title: What lessons can be learned about asthma phenotypes in children from cohort studies?
abstract: 'Phenotyping' asthma by multivariate analyses and more recently by unsupervised analysis has been performed in children cohorts. We describe the key findings that have emerged from these cohorts. It would appear that there are three wheeze phenotypes in children of preschool age: the mild episodic viral wheeze phenotype; the multitrigger atopic wheeze; and, less often encountered, the severe non-atopic wheeze. Early onset of allergy in asthma (more prevalent in boys) is associated with poor prognosis unlike the severe non-atopic wheeze phenotype which has a female predominance. The prognosis of the severe non-atopic wheeze depends on time of onset (early or late) of allergic expression. At school age, the risk of severe asthmatic exacerbations is associated with eosinophil predominant inflammation frequently related to allergic asthma, whereas neutrophil inflammation is associated with moderate-to-severe asthma with poorer lung function. Nevertheless, allergic asthma is also a heterogeneous disease with a severe allergic phenotype strongly associated with atopic dermatitis and very high eosinophil-driven inflammatory markers. Further studies are required to find non-invasive biological markers in very young children to better define wheezing phenotypes associated with an elevated risk of developing severe asthma with a view to personalizing treatment.
authors.affiliation: Allergology Department, Centre de l'Asthme et des Allergies. Hôpital d'Enfants Armand-Trousseau (APHP) -, APHP, Paris 75012, France.|Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Equipe EPAR, Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Just
authors.affiliation: Laboratoire de statistiques théoriques et appliquées, Université Pierre et Marie Curie - Paris 06, Paris, France.
authors.forename: P
authors.initials: P
authors.lastname: Saint Pierre
authors.affiliation: Allergology Department, Centre de l'Asthme et des Allergies. Hôpital d'Enfants Armand-Trousseau (APHP) -, APHP, Paris 75012, France.|Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Equipe EPAR, Paris, France.
authors.forename: F
authors.initials: F
authors.lastname: Amat
authors.affiliation: Allergology Department, Centre de l'Asthme et des Allergies. Hôpital d'Enfants Armand-Trousseau (APHP) -, APHP, Paris 75012, France.
authors.forename: R
authors.initials: R
authors.lastname: Gouvis-Echraghi
authors.affiliation: Allergology Department, Centre de l'Asthme et des Allergies. Hôpital d'Enfants Armand-Trousseau (APHP) -, APHP, Paris 75012, France.|Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Equipe EPAR, Paris, France.
authors.forename: N
authors.initials: N
authors.lastname: Lambert-Guillemot
authors.affiliation: Allergology Department, Centre de l'Asthme et des Allergies. Hôpital d'Enfants Armand-Trousseau (APHP) -, APHP, Paris 75012, France.|Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Equipe EPAR, Paris, France.
authors.forename: T
authors.initials: T
authors.lastname: Guiddir
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Equipe EPAR, Paris, France.
authors.forename: I
authors.initials: I
authors.lastname: Annesi Maesano
mesh_terms: D001249:Asthma / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype
keywords: Allergy; Asthma; Phenotype; children; cohort