Trial Outcomes & Findings for Imaging Study of the Lungs During an Allergic Asthma Attack (NCT NCT01547286)

NCT ID: NCT01547286

Last Updated: 2017-11-22

Results Overview

Blood flow relative to the mean blood flow of the lung (mean normalized perfusion) inside areas that have reduced ventilation (Vdefs) relative to outside the Vdefs. Or, another way of writing this is: (Blood flow inside Vdefs/mean blood flow of the lung)/(Blood flow outside Vdefs/mean blood flow of the lung).

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

7 participants

Primary outcome timeframe

3 hours after allergen administration

Results posted on

2017-11-22

Participant Flow

Subjects were recruited using an IRB approved advertisement from December 2012 - January 2013. Potential subjects completed two screening visits, during which the informed consent was obtained, clinical assessment, spirometry, methacholine challenge and allergic skin tests were performed. All screening visits took place at our pulmonary clinics.

This is a single group design study. Subjects were instructed to withhold their asthma and allergy medications before the screening and bronchial allergen challenge tests. The duration of the medication withholding depended on which medications they were using at that time.

Participant milestones

Participant milestones
Measure
Allergic Asthmatic
This is a single physiological group study where each subject served as their own control. All eligible subjects underwent a methacholine challenge test, clinical assessment and skin tests to ascertain the diagnosis of allergic asthma. Both methacholine and skin test results were used to determine the start dose of the bronchial allergen challenge test. CT and PET with Nitrogen-13 (13NN) saline as a radiotracer images were obtained during the early and late phases after allergen challenge.
Overall Study
STARTED
7
Overall Study
COMPLETED
5
Overall Study
NOT COMPLETED
2

Reasons for withdrawal

Reasons for withdrawal
Measure
Allergic Asthmatic
This is a single physiological group study where each subject served as their own control. All eligible subjects underwent a methacholine challenge test, clinical assessment and skin tests to ascertain the diagnosis of allergic asthma. Both methacholine and skin test results were used to determine the start dose of the bronchial allergen challenge test. CT and PET with Nitrogen-13 (13NN) saline as a radiotracer images were obtained during the early and late phases after allergen challenge.
Overall Study
Did not meet all eligibility criteria
1
Overall Study
Physician Decision
1

Baseline Characteristics

Imaging Study of the Lungs During an Allergic Asthma Attack

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Allergic Asthmatic
n=7 Participants
Standardized Cat Allergen Extract and Standardized Dust Mite Allergen: The route of administration will be topical application of the titrated allergen via nebulized droplets to the lungs. The starting dose of allergen will be 3 dose dilutions below the estimated PC20-allergen delivered for 5 minutes at tidal breathing, followed by FEV1 at 10-minute intervals until the lowest FEV1 is established. If the %FEV1 fall is \< 20%, the next concentration is given, until the FEV1 falls ≥ 20%. When this happens the FEV1 will be followed at 10, 20, 30, 45, and 60 minutes, then hourly for 7 hours. The early asthmatic response is the maximum %FEV1 fall between 0 and 3 hours and the late asthmatic response between 3 and 7 hours post allergen challenge.CT imaging, functional PET imaging: Physiology study using CT and PET imaging with Nitrogen-13 (13NN) saline as radiotracer; images obtained during the early and late phases after allergen challenge. Nebulized methacholine inhalation: Standard
Age, Categorical
<=18 years
0 Participants
n=5 Participants
Age, Categorical
Between 18 and 65 years
7 Participants
n=5 Participants
Age, Categorical
>=65 years
0 Participants
n=5 Participants
Age, Continuous
22.7 years
STANDARD_DEVIATION 5.08 • n=5 Participants
Sex: Female, Male
Female
6 Participants
n=5 Participants
Sex: Female, Male
Male
1 Participants
n=5 Participants
Region of Enrollment
United States
7 participants
n=5 Participants

PRIMARY outcome

Timeframe: 3 hours after allergen administration

Blood flow relative to the mean blood flow of the lung (mean normalized perfusion) inside areas that have reduced ventilation (Vdefs) relative to outside the Vdefs. Or, another way of writing this is: (Blood flow inside Vdefs/mean blood flow of the lung)/(Blood flow outside Vdefs/mean blood flow of the lung).

