Antibodies to Aspergillus Fumigatus. Characterization of a Haemagglutinogen

Abstract

Rabbit antiserum to A. fumigatus and sera from patients with and without aspergiilosis were tested for anti‐haemolysins, CFT antibodies, precipitins and haemagglutinins using extracts of homogenized, disrupted fungi as antigen preparations. The rabbit serum reacted in all 4 tests, while the human sera gave significant reactions in precipitation and tanned cell indirect haemagglutination (IHA) only. Of 9 human sera which gave precipitation in double diffusion in agar, only the 5 which were positive in IHA were from patients with definite aspergiilosis. Some sera precipitated extracts of fungi of other species, and even of other genera. IHA was the most sensitive and specific test. Results of phenol/water extraction of the lyophilized A. fumigatus extracts, of gel filtration, and of preparative ultracentrifugation indicated that the sensitizing antigen in IHA was a precipitinogen of protein nature with a m.w. of approximately 150,000. The haemolysins in the extracts were probably phospholipases.