Extra cellular Superoxide Dismutase activity in lung injuries due to Sulfur Mustard

Background: Pulmonary complications are known to occur in over half of the patients exposed to sulfur mustard (SM). There is controversial regarding the role of extracellular superoxide dismutase (EC-SOD) in different airway diseases. Objective: The aim of this study was to evaluate the correlation between lung function and EC-SOD activity in patient with lung injuries due to SM. Methods: This was a case-control study carried out on 220 patients with lung complication due to SM in the city of Sardasht (Iran) in 2007. Spirometry was used to assess pulmonary function followed by measurement of EC-SOD activity. T test was employed to examine the differences between study groups. Pearson correlation coefficient was also used to find the possible correlation between EC-SOD activity and the lung function. Findings: The mean EC-SOD activity in control group (70.5±10.8U/L) was higher than that of moderate to severe group 67.0±6.1 U/L (p<0.001). There was no significant difference for mean EC-SOD activity between mild and control groups. Significant and direct association between EC-SOD activities and lung function was established (p<0.001). Conclusion: According to our findings, inactivation of EC-SOD may lead to progressive inflammation and lung injury due to sulfur mustard.