Matrix metalloproteinase-9 increases in the sputum from allergic occupational asthma patients after specific inhalation challenge.

Background: Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play a role in the pathogenesis of asthma. MMP-9 increases in the sputum of asthmatic patients after bronchial challenge with common allergens. We sought to assess whether a high-molecular-weight occupational allergen was able to induce changes in MMP-9 as well as in other MMPs and TIMPs in subjects with occupational asthma.

Matrix metalloproteinases and tissue inhibitors of metalloproteinases in nasal lavage after an inhalation challenge with flour.

Objectives/hypothesis: The existence of nasal mucosa remodeling in allergic rhinitis is controversial. Few data are available on the dynamics of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in nasal fluid after an allergen challenge. We examined whether an immediate allergic reaction that induces nasal congestion and inflammation is able to also induce changes in remodeling parameters in nasal fluid.

Investigation of occupational asthma: sputum cell counts or exhaled nitric oxide?

Background: The measure of sputum eosinophil counts is a useful tool in the investigation of occupational asthma (OA), but processing sputum is time consuming. Measuring the fractional concentration of exhaled nitric oxide (FENO) may be an alternative in clinical practice. The aim of this study was to assess the respective changes of sputum eosinophil counts and FENO following exposure to occupational agents in the routine practice of two tertiary centers in North America and Europe.

Rhinitis in subjects with work-exacerbated asthma.

Objectives: This study aimed at characterizing the nature, severity, and timing of nasal and ocular symptoms in subjects with work-exacerbated asthma (WEA).

Methods: Among the 363 subjects referred to a tertiary-care hospital for the investigation of work-related asthma symptoms, 105 subjects who demonstrated non-specific bronchial hyperresponsiveness to histamine, but a negative response to a specific inhalation challenge with the suspected occupational agent(s) were considered as having WEA. Their characteristics were compared with those of 172 subjects with occupational asthma (OA), ascertained by a positive response to a specific inhalation challenge.