Precipitating antibodies against Micropolyspora phaeni in sera from mushroom workers

A new method for determining precipitating antibodies in allergic alveolitis is presented. The principle used is immunoelectrophoresis, either as a counterelectrophoresis or as a crossed immunoelectrophoresis with intermediate gel. Twenty-two mushroom workers without anamnestic signs of allergic alveolitis and 15 control persons were investigated. Twelve mushroom workers (55%) had precipitating antibodies as determined by crossed immunoelectrophoresis, and nine of these persons had antibodies demonstrated with counterelectrophoresis. Thus, the sensitivity seems greater in the crossed immunoelectrophoresis, but we find that the simpler counterelectrophoresis is an excellent screening procedure in patients suspected of allergic alveolitis. In the controls only one person had precipitating antibodies, though the antigen tested for Micropolyspora phaeni exists ubiquitously. It seems probable from this study that the antigenic load is important, although it is remarkable that no mushroom worker with precipitating antibodies against M. phaeni had ever experienced symptoms compatible with allergic alveolitis.