Stability of Candida albicans allergens during storage

Stability of Candida albicans allergens was studied under various storage conditions. Lyophilized extract was reconstituted with human serum albumin (NSA) diluent, glycerol-free and in the presence of 10% or 50% glycerol and stored at various temperatures for different time periods. All extracts were tested at the same time with immunoblotting using C. albicans allergic patient sera and galactosidase-labelled anti-IgE. The highest number of detected allergens in the immunoblotting pattern was found in the presence of 50% glycerol at +6 degrees C. The most important allergen of C. albicans, the 46 kD protein allergen was stable up to 10 weeks at +6 degrees C in the presence of 50% glycerol but thereafter began to lose its IgE-binding capacity. After 30 weeks more than 50% of the IgE binding had disappeared. The 27 kD protein, another important allergen, was also labile but retained the allergenicity better than the 46 kD one. The 29 kD protein allergen was stable at all storage conditions, except +37 degrees C tested even after one year. More than 6 months storage at +6 degrees C or higher temperature is, however, unacceptable even in the presence of the 50% glycerol. These findings have particular importance in the diagnosis and treatment of allergic diseases.