Circulating biomarkers of oxidative stress in chronic obstructive pulmonary disease: a systematic review

Abstract

Chronic obstructive pulmonary disease (COPD) is a progressive condition characterized by airflow limitation associated with an abnormal inflammatory response of the lungs to noxious particles and gases, caused primarily by cigarette smoking. Increased oxidative burden plays an important role in the pathogenesis of COPD. There is a delicate balance between the toxicity of oxidants and the protective function of the intracellular and extracellular antioxidant defense systems, which is critically important for the maintenance of normal pulmonary functions. Several biomarkers of oxidative stress are available and have been evaluated in COPD. In this review, we summarize the main literature findings about circulating oxidative stress biomarkers, grouped according to their method of detection, measured in COPD subjects.

Keywords: Biomarkers; Chronic obstructive pulmonary disease; Oxidative stress; Peripheral blood.

Fig. 1

A mechanism showing the central role of oxidative stress in the pathophisiology of COPD. The imbalance between oxidants and antioxidants in favor of oxidants leads to harmful damage. Oxidative stress amplifies the inflammatory response influencing intracellular signaling pathways that drive the release of inflammatory mediators, impairing fagocytosis of apoptotic cells and weakening the ability of corticosteroids to repress proinflammatory genes expression. Inflammation, lipid peroxidation, protein oxidation and DNA damage results in tissue damage, alteration of protein functions and gene expression, remodeling of extracellular matrix and mucus secretion