Abstract
The ELISA [enzyme-linked immunosorbent assay] was used for detection of specific Ig[immunoglobulin]G antibodies to Micropolyspora faeni antigens in 158 farmers with a history of exposure to moldy hay, 88 of whom had a diagnosis of farmers'' lung. The farmers'' lung group had significantly higher values in the ELISA than the 70 exposed but asymptomatic farmers (P < 0.001) and 31 adult controls (P < 0.001). The asymptomatic farmers also had significantly higher values than the control group (P < 0.02). The ELISA correlated better with the clinical diagnosis than the Ouchterlony agar-gel double-diffusion (precipitin) test. None of the control group gave positive reactions in the ELISA or the precipitin tests. The ELISA is therefore a sensitive, specific and quantitative test which is readily available and widely applicable.