Complement consumption in the diagnosis of pigeon breeders' disease

Two laboratory techniques have been applied for the diagnosis and follow-up of pigeon breeders' disease, viz. detection of precipitins against specific antigens from pigeon droppings and assays of human haemolytic complement (huC) consumption by pigeon dropping antigens. A simple laboratory test of huC consumption by pigeon antigens is described, revealing high huC sensitivity in almost all sera of pigeon breeders with manifest or former disease. False-positive results were seldom observed. Discontinuation of antigen exposure and/or corticosteroid therapy had no effect on the huC consumption level in the test system, despite precipitin titres falling below the level of detection. Titration studies revealed an initial decrease of the huC-consuming serum factors, but titres settled at a definite constant level, even after antigen avoidance for many years. Combined application of both the precipitin test and the huC consumption test appears to be a good procedure for the laboratory diagnosis of pigeon breeders' disease.