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

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.

Conditions

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

Interventions

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).

Sponsors & Collaborators

• Dalhousie University

  collaborator OTHER

• The Hospital for Sick Children

  lead OTHER

Principal Investigators

• Padmaja Subbarao, MD · The Hospital for Sick Children

Eligibility

Min Age

3 Years

Max Age

5 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2014-06-30

Primary Completion

2020-12-31

Completion

2020-12-31

Countries

• Canada

Study Locations