Comparative anti-Pseudomonas aeruginosa activity of chemically modified and native immunoglobulin G (human), and potentiation of antibiotic protection against Pseudomonas aeruginosa and group B Streptococcus in vivo.

ABSTRACT

Immunoglobulin G intravenous is prepared by controlled reduction and alkylation of approximately four interheavy chain disulfide bonds per molecule. To determine if the protective activity of antibody modified by this process is diminished, mice were treated with identical doses of reduced and alkylated IgG and native IgG prepared from the same plasma pool. Three hours later mice were given a 10 percent body surface burn followed by challenge with the seven Fisher-Devlin-Gnabasik immunotypes of Pseudomonas aeruginosa. Against five of the seven immunotypes, the 50 percent protective doses were approximately 100 mg or less per kg body weight. Overall there was no significant difference in protection afforded to the mice by the two immunoglobulin preparations indicating that in vivo the activity of IgG against P. aeruginosa remains unimpaired by reduction and alkylation. In the second part of this study, immunoglobulin G intravenous significantly enhanced the activity of tobramycin and carbenicillin in the treatment of P. aeruginosa infection in burned mice and of penicillin G in the treatment of group B Streptococcus 1C infection in normal mice.