Oxidative Stress Markers in Sputum

Abstract

Although oxidative stress is thought to play a pivotal role in the pathogenesis of inflammatory airway diseases, its assessment in clinical practice remains elusive. In recent years, it has been conceptualized that oxidative stress markers in sputum should be employed to monitor oxidative processes in patients with asthma, chronic obstructive pulmonary disease (COPD), or cystic fibrosis (CF). In this review, the use of sputum-based oxidative markers was explored and potential clinical applications were considered. Among lipid peroxidation-derived products, 8-isoprostane and malondialdehyde have been the most frequently investigated, while nitrosothiols and nitrotyrosine may serve as markers of nitrosative stress. Several studies have showed higher levels of these products in patients with asthma, COPD, or CF compared to healthy subjects. Marker concentrations could be further increased during exacerbations and decreased along with recovery of these diseases. Measurement of oxidized guanine species and antioxidant enzymes in the sputum could be other approaches for assessing oxidative stress in pulmonary patients. Collectively, even though there are promising findings in this field, further clinical studies using more established detection techniques are needed to clearly show the benefit of these measurements in the follow-up of patients with inflammatory airway diseases.

The Role of Oxidative Stress in Severity of Obstructive Pulmonary Complications in Sputum of Sulfur Mustard-Injured Patients

“…MDA as a marker of lipid peroxidation in laboratory diagnostics may be seen as the most important decomposition product of clinically relevant polyunsaturated fatty acids [16,17]. Our results demonstrate that sputum MDA level was significantly higher in moderate and severe groups by 18.41 and 32.01% of control, respectively.…”

“…However, there was no significant correlation between plasma antioxidant system status and spirometric data in subjects with COPD [11]. The discrepancies between the studies may be due to the differences in study populations [17]. There was only minimal association between pulmonary function parameters and the serum levels of MDA and GSH in patients intoxicated with SM [16].…”

“…The mRNA expressions of Mn-SOD and Cu Zn-SOD were significantly increased in the lungs of SM-exposed patients [27]. SOD, CAT and GST activities may be increased or decreased in various pulmonary diseases including asthma and COPD [6,11,17,25]. Jafari and Ghanei reported a significant increase in SOD and CAT activities in plasma, erythrocytes, and brochoalveolar lavage fluid (BAL) and GST activity in BAL of patients with SM-induced lung injuries [8].…”

“…"The detection of imbalance between oxidant and antioxidant statuses might be more difficult due to the number of confounding factors (comorbidities, nutrition, etc.)" [17]. MDA levels in the sputum and exhaled breath condensate and plasma of patients with different pulmonary diseases have been reported to be in the range of controls [31] or elevated compared to healthy controls [6].…”

“…This method is frequently used to show oxidative stress in many studies concerning pulmonary diseases [6,17].…”