Antibody responses in patients with farmer's lung disease to antigens from Thermoactinomyces vulgaris.

A serological analysis of mycelial antigens of Thermoactinomyces vulgaris in immunodiffusion with human sera revealed five individual antigens. Three antigens were proteins, sensitive to pronase and soluble in phenol. Two were cationic polysaccharides, sensitive to sodium periodate, and containing glucosamine and muramic acid. Latex coated with mycelial antigens was compared with precipitin tests in detecting antibodies to T. vulgaris; the number of positive results detected by each test differed slightly, and a combination of the two tests detected the highest number. Counterimmunoelectrophoresis (CIE) was shown to be a very sensitive method for detecting precipitins, but not for their measurement. A prospective evaluation of immunodiffusion, latex agglutination and CIE as potential serodiagnostic techniques for farmer's lung disease is suggested.