Vitamin D, high-sensitivity C-reactive protein, and airway hyperresponsiveness in infants with recurrent respiratory symptoms

Background: Vitamin D insufficiency might be associated with biased T-cell responses resulting in inflammatory conditions such as atopy and asthma. Little is known about the role of vitamin D in low-grade systemic inflammation and airway hyperresponsiveness (AHR) in young children. Objective: To evaluate whether vitamin D insufficiency and increased serum high-sensitivity C-reactive protein (hs-CRP) are linked to AHR in symptomatic infants. Methods: Seventy-nine infants with recurrent or persistent lower respiratory tract symptoms underwent comprehensive lung function testing and a bronchial methacholine challenge test. In addition, skin prick tests were performed and serum 25-hydroxyvitamin D (S-25-OHD), hs-CRP, total immunoglobulin E, and blood eosinophil levels were determined. Results: S-25-OHD was lowest in infants with blood eosinophilia and AHR (n = 10) compared with those with eosinophilia only (n = 6) or AHR only (n = 50) or those with neither (n = 13; P = .035). Moreover, vitamin D insufficiency (S-25-OHD <50 nmol/L) was most common in infants with blood eosinophilia and AHR (P = .041). Serum hs-CRP was lower in infants with recurrent physician-diagnosed wheezing (P = .048) and in those with blood eosinophilia (P = .015) than in infants without these characteristics and was not associated with S-25-OHD or AHR. S-25-OHD levels were significantly lower (median 54 nmol/L) during the autumn-winter season than in the spring-summer season (median 63 nmol/L; P = .026). Conclusion: Vitamin D insufficiency could underlie eosinophilia and AHR in infants with troublesome lung symptoms, whereas hs-CRPemediated low-grade systemic inflammation is rare in early childhood wheezing. (C) 2017 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.Peer reviewe

The link between early childhood lower airway symptoms, airway hyperresponsiveness, and school-age lung function

Background: The role of early airway hyperresponsiveness (AHR) in the lung function of school-age children is currently unclear. Objective: To conduct a prospective follow-up study of lung function in schoolchildren with a history of lower airway symptoms and AHR to methacholine in early childhood and to compare the findings to schoolchildren with no previous or current lung diseases. We also explored symptoms and markers of type 2 inflammation. Methods: In 2004 to 2011, data on atopic markers, lung function, and AHR to methacholine were obtained from 193 symptomatic children under 3 years old. In 2016 to 2018, a follow-up sample of 84 children (median age, 11 years; IQR, 11-12) underwent measurements of atopic parameters, lung function, and AHR to methacholine. Moreover, in 2017 to 2018, 40 controls (median age, 11 years; IQR, 9-12) participated in the study. Results: Schoolchildren with early childhood lower airway symptoms and increased AHR had more frequent blood eosinophilia than their peers without increased AHR and lower prebronchodilator forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity Z-scores than those without increased AHR and controls. Post-bronchodilator values were not significantly different between the two AHR groups. Atopy in early childhood (defined as atopic eczema and at least 1 positive skin prick test result) was associated with subsequent lung function and atopic markers, but not AHR. Conclusion: In symptomatic young children, increased AHR was associated with subsequent obstructive lung function, which appeared reversible by bronchodilation, and blood eosinophilia, indicative of type 2 inflammation.Peer reviewe

Pets, furry animal allergen components, and asthma in childhood

Abstract Background The use of component‐resolved allergy diagnostics has provided a clearer understanding of the species‐specific sensitization and severity of potential allergic reactions. This cross‐sectional study aimed to determine whether sensitization to allergen components in furry animals is indicative of blood eosinophilia, a positive fractional exhaled nitric oxide (FeNO) test, abnormal lung function, and asthma symptoms in children. Additionally, we investigated whether having pets during childhood affects the development of asthma or allergic sensitization to furry animals. Methods We recruited 203 children aged 4–17 years with asthma diagnosis based on abnormal lung function and 33 controls. IgE‐sensitization to allergen components for dogs, cats, and horses was analyzed using a multiplex microarray. Children were tested with FeNO, impulse oscillometry, spirometry, methacholine challenge, and skin prick test. A questionnaire was used to investigate pet ownership and symptom profile. Results FeNO results and blood eosinophilia revealed a correlation with sensitization to all furry animal allergens, particularly lipocalins (r = 0.203–0.560 and 0.206–0.560, respectively). Can f 3 was found to correlate with baseline R5 (r = 0.298). No association between methacholine challenge results and sensitization to furry animal allergens was found. Children with asthma who were sensitized to Can f 1, Can f 6, or both frequently reported asthma symptoms. Dog ownership was associated with a lower level of IgE‐sensitization to lipocalins, fewer asthma symptoms, and less blood eosinophilia. Conclusion Furry animal allergen component IgE‐sensitization is a risk factor for type 2‐inflammation and asthma symptoms