Type-specific immunity in pseudomonas diseases.

Abstract

Abstract Sera from normal subjects and from patients with pseudomonas infections were studied for the presence of precipitins and hemagglutinins to the purified lipopolysaccharide antigens of the seven Fisher-Devlin-Gnabasik pseudomonas immunotypes. Sera were also tested for their capacity to protect mice against challenge by these strains. Sera from normal subjects did not contain precipitins and had hemagglutinin titers after mercaptoethanol treatment of less than 64 against all of the seven purified antigens. Sera from 15 of 22 patients with pseudomonas infections contained precipitins to one or more antigens. Eight sera contained precipitins to only one antigen. Sera of 11 patients with pseudomonas infections had hemagglutinin titers after mercaptoethanol treatment of greater than 64, in each instance to only 1 antigen. Sera with hemagglutinin titers of greater than 64 either before or after mercaptoethanol treatment and with detectable precipitins produced greater mouse protection than sera with hemagglutinin titers of less than 64 and negative precipitins. Most individual sera had higher mouse protective titers against strains to which the hemagglutinin titer was higher. Mercaptoethanol-treated sera from all patients tested protected mice in higher titer of sera against strains to which the hemagglutinin titer after mercaptoethanol treatment was greater than 64. The majority of sera tested also had higher mouse protective titers against strains to which precipitins were present. Acquired immunity to pseudomonas infection in man, as determined by these studies, is largely type-specific.