Experimental pneumonia due to Pseudomonas aeruginosa in leukopenic dogs: prolongation of survival by combined treatment with passive antibody to Pseudomonas and granulocyte transfusions.

Treatment with type-specific IgG antibody to Pseudomonas aeruginosa significantly increased rates of survival after experimental induction of pseudomonas pneumonia in leukopenic dogs. Longer survival times were correlated with higher titers of circulating antibody in serum; however, no animals treated with antibody alone were long-term survivors. Subsequent development of sepsis or the recovery of Pseudomonas from infected lung tissue was not altered by treatment with antibody. Therapy with granulocyte transfusions plus gentamicin was associated with a 27% rate of long-term survival. Passive immunization with IgG (reciprocal mean hemagglutination titer, 52) in addition to granulocyte transfusions and treatment with gentamicin resulted in a rate of long-term survival of 67% (P less than 0.05). Dogs that died while receiving this combination therapy still had a survival time significantly longer than those of controls or animals treated only with granulocytes and antibiotic.