[Allergenic activity of mites in house dust].

The predominant role of mites in house dust respiratory allergy is now well established. Our laboratory has spent an important part of its time and activity studying the antigens present in D. farinae mites extracts and characterising the specific allergens responsible of respiratory allergy to D. farinae. Physicochemical and immunochemical studies let us to define major allergens in different biochemical fractions obtained from D. farinae extracts used for diagnostic and therapeutic purposes. Amongst the D. farinae specific antigens defined, one (Ag 11) is a specific major allergen and it has been isolated and chemically analysed. It is polypeptide of molecular weight of 28,000 d with p I not equal to 7 containing 5% of cysteine residues. The good stability and resistance to denaturation are in favour of numerous disulfide bonds.