The Turkish Journal of Pediatrics
2013 , Vol 55 , Num 1
The Role of Serum Pseudomonas aeruginosa Antibodies in the Diagnosis and Follow-Up of Cystic Fibrosis
1Unit of Pediatric Pulmonary Medicine, Department of Pediatrics and 2Department of Microbiology and Clinical Microbiology,
Hacettepe University Faculty of Medicine, Ankara, Turkey. E-mail: ddogru@hacettepe.edu.tr
In cystic fibrosis (CF), if Pseudomonas aeruginosa (Pa) infection is not diagnosed
and treated early, chronic colonization occurs, which causes rapid decline in
pulmonary functions. The aim of this study was to evaluate Pa antibodies,
compare them with Pa cultures and determine their role in early diagnosis
and follow-up. Ninety CF patients were included; they were divided into
chronic, intermittent, negative, and mucoid groups. They were evaluated every
3-6 months. In each visit, pulmonary function tests and sputum cultures
were obtained, and Pa antibodies exotoxin A (ExoA), elastase (ELA) and
alkaline protease (AP) were determined in the serum by enzyme-linked
immunosorbent assay (ELISA). The most specific test that discriminated
chronic colonized patients from noncolonized patients was Pa culture, and
the presence of at least one antibody had the highest sensitivity. AP had
the highest specificity, and ELA had the highest sensitivity. All antibodies
were highest in the mucoid group. ELA was highest in chronic and lowest
in the negative group. The presence of antibodies was much higher than
positive Pa cultures in patients younger than five years of age. A negative
correlation between forced expiratory volume in 1 second (FEV1) and AP was
determined only in the mucoid group. In the two-year follow-up, antibody
presence did not show a regular pattern. In CF, Pa antibodies can be early
markers for diagnosis, especially in young children who cannot expectorate,
but they should only be used together with sputum cultures for long-term
follow-up and treatment.
Keywords :
alkaline protease, cystic fibrosis, elastase, exotoxin A, Pseudomonas
aeruginosa antibodies.