Background: Sulfur mustard (SM) is an alkylating chemical warfare agent that was widely used during World War I and by Iraqi forces against Iranian soldiers. We aimed to study late toxic effects of SM on the blood and the immune system of severely intoxicated Iranian veterans.
Methods: All SM-poisoned veterans in the province of Khorasan, Iran who had severe clinical complications were studied. Blood cell count, flow cytometric analysis of immune cells, serum protein electrophoresis, and determination of serum immunoglobulins and complement components levels were performed for the patients and 35 healthy age-matched controls. Hematological and immunological parameters were compared between the patients and the control group, using Mann-Whitney U test.
Results: Forty male subjects (aged 43.8+/-9.8 years) who had confirmed SM poisoning 16 to 20 years prior to this study were investigated. Total counts for WBC and RBC, as well as Hct percentage were significantly (p<or=0.042) higher in the patients than in the controls. The percentages of monocytes and CD3(+) T-lymphocytes were significantly higher (p=0.013 and p=0.037, respectively) and the percentage of CD16+56 positive cells was significantly lower in patients (p=0.006). IgM and C3 levels were significantly higher in patients (p<or=0.030). The absolute level of alpha(1) globulin, as well as absolute levels and the percentages of alpha(2) and beta globulins were significantly higher in patients compared to the control group (p<or=0.024).
Conclusions: SM can cause long-term effects on the immune system in patients with severe intoxication. The impaired immunity is probably responsible for the increased risk of infections in these patients.