Humoral immunoresponse of pigeons to Aspergillus fumigatus antigens.

The aim of this study was to develop an immunological model of avian Aspergillosis by studying the humoral response of pigeons to Aspergillus fumigatus antigens. Immunization was performed by administering weekly injections of A. fumigatus extracts for 70 days (10 weeks). A new booster injection was given 270 days (9 months) following the last immunization. Results showed an early Aspergillus-specific humoral immunoresponse which reached a maximum level at 42-63 days (6-9 weeks) post-immunization. Using the ELISA method, it could be observed that A. fumigatus-specific IgG became elevated in the 2nd week and reached a maximum titre at 63rd day (9th week). In contrast, A. fumigatus-specific IgM levels appeared early showing maximum levels at the 2nd week, after which they declined despite the maintenance of antigenic stimulation. Termination of immunization resulted in the decrease of specific humoral immunoresponse with minimal levels of specific antibodies detectable 210 days (7 months) later. A booster injection given at 270 days (9 months) induced a very fast Aspergillus-specific IgM and IgG immunoresponse, reaching levels of antibodies similar to those observed during the immunization period.