Characterization of allergenic fractions from Drechslera monoceras

Drechslera monoceras, a fungus of the Deuteromycota phylum, is fairly frequent in Brazil, and is spread through the atmosphere. In previous studies done in the city of Sao Paulo, it was found that in relation to 42 other fungi extracts, the crude extract of this fungi demonstrated a more intense cutaneous reaction in patients with respiratory allergies. Biochemical, antigenic and allergenic evaluations were carried out at various growth stages of this fungus. Based on these facts, the purpose of this research was the fractionation and allergenic characterization of the allergenic extract of D. monoceras to be used in diagnosis and immunotherapy in patients with positive cutaneous reaction to this fungus. In the city of Sao Paulo, 13 of 248 patients with respiratory allergy (asthma and/or rhinitis) showed positive reaction following cutaneous tests (skin prick tests). The crude extract of D. monoceras was fractionated by SDS-PAGE. The visible fractions were then separated by electroelution to be inoculated into BALB/c mice to evaluate the production of IgE antibody. The IgE content was detected by passive cutaneous anaphylaxis test in Wistar rats, and two fractions of approximate molecular weights of 14.4 and 36 KDa reacted to the test. The in vitro allergenic characterization was carried out by Western blotting, and three fractions of approximate molecular weights of 14.4, 36 and 60 KDa were positive. It was concluded that the extract of D. monoceras has at least three allergenic determinants, which can be used for diagnosis and immunotherapy in patients with respiratory allergy to this fungi.