Abstract
Background: We previously demonstrated that malondialdehyde (MDA), an established by-product of lipid peroxidation can be precisely measured in the sputum, and is a useful marker of oxidative stress in patients with chronic obstructive pulmonary disease. In this study MDA was investigated in the airways of patients with cystic fibrosis (CF).
Methods: Levels of MDA in exhaled breath condensate (EBC) as well as in sputum were measured in 41 clinically stable CF patients (males: 25, age: 25.0±9.1 years, FEV1: 54.4±4.0%) and in 19 healthy controls. Measurement was performed by high-performance liquid chromatography (HPLC). Data are presented as mean±SEM.
Results: MDA levels both in sputum and EBC were significantly increased in patients with CF compared to healthy controls (sputum: 293.4±19.7 vs. 85.9±11.3 nmol/L, p<0.001; EBC: 139.9±6.7 vs. 73.1±5.1 nmol/L, p<0.001). Levels in sputum were ∼2.3-fold higher than in EBC. No correlations were observed between MDA values and fractional exhaled nitric oxide, blood gas or lung function parameters (p>0.05). By contrast, we found a significant association between sputum MDA levels and CRP values (r=0.434, p=0.012). The intra- and inter-assay repeatability of MDA measurement was similar between EBC and sputum (intra-assay: CV: 9.5±4.0 vs. 7.3±1.6%, p=0.53, Bland-Altman test: -75.8 and 36.1 vs. -72.2 and 58.0; inter-assay: CV: 11.9±3.8 vs. 12.1±4.1%, p=0.77, Bland-Altman test: -144.9 and 76.8 vs. -167.9 and 89.3).
Conclusions: MDA appears to be a useful marker for assessing oxidative stress within the airways of patients with CF.
- © 2014 ERS