IgA and IgG antibody activities of serum and bronchoalveolar fluid from symptomatic and asymptomatic pigeon breeders.

Serum IgA and IgG antibody activities against pigeon serum were measured in 16 symptomatic pigeon breeders, 20 asymptomatic pigeon breeders, and 3 normal subjects by radioimmunoassay. The IgA and IgG antibody activities against pigeon antigen of the group of patients with disease was significantly greater than those of patients in the asymptomatic and the control group. The overlap of results for the symptomatic and asymptomatic breeders limits the diagnostic value of these individual IgA or IgG antibody determinations. Bronchoalveolar fluid and serum samples from a smaller group of pigeon breeders who underwent lung lavage were available for studies of antibody activity against pigeon serum. Ten asymptomatic and 6 symptomatic breeders were available for study. Both IgG and IgA antibody activities were detected by radioimmunoassay in serum samples and bronchoalveolar fluid. The IgA antibody activity determined by the radioimmunoassay was higher in the respiratory secretions.