Sensitivity of IgG-ELISA for detecting airborne pollen antigens of Betulaceae

The reasons for the occurrence of high birch pollen antigen concentrations in the air, especially in small particle sizes and before the birch flowering period, have been closely studied. Some particles with pollen antigenic activity are known to be emitted from other parts of the tree in addition to the catkins. Pollen from related species which flower before the birch, or simultaneously with it, may provide another explanation for these antigen peaks. In the study reported here, birch pollen antigenic activity before flowering was analysed in 1993 and 1994 using IgG-ELISA with polyclonal antibodies. A clear indication of the emission of small micronic particles with pollen antigenic activity before birch flowering was a peak before and during the pollen period of alder. Alder is the first tree to flower in the spring in Finland. Because of the high homology in the major allergens of the family Betulaceae, either polyclonal antibodies against birch pollen or monoclonal Bet v I can be recommended for both aerobiological monitoring and information service.