Enzyme-linked immunosorbent assay for quantifying antigens of Dermatophagoides farinae and D. pteronyssinus (Acari: Pyroglyphidae) in house dust samples.

Double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody as capture and detector antibodies was developed for quantifying antigens of Dermatophagoides farinae Hughes and D. pteronyssinus (Trouessart) mites contained in house dust samples. This monoclonal antibody was directed against mite antigens that were also reactive to immunoglobulin E antibody in all of 10 serum samples obtained from patients allergic to mites. Histological study using fluorescent antibody revealed that the monoclonal antibody was bound to the major part of the D. farinae mite body section including fecal matter and cuticles. The detection limit of the assay system was 0.17 microgram of soluble antigens of both mite species and the antigen amount corresponding to 0.5 mites per microplate well, whether in live or dead mites. This system did not react to antigens of Tyrophagus putrescentiae (Schrank) and Cheyletus malaccensis Oudemans. Slight inhibition of less than or equal to 21.3% was observed with nonspecific substances contained in house dust, such as wool, cotton, human dander, human hair, soil, and biscuit, but no direct ELISA reactions were obtained with any of these materials. In 49 house dust samples, ELISA was significantly correlated with the conventional microscopic observation method.