Small Airways Response to Naturalistic Cat Allergen Exposure in Subjects with Asthma

Details

• Personal Author:
  Corren J ; Gjertson DW ; Goldin JG ; Kennedy NJ ; Kim HJ ; Kleerup EC ; Newman KB ; Silverman JM ; Tashkin DP ; Truong DA ; Zeidler MR
• Description:
  Background: It is currently unclear whether the small airways (diameter <2 um) contribute significantly to late asthmatic reactions to inhaled allergen. Objectives: We sought to determine whether naturalistic exposure to cat allergen induced late responses in the small airways as measured by pulmonary function testing and high-resolution computed tomography (HRCT) of the chest performed at end-expiration. Methods: In a group of 10 subjects with cat-induced asthma, physiologic studies (spirometry and lung volumes, including closing volume) and HRCT were performed before and 6 and 23 hours after a cat room challenge that caused a 20% or greater acute fall in FEV1. Results: There was no significant decline in FEV1 at 6 or 23 hours after cat exposure. Forced expiratory flow at 25% to 75% of forced vital capacity was significantly decreased at 6 hours after the challenge and returned to normal by 23 hours. HRCT image analysis as well as closing volume demonstrated increased air trapping from baseline at both 6 and 23 hours after the challenge. In addition, image analysis demonstrated a significant increase in small airways hyperresponsiveness to methacholine at 23 hours after the challenge. No significant mean changes were noted in lung volumes at either 6 or 23 hours or in PC20 FEV1 at 23 hours postchallenge. Conclusion: These findings demonstrate that naturalistic exposure to cat allergen results in significant small airways obstruction and hyperresponsiveness persisting for at least 23 hours, at which time these changes cannot be detected by conventional physiologic measures. Clinical implications: Physiologically silent distal lung inflammation persists after an antigenic challenge. [Description provided by NIOSH]
• Subjects:
  Animals Antigens Asthma Asthma, Occupational Hypersensitivity Lung Occupational Health Respiratory System Safety
• Keywords:
  Allergic Reactions Author Keywords: Asthma Bronchial Hyperreactivity Computer-assisted Fel D 1 Protein Image Analysis Lung Function Pulmonary Function Tests Respiratory Function Tomography X-ray Computed

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• ISSN:
  0091-6749
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  California ; New York ; OSHA Region 2 ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  118
• Issue:
  5
• NIOSHTIC Number:
  nn:20058389
• Citation:
  J Allergy Clin Immunol 2006 Nov; 118(5):1075-1081
• Contact Point Address:
  Jonathan Corren, MD, Allergy Research Foundation, 11620 Wilshire Blvd, Suite 200, Los Angeles, CA 90025
• Email:
  jcorren@ucla.edu
• Federal Fiscal Year:
  2007
• Performing Organization:
  University of California Los Angeles
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Journal of Allergy and Clinical Immunology
• End Date:
  20270630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:42fd3199d18d6c553cb6082491e54f14f3909db7232ca3d80371bba689df2e03bf6606d1013127864324ab0ba932fe3a97cb17149469cf63f359649f0cbef729
• Download URL:
  https://stacks.cdc.gov/view/cdc/221499/cdc_221499_DS1.pdf
• File Type:
  [PDF - 551.50 KB ]