Study of IgG antibodies to Pseudomonas aeruginosa in early cystic fibrosis infection

Intermittent colonization, which then becomes chronic, characterises pseudomonas lung infection in cystic fibrosis (C.F.) patients. Bacteriologic studies do not always detect this evolution, which, however, may be identified by serological examinations. The aim of this study was to apply the immunoblotting method in order to monitor the antibody response toward a Ps. aeruginosa standard antigen (St-Ag). The results were analyzed and focussed on the bacterial and clinical data. Patients with intermittent colonization were studied between 1995 and 1997. Ninety per cent of the patients were positive to total IgG and subclass IgG(1) in correspondence with the bacteriological finding. Further investigation-is called for regarding the presence of IgG(4) in order to establish whether it could be considered an index of chronic status.