Validation of 8-isoprostane and prostaglandin E2 measurements in exhaled breath condensate

• Published in: Inflammation research 2003-12, Vol.52 (12), p.502
• Main Authors: Montuschi, P, Ragazzoni, E, Valente, S, Corbo, G, Mondino, C, Ciappi, G, Ciabattoni, G
• Format: Article
• Language: English
• ISSN: 1023-3830; 1420-908X
• DOI: 10.1007/s00011-003-1212-6

Objective:To qualitatively validate radioimmunoassays for 8-isoprostane and prostaglandin (PG) E2 in exhaled breath condensate. Subjects:Twenty-two subjects with different lung diseases attended the outpatient clinic on one occasion for exhaled breath condensate collection. Methods:Samples were pooled together and purified by reverse phase high performance liquid chromatography (RP-HPLC). The eluted fractions were assayed for 8-isoprostane-like immunoreactivity and PGE2-like immunoreactivity by radioimmunoassays. In addition, simultaneous measurements of exhaled breath condensate unextracted samples with two anti-8-isoprostane and anti-PGE2 sera with different cross-reactivity were performed. Results:A single peak of 8-isoprostane-like immunoreactivity and PGE2-like immunoreactivity co-eluting with 8-isoprostane (retention time: 13 min) and PGE2 (retention time: 21 min) standards, respectively, was identified by radioimmunoassays. Testing with two different antisera showed similar results for both 8-isoprostane-like immunoreactivity (limits of agreement = 4.5 pg/ml and - 4.1 pg/ml, n = 12) and PGE2-like immunoreactivity (limits of agreement = 6.1 pg/ ml and - 6.1 pg/ml, n = 12). Conclusion: This study provides evidence for the specificity of the radioimmunoassays for 8-isoprostane and PGE2 in exhaled breath condensate. This is critical for proposing these markers as a non-invasive way for monitoring airway inflammation.