Associations between blood levels of polychlorinated dibenzo-P-dioxins/furans and polychlorinated biphenyls with immune systems

Objective: This study assessed the associations between blood levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) and humoral and cell-mediated immune response. Methods: The subjects included 53 male workers who had worked at industrial waste incinerators for more than one year. The experimental groups were divided into indoor, field, and incinerator workers according to working process. Data on their lifestyles and occupational characteristics were collected using a survey, and blood levels of PCDDs, PCDFs, and PCBs were analyzed to determine their associations with T-lymphocyte subpopulations and immunoglobulin levels. Results: The results showed that total blood dioxins PCB levels were higher in field and incinerator workers (20.46±22.21 and 21.97±18.05 pg toxic equivalence [TEQ]/g fat, respectively) than in indoor workers (7.69± 2.05 pg TEQ/g fat). CD3 +, CD4 +, CD8 +, and CD4 + CD45RO + cells among T-lymphocyte subpopulations and IgE and IgM levels among immunoglobulins were slightly higher in field and incinerator workers than those in indoor workers, with no statistical significance (p<0.05). Multiple linear regression analysis with T-lymphocyte subpopulations and immunoglobulins as dependent variables and PCDDS, PCDFs, and PCBs as independent variables showed that PCBs were negatively associated with CD3 + levels (B value =-56.890, 95% confidence interval [CI] =-104.39→-9.392, p< 0.05) and were positively associated with the CD4+/ CD8 + ratio (B value =0.149, 95% CI =0.001-0.297, p<0.05). In addition, PCB levels were associated with IgE (B value =248.703, 95% CI =153.79-343.62, p< 0.01), IgG (B value =52.078, 95% CI =0.344-103.812, p<0.05) and IgM levels (B value =53.153, 95% CI = 32.087-74.219, p<0.01). Conclusion: These findings was obtained from a small number of subjects; hence, further studies including more subjects are necessary to validate the associations between blood levels of PCDDs, PCDFs, and PCBs and immune function.