Are Polymorphisms In Metabolism Protective Or A Risk For Reduced White Blood Cell Counts In A Chinese Population With Low Occupational Benzene Exposures?

Background: Genetic variations in metabolic enzyme genes may enhance hematotoxicity in benzene-exposed populations. Objective: To investigate the association between polymorphisms of metabolism genes and white blood cells (WBCs).Methods: Three hundred and eighty-five benzene-exposed workers and 220 unexposed indoor workers were recruited in China. We explored the relationship between metabolic enzymes polymorphisms [ glutathione S-transferase T1/M1 (GSTT1/M1) null, glutathione S-transferase P1 (GSTP1) rs1695, Cytochrome P450 2E1 (CYP2E1) rs3813867, rs2031920, rs6413432, microsomal epoxide hydrolase (mEH) rs1051740, rs2234922] by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis and WBC.Results: The exposed group had lower WBC counts (P<0.001) than the unexposed group. Increased susceptibility to hematotoxicity, as evidenced by lower WBC counts, was found in workers with null-GSTT1 (P=0.045), null-GSTM1 (P=0.030), rs2031920 (P=0.020), and rs3813867 (P=0.014) genotypes. White blood cell counts were also lower in workers with null-GSTT1 and null-GSTM after adjusting for age, gender, smoking, and alcohol consumption.Conclusion: Null-GSTT1 and null-GSTM1 genotypes and Cytochrome P4502E1 (CYP2E1: rs2031920, rs3813867) may support the hematotoxicity of benzene-exposed workers in China, and we can make use of it to select susceptible population.