Outcome measures

Outcome measures
Measure
Allergic Asthmatic
n=5 Participants
Standardized Cat Allergen Extract and Standardized Dust Mite Allergen: The route of administration will be topical application of the titrated allergen via nebulized droplets to the lungs. The starting dose of allergen will be 3 dose dilutions below the estimated PC20-allergen delivered for 5 minutes at tidal breathing, followed by FEV1 at 10-minute intervals until the lowest FEV1 is established. If the %FEV1 fall is \< 20%, the next concentration is given, until the FEV1 falls ≥ 20%. When this happens the FEV1 will be followed at 10, 20, 30, 45, and 60 minutes, then hourly for 7 hours. The early asthmatic response is the maximum %FEV1 fall between 0 and 3 hours and the late asthmatic response between 3 and 7 hours post allergen challenge. CT imaging, functional PET imaging: Physiology study using CT and PET imaging with Nitrogen-13 (13NN) saline as radiotracer; images obtained during the early and late phases after allergen challenge Nebulized methacholine inhalation: Standard
Percentage Change in the Ratio of Mean-normalized Perfusion Within Ventilation Defective Regions Relative to Outside
-17.8 percentage
Standard Deviation 5.1

PRIMARY outcome

Timeframe: 7 hours after allergen administration

Blood flow relative to the mean blood flow of the lung (mean normalized perfusion) inside areas that have reduced ventilation (Vdefs) relative to outside the Vdefs. Or, another way of writing this is: (Blood flow inside Vdefs/mean blood flow of the lung)/(Blood flow outside Vdefs/mean blood flow of the lung).

Outcome measures

Outcome measures
Measure
Allergic Asthmatic
n=5 Participants
Standardized Cat Allergen Extract and Standardized Dust Mite Allergen: The route of administration will be topical application of the titrated allergen via nebulized droplets to the lungs. The starting dose of allergen will be 3 dose dilutions below the estimated PC20-allergen delivered for 5 minutes at tidal breathing, followed by FEV1 at 10-minute intervals until the lowest FEV1 is established. If the %FEV1 fall is \< 20%, the next concentration is given, until the FEV1 falls ≥ 20%. When this happens the FEV1 will be followed at 10, 20, 30, 45, and 60 minutes, then hourly for 7 hours. The early asthmatic response is the maximum %FEV1 fall between 0 and 3 hours and the late asthmatic response between 3 and 7 hours post allergen challenge. CT imaging, functional PET imaging: Physiology study using CT and PET imaging with Nitrogen-13 (13NN) saline as radiotracer; images obtained during the early and late phases after allergen challenge Nebulized methacholine inhalation: Standard
Percentage Change in the Ratio of Mean-normalized Perfusion Within Ventilation Defective Regions Relative to Outside
-26.3 percentage
Standard Deviation 9.8

SECONDARY outcome

Timeframe: 3 hours after allergen administration

Coefficient of variation squared of the perfusion in the imaged lung. This measures the overall heterogeneity of perfusion in the imaged lung.

Outcome measures

Outcome measures
Measure
Allergic Asthmatic
n=5 Participants
Standardized Cat Allergen Extract and Standardized Dust Mite Allergen: The route of administration will be topical application of the titrated allergen via nebulized droplets to the lungs. The starting dose of allergen will be 3 dose dilutions below the estimated PC20-allergen delivered for 5 minutes at tidal breathing, followed by FEV1 at 10-minute intervals until the lowest FEV1 is established. If the %FEV1 fall is \< 20%, the next concentration is given, until the FEV1 falls ≥ 20%. When this happens the FEV1 will be followed at 10, 20, 30, 45, and 60 minutes, then hourly for 7 hours. The early asthmatic response is the maximum %FEV1 fall between 0 and 3 hours and the late asthmatic response between 3 and 7 hours post allergen challenge. CT imaging, functional PET imaging: Physiology study using CT and PET imaging with Nitrogen-13 (13NN) saline as radiotracer; images obtained during the early and late phases after allergen challenge Nebulized methacholine inhalation: Standard
Coefficient of Variation Squared of Perfusion
0.11 unitless
Standard Deviation 0.03

SECONDARY outcome

Timeframe: 7 hours after allergen administration

Coefficient of variation squared of the perfusion in the imaged lung. This measures the overall heterogeneity of perfusion in the imaged lung.

Outcome measures

Outcome measures
Measure
Allergic Asthmatic
n=5 Participants
Standardized Cat Allergen Extract and Standardized Dust Mite Allergen: The route of administration will be topical application of the titrated allergen via nebulized droplets to the lungs. The starting dose of allergen will be 3 dose dilutions below the estimated PC20-allergen delivered for 5 minutes at tidal breathing, followed by FEV1 at 10-minute intervals until the lowest FEV1 is established. If the %FEV1 fall is \< 20%, the next concentration is given, until the FEV1 falls ≥ 20%. When this happens the FEV1 will be followed at 10, 20, 30, 45, and 60 minutes, then hourly for 7 hours. The early asthmatic response is the maximum %FEV1 fall between 0 and 3 hours and the late asthmatic response between 3 and 7 hours post allergen challenge. CT imaging, functional PET imaging: Physiology study using CT and PET imaging with Nitrogen-13 (13NN) saline as radiotracer; images obtained during the early and late phases after allergen challenge Nebulized methacholine inhalation: Standard
Coefficient of Variation Squared of Perfusion
0.15 unitless
Standard Deviation 0.07

Adverse Events

Allergic Asthmatic

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Robert Scott Harris, MD

Massachusetts General Hospital

Phone: 617-726-9429

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place