The Development of Novel Clinical Tests to Diagnose and Monitor Asthma in Preschool Children (WheezyER)

The Hospital for Sick Children

Status: Completed

Conditions: Food Allergy; Wheeze; Asthma; Virus; Obstructive Sleep Apnea

Treatments: Procedure: Multiple-Breath Washout; Procedure: Nasal Brush; Procedure: Spirometry; Procedure: Allergy Skin Test; Procedure: Bronchodilator response; Procedure: Forced Oscillation Technique; Drug: salbutamol; Procedure: Basophil activation test; Procedure: Nasal swab; Procedure: Blood sample

Study type: Observational

Funder types: Other

Identifiers

NCT02743663

1000041089

Details and patient eligibility

About

The study will ascertain the ability of preschool lung function tests to distinguish healthy children from those with wheeze, and to differentiate phenotypes of wheezy children (high and low risk for asthma as defined by API) in order to predict response to therapy, and to explore the correlation between preschool lung function test results and symptoms, in order to develop objective methods for monitoring asthma.

Full description

In Canada, the most common chronic disease of childhood is asthma. Childhood asthma places a significant burden on the health care system (refn). No objective preschool asthma diagnostic tools exist, and the current gold-standard, the Asthma Predictive Index, does not provide information about lung function and symptom management. In this study, it is hypothesized that the lung clearance index (LCI), a value derived from the multiple breath washout test, will be the most sensitive, responsive discriminative test for preschool asthma. If it proves useful in the monitoring and diagnosis of preschool asthma, LCI has the potential to improve the clinical management and thus potentially significantly reduce hospitalization rates for preschool children suffering with asthma. In this unique data set, the investigators will also compare the relative utility of the forced oscillation technique (FOT) and preschool spirometry with the LCI in order to detect abnormalities amongst those children at high risk for preschool asthma. In addition, the impact of sleep apnea as a risk factor for and modifier of asthma will be investigated in this study. Furthermore, changes to the composition of the nasal microbiome during and after a wheezing episodes and the role of viral infections in wheezing exacerbations will be explored. Finally, the utility of new methods of diagnosing food allergy, such as the basophil activation test, will be examined in this Canadian cohort.

Enrollment: 121 patients

Sex: All

Ages: 3 to 5 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria (Wheezing Subjects):

• 3 to 5 years of age (36 to 71 months)
• Diagnosis of Asthma made by a physician in the emergency department
• History of at least two other wheezing episode within the previous 12 months
• Received salbutamol within 4hrs before emergency department visit, during current emergency department visit, or was prescribed salbutamol at discharge from emergency department.

Inclusion Criteria (Healthy Controls):

• 3 to 5 years of age (36 to 71 months)
• Free of a respiratory infection for a minimum of 4 weeks prior to the testing visit

Exclusion Criteria (both subjects and controls):

• History or coexistence of renal, chronic pulmonary, cardiac, neurological or systemic disease
• Born pre-term (< 35 weeks GA)
• Insufficient command of the English language

Trial design

121 participants in 2 patient groups

Wheezing subjects

Description:

Two study visits will be completed with wheezing subjects. The baseline visit will be completed within a 5 day window from the child's discharge from the emergency department. The follow-up visit will be completed 3 months after the baseline visit. At both visits, participants will provide a nasal swab and urine sample, complete three breathing tests: multiple-breath washout, forced oscillation technique, and Spirometry. In addition, at the follow-up visit, children will have an allergy skin test done, a nasal brush to collect epithelial cells and provide a blood sample. Whole blood will be used for basophil activation test (BAT). Children age 4+ will also complete post-bronchodilator testing using Salbutamol to capture information about bronchodilator response.

Treatment:

Procedure: Multiple-Breath Washout

Procedure: Allergy Skin Test

Procedure: Basophil activation test

Procedure: Spirometry

Procedure: Nasal swab

Drug: salbutamol

Procedure: Forced Oscillation Technique

Procedure: Bronchodilator response

Procedure: Nasal Brush

Procedure: Blood sample

Healthy cohort

Description:

One study visit will be completed with healthy participants. At this visit, three breathing tests will be performed: multiple-breath washout, forced oscillation technique, and spirometry. As well, an allergy skin test will be performed at the visit.

Treatment:

Procedure: Multiple-Breath Washout

Procedure: Allergy Skin Test

Procedure: Spirometry

Procedure: Forced Oscillation Technique