Evaluation of mRNA Expression Levels of TNFα, TNFR1 and IL1β in Lung Tissue 20 Years after Sulfur-mustard Exposure.

Despite many years having passed since exposure to sulfur mustard (SM) gas, there are many exposed subjects who are still suffering from delayed pulmonary complications. The levels of pro-inflammatory cytokines in the lung of these subjects have not been investigated in delay phase. In this study, we evaluated mRNA expression of pro-inflammatory  cytokines (tumor necrosis factor alpha (TNFα), tumor necrosis factor receptor type 1 (TNFR1), and interleukin 1 beta (IL-1β)  ) in lung biopsy of SM-exposed subjects and compared them with control (non-exposed) subjects. We used formalin-fixed, paraffin-embedded (FFPE) tissue for this purpose. Lung FFPE blocks of SM-exposed subjects (30 samples) and a control group (30 samples) were collected from archival pathology department. The total mRNA of FFPE tissues were extracted and the mRNA expression of pro-inflammatory  cytokines were determined by quantitative Real Time PCR (RT-qPCR). The obtained results from two groups were compared to each other and non-parametric statistical analyses were carried out on them. Our studies showed that the mRNA expression of TNFα, TNFR1 and IL-1β  in lung tissue of SM injured and control people have no significant difference (p-value= 0.159, 0.832 and 0.314 respectivly). TNFR1 showed direct correlation with TNFα (r=0.867, p=0.002) and IL-1β (r= 0.65, p=0.006). The evaluation of mRNA expression in pro-inflammatory cytokines in lung of SM-exposed subjects after 20 years showed that these mediators are similar to those of non-exposed group and there was no acute inflammation in lung of these patients.