Comparative Study of Pathophysiological Mechanisms and Bronchial Response in Occupational Asthma to Wheat Flour and Quaternary Ammonium Compounds During Standardized Bronchial Provocation Tests

Overview

Occupational asthma (OA) caused by high molecular weight (HMW) substances have been shown to induce predominantly an eosinophilic inflammation. In contrast, OA caused by low molecular weight (LMW) substances results in a neutrophilic inflammation. In addition, data regarding phenotype of lymphocytes in OA caused by HMW and LMW substances are scarce. The use of a new equipment will allow the realization of specific standardized bronchial challenges (BC) to occupational agents. Thus, we propose to study in more detail the cellular mechanisms involved during BC to HMW and LMW occupational agents in a double-blind placebo controlled study.

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Crossover Assignment
    • Primary Purpose: Other
    • Masking: Triple (Participant, Care Provider, Investigator)
  • Study Primary Completion Date: December 12, 2019

Interventions

  • Other: standardized bronchial challenge test (SCL SCL • • GenaSOL ™ GenaSIC ™)
    • At Visit 1: Patients are selected and they will receive a metacholine challenge test during and outside of work. After randomization, patients undergo a standardized bronchial challenge test (SCL SCL • • GenaSOL ™ GenaSIC ™) to either an wheat flour allergen extract or didecyldimethylammonium chloride or placebo. Each bronchial challenge test is followed by blood sampling at different time points and induced sputum. The immediate bronchial response and late bronchial response will be recorded.

Arms, Groups and Cohorts

  • Placebo Comparator: Placebo
  • Active Comparator: flour allergen extract or quaternary ammonium compound

Clinical Trial Outcome Measures

Primary Measures

  • Assessment of cellular inflammation in peripheral blood and induced sputum
    • Time Frame: 33 months
    • Before and after bronchial challenge: assessment of cellular inflammation in peripheral blood and induced sputum, exhaled NO; assessment of peripheral T lymphocyte phenotype.

Participating in This Clinical Trial

Inclusion Criteria

For patients with occupational asthma to wheat flour:

  • Clinical history, – A positive skin test to wheat flour and / or specific IgE to wheat flour For patients with occupational asthma to quaternary ammonium compounds: -Clinical history, For two types of asthma: – Patients must have a worsening of bronchial hyperreactivity during work compared to a rest period assessed by a metacholine challenge – FEV before challenge (nonspecific and specific) must be> 70%. Exclusion Criteria:

Asthmas:

  • no occupational asthma: – secondary to clinically relevant sensitization to an allergen domestic – aggravated at work.

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 50 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • University Hospital, Strasbourg, France
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Frédéric De BLAY, MD, Principal Investigator, University Hospital, Strasbourg, France

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