Organic dust toxic syndrome (ODTS) is associated with inhalation of high
concentrations of organic materials and is a noninfectious illness characterized by fever,
malaise, myalgia, and neutrophilic inflammation of the lower respiratory tract. Studies
in our laboratory of fungi in fresh lumber have demonstrated that yeasts may
predominate and have raised the issue of potential exposure of sawmill workers to
yeasts. Zymosan, a cell wall preparation from Saccharomyces cerevisiae, is a potent
stimulator of alveolar macrophages (AM). In the present study, preparations from the
cell walls of Pichia fabianii, Candida sake, Trichosporon capitatum, Rhodotorula
glutinis, and Cryptococcus laurentii were compared with zymosan and -1,3-glucan for
their ability to stimulate AM and activate complement. All species activated
complement. P. fabianii, C. sake, T. capitatum, R. glutinis, C. laurentii, as well as
zymosan and glucan, stimulated superoxide anion and leukotriene B4 production in a
dose-dependent fashion, but R. glutinis and C. laurentii were much less active.
Zymosan, glucan, P. fabianii, and R. glutinis treatment of AM resulted in increased
phagocytosis of labeled sheep RBCs, whereas there was no effect with C. sake or C.
laurentii and T. capitatum significantly inhibiting phagocytosis. These results suggest
that exposure to high concentrations of yeast could provoke pulmonary inflammation
resulting in an episode of ODTS