[A case of summer-type hypersensitivity pneumonitis with bronchoalveolar lavage performed 4 years before onset]

A 51-year-old man with chief complaints of cough, fever, and dyspnea was admitted to our hospital. Based on a home provocation test, transbronchial lung biopsy specimens, and a serum antibody, we diagnosed summer-type hypersensitivity pneumonitis. In 1983 when the patient was 46 years old, thymectomy was performed for thymoma. Prior to surgery, bronchoalveolar lavage (BAL) was performed. Total cell count and neutrophils had already increased in BALF. Furthermore, the increase in BALF cell neutrophil count was also seen at the time of admission and after the home provocation test. Because an increase of neutrophils in BALF cells was seen not only at onset but before onset, further studies are required to clarify the role of neutrophils and the factors that increase them in hypersensitivity pneumonitis.