Asthma and allergic rhinitis risk depends on house dust mite specific IgE levels in PARIS birth cohort children

Abstract

Background: The natural history of allergic sensitization in childhood, and its impact on allergic disease development, needs to be clarified. This study aims to identify allergic sensitization and morbidity patterns during the first 8 years of life.

Methods: The study was conducted in the on-going population-based prospective Pollution and Asthma Risk: an Infant Study (PARIS) birth cohort. Sensitization profiles were identified by k-means clustering based upon allergen-specific IgE levels measured at 18 months and 8/9 years. Allergic morbidity profiles were identified by latent class analysis based on symptoms, symptom severity, treatments, and lifetime doctor-diagnoses of asthma, allergic rhinitis, and atopic dermatitis and on lower respiratory infections before 2 years.

Results: Five sensitization and 5 allergic morbidity patterns were established in 714 children. Children not sensitized or with isolated and low allergen-specific sensitization were grouped together (76.8%). A profile of early and transient sensitization to foods that increased the risk of asthma later in childhood was identified (4.9%). Children strongly sensitized (≥3.5 kU_A/L) to house dust mite at 8/9 years (9.0%) had the highest risk of asthma and allergic rhinitis. Finally, timothy grass pollen at 8/9 years sensitization profile (5.3%) was related to respiratory allergic diseases, as was early onset and persistent sensitization profile (4.1%), this latter being also strongly associated with atopic dermatitis.

Conclusions & clinical relevance: We show that accurate assessment of the risk of allergic disease should rely on earliness and multiplicity of sensitization, involved allergens, and allergen-specific IgE levels, and not considering solely allergic sensitization as a dichotomous variable (allergen-specific IgE ≥0.35 kU_A/L), as usually done. This is particularly striking for house dust mite. We are hopeful that, pending further confirmation in other populations, our findings will improve clinical practice as part of an approach to allergic disease prevention.

Keywords: AIC, Akaike Information Criteria; Allergic morbidity; BAMSE, Stockholm Children Allergy and Environmental Prospective Birth Cohort; BIC, Bayesian Information Criteria; BMI, body mass index; Birth cohort; COPSAC2000, Copenhagen Prospective Study on Asthma in Childhood 2000; Cluster analysis; ISAAC, International Study of Asthma and Allergies in Childhood; IgE, Immunoglobulin E; LCA, latent class analysis; LRI, lower respiratory infections; Latent class analysis; MAS, Multicenter Allergy Study; MeDALL, Mechanisms of the Development of ALLergy; OR(a), (adjusted) odds ratio; PARIS, Pollution and Asthma Risk: an Infant Study; PASTURE, Protection Against Allergy: Study in Rural Environments; SES, socio-economic status; Specific IgE levels.

Fig. 1

Flow chart of PARIS birth cohort children participating in the health examination when 8/9 years old

Fig. 2

Sensitization to (a) inhalant and (b) food allergens at 8/9 years of age in PARIS birth cohort children (N = 1007)

Fig. 3

Unsupervised identification of allergic sensitization profiles over the first 8 years of life in PARIS birth cohort children, identification based upon allergen-specific IgE levels at both ages 18 months and 8/9 years (N = 714)

Fig. 4

Allergic morbidity at 8/9 years of age in terms of current symptoms, lifetime doctor-diagnoses, and current medication intake, in PARIS birth cohort children (N = 1080). ∗Concerning symptoms, only when accompanied by itchy/watery eyes

Fig. 5

Unsupervised identification of allergic morbidity profiles over the first 8 years of life in PARIS birth cohort children, identification based upon symptoms, symptom severity, doctor-diagnoses, and medication intake at both ages 18 months and 8/9 years (N = 714). Crosshatched: severe symptoms. ¹Occurred in the past 12 months. ²Lifetime doctor-diagnosis. ³Intermittent itchy rash affecting the folds of the elbows, behind the knees, in front of the ankles, under the buttocks, or around the neck, ears, or face in the past 12 months. ⁴Epidemiologic definition: two criteria among the triad of respiratory symptoms (wheezing and/or tightness of chest and/or asthma attack) in the past 12 months, lifetime doctor diagnosis, and medication intake in the past 12 months. ⁵Sneezing or runny/blocked nose when the child did not have a cold or the flu in the past 12 months. ⁶Nose symptoms accompanied by itchy/watery eyes in the past 12 months. ⁷Epidemiologic definition: nose symptoms in the past 12 months with concomitant positive Phadiatop®. ⁸Epidemiologic definition: skin symptoms in the past 12 months