Precipitins to different avian serum antigens in bird fancier's lung and coeliac disease

Precipitins to avian serum antigens have been found in the sera of bird fanciers and, until now, they have been considered strong supporting evidence for a clinical diagnosis of bird fancier's lung (BFL). We now report that 35% of patients with coeliac disease, none of whom had recently kept a bird, had precipitins against an avian serum antigen common to all the avian species tested, but which was distinct from the antigens usually associated with BFL, This antigen was a component of hen egg yolk but not of bird droppings. In patients with BFL the antibody response results from inhaled antigens in the bird droppings, whereas the antibody response in patients with coeliac disease probably results from eating uncooked or soft-boiled eggs.