Serum level of IL-22 in chemical victims with pulmonary complications

Respiratory tract complications are considered as one of the most serious long-term effects of sulfur mustard (SM). Immune responses and inflammatory mediators seem to play the primary role in clinical complications. IL-22 - a member of IL-10 family of cytokines - has important role in various pulmonary clinical situations. In this study، the association between serum levels of IL-22 and long term pulmonary complications in SM exposed population was assessed. This study was conducted on 219 seriously sulfur mustard lung injured and 54 unexposed healthy controls. The clinical evaluations and Spirometry were done for all patients. Severity of pulmonary involvement was assessed by the classification of medical committee of veteran’s affair. The exposed subjects were categorized into two major subgroups [sever (n=142) and mild-moderate (n=57)] based on spirometry findings. 2 ml of peripheral blood was drawn into vacutainer tubes; the sera were separated and kept frozen at −70 °C until laboratory tests. Human IL-22 DuoSet® ELISA Development Kits (R&D Systems) were used to measure the IL-22 levels in the sera. There were no significant differences between the serum level of IL-22 in the SM exposed participants and the control group، and no differences was found between the groups with sever and mild-moderate lung complications. However، there were a significant correlation between serum levels of IL-22 and age. Although there were no significant differences in the serum levels of IL-22 in the SM exposed participants compared to the control group، but this finding doesn’t roll out the role of IL-22 in pathogenesis of long term respiratory complications of sulfur mustard، because it may have local significant changes in lung. Therefore، locally assessment of IL-22 would be valuable.