Heterogeneity of immune responses to various Aspergillus species in patients with allergic respiratory diseases.

ABSTRACT

In the present study, allergenic significance of thirteen species of Aspergillus and their allergenic and antigenic relationship was studied. Of the 3025 ID tests performed with the 13 species of Aspergillus on 289 patients suffering with allergic respiratory diseases, 627 (20.7%) were positive (1+ to 4+), 386 (12.8%) being significantly positive (2+ to 4+) . Of the 64 patients eliciting a positive cutaneous response to at least one species, 42(65.6%) were positive to 5 or less number of species while others showed a broad spectrum of positive skin reactivity to different Aspergillus extracts. In RAST inhibition assays using pooled sera ofpatients sensitive to A. tamarii dose related inhibition was produced by homologous as well as 5 of the 12 heterologous species. Similarly, in A. terreus RAST inhibition was observed with homologous and A. tamarii extracts only. Our results suggested the presence of both species specific as well as shared allergenic components among different Aspergillus species. In TDIEP experiments using rabbit antisera to A. tamarii and A. terreus extracts multiple precipitin bands were observed with the homologous extracts. However, only 1-2 bands were produced by 6 heterologous Aspergillus species in each system. Collectively, these results gave evidence that there is heterogeneity of immune response in the patients with allergic respiratory diseases to different species of Aspergillus and also in rabbits immunized with Aspergillus extracts.