Rationale: The effect of early life wheezing on respiratory function and continued symptoms through adolescence has not been fully described. Using data from a population-based birth cohort in Tucson, Arizona, we previously described four phenotypes based on the occurrence of wheezing lower respiratory illnesses before age 3 yr and active wheeze at age 6 yr: never wheezers (n ϭ 425), transient early wheezers (n ϭ 164), persistent wheezers (n ϭ 113), and lateonset wheezers (n ϭ 124). Objective: We sought to determine the prognosis for these phenotypes, with reference to lung function and symptoms, through adolescence. Methods: Current wheeze was assessed by questionnaire, lung function was measured by conventional spirometry, and atopy was determined by skin prick tests. Results: The prevalence of atopy and wheeze by age 16 yr was similar for never and transient wheezers and for persistent and late-onset wheezers. Both transient early, and persistent wheezers had significantly lower FEF 25-75 (-259 ml/s, p Ͻ 0.001, and -260 ml/s, p ϭ 0.001, respectively), FEV 1 (-75 ml, p ϭ 0.02, and -87 ml, p ϭ 0.03, respectively), and FEV 1 :FVC ratio (-1.9%, p ϭ 0.002, and -2.5%, p ϭ 0.001, respectively) through age 16 yr compared with never wheezers. Late-onset wheezers had levels of lung function similar to those of never wheezers through age 16 yr. There was no significant change in lung function among subjects with any of the four phenotypes, relative to their peers, from age 6 to 16 yr. Conclusion: Patterns of wheezing prevalence and levels of lung function are established by age 6 yr and do not appear to change significantly by age 16 yr in children who start having asthmalike symptoms during the preschool years.

Background-Together with smoking, the level of lung function attained in early adulthood is among the strongest predictors of chronic obstructive pulmonary disease. Whether airway function measured shortly after birth is a determinant of this level is currently unknown.

Background It is increasingly evident that microbial colonization of the respiratory tract might have a role in the pathogenesis of asthma. Objective We sought to characterize and compare the microbiome of induced sputum in asthmatic and nonasthmatic adults. Methods Induced sputum samples were obtained from 10 nonasthmatic subjects and 10 patients with mild active asthma (8/10 were not using inhaled corticosteroids). Total DNA was extracted from sputum supernatants and amplified by using primers specific for the V6 hypervariable region of bacterial 16s rRNA. Samples were barcoded, and equimolar concentrations of 20 samples were pooled and sequenced with the 454 GS FLX sequencer. Sequences were assigned to bacterial taxa by comparing them with 16s rRNA sequences in the Ribosomal Database Project. Results All sputum samples contained 5 major bacterial phyla: Firmicutes, Proteobacteria, Actinobacteria, Fusobacterium, and Bacteroidetes, with the first 3 phyla accounting for more than 90% of the total sequences. Proteobacteria were present in higher proportions in asthmatic patients (37% vs 15%, P < .001). In contrast, Firmicutes (47% vs 63%, P = .17) and Actinobacteria (10% vs 14%, P = .36) were found more frequently in samples from nonasthmatic subjects, although this was not statistically significant. Hierarchical clustering produced 2 significant clusters: one contained primarily asthmatic samples and the second contained primarily nonasthmatic samples. In addition, samples from asthmatic patients had greater bacterial diversity compared with samples from nonasthmatic subjects. Conclusion Patients with mild asthma have an altered microbial composition in the respiratory tract that is similar to that observed in patients with more severe asthma.

Background-Incidence of asthma increases during the early adult years, but the relative influence of sex and early life factors in determining newly diagnosed asthma in young adults is unknown.

The relationships of asthma and allergic rhinitis with individual immediate skin test responses were examined for preferential associations and for changes with age in children raised in a semiarid environment. Prevalence of physician-diagnosed asthma was 9.8% at age 6 (n = 948) and 15.5% at age 11 (n = 895). Immediate skin test responses to Bermuda grass were the most prevalent among children with allergic rhinitis and control subjects, whereas responses to the mold, Altenaria alternata, were the most prevalent among asthmatics. Skin test responses for crude house dust, Dermatophagoides farinae, and cat had low prevalences in all groups. By logistic regression, Alternaria was the only allergen independently associated with increased risk for asthma at both ages 6 and 11. Allergic rhinitis showed independent association with sensitization to Bermuda grass and mulberry tree pollen at age 11 but did not show an independent relation to any single allergen at age 6. Logistic regression further revealed that persistent asthma (diagnosed before age 6) was independently associated with Alternaria skin tests at both ages 6 and 11, whereas new asthma (diagnosed after age 6) was associated with Alternaria skin tests at age 6 but not at age 11. We conclude that Alternaria is the major allergen associated with the development of asthma in children raised in a semiarid environment and that skin test responses at age 6 are more closely linked to asthma than those at age 11.

Background The association between vitamin D status at birth and childhood allergic outcomes is uncertain. The desert climate of Tucson offers a unique setting for studying the health effects of higher exposure to vitamin D. Objective To assess relations between cord blood 25-hydroxyvitamin D (25[OH]D) levels and allergic outcomes through age 5 years. Methods Cord blood 25(OH)D levels were measured in 219 participants in the Tucson Infant Immune Study, a population-based birth cohort. Plasma total IgE and specific IgE to 6 aeroallergens were measured at 1, 2, 3 and 5 years. Skin-prick test (SPT) positivity (wheal ≥ 3mm), and physician-diagnosed active allergic rhinitis and asthma were assessed at age 5. Longitudinal models were used to assess relations between 25(OH)D and IgE outcomes. Logistic regression models were used to assess relations with SPT positivity, allergic rhinitis and asthma. Results The median cord blood 25(OH)D level was 64 nmol/L (interquartile range, 49 to 81 nmol/L). Relative to the reference group (50–74.9 nmol/L), both low (<50 nmol/L) and high (≥ 100 nmol/L) levels were associated with increased total IgE (coef.=0.27, P=0.006; and coef.=0.27, P=0.04, respectively) and inhalant specific IgE (OR=2.4, P=0.03; and OR=4.0, P=0.01, respectively) through age 5 years. High 25(OH)D levels also were associated with increased SPT positivity (OR=4.0, P=0.02). By contrast, 25(OH)D level was not significantly associated with allergic rhinitis or asthma. Conclusion Both low and high levels of cord blood 25(OH)D were associated with increased aeroallergen sensitization. The association between vitamin D status and actual allergic diseases merits further study.

A distinct group of individuals in a nonselected population demonstrates a persistently low lung function trajectory that may be partly established at birth and predisposes them to chronic obstructive pulmonary disease later in life.

BACKGROUND: Diminished lung function and increased prevalence of asthma have been reported in children with a history of early lower respiratory illnesses (LRIs), including pneumonia. Whether these associations persist up to adulthood has not been established.