Chemokines, MMP-9 and PMN elastase in spontaneous sputum of sulfur mustard exposed civilians: Sardasht-Iran Cohort Study

Abstract

Chemokines play an important role in acute and chronic pulmonary diseases. The aim of this study was to evaluate the levels of chemokines, MMP-9, and PMN elastase in spontaneous sputum and serum of patients 20 years after SM exposure. In context of Sardasht-Iran Cohort Study (SICS) 40 male volunteers with a history of SM exposure in June 1987 and complain of excessive sputum were recruited. The volunteers were clinically examined and their history was collected by internists. Sputum and serum levels of IL-8, fractalkine, MCP-1, RANTES, MMP-9, and PMN elastase were measured using ELISA kits (R&D System). Spirometries were performed on all the participants. Sputum level of fractalkine was significantly lower in the hospitalized group (N=16, Median=1.05; IQR=0.41-2.62) than non-hospitalized group (N=18, 4.031; IQR=0.947-8.203) (p=0.042). However, serum levels of fractalkine were higher in the hospitalized group (Mean±SD=2.08±5.09) than in the non-hospitalized (Mean±SD=0.53±0.87) group (T-test, p=0.03). Serum levels of PMN-elastase were also higher in the hospitalized group (Mean±SD; 64,794.43±26,820.08) than in the non-hospitalized group (Mean±SD=44,049.33±17,675.85) (p=0.017). There was no relationship between the cytokines and the studied factors in sputum and the GOLD classification, but the serum levels of fractalkine and MMP-9 were significantly higher in the more severe (grades 3-4) group. There was no significant correlation between sputum and serum levels of measured inflammatory mediators and pulmonary complications in the patients who were exposed to SM 20 years earlier. Pathophysiologic process involved in SM induced pulmonary problems might be different from those in other chronic pulmonary diseases such as COPD and asthma.