Serum soluble Fas ligand and nitric oxide in long-term pulmonary complications induced by sulfur mustard: Sardasht-Iran Cohort Study.

Sulfur mustard (SM) has short- and long-term toxicity against various organs including the respiratory system. However, the basic and molecular mechanisms of SM long-term toxicity have not clearly been defined. Thus, the aim of this study was to evaluate the association of soluble Fas ligand (sFasL) as well as nitric oxide (NO) serum levels with long-term pulmonary complications in a SM exposed population 20 years after SM exposure. In this historical cohort study 372 male SM exposed subjects and 128 age-matched unexposed controls were studied. Clinical evaluation and pulmonary function tests were carried out for all participants and serum concentrations of sFasL and NO measured. According to our results, the serum levels of sFasL and NO were not significantly different between the exposed and control groups. However, the serum levels of sFasL in the exposed group with pulmonary problems were significantly higher than their corresponding in the control group (116.711+/-81.166 vs 86.027+/-30.199 and p=0.028). Furthermore a significant elevation in sFasL levels was found in the exposed subjects with pulmonary problems compared to those exposed participants without pulmonary problems (116.711+/-81.166 vs 90.692+/-57.853 and p=0.004). Based on Global Initiative for chronic Obstructive Lung Disease (GOLD) classification analysis a positive correlation was observed between sFasL levels and pulmonary problems. There was also a significant negative correlation between sFasL and the white blood cell (WBC) count in the SM exposed cohort, but not in the control group. No significant association was shown between NO and pulmonary impairment in the SM exposed subjects. Thus, our results indicate that elevated serum levels of sFasL may be associated with progression of pulmonary diseases in the SM exposed subjects.