Follow-up of Children With Severe Asthma at Adult Age

Asthma is one of the most frequent pediatric chronic disease; between 30% and 50% of preschoolers have one to more episodes of wheezing, but less than half of them will have asthma persisting during childhood .Over the past decades, several longitudinal studies have described the different trajectories of asthma depending on the initial phenotype. The results of the MAS study (Melbourne Asthma Study), including 330 patients followed from the age of 7 to the age of 35 and then 50 years, showed that the most symptomatic asthma at school age was most at risk of persisting into adulthood. Risk factors for persisting symptomatic asthma were female gender, history of atopic dermatitis, changes in respiratory function in childhood, parental history of asthma, early onset of asthma, and frequency exacerbations in childhood. Thus, severe childhood asthma is more likely to persist in adulthood while mild asthma is more likely to go into remission. Long-term remission is still possible; in the MAS cohort, 15% of patients with severe childhood asthma were in complete remission by the age of 50 years.Severe asthma is poorly represented in studies from the general population or neonatal cohorts, as it remains rare in children. However, there are several clinical studies supporting at least a partial improvement in symptoms in adulthood. Thus, in a Dutch cohort of asthmatic children followed in a tertiary center and re-assessed in their 2nd and 3rd decades, asthma symptoms returned to at least partial remission in 52% of patients. However, only a minority of them (42%) had complete remission of their symptoms and normal respiratory function.Most of the clinical cohort studies examining the prognosis of asthma during time explored separately children and adults. Some biomarkers are lacking in children and the passage from childhood to adulthood is not explored. The usual phenotypic description takes into account the presence or absence of atopy, the frequency of symptoms, the factors triggering exacerbations, the severity of the disease, some biomarkers of inflammation and the level of control under treatment. The difficulty of accessing biomarkers from the deep lung in children and the binary analysis of some variables such as atopy make the description and the analysis of risk factors for persistence of asthma in adulthood difficult.

In addition, the prognosis of asthma is not only influenced by biological and environmental factors, but also by social factors throughout life. Thus, a low socioeconomic level is a recognized risk factor for severe acute asthma and poor asthma control.Finally, beyond the medium and long term prognosis, severe asthma is associated with an impaired quality of life, in children as well as in adults.In this context, the main objective of this study is to determine the course of asthma from childhood to young adulthood in a population of children with severe persistent asthma. The secondary objectives are to determine the phenotypic evolution of asthma (in particular atopic co-morbidities); to Compare the severity of asthma in adulthood according to the initial phenotypes of asthma in childhood, integrating clinical, functional, radiological, and biological parameters (including biomarkers from the deep lung);to describe the quality of life of these patients in adulthood and their socio-economic status.The primary endpoint is the classification of the severity and control of asthma in adulthood according to the GINA criteria.The secondary endpoints will be :

• When assessing severe asthma in childhood: Demographic data: age, sex, term of birth, socio-economic level of parents according to INSEE (high, intermediate or low), geographic origin of parents, body mass index.

Environmental data: exposure to irritants and potential allergens. Anamnestic data: history of familial asthma, time to disease progression, history of pneumonia, bronchopulmonary dysplasia.

Associated co-morbidities: existence of allergic rhinitis assessed by the SFAR diagnostic score and the ARIA severity score, atopic dermatitis, food allergy, clinical gastroesophageal reflux disease or proven by pHmetry.