BACKGROUND: Serological methods to monitor Pseudomonas aeruginosa colonisation in patients with cystic fibrosis (CF) are advocated but the diagnostic value of a commercially available P aeruginosa antibody test to detect early and chronic P aeruginosa colonisation in a non-research setting has not been assessed. METHODS: Colonisation with P aeruginosa was estimated by regular culture of sputum or oropharyngeal swabs during three consecutive years in 220 patients with CF aged 0-65 years. Commercially available ELISA tests with three P aeruginosa antigens (elastase, exotoxin A, alkaline protease) were performed at the end of the study period. In a subgroup of 57 patients (aged 4-14 years) serological tests were performed annually. RESULTS: Using culture as the reference standard, the ELISA tests using the advised cut off values had a sensitivity of 79% and a specificity of 89% for chronic colonisation. Receiver-operator characteristic curves were created to optimise cut off values. Applying these new cut off values resulted in a sensitivity of 96% and a specificity of 79%. All three individual serological tests discriminated well between the absence and presence of chronic P aeruginosa colonisation. The sensitivity of the individual antibody test was 87% for elastase, 79% for exotoxin A, and 76% for alkaline protease. First colonisation was preceded by positive serological results in only five of 13 patients (38%). CONCLUSION: In patients with CF, serological tests using specific antigens are sensitive for diagnosing chronic P aeruginosa colonisation. However, the failure of serological tests to detect early colonisation in young patients emphasises the need for continued reliance on cultures.
BACKGROUND: Serological methods to monitor Pseudomonas aeruginosa colonisation in patients with cystic fibrosis (CF) are advocated but the diagnostic value of a commercially available P aeruginosa antibody test to detect early and chronic P aeruginosa colonisation in a non-research setting has not been assessed. METHODS: Colonisation with P aeruginosa was estimated by regular culture of sputum or oropharyngeal swabs during three consecutive years in 220 patients with CF aged 0-65 years. Commercially available ELISA tests with three P aeruginosa antigens (elastase, exotoxin A, alkaline protease) were performed at the end of the study period. In a subgroup of 57 patients (aged 4-14 years) serological tests were performed annually. RESULTS: Using culture as the reference standard, the ELISA tests using the advised cut off values had a sensitivity of 79% and a specificity of 89% for chronic colonisation. Receiver-operator characteristic curves were created to optimise cut off values. Applying these new cut off values resulted in a sensitivity of 96% and a specificity of 79%. All three individual serological tests discriminated well between the absence and presence of chronic P aeruginosa colonisation. The sensitivity of the individual antibody test was 87% for elastase, 79% for exotoxin A, and 76% for alkaline protease. First colonisation was preceded by positive serological results in only five of 13 patients (38%). CONCLUSION: In patients with CF, serological tests using specific antigens are sensitive for diagnosing chronic P aeruginosa colonisation. However, the failure of serological tests to detect early colonisation in young patients emphasises the need for continued reliance on cultures.
Authors: M Rosenfeld; J Emerson; F Accurso; D Armstrong; R Castile; K Grimwood; P Hiatt; K McCoy; S McNamara; B Ramsey; J Wagener Journal: Pediatr Pulmonol Date: 1999-11
Authors: J L Burns; R L Gibson; S McNamara; D Yim; J Emerson; M Rosenfeld; P Hiatt; K McCoy; R Castile; A L Smith; B W Ramsey Journal: J Infect Dis Date: 2000-12-27 Impact factor: 5.226
Authors: Helle Krogh Johansen; Lena Nørregaard; Peter C Gøtzsche; Tacjana Pressler; Christian Koch; Niels Høiby Journal: Pediatr Pulmonol Date: 2004-05
Authors: Susan E H West; Lan Zeng; Bee Leng Lee; Michael R Kosorok; Anita Laxova; Michael J Rock; Mark J Splaingard; Philip M Farrell Journal: JAMA Date: 2002-06-12 Impact factor: 157.335
Authors: Michael Anstead; Sonya L Heltshe; Umer Khan; Joseph T Barbieri; Markus Langkamp; Gerd Döring; Shimoni Dharia; Ronald L Gibson; Miriam M Treggiari; James Lymp; Margaret Rosenfeld; Bonnie Ramsey Journal: J Cyst Fibros Date: 2012-09-01 Impact factor: 5.482
Authors: Luiz Vicente Ribeiro Ferreira da Silva Filho; Flavia de Aguiar Ferreira; Francisco José Caldeira Reis; Murilo Carlos Amorim de Britto; Carlos Emilio Levy; Otavio Clark; José Dirceu Ribeiro Journal: J Bras Pneumol Date: 2013 Jun-Aug Impact factor: 2.624