Basidiospore extracts: evidence for common antigenic/allergenic determinants

Spore extracts, prepared from Armillariella tabescens, Pleurotus ostreatus, Coprinus quadrifidus, Amanita muscaria, Ganoderma lucidum, Psilocybe cubensis, Pisolithus tinctorius, Scleroderma sp. and Calvatia cyathiformis, were examined for antigenic/allergenic relationships by Ouchterlony and radioallergosorbent testing (RAST) inhibition, respectively. Ouchterlony, using hyperimmunized rabbit sera, demonstrated a high degree of cross-antigenicity among the extracts tested; however, some unique antigens were also present. RAST inhibition, evaluated by comparing extract concentrations which inhibited the RAST by 50% (IC-50), varied with the allergen tested. P. cubensis was the most potent inhibitor (IC-50 ranged from 0.034 mg/ml for A. tabescens RAST to 0.29 mg/ml for G. lucidum RAST). P. tinctorius was the least potent inhibitor, failing to reach IC-50 at 10 mg/ml for any basidiospore extract. Evaluation of slopes and intercepts of the dose-response lines demonstrated qualitative and quantitative differences among allergens in these extracts. These results indicate the presence of shared allergenic epitopes, and suggest that representative extract panels could be developed for future use in diagnosis and treatment of basidiospore-sensitive individuals.