[Passive immunotherapy for treatment of endobronchitis in cystic fibrosis]

Chronic endobronchial infection with Pseudomonas aeruginosa is a major clinical problem in cystic fibrosis, a genetic disorder of epithelial ion transport and mucus secretion. Functional defects in the opsonic antibody response to critical surface antigens of P. aeruginosa, including lipopolysaccharide and mucoid exopolysaccharide (alginate), have been implicated in the initial colonization and/or persistence of infection of the respiratory tract of cystic fibrosis patients with this bacterium. These defects are correctable in vitro with functional opsonic antibodies against P. aeruginosa present in intravenously administered immunoglobulins (ivIg). Moreover, functional opsonic polyclonal and monoclonal antibodies against P. aeruginosa are protective in animal models of chronic pseudomonal endobronchitis. Two pilot studies on passive immunotherapy with ivIg--one with standard ivIg and one with hyperimmune globulin enriched with anti-Pseudomonas lipopolysaccharide antibodies (Psomaglobin N)--have demonstrated safety and short-term efficacy in terms of improved pulmonary function. Multicenter placebo-controlled trials of passive immunotherapy with conventional ivIg and hyperimmune globulin enriched with antibodies against P. aeruginosa alginate are planned in the United States.