Risk factors for persistence of asthma in children: 10-year follow-up.

OBJECTIVE: Risk factors related to the outcome of childhood asthma are not yet well established. We aimed to investigate the long-term outcome for children with asthma to determine the risk factors in predicting persistence of disease. METHODS: Sixty-two children with asthma were evaluated retrospectively at the end of a 10-year follow-up. Patients were asked to complete a questionnaire requesting clinical information, and underwent physical examination, skin prick testing, a pulmonary function test and bronchial provocation testing. Immunologic parameters evaluated were allergen-specific IgE and IgG4 levels, and allergen-induced generation of CD4(+)CD25(+) cells. RESULTS: Mean age at final assessment was 15.9 ± 3.6 years, and duration of follow-up was 10.30 ± 1.27 years. Fifty percent of patients outgrew their asthma during the 10-year follow-up period. All the non-atopic patients outgrew their disease during the study period, whereas 67% of atopic patients did not. We identified two risk factors independently related to the persistence of symptoms: presence of bronchial hyper-responsiveness and presence of rhinitis. Atopic children who were in remission demonstrated significantly higher allergen-induced CD4(+)CD25(+) T cells compared to healthy controls. CONCLUSIONS: Atopy, presence of rhinitis, positive and presence of bronchial hyper-reactivity are important risk factors for the persistence of asthma in children. Allergen-induced CD4(+)CD25(+) T cells were higher in the atopic children who outgrew their disease, implicating an immunological mechanism of asthma remission in children.

Efficacy of long-term sublingual immunotherapy as an adjunct to pharmacotherapy in house dust mite-allergic children with asthma.

Although sublingual immunotherapy (SLIT) is accepted to be a viable alternative of specific-allergen immunotherapy, the efficacy of long-term SLIT in asthmatic children is not well established. The efficacy of 3 yr of SLIT in addition to pharmacotherapy was compared with pharmacotherapy alone in a prospective, open, parallel-group, controlled study. Children with asthma aged 4-16 yr, sensitive to house dust mite (HDM) were followed up for a run-in period of 1 yr and then grouped as those who would receive SLIT + pharmacotherapy (n = 62) or pharmacotherapy alone (n = 28). All patients were evaluated based on symptom-medication scores and lung function tests every 3 months, as well as skin-prick test and serum total immunoglobulin E (IgE) levels annually for 3 yr. Children in the SLIT + pharmacotherapy group demonstrated significantly lower mean daily dose and annual duration of inhaled corticosteroid (ICS) usage when compared with controls. At the end of the 3 yr, within-group comparisons revealed statistically significant decreases in the dose and duration of ICS only in the SLIT group. Furthermore, 52.4% of subjects in the SLIT + pharmacotherapy group were able to discontinue ICS treatment for at least 6 months, which was only 9.1% for the pharmacotherapy group. Three years of SLIT as an adjunct to pharmacotherapy resulted in reduction of both the duration and dose of ICSs and successful discontinuation of ICSs along with improvement in lung functions in HDM-allergic children with asthma.