Early Respiratory Infections, Asthma, and Allergy: 10-Year Follow-up of the Oslo Birth Cohort

Abstract

ABSTRACT. Objective. It has been hypothesized that early infections protect against the development of atopic disease, but there have been few long-term follow-up studies. We estimated the associations between early respiratory infections and doctor-diagnosed asthma, allergic rhinitis, and skin-prick sensitization in children at 10 years of age in the Oslo Birth Cohort, established in 1992-1993. We also considered birth order and attendance at a child care center as proxy measures of increased exposure to infections early in life.Methods. A total of 2540 children were followed from birth to the age of 10 years. Experiences of respiratory infections were recorded in follow-up surveys at 6 and 12 months. At age 10, questions were asked about current symptoms of asthma and allergic rhinitis and about having ever received a doctor diagnosis for these diseases. A subsample (n ‫؍‬ 1740) of the cohort was tested for skinprick test reactivity.Results. Current asthma was related to lower respiratory tract infection (adjusted odds ratio [OR]: 2.1; 95% confidence interval: 1.3-3.0) and croup (adjusted OR: 2.3; 95% confidence interval: 1.3-4.2) in the first year. ORs for allergic rhinitis and skin-prick sensitization were smaller but mainly positive. Birth order and child care attendance at age 1 year were not significantly associated with any of the studied outcomes.Conclusions. Early respiratory infections did not protect against the development of asthma, allergic rhinitis, or sensitization to common allergens during the first 10 years of life but increased the risk for asthma symptoms at age 10 in this population. H aving older siblings has been found to be inversely associated with asthma and other atopy-related disorders. [1][2][3][4][5][6] Some studies have also shown that these disorders are inversely associated with child care attendance outside the home, 6-10 whereas other studies have not been able to confirm these findings. 11-13 A common interpretation of these results has been that older siblings and child care attendance are indirect measures of earlylife infections and that early-life infections have a preventive effect on the development of atopic disorders. A number of studies have also assessed the relation between atopic disorders and direct measures of early-life infections, 11,13-23 but fewer have been able to do this prospectively. [13][14][15][18][19][20][21][22] Studies that have used direct measures of infections have shown less consistent results than the studies that have used indirect measures, and the inverse relation has often been restricted to subgroups of diseased individuals, mainly those with atopic predisposition. Furthermore, childhood asthma has been found to be more common in children who experienced at least 1 specific type of early respiratory infection, namely respiratory syncytial virus infection. [24][25][26][27] The inverse relation between early-life infections and the development of atopic disorders is supported by a plausible biological mechanism, according to which early-lif...

Characterizing wheeze phenotypes to identify endotypes of childhood asthma, and the implications for future management

“…In the TCRS, this association was found to be confounded by maternal asthma. [9,57] There was lack of agreement with regards to the association of day-care with persistent wheeze, with ALSPAC finding that day-care was associated with an increase in persistent wheeze [36], TCRS finding that day-care was protective [27]. Similarly, ALSPAC identified a significant positive association between persistent wheeze and number of older siblings [32,36], whereas TCRS found that this was the only wheeze phenotype where the presence of older siblings reduced the risk of persistent wheeze [27].…”

“…An example of an inconsistent association with asthma is day-care attendance. Different studies have indicated that day-care attendance increases the risk [7], is protective [8] and has no effect [9] on the development of asthma. It is likely that imprecise phenotype definition together with the failure to take account of interactions between the environment and genetic predispositions (day care -TLR2, endotoxin -CD14 being but two examples) [10][11][12] have hampered our attempts to 'explain' asthma.…”

Acute, but Not Resolved, Influenza A Infection Enhances Susceptibility to House Dust Mite-Induced Allergic Disease

“…4S. 4 All appropriate isotype controls were used (BD Biosciences). Abs were titrated to determine optimal concentration.…”

“…A growing number of epidemiologic studies have shown that certain respiratory viral infections in infancy are associated with increased atopy to common allergens and an overall increased risk of asthma in school-aged children (4,5). Such an outcome seems intuitive in the case of infections with respiratory syncytial virus (RSV) which induces Th2-polarized immunity (6,7) and can, thereby, establish a lung environment that facilitates subsequent sensitization to allergens.…”

Asthma and Viral Infections in Children

“…), и потому не была установлена причинно-следственная связь. Более того, такое воздействие различно у разных вирусов [1][2][3][4][5][6].…”