日本酒醸造の従事者に生じた麹菌(Aspergillus oryzae)が原因と考えられる気管支喘息の1例

Hiroaki Kume, Hikaru Tomita, Atsuro Fukuhara

A-55-year-old man who have been working in a Sake (Japanese rice wine) brewer for 27 years, came to the outpatient clinic because cough, dyspnea, and wheeze gradually worsen. These symptoms occurred immediately after exposure to Aspergillus oryzae in the brewing process since age 43. A dust mask was required to reduce these symptoms, but that work was interrupted by exacerbation of these symptoms. These symptoms disappeared when he was away from the on-site work. The SMART therapy using combined inhaler of budesonide (ICS) with formoterol (LABA) was effective to reduce these symptoms. In serological test total IgE antibody and Aspergillus specific IgE antibodies increased, whereas Aspergillus precipitating antibody and Asp f 1 (a major allergen of Aspergillus fumigatus) specific IgE antibody were negative. Eosinophilia in peripheral blood was not observed, and FeNO was not increased. Values of peak expiratory flow was reduced by 20.8% after exposure to Aspergillus oryzae in that work. Lung function test including reversibility test was intact, but FEV1 was fluctuated up to 400mL (15.9%) in the clinical course. Based on these variable clinical manifestations, laboratory data, and lung function test findings, this case was diagnosed as adult-onset atopic (Aspergillus-sensitized) bronchial asthma without allergic bronchopulmonary aspergillosis. Involvement of eosinophilic inflammation is unknown. Allergen may be considered to be Aspergillus oryzae, because these symptoms do not occur in any environment without exposure to Aspergillus oryzae. This patient is the first case of occupational asthma related to Aspergillus oryzae in a Japanese rise wine brewer.