Is Sputum Eosinophilia a Prognosis Factor for Occupational Asthma?

Details

• Personal Author:
  Blais L ; Lemiere C ; Maghni K
• Description:
  Background: Asthma is a heterogeneous disease. Recent evidence shows that subgroups of asthmatic subjects have different responses to asthma therapy. For example, some medication was ineffective when given to a broad asthma population but highly effective when given to a group of patients with distinct clinical characteristics. The identification of those subgroups represents an important advance in the management and treatment of the disease since it allows the use of a personalized and, effective treatment. There is a lack of studies that attempted to identify such subgroups in subjects with occupational asthma (OA). The broad aim of this study was to assess whether subgroups of subjects with a different inflammatory response (eosinophilic vs. non-eosinophilic responders) on exposure to occupational agents have different clinical characteristics. Methods: We performed a cross sectional study of 44 subjects who had been diagnosed with OA using specific inhalation challenges at least 2 years prior to the present study. They were composed of non-eosinophilic responders (no increase in airway inflammation after exposure to the agent they were sensitized to) and eosinophilic responders (increase in eosinophilic inflammation after exposure to the sensitizer). The clinical characteristics of those two groups of subjects (eosinophilic and non-eosinophilic responders) were compared. Results: At the time of diagnosis and during specific inhalation challenges, 15 subjects were non eosinophilic responders (change in their sputum eosinophil count less than 2% (0(2.5)%) after exposure to the offending agents) whereas 29 of them showed an increase in their sputum eosinophil count greater than 2% (14.3(22.8) (eosinophilic responders). At the time of the performance of the specific inhalation challenges, non-eosinophilic responders had a slightly greater airflow limitation but did not show a greater airway hyperresponsiveness compared with the eosinophilic responders. At the time of the present study (approximately 5 years after the performance of specific inhalation challenges), the non-eosinophilic responders had a poorer respiratory function and a poorer control of their asthma compared to the eosinophilic responders. Furthermore, they showed a greater worsening of their respiratory function over time (during the interval between the performance of specific inhalation challenge and the present study) compared to the eosinophilic responders. Conclusion: We believe that this is the first study that shows that subgroups of subjects with occupational asthma with different inflammatory characteristics do not have the same prognosis. This results needs to be confirmed in a study of a larger scope. If we confirm that non-eosinophilic responders have a poorer prognosis than eosinophilic responders, we will need to identify the underlying pathophysiological mechanisms to prevent the deterioration of the asthma of those subjects. [Description provided by NIOSH]
• Subjects:
  Asthma Asthma, Occupational Immune System Occupational Health Respiratory System Respiratory Tract Diseases Safety
• Keywords:
  Cross Sectional Studies Immune Reaction Occupational Asthma Respiratory Diseases Respiratory Function
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-24
• NIOSHTIC Number:
  nn:20057146
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, R03-OH-009734, 2012 Nov; :1-24
• Contact Point Address:
  Catherine Lemiere, Research Center, Hôpital du Sacré-Coeur de Montréal, 5400, Gouin Blvd. West, Montreal (Quebec) Canada, H4J 1C5
• Email:
  catherine.lemiere@umontreal.ca
• Federal Fiscal Year:
  2013
• NORA Priority Area:
  Services
• Performing Organization:
  Sacre Coeur Montreal Hospital (Hôpital du Sacré-Coeur de Montréal)
• Peer Reviewed:
  False
• Start Date:
  20100901
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20120831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:8c617dbc972a95af05e2eac876039e8eeac6b52924bf85ee2828a81bad121521ce33c1243462ecbf47833c9907237fdbbee3be62009323def8b8e004df6c304e
• Download URL:
  https://stacks.cdc.gov/view/cdc/218924/cdc_218924_DS1.pdf
• File Type:
  [PDF - 152.58 KB ]