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In idiopathic pulmonary fibrosis (IPF), lung accumulation of excessive extracellular iron and macrophage haemosiderin may suggest disordered iron homeostasis leading to recurring microscopic injury and fibrosing damage.The current study population comprised 89 consistent IPF patients and 107 controls. 54 patients and 11 controls underwent bronchoalveolar lavage (BAL). Haemosiderin was assessed by Perls' stain, BAL fluid malondialdehyde (MDA) by high-performance liquid chromatography, BAL cell iron-dependent oxygen radical generation by fluorimetry and the frequency of hereditary haemochromatosis HFE gene variants by reverse dot blot hybridisation.Macrophage haemosiderin, BAL fluid MDA and BAL cell unstimulated iron-dependent oxygen radical generation were all significantly increased above controls ( p<0.05). The frequency of C282Y, S65C and H63D HFE allelic variants was markedly higher in IPF compared with controls (40.4% versus 22.4%, OR 2.35, p=0.008) and was associated with higher iron-dependent oxygen radical generation (HFE variant 107.4±56.0, HFE wild type (wt) 59.4±36.4 and controls 16.7±11.8 fluorescence units per 10 5 BAL cells; p=0.028 HFE variant versus HFE wt, p=0.006 HFE wt versus controls).The data suggest iron dysregulation associated with HFE allelic variants may play an important role in increasing susceptibility to environmental exposures, leading to recurring injury and fibrosis in IPF. @ERSpublications HFE gene variants that cause iron-related fibrosing diseases implicate lung iron dysregulation in IPF pathogenesis

Cigarette smoking has been causally linked several diseases, primarily lung cancer and chronic obstructive lung disease (COPD). The diagnosis of COPD currently involves an assessment of smoking and/or occupational exposures, a history of cough, sputum and dyspnea and spirometric measures of airflow obstruction and since spirometric measures take long follow up times to detect significant changes, surrogate measures of outcome capable of predicting long-term health changes have been sought for. These include biomarkers of oxidative stress, inflammation and tissue damage in sputum, bronchoalveolar lavage, exhaled breath and serum. Published biomarker studies have not always accurately compared patients with COPD with age-matched cigarette smokers and non-smoking normal subjects without significant airflow limitation, also comparable for other exposures. Consequently, the interpretation of biomarker association studies is somewhat difficult. The purpose of this narrative review is to summarize publications reporting cellular, soluble or volatile marker of obstructive lung disease in populations of healthy non-smokers and healthy smokers, in order to determine whether the biomarkers examined could be specifically associated with exposure to tobacco smoke rather than with inflammation and airway hyper-reactivity. As induced sputum has been the most widely used investigative tool, this review has been aimed at assessing induced sputum biomarkers, referring to lung biopsy, bronchoalveolar lavage and exhaled breath markers as supporting evidence for biomarkers associations identified with induced sputum studies.

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