Lymphocyte phenotype analysis and chromosome aberration frequency of workers occupationally exposed to styrene, benzene, polycyclic aromatic hydrocarbons or mixed solvents.

The aim of our study was to investigate the immunotoxicity of benzene, styrene and polycyclic aromatic hydrocarbon exposure, to establish the correlation between immunological and genotoxicological parameters, and to assess the possible effect of confounding factors such as age and smoking. The immune status of the donors was characterized by measuring the surface antigens of peripheral lymphocytes. The studied antigens were the following: CD3, CD4, CD8, CD14, CD19, CD25, CD38, CD45, CD45RO, CD54, CD56, CD62L, CD71 and HLA-DR. In our studies, we compared the immunological and genotoxicological parameters (chromosome aberration, sister chromatid exchange frequency, unscheduled DNA synthesis) of the different groups with healthy controls. Analysis revealed changes in the expression of surface antigens on peripheral lymphocytes in correlation with exposure. Confounding factors, such as smoking, increased the proportion of CD4 positive T lymphocytes and influenced the surface expression of several antigens. In our investigation the occurrence of chromosome aberrations negatively correlated with CD25 (IL-2R) expression in both CD4 and CD8 positive T cells. The presented data suggest that solvents such as benzene, styrene and PAHs activate peripheral lymphocytes, and cause changes in the incidence of CD25+/CD4+ T lymphocytes that may represent a distinct subset of immune-regulatory T cells.