The Association of Prenatal Vitamin D Sufficiency With Aeroallergen Sensitization and Allergic Rhinitis in Early Childhood

BACKGROUND

The role of prenatal vitamin D sufficiency and supplementation in the development of childhood aeroallergen sensitization and allergic rhinitis remains uncertain.

OBJECTIVE

To describe the association of prenatal vitamin D sufficiency with childhood allergic outcomes in participants of the Vitamin D Antenatal Asthma Reduction Trial, a randomized controlled trial of prenatal vitamin D supplementation.

METHODS

We included 414 mother-offspring pairs with offspring aeroallergen sensitization data available at age 6 years in this analysis. We examined the association between prenatal vitamin D sufficiency status, based on vitamin D levels measured in the first and third trimesters, or vitamin D supplementation treatment assignment with the outcomes of aeroallergen sensitization, parent-reported clinical allergic rhinitis, parent-reported clinical allergic rhinitis with aeroallergen sensitization, food sensitization, any sensitization, eczema, and total IgE at ages 3 and 6 years.

RESULTS

Compared with early and late insufficiency, early prenatal vitamin D insufficiency with late sufficiency was associated with reduced development of clinical allergic rhinitis with aeroallergen sensitization at 3 years (adjusted odds ratio [aOR] = 0.34; 95% confidence interval [CI], 0.13-0.82; P = .02) and 6 years (aOR = 0.54; 95% CI, 0.29-0.98; P = .05). At 6 years, clinical allergic rhinitis with sensitization was significantly decreased in offspring whose mothers received high-dose vitamin D (aOR = 0.54; 95% CI, 0.32-0.91; P = .02) compared with offspring whose mothers who received low-dose vitamin D. Associations of prenatal vitamin D with aeroallergen sensitization were strengthened among children who also developed asthma or who had a maternal history of atopy.

CONCLUSIONS

Among mothers with first-trimester vitamin D insufficiency, we detected a protective effect of third-trimester prenatal vitamin D sufficiency on the development of clinical allergic rhinitis with aeroallergen sensitization at ages 3 and 6 years.

Aeroallergen Sensitization, Serum IgE, and Eosinophilia as Predictors of Response to Omalizumab Therapy During the Fall Season Among Children with Persistent Asthma

BACKGROUND

Perennial aeroallergen sensitization is associated with greater asthma morbidity and is required for treatment with omalizumab.

OBJECTIVE

To investigate the predictive relationship between the number of aeroallergen sensitizations, total serum IgE, and serum eosinophil count, and response to omalizumab in children and adolescents with asthma treated during the fall season.

METHODS

This analysis includes inner-city patients with persistent asthma and recent exacerbations aged 6-20 years comprising the placebo- and omalizumab-treated groups in 2 completed randomized clinical trials, the Inner-City Anti-IgE Therapy for Asthma study and the Preventative Omalizumab or Step-Up Therapy for Fall Exacerbations study. Logistic regression modeled the relationship between greater degrees of markers of allergic inflammation and the primary outcome of fall season asthma exacerbations.

RESULTS

The analysis included 761 participants who were 62% male and 59% African American with a median age of 10 years. Fall asthma exacerbations were significantly higher in children with greater numbers of aeroallergen-specific sensitizations in the placebo group (odds ratio [OR], 1.33; 95% confidence interval [CI], 1.11-1.60; P < .01), but not in the omalizumab-treated children (OR, 1.08; 95% CI, 0.91-1.28; P = .37), indicating a significant differential effect (P < .01). Likewise, there was a differential effect of omalizumab treatment in children with greater baseline total serum IgE levels (P < .01) or greater baseline serum eosinophil counts (P < .01). Multiple aeroallergen sensitization was the best predictor of response to omalizumab; treated participants sensitized to ≥4 different groups of aeroallergens had a 51% reduction in the odds of a fall exacerbation (OR, 0.49; 95% CI, 0.30-0.81; P < .01).

CONCLUSIONS

In preventing fall season asthma exacerbations, treatment with omalizumab was most beneficial in children with a greater degree of allergic inflammation.

Latent Class Analysis of School-Age Children at Risk for Asthma Exacerbation

BACKGROUND

Factors responsible for asthma exacerbations in children are complex and may differ from those that drive asthma severity.

OBJECTIVE

To identify latent classes of children at risk for asthma exacerbation and determine whether latent class assignment is useful in the prediction of future exacerbation.

METHODS

Latent class analysis was performed on 513 children aged 6 to 17 years at risk for asthma exacerbation, with 31 variables encompassing demographics, medical history, treatment, symptoms, lung function, sensitization, and type 2 inflammation. Primary and secondary outcomes included exacerbation occurrence by 12 months and time to first exacerbation, respectively.

RESULTS

Four latent classes were identified with differing demographic features, sensitization and type 2 inflammatory markers, prior exacerbation severity and health care utilization, and lung function. Exacerbations occurred in 22.4% of class 1 ("lesser sensitization with normal lung function"), 27.9% of class 2 ("lesser sensitization with prior severe exacerbation and normal lung function"), 45.3% of class 3 ("multiple sensitization with reversible airflow limitation"), and 64.3% of class 4 ("multiple sensitization with partially reversible airflow limitation") (P < .001). Time to exacerbation also followed similar trends and was shortest in the latent classes with multiple sensitization and airflow limitation (P < .001). Outcomes were driven largely by children with exacerbation-prone asthma (defined as ≥3 exacerbations in the prior year), who were present in each class but most strongly represented in classes 3 and 4.

CONCLUSIONS

Children at risk for asthma exacerbation are a heterogeneous group. Sensitization, prior exacerbation severity, and lung function variables may be particularly useful in identifying children at greatest risk for future exacerbation.

Heterogeneity of Mild to Moderate Persistent Asthma in Children: Confirmation by Latent Class Analysis and Association with 1-Year Outcomes

BACKGROUND

Compared with adults, phenotypic characterization of children with asthma is still limited and it remains difficult to predict which children with asthma are at highest risk for poor outcomes.

OBJECTIVE

To identify latent classes in a large population of treatment-adherent children with mild to moderate asthma enrolled in clinical trials and determine whether latent class assignment predicts future lung function abnormalities and exacerbation rate.

METHODS

Latent class analysis was performed on 2593 children with mild to moderate asthma aged 5 18 years, with 19 variables encompassing demographic characteristics, medical history, symptoms, lung function, allergic sensitization, and type 2 inflammation. Outcomes included lung function and the annualized exacerbation rate at 12 months of follow-up.

RESULTS

Five latent classes were identified with differing demographic features, asthma control, sensitization, type 2 inflammatory markers, and lung function. Exacerbation rates were 1.30 ± 0.12 for class 1 (multiple sensitization with partially reversible airflow limitation), 0.90 ± 0.05 for class 2 (multiple sensitization with reversible airflow limitation), 0.87 ± 0.08 for class 3 (lesser sensitization with reversible airflow limitation), 0.87 ± 0.05 for class 4 (multiple sensitization with normal lung function), and 0.71 ± 0.06 for class 5 (lesser sensitization with normal lung function). Lung function abnormalities persisted in class 1 at 12 months.

CONCLUSIONS

Children with mild to moderate asthma are a heterogeneous group. Allergic sensitization and lung function may be particularly useful in identifying children at the greatest risk for future exacerbation. Additional studies are needed to determine whether latent classes correspond to meaningful phenotypes for the purpose of personalized treatment.

Aeroallergen sensitization and associated comorbid diseases of an adult Filipino population with allergic rhinitis

Background

There is a large global variation in sensitization patterns to aeroallergens due to differences in climate, urbanization, and lifestyle. Knowledge of the most common inhalant allergens is important for appropriate prevention and management of allergic rhinitis (AR).

Objective

This study aims to provide data on aeroallergen sensitization patterns and associated comorbid diseases of adult Filipinos with AR.

Methods

Medical records of adult Filipinos seen in an Otolaryngology-Allergy Clinic from January 2011 to 2016 were reviewed. Inclusion criteria used was presence of clinically defined AR and positive skin test to at least one aeroallergen in the test panel. Demographics, comorbid conditions, and results of skin prick test were determined. Standard descriptive statistics were used for analysis.

Results

One hundred ninety-one adult patients were included in this study. Mean age was 38.8 years, and majority lived in an urban area (71.2%). Most patients exhibited polysensitization (97.4%). All exhibited sensitization to indoor and 86.9% to outdoor allergens. The most common indoor allergens were Dermatophagoides pteronyssinus (97.4%), Dermatophagoides farinae, (95.8%), cockroach (80.1%), and molds (72.8%). Bermuda (67%), Johnson grass (58.7%), and Acacia (58.2%) were the most common outdoor allergens. Urticaria (18.8%), dermatitis (16.8%), and asthma (11.5%) were the most common associated comorbid disease. Twelve percent of patients had more than one associated comorbid disease. Asthma + urticaria followed by asthma + dermatitis were the most common co-morbid combinations. One patient had three comorbid diseases: asthma + urticaria + rhinosinusitis.

Conclusion

Compared to earlier studies, aeroallergen sensitization patterns of Filipinos remain unchanged. This study also identifies for the first time, the associated comorbid diseases of AR in this population. Understanding these factors can guide treatment strategies to reduce disease burden.

Exposure amount and timing of solar irradiation during pregnancy and the risk of sensitization in children

BACKGROUND

Solar irradiation affects sensitization to aeroallergens and the prevalence of allergic diseases. Little is known, however, about how the time and amount of solar irradiation during pregnancy affects such risks in children. We aimed to find out how solar irradiation during pregnancy affects sensitization to aero-allergens and the prevalence of allergic diseases in children.

METHODS

This population-based cross-sectional study involved 7301 aged 6 years and aged 12 years children. Maternal exposure to solar irradiation during pregnancy was evaluated using data from weather stations closest to each child's birthplace. Monthly average solar irradiation during the second and third trimesters was calculated with rank by quartiles. Risks of allergic sensitization and allergic disease were estimated.

RESULTS

Relative to the first (lowest) quartile, the adjusted odds ratio (aOR) for allergic sensitization in the fourth (highest) quartile was lowest within solar irradiation during pregnancy months 5-6 (aOR = 0.823, 95% CI 0.720-0.942, p < 0.05). During months 9-10, the aOR for allergic sensitization for the fourth was higher than the first quartile of solar irradiation (aOR = 1.167, 95% CI 1.022-1.333, p < 0.05). Similar results were observed when solar irradiation was analyzed as a continuous variable during months 5 (aOR = 0.975, 95% CI 0.962-0.989, p < 0.001) and month 9 (aOR = 1.018, 95% CI 1.004-1.031, p = 0.003). Increased solar irradiation during months 7-8 increased the risk of asthma (aOR = 1.309, 95% CI 1.024-1.674, p = 0.032).

CONCLUSIONS

Maternal exposure to solar irradiation during the second trimester of pregnancy associated with reduced aeroallergen sensitization, whereas solar irradiation during the third trimester was related to increased sensitization to aeroallergens.