The immune cells profiles of individuals with sulfur mustard-induced serious long-term respiratory complications

Abstract

Sulfur mustard (SM) induced pulmonary disorder is a heterogeneous disease characterized by uncontrolled inflammatory immune responses. In this cross-sectional study carried out in Isfahan-Iran, our objective was to thoroughly evaluate the clinical health and peripheral blood leukocyte profiles of adult veterans exposed to SM 25-30 years. In total, 361 people were studied in two groups, 287 chemical veterans with pulmonary complications and 64 healthy individuals as a control group. The participants underwent a comprehensive lung evaluation, including physical examination, Pulmonary Assessment, and Spirometry Assessment. Blood samples were collected in EDTA-treated tubes and flow cytometry analysis was employed to study different population of leukocytes including lymphocytes, monocytes, and natural killer cells. In our results, SM-exposed patients showed a significant increase in mean WBC and lymphocyte absolute count. However, the frequency of CD14+ monocytes and CD3+ CD4+ CD25+(Hi) as regulatory T cell subsets significantly decreased in SM-exposed patients. In addition, there was a negative correlation between CD45+ CD14+ cells and residual volume (RV). The population of NK cells showed a negative correlation with forced expiratory volume in the first one second to the forced vital capacity (FEV1/FVC). On the other hand, the percentage of CD19+ B cells positively correlated with Mid-maximum expiratory flow (MMEF) rate, ppm Reading, Carboxyhemoglobin (CoHb), and FEV1, and it was negatively correlated with airway resistance (RAW). Evaluation of CD3+ CD8+ cytotoxic T cells frequency negatively correlated with CoHb, ppm Reading, total lung capacity (TLC), and RV. Furthermore, the count of CD3+ CD4+ T cells demonstrated a negative correlation with TLC. The percentage of CD3+ CD4+ CD25+ cells was positively correlated with ppm reading and CoHb. Overall, our findings revealed modifications in total lymphocyte dynamics and a decrease in the percentage and absolute number of regulatory T cells, compromising the regulatory arm of the immune system to modulate SM-induced inflammatory damages.