Immunoregulatory abnormalities in patients with pigeon breeder's disease.

T-cell suppression induced by concanavalin-A (Con-A) and the prostaglandin suppressor system (PSS) were studied in 14 patients with pigeon breeder's disease (PBD), 12 and 10 asymptomatic breeders, and 8 controls. Our results showed that PBD patients display a significant decrease in T-cell-induced suppression (29.6 +/- 15.3% vs. 61.2 +/- 9.3% in controls p less than 0.05); whereas asymptomatic breeders respond heterogeneously: 5 showed decreased suppression and 7 were within the normal range obtained in controls. In contrast, the patients presented a higher PSS index compared with the other 2 groups, suggesting an inverse relationship between the 2 systems. These findings indicate that there are relevant differences between PBD patients, asymptomatic breeders, and normal subjects in some immune interactions, which may at least partially explain the characteristic cellular and humoral hyperreactivity observed in patients with this disease.