INDIRECT HAEMAGGLUTINATION FOR DEMONSTRATION OF ANTIBODIES TO ASPERGILLUS FUMIGATUS

Subhaemolytic amounts of saline extracts of homogenized, disrupted A. fumigatus sensitized tanned erythrocytes for agglutination to high titres (8,192) by an antiserum to A. fumigatus. Extracts of 5 different strains of A. fumigatus were equally active. Erythrocytes sensitized by similarly prepared extracts of P. notatum and an unclassified Aspergillus strain gave low titres (64 and 128), while extracts of some other fungi and bacteria had no sensitizing activity in tests with the antiserum. Results of absorption and inhibition experiments using the various preparations indicated that the sensitizing antigen(s) in extracts of A. fumigatus may be species specific. Results obtained with 441 human sera showed good correlation between high titres and presence of aspergillosis. Titres above 128 are highly indicative of active disease.