[Microparticulate aerosols and respiratory allergy]

The assessment of allergenic activity in submicronic particles could explain some unknown aspects of pollinosis pathogenesis. Twenty-five 0.5 discs have been obtained using a high volume sampler (Hi Vol Andersen) equipped with 0.3 micron Whatman paper filters. These discs have been challenged with a concentrated pool of sera of Parietaria allergic patients by RIA in order to evaluate the presence of allergenic activity on filters. Discs of non sampled filters and discs of sampled filters challenged with serum pool of patients sensitized to house dust mites were used as controls. The percentage of bound radioactivity was detected by gamma-counter. The radioactivity bound to sampled discs with Parietaria sera was 2.3 +/- 0.55 (Standard Deviation); radioactivity detected on control discs was comparable to background values detected by counter. These preliminary date might suggest that submicronic particles of Parietaria can retain some allergenic activity.