Influence of polymorphism of GSTM1 gene on association between glycophorin a mutant frequency and urinary PAH metabolites in incineration workers

The association between urinary 1-hydroxypyrene glucuronide (1-OHPG) levels, as an internal measure of polycyclic aromatic hydrocarbon (PAH) exposure, and glycophorin A (GPA) mutation frequency, as an early biologic effect indicator, was determined to establish whether genetic polymorphisms of glutathione S-transferase (GST) isoforms GSTM1 and GSTT1 play a role. Eighty-one workers including 38 employees directly involved in incinerating industry wastes were recruited from a company located in South Korea. