Randomized controlled trial of primary prevention of atopy using house dust mite allergen oral immunotherapy in early childhood.

BACKGROUND: Children born to atopic parents are at increased risk of sensitization to environmental allergens. OBJECTIVE: We sought to demonstrate proof of concept for oral immunotherapy to high-dose house dust mite (HDM) allergen in infancy in the prevention of allergen sensitization and allergic diseases. METHODS: This was a prospective, randomized, double-blind, placebo-controlled, proof-of-concept study involving 111 infants less than 1 year of age at high risk of atopy (≥ 2 first-degree relatives with allergic disease) but with negative skin prick test responses to common allergens at randomization. HDM extract (active) and appropriate placebo solution were administered orally twice daily for 12 months, and children were assessed every 3 months. Coprimary outcomes were cumulative sensitization to HDM and sensitization to any common allergen during treatment, whereas development of eczema, wheeze, and food allergy were secondary outcomes. All adverse events were recorded. RESULTS: There was a significant (P = .03) reduction in sensitization to any common allergen (16.0%; 95% CI, 1.7% to 30.4%) in the active (5 [9.4%]) compared with placebo (13 [25.5%]) treatment groups. There was no treatment effect on the coprimary outcome of HDM sensitization and the secondary outcomes of eczema, wheeze, and food allergy. The intervention was well tolerated, with no differences between active and placebo treatments in numbers or nature of adverse events. CONCLUSION: Prophylactic HDM oral immunotherapy is well tolerated in children at high heredity risk. The results met the trial's prespecified criteria for proof of concept in reducing sensitization to any allergen; however, no significant preventive effect was observed on HDM sensitization or allergy-related symptoms.

Are exhaled nitric oxide measurements using the portable NIOX MINO repeatable?

BACKGROUND: Exhaled nitric oxide is a non-invasive marker of airway inflammation and a portable analyser, the NIOX MINO (Aerocrine AB, Solna, Sweden), is now available. This study aimed to assess the reproducibility of the NIOX MINO measurements across age, sex and lung function for both absolute and categorical exhaled nitric oxide values in two distinct groups of children and teenagers. METHODS: Paired exhaled nitric oxide readings were obtained from 494 teenagers, aged 16-18 years, enrolled in an unselected birth cohort and 65 young people, aged 6-17 years, with asthma enrolled in an interventional asthma management study. RESULTS: The birth cohort participants showed a high degree of variability between first and second exhaled nitric oxide readings (mean intra-participant difference 1.37 ppb, 95% limits of agreement -7.61 to 10.34 ppb), although there was very close agreement when values were categorised as low, normal, intermediate or high (kappa = 0.907, p < 0.001). Similar findings were seen in subgroup analyses by sex, lung function and asthma status. Similar findings were seen in the interventional study participants. CONCLUSIONS: The reproducibility of exhaled nitric oxide is poor for absolute values but acceptable when values are categorised as low, normal, intermediate or high in children and teenagers. One measurement is therefore sufficient when using categorical exhaled nitric oxide values to direct asthma management but a mean of at least two measurements is required for absolute values.

Relationships between age of puberty onset and height at age 18 years in girls and boys.

BACKGROUND: Changes during puberty may influence final adult height. Height is related to multiple health conditions, including lung function. We investigated the association between the age of onset of five puberty events and height at age 18 years, analyzing boys and girls separately. METHODS: Of 1456 children recruited into the Isle of Wight birth cohort (1989-1990), 1313 were followed up at age 18 years. Height was measured, and age of pubertal onset was collected at age 18 years. Cluster analysis was performed on the five puberty events in boys and girls and linear regression was applied with the clusters predicting height at age 18 years. Individual linear regression analyses assessed the age of onset of each pubertal event as a potential predictor for height at age 18 years. RESULTS: Of the 1313 children followed up at age 18 years, 653 were males and 660 were females. All puberty variables had high internal consistency. In girls, earlier age of menarche, breast development, and growth spurt were related to shorter height. In boys, earlier age of growth spurt and slower progression through puberty were related to taller height at age 18 years. CONCLUSIONS: Given that boys and girls may have opposing associations between pubertal timing and adult height and that height is an important predictor of lung function, the effect of pubertal timing on respiratory health should be explored.