Relationships among aeroallergen sensitization, peripheral blood eosinophils, and periostin in pediatric asthma development.

BACKGROUND: Biomarkers, preferably noninvasive, that predict asthma inception in children are lacking. OBJECTIVE: Little is known about biomarkers of type 2 inflammation in early life in relation to asthma inception. We evaluated aeroallergen sensitization, peripheral blood eosinophils, and serum periostin as potential biomarkers of asthma in children. METHODS: Children enrolled in the Childhood Origins of ASThma study were followed prospectively from birth. Blood samples were collected at ages 2, 4, 6, and 11 years, and serum-specific IgE levels, blood eosionophil counts, and periostin levels were measured in 244 children. Relationships among these biomarkers, age, and asthma were assessed. RESULTS: Serum periostin levels were approximately 2- to 3-fold higher in children than previously observed adult levels. Levels were highest at 2 years (145 ng/mL), and did not change significantly between 4 and 11 years (128 and 130 ng/mL). Age 2 year periostin level of 150 ng/mL or more predicted asthma at age 6 years (odds ratio [OR], 2.3; 95% CI, 1.3-4.4). Eosinophil count of 300 cells/µL or more and aeroallergen sensitization at age 2 years were each associated with increased risk of asthma at age 6 years (OR, 3.1; 95% CI, 1.7-6.0 and OR, 3.3; 95% CI, 1.7-6.3). Children with any 2 of the biomarkers had a significantly increased risk of developing asthma by school age (≥2 biomarkers vs none: OR, 6.6; 95% CI, 2.7-16.0). CONCLUSIONS: Serum periostin levels are significantly higher in children than in adults, likely due to bone turnover, which impairs clinical utility in children. Early life aeroallergen sensitization and elevated blood eosinophils are robust predictors of asthma development. Children with evidence of activation of multiple pathways of type 2 inflammation in early life are at greatest risk for asthma development.

Microbes, allergic sensitization, and the natural history of asthma.

PURPOSE OF REVIEW: Understanding factors that lead to asthma development in early life is essential to developing strategies aimed at primary or secondary prevention. RECENT FINDINGS: This article will review current evidence addressing the development of early life allergic sensitization in relation to microbes and the gut and airway microbiome. Wheezing illnesses, particularly viral, remain a significant risk factor for asthma inception; however, bacterial pathogens have recently emerged as an additional important contributor to asthma risk, either alone or as cofactors with viral infections. The combined influence and interaction of early life viral wheezing and aeroallergen sensitization is important, with allergic sensitization preceding the onset of viral wheeze. Lastly, we review recent data from longitudinal studies regarding the development of irreversible airway obstruction and its impact on the natural history of asthma. SUMMARY: The development of asthma remains complex and incompletely understood. There is interplay between genetic predisposition and environmental exposures, including allergens and microbes. Interventions aimed at these risk factors during the preschool years may prevent the longitudinal course of asthma progression to irreversible airway obstruction.

Dust Mite-Induced Perennial Allergic Rhinitis in Pediatric Patients and Sublingual Immunotherapy.

Allergic rhinitis (AR) is a common illness in children and can impair their quality of life. Furthermore, many children remain symptomatic despite maximizing systemic antihistamine and topical therapies. It is at this clinical juncture that immunotherapy may be considered. The efficacy and safety associated with both subcutaneous (SCIT) and sublingual (SLIT) approaches are reviewed and positioned as treatment options for pediatric patients, with specific focus on current literature as it relates to SLIT in children, including those with perennial allergic rhinitis. Although there is more extensive experience with SLIT treatment in Europe, grass and ragweed tablet forms of SLIT are approved in the US. Approaches to the care of pediatric patients with allergic rhinitis are presented.