Abstract
The specific IgG antibodies to Thermoactinomyces vulgaris and Micropolyspora faeni associated with farmer's lung disease were detected by an ELISA and compared with the standard double immunodiffusion assay. In the farmer's lung group, all sera were precipitin positive against Thermoactinomyces vulgaris and/or Micropolyspora faeni, and revealed significantly high levels of IgG antibody activities against these antigens. We found 18 asymptomatics in a medical examination survey carried out on the dairy farming population of the northern area of Iwate prefecture. Although their sera were precipitin-positive against some antigens involving Thermoactinomyces vulgaris and/or Micropolyspora faeni, IgG antibody activities to these antigens as a group were significantly more reduced than the symptomatic farmer's lung group. Dairy farming controls and normal controls revealed low antibody activities. From these studies, we concluded that the assay of specific IgG antibody activities to thermophilic actinomycetes by ELISA was a useful test for the diagnosis and screening of farmer's lung disease.
