63 Pseudomonas aeruginosa pulmonary infection in CF patients in a Brazilian reference center: Antibody response monitoring

Abstract

Objective The diagnosis of P. aeruginosa ( P.a .) pulmonary infection in CF is often difficult, due to the lack of a representative clinical specimen. In this study, we sought to evaluate the prognostic and diagnostic values of a serological test for detection of specific serum IgG antibodies to P.a. in a longitudinal analysis. Methods 78 patients were classified according to their P.a. colonization/infection status (Leeds criteria) and their antibody levels were evaluated in different periods of serum sample collection by an ELISA technique previously standardized with a polyvalent P. aeruginosa antigen (St-Ag:1–17). Results The antibody levels increased progressively over time and we could detect the presence of infection until 15 months before the first positive microbiological culture for P.a . Patients with positive antibody levels in the baseline showed a higher risk of evolution in the colonization/infection status ( P.a. negative to P.a . positive) (OR = 3.13, p P.a. in the baseline showed significantly higher antibody levels in 2 of 4 periods of sample collection. Conclusion The detection of specific serum IgG antibodies to P.a. may be an useful diagnostic tool for the early detection of P.a. pulmonary infection in CF, complementing microbiological results, which may allow the early intervention with antimicrobial therapy and decrease the decline of the pulmonary function.