Potential diagnostic role of galactomannan and β-D-glucan in occupational asthmatics in wheat mills

Occupational asthma is defined as variable airway obstruction due to exposure to a specific substance in the workplace environment. The aim of the study was to find out the frequency of occupational asthma in wheat mill workers and to explore the role of fungi biomarkers (galactomannan (GM) and β-D-glucan (βDG)) in occupational asthma. Subjects and methods: Assessment of fungi in air was done. Spirometric function of workers (n=120) were assessed during diurnal (before and 15 minutes after inhalation of salbutamol) and nocturnal time. Blood samples were analyzed to measure serum GM and βDG and allergen specific immunoglobulin E. The workers were asked about asthma symptoms. Results and conclusion: A significant proportion of workers had occupational asthma (25%) and only four workers (3.3%) had non-occupational asthma (excluded from the study). The rest were normal (86 workers). Penicillium and Aspergillus were the only species found in the air environment. Mean GM concentration (GM-c) was significantly higher among occupational asthmatics than normal workers. The estimated risk of occupational asthma (Odds ratio) was 13.3 times higher among workers with high GM-c (>1 pg/ml). Ln (GM) was the only significant predictor of PEFR variability. GM has a potential diagnostic role in occupational asthma due to fungal exposure among wheat mill workers. βDG did not have a role in occupational asthma. We recommend that wheat mill flour workers should do periodic spirometric functions and serum GM every 6 - 12 months for early diagnosis and control of occupational asthma.