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

University Hospital, Strasbourg, France

Status: Terminated

Conditions: Occupational Asthma

Treatments: Other: standardized bronchial challenge test (SCL SCL • • GenaSOL ™ GenaSIC ™)

Study type: Interventional

Funder types: Other

Identifiers

NCT01783873

4707

Details and patient eligibility

About

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.

Enrollment: 35 patients

Sex: All

Ages: 18 to 50 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Triple Blind

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35 participants in 2 patient groups, including a placebo group

Placebo

Placebo Comparator group

Treatment:

Other: standardized bronchial challenge test (SCL SCL • • GenaSOL ™ GenaSIC ™)

flour allergen extract or quaternary ammonium compound

Active Comparator group

Treatment:

Other: standardized bronchial challenge test (SCL SCL • • GenaSOL ™ GenaSIC ™)