Evaluation of serum immunoglobulins and their relevance to chronic lung disease in mustard gas victims

Despite the fact that 8 years has elapsed since the end of the imposed war, chemically injured victims are still suffering from various long-term complications, most of them respiratory in nature. The progressive nature of respiratory problems in these patients suggests that the immune system must be involved to initiate a cascade which ends up causing lung injuries. To evaluate this, humoral immunity was assessed in 179 mustard gas victims in 1992. The patients were followed up for the next 4 years. These included 172 male and 7 female patients with a mean age of 33 years and an average of 6.1 years post-exposure to mustard gas. After physical examination and spirometric evaluation, these patients were divided into 3 groups based on the severity of their respiratory problems, i.e. "severe" [group 1], "moderate" [group 2] and "mild" [group 3]. IgG, IgA, C3 and C4 were measured using SRID technique and IgE by ELISA. The results in each group were compared with the control group consisting of 49 healthy, randomly selected volunteers. Mean age was 32 years in this group. The results indicate that there is a significant fall in IgG, IgA, C3 and C4 levels in group 3 [p=0.009, 0.01, 0.004, and 0.002, respectively] as compared to the control group. IgG had also dropped significantly in groups 2 and 1. On the other hand in group 3.19.6% and 15.2% of patients had lower than normal IgG and IgA levels, respectively. In group 2, 7.7% of patients had low IgG and 5.8% had low IgA levels. These figures were 10% and 3.8% for IgG and IgA in group 1. Of a total of 7 patients in group 3 with low IgA levels, four patients also had low IgG levels. Two of these patients gradually developed more serious respiratory problems and were classified as group 1 after two years. We concluded that: 1] mildly injured patients [group 3] have lower IgG and IgA as well as C3 and C4 levels, and 2]among these patients those who demonstrate low IgG levels are more prone to develop progressive respiratory problems in the future