NCT02743663

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

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 121 (actual)
• Sponsor: The Hospital for Sick Children · Academic / Other
• Sex: All
• Age: 3 Years – 5 Years
• Healthy volunteers: Accepted

Summary

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.

Detailed 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.

Conditions

• Asthma
• Wheeze
• Obstructive Sleep Apnea
• Food Allergy
• Virus

Interventions

Type	Name	Description
PROCEDURE	Bronchodilator response	Bronchodilator (Salbutamol - dose dependent on participant prescription) to wheezing subjects. 15 minutes after bronchodilator, spirometry and FOT repeated.
PROCEDURE	Allergy Skin Test	Child will be tested for allergies to 17 different allergens, and positive (histamine) and negative (glycerin) controls, for a total of 19 allergens.
PROCEDURE	Multiple-Breath Washout	Facemask in children 3-5 yrs, Wash-in phase: medical air inhaled during tidal breathing until steady state. Bias flow switched to 100% oxygen. Wash-out phase: patient breathes in 100% oxygen until nitrogen levels reach \~2%. Each test in duplicate and average is calculated.
PROCEDURE	Forced Oscillation Technique	Sterile mouthpiece attached to FOT device. Patient is tested seated with noseclips and mouthpiece. FOT device produces oscillations at different frequencies (from that flow into lungs. Device measures resistance and reactance in lungs.
PROCEDURE	Spirometry	Forced exhale manoeuvre completed by participant into flow meter, measuring forced exhale volumes and speed.
DRUG	salbutamol	Given during bronchodilator response.
PROCEDURE	Nasal Brush	Nasal brush of 1 inferior turbinate to collect epithelial cells. Collected on either nare, choice dependent on how clear the nare is (i.e. no mucous, no nasal mucosal edema, no major structural impediments).
PROCEDURE	Blood sample	8mLs of venous blood collected using a butterfly needle of appropriate gauge. Blood sample used to collect CBC values, total IgE, serum, DNA, plasma, and whole blood.
PROCEDURE	Basophil activation test	Collect basophils from whole blood sample, and expose cells to food allergens in flow cytometry machine to measure allergic response, if any.
PROCEDURE	Nasal swab	Gentle swabbing of both nasal openings to collect mucous sample for analysis of microbial contents (i.e. bacteria, virus, fungi).

Timeline

• Start date: 2014-06-01
• Primary completion: 2020-12-01
• Completion: 2020-12-01
• First posted: 2016-04-19
• Last updated: 2021-02-08

Locations

1 site across 1 country: Canada