Avian erythrocyte agglutination tests with the sera of bird fanciers

The agglutination of avian red cells, particularly pigeon and budgerigar cells, by sera from patients who had been exposed to birds and had respiratory symptoms, as well as from healthy bird fanciers, has been used to detect the presence of avian specific antibody. Agglutination tests performed by standard techniques using bird erythrocytes can be read within 45 minutes. One hundred and sixty-five sera were tested, and the 44 which were precipitin positive gave a positive agglutination test with one exception. Of 61 sera which gave positive agglutination tests, 43 gave positive precipitin tests with unconcentrated serum and seven others after fourfold concentration of the serum. Avian antibodies were demonstrated in the remaining 11 sera by radioimmunoelectrophoretic tests. Absorption of the sera with pigeon IgG and IgM and the use of animal antisera directed against pigeon IgG showed that the agglutination reactions were mediated by antibodies directed against pigeon IgG and IgM, and against light chains derived from pigeon IgG.