Hospital, Manchester, United Kingdom. a.simpson@fs1.with.man.ac.uk
Soderstrom
Lars
L
Ahlstedt
Staffan
S
Murray
Clare S
CS
Woodcock
Ashley
A
Custovic
Adnan
A
D000403:Airway Resistance / Q000276:immunology; D000485:Allergens; D000818:Animals; D000918:Antibody Specificity; D001249:Asthma / Q000209:etiology / Q000276:immunology / Q000503:physiopathology; D002415:Cats; D002675:Child, Preschool; D015331:Cohort Studies; D004285:Dogs; D004391:Dust / Q000276:immunology; D005260:Female; D006801:Humans; D007114:Immunization; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D011446:Prospective Studies; D039981:Pyroglyphidae / Q000276:immunology; D012135:Respiratory Sounds / Q000209:etiology / Q000276:immunology* / Q000503:physiopathology; D012307:Risk Factors; D012882:Skin Tests
D000485:Allergens; D004391:Dust; D007073:Immunoglobulin E