In vitro activation of the alternative pathway of complement by settled grain dust.
Olenchock-SA; Mull-JC; Major-PC; Peach-MJ; Gladish-ME; Taylor-G
J Allergy Clin Immunol 1978 Nov; 62(5):295-300
The effects of settled grain dust on the human serum complement cascade were investigated. Settled grain dust from several active grain elevators in the Superior Duluth areas of the United States was mixed with normal human serum. Aliquots were analyzed for factor-B conversion and hemolytic activity. Factor-B conversion also was tested after addition of various chelators. Complement consumption also was tested in dust treated sera from C4 deficient guinea pigs. Factor-B conversion and reductions in hemolytic complement consumption were dose related. Dust induced factor-B conversion was inhibited by ethylenediaminetetraacetate but not by ethylene-glycol-bis-(beta-amino-ethyl-ether)-N,N'-tetraacetic-acid. Complement reductions also were seen in the treated sera from C4 deficient guinea-pigs. The authors conclude that these samples of grain dust produce hemolytic consumption via the alternative pathway. They suggest that chronic low level exposure to aerosolized, biologically active grain dust could cause respiratory disorders among grain workers.
NIOSH-Author; Hematology; Plants; Airborne-dusts; Immunology; Humans; Laboratory-animals; Dose-response; Metabolism; Biochemistry; Pulmonary-system-disorders
The Journal of Allergy and Clinical Immunology