Increased cysteinyl-leukotrienes and 8-isoprostane in exhaled breath condensate from systemic sclerosis patients.

Objectives: SSc is a systemic CTD characterized by fibrosis in skin and internal organs. Interstitial lung disease is a frequent complication with fibrosis in the lung parenchyma. The fibrotic process is believed to be influenced by leukotrienes (LTs) and also by oxidative stress. The aim of this study was to investigate the amount of LTs and 8-isoprostane, a marker of oxidative stress, in exhaled breath condensate (EBC) from SSc patients.

Methods: Twenty-two SSc patients with median disease duration of 2.1 years were investigated. Fifteen patients had lcSSc, four patients had dcSSc and three patients only fulfilled criteria for limited SSc. Sixteen healthy controls were enrolled. Cysteinyl-LTs (CysLTs), LTB4 and 8-isoprostane were measured in EBC with EIA and related to the radiologic extent of pulmonary fibrosis.

Results: Compared with controls, SSc patients displayed higher median (interquartile range) CysLT [6.1 (5.3-6.8) vs 4.9 (3.7-6.3) pg/ml; P=0.040], 8-isoprostane [0.23 (0.20-0.46) vs 0.19 (0.12-0.20) pg/ml; P=0.0020], but similar levels of LTB4 [0.70 (0.50-0.83) vs 0.60 (0.42-0.70) pg/ml]. CysLT correlated to LTB4, while 8-isoprostane did not correlate to any of the LTs. None of the biomarkers measured in EBC correlated to radiologic findings.

Conclusion: Increased levels of CysLT and 8-isoprostane in EBC from patients with SSc reflect the inflammatory pattern involving LTs as well as oxidative stress. These findings may indicate a possible non-invasive assessment of pulmonary involvement in SSc with a potential value for assessment of disease progress and therapy evaluation.