Hypersensitivity pneumonitis induced by Trichosporon cutaneum

We isolated Trichosporon cutaneum from the houses of patients with hypersensitivity pneumonitis and investigated its possible role as an etiologic agent in 21 cases of the disease. A high titer of anti-T. cutaneum antibody was observed in serum samples from 20 (95.2%) of the 21 patients, but only a low titer was found in less than 9% of the control serum samples. Anti-Cryptococcus neoformans antibody was also observed in the patients' serum samples, but it appeared, in most samples, to be a cross-reaction to T. cutaneum antigen. This was because the anti-C. neoformans antibody was completely absorbed with T. cutaneum, but the anti-T. cutaneum antibody was only partly absorbed with C. neoformans. Besides, no C. neoformans was isolated from the patients' environment. A bronchoprovocation test with T. cutaneum was done on one patient, with a positive result. We also found T. cutaneum in bird droppings containing nutrients for this organism. To our knowledge, this is the first report on hypersensitivity pneumonitis induced by T. cutaneum.