Fungal allergens from important allergenic fungi imperfecti

Abstract

Occurrence of several fungal species in the environment seems to be related to hypersensitivity disorders in humans. Fungal allergen studies reported in the literature are reviewed regarding to Aspergillus, Alternaria, Penicillium and Cladosporium genera. In this paper, we study by means of in vivo (Skin Prick Test) and in vitro (RAST and immunoblotting) the classical question of the best source of allergenic material using a population of asthmatic patients sensitized to different mould genera. In Alternaria alternata, RAST values are considerably higher in metabolic extracts (culture filtrate) than in somatic ones (myceliar). In Alternaria alternata and Penicillium chrysogenum, low molecular weight allergens (< 30 kDa) show higher IgE-binding activity in culture filtrate extracts. In Aspergillus fumigatus we find some relevant allergens in the mycellium. Different fractions have also been used in skin tests and culture filtrate extracts showing higher potency than myceliar ones, what is in agreement with the former results. We found in Penicillium chrysogenum that the 67 kDa allergen, similar to what described by Shen et al (1991), showed inespecific binding to anti-IgE conjugate used in the development of the immunoblotting technique. Whether or not this component could be a major allergen is discussed. We discuss about the importance of the biology of fungi in the sensitization and development of mould allergy.