Trajectories of childhood immune development and respiratory health relevant to asthma and allergy.

Events in early life contribute to subsequent risk of asthma; however, the causes and trajectories of childhood wheeze are heterogeneous and do not always result in asthma. Similarly, not all atopic individuals develop wheeze, and vice versa. The reasons for these differences are unclear.

Vitamin D in fetal development: findings from a birth cohort study.

Birth cohort studies provide an invaluable resource for studies of the influence of the fetal environment on health in later life. It is uncertain to what extent maternal vitamin D status influences fetal development. Using an unselected community-based cohort of 901 mother-offspring pairs (the Western Australian Pregnancy Cohort [Raine] Study), we examined the relationship between maternal vitamin D deficiency at 18 weeks' pregnancy and long-term health outcomes of offspring who were born in Perth, Western Australia (32° South), in 1989-1991.

Anti-infective proteins in breast milk and asthma-associated phenotypes during early childhood.

Background: The impact of breast milk feeding on susceptibility to asthma in childhood is highly controversial, due in part to failure of the majority of studies in the area to adequately account for key confounders exemplified by respiratory infection history, plus the effects of recall bias.

Methods: As part of a prospective cohort study on the role of respiratory infections in asthma development in high-risk children, we measured the concentration of a panel of anti-infective proteins in maternal milk samples and analyzed associations between these and subsequent atopy-, infection-, and asthma-related outcomes prospectively to age 10 years.

Results: We observed significant but transient inverse associations between the concentration of milk proteins and susceptibility to upper respiratory infections in year 1 only, and parallel but positive transient associations with early lower respiratory infections and atopy.

Low maternal serum vitamin D during pregnancy and the risk for postpartum depression symptoms.

Pregnancy is a time of vulnerability for vitamin D insufficiency, and there is an emerging literature associating low levels of 25(OH)-vitamin D with depressive symptoms. However, the link between 25(OH)-vitamin D status in pregnancy and altered risk of postnatal depressive symptoms has not been examined. We hypothesise that low levels of 25(OH)-vitamin D in maternal serum during pregnancy will be associated with a higher incidence of postpartum depressive symptoms.

Vitamin D deficiency at 16 to 20 weeks' gestation is associated with impaired lung function and asthma at 6 years of age.

Rationale: Vitamin D deficiency is associated with chronic lung disease. We have previously shown in an in vivo mouse model that maternal vitamin D deficiency is associated with alterations in early life lung structure and function. However, there are limited data to support a relationship between maternal vitamin D deficiency during the early stages of lung development and postnatal lung function in human populations.

Maternal vitamin D levels during pregnancy and offspring eating disorder risk in adolescence.

Objective: To determine if maternal vitamin D concentrations at 18 weeks gestation predict offspring eating disorder risk in adolescence.

Method: Participants were 526 Caucasian mother-child dyads from the Western Australian Pregnancy Cohort (Raine) Study. The Raine Study has followed participants from 18 weeks gestation to 20 years of age.

Respiratory impedance and bronchodilator responsiveness in healthy children aged 2-13 years.

Background: The forced oscillation technique (FOT) can be used in children as young as 2 years of age and in those unable to perform routine spirometry. There is limited information on changes in FOT outcomes in healthy children beyond the preschool years and the level of bronchodilator responsiveness (BDR) in healthy children. We aimed to create reference ranges for respiratory impedance outcomes collated from multiple centers.

Maternal vitamin D levels and the autism phenotype among offspring.

We tested whether maternal vitamin D insufficiency during pregnancy is related to the autism phenotype. Serum 25(OH)-vitamin D concentrations of 929 women were measured at 18 weeks' pregnancy. The mothers of the three children with a clinical diagnosis of autism spectrum disorder had 25(OH)-vitamin D concentrations above the population mean.

Maternal serum vitamin D levels during pregnancy and offspring neurocognitive development.

Objectives: To determine the association between maternal serum 25(OH)-vitamin D concentrations during a critical window of fetal neurodevelopment and behavioral, emotional, and language outcomes of offspring.

Methods: Serum 25(OH)-vitamin D concentrations of 743 Caucasian women in Perth, Western Australia (32°S) were measured at 18 weeks pregnancy and grouped into quartiles. Offspring behavior was measured with the Child Behavior Checklist at 2, 5, 8, 10, 14, and 17 years of age (n range = 412-652).

Antibacterial antibody responses associated with the development of asthma in house dust mite-sensitised and non-sensitised children.

Background: Infants who develop house dust mite (HDM) allergy and HDM-sensitised children with severe persistent asthma have low antibody responses to the P6 antigen of Haemophilus influenzae.

Objective: To measure the development of antibody to two ubiquitous bacteria of the respiratory mucosa in a prospective birth cohort at high risk of allergic disease and to assess which responses are associated with asthma and atopy.

Methods: IgG1 and IgG4 antibody to H influenzae (P4 and P6) and Streptoccocus pneumoniae (PspA and PspC) surface antigens was measured in yearly blood samples of children aged 1-5 years.

Exhaled breath temperature in healthy children is influenced by room temperature and lung volume.

Background: Exhaled breath temperature (EBT) has been proposed for the non-invasive assessment of airway inflammation. Previous studies have not examined the influence of room temperature or lung size on the EBT.

Objective: This study aimed to address these issues in healthy children.

Management of childhood asthma in Western Australia.

Aims: The study aimed to determine how childhood asthma is managed in Western Australia by general practitioners (GPs) and specialist paediatricians.

Methods: A questionnaire survey was sent to 992 GPs and specialist paediatricians, asking about practice and preferences regarding maintenance management of childhood asthma and treatment of acute asthma. Questions about asthma in infants, pre-school and school-aged children were asked separately.

Assessment of bronchodilator responsiveness in preschool children using forced oscillations.

Background: The forced oscillation technique (FOT) requires minimal patient cooperation and is feasible in preschool children. Few data exist on respiratory function changes measured using FOT following inhaled bronchodilators (BD) in healthy young children, limiting the clinical applications of BD testing in this age group. A study was undertaken to determine the most appropriate method of quantifying BD responses using FOT in healthy young children and those with common respiratory conditions including cystic fibrosis, neonatal chronic lung disease and asthma and/or current wheeze.

Early-life respiratory viral infections, atopic sensitization, and risk of subsequent development of persistent asthma.

Background: Severe lower respiratory infections (LRIs) and atopic sensitization have been identified as independent risk factors for asthma.

Objective: The nature of potential interactions between these risk factors was the subject of this study.

Methods: A community-based cohort of 198 children at high atopic risk was followed from birth to 5 years.

Occurrence and management of acute respiratory illnesses in early childhood.

Aim: Acute respiratory illnesses (ARI) impose massive economic burden on health services. The growing costs, limited benefits of pharmacotherapeutic agents, and alarming rise in antibiotic resistance poses a major health challenge. Analysis of the nature and burden of ARI through well-designed epidemiologic studies will help in the development of a uniform public health approach to identify methods to reduce disease transmission and maximise prevention strategies.

Respiratory function in healthy young children using forced oscillations.

Background: Monitoring of respiratory function is important in the diagnosis and management of respiratory disease. The forced oscillation technique requires minimal patient cooperation and is ideal for the determination of respiratory function in young children. This study aimed to develop reference ranges and to document the repeatability in healthy young children using commercially available forced oscillation equipment.

Role of respiratory viruses in acute upper and lower respiratory tract illness in the first year of life: a birth cohort study.

Introduction: Although acute respiratory illnesses (ARI) are major causes of morbidity and mortality in early childhood worldwide, little progress has been made in their control and prophylaxis. Most studies have focused on hospitalized children or children from closed populations. It is essential that the viral etiology of these clinical diseases be accurately defined in the development of antiviral drugs.

Atopy, eczema and breast milk fatty acids in a high-risk cohort of children followed from birth to 5 yr.

Background: The incidence of atopic diseases such as eczema is increasing in westernized societies. The suggestion that there is a "protective" association between the unique fatty acid composition of breast milk, particularly the omega-3 (n-3) and omega-6 (n-6) essential polyunsaturated fatty acid content, and the development of atopic disease in children was investigated in a cohort study of 263 infants born into families with a history of allergy (one or both parents had asthma, hayfever, eczema). The objectives of this study were to determine the lipid profile [specifically in relation to long-chain polyunsaturated fatty acid (LC-PUFA) composition] in maternal breast milk samples collected at 6 wk and at 6 months following birth, and to investigate the potential role of these fatty acids in modulating the phenotype of children at high genetic risk of developing atopic disease.

Support for 2 variants of eczema.

Background: Studies investigating the natural history and risk factors for eczema have historically considered eczema as a single entity, without regard for the individual's atopic status. The association between atopy and eczema is complex, and as many as (2/3) of patients with eczema are not atopic.

Objective: To investigate the risk factors for eczema in relation to the child's atopic status in a cohort of high-risk children.