title: The quantitation of antibody in farmer's lung syndrome using a radioimmunoassay. Results of a clinical survey and comparison of three serological methods.
abstract: Three serological tests for antibody to Micropolyspora faeni, the precipitin test (Ouchterlony double diffusion test in two dimensions) the fluorescent antibody test (double-layer technique using patient's serum in middle layer) and a quantitative radioimmunoassay for IgG antibody were applied to cases of farmer's lung syndrome and compared as to their value in diagnosis and management of these cases. Of twenty-one cases with clinical symptoms only ten (48%) had positive precipitin tests, while all (100%) showed a positive fluorescent antibody test. Sixteen (76-4%) were found by the radioimmunoassay to have antibody in excess of the normal controls. The remaining five cases with symptoms had a range of antibody levels which overlapped with those of symptom-free individuals (with sera negative to fluorescent antibody tests). The precipitin test was positive above a level of 75 mug/ml of IgG antibody as determined by the radioimmunoassay, whilst the cases judged by the fluorescent antibody test to be positive were all above a level of 35 mug/ml of IgG antibody. Application of the radioimmunoassay to a group of farmers in the West of Scotland successfully detected high antibody levels in all with clinical evidence of farmer's lung syndrome; farmers who were symptom-free also had measurable antibody. The advantages of a quantitative test for antibody levels in the management of cases of this disease are discussed.
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis*; D005203:Farmer's Lung / Q000209:etiology / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D005779:Immunodiffusion; D007074:Immunoglobulin G / Q000032:analysis; D008848:Micromonosporaceae / Q000276:immunology; D011863:Radioimmunoassay
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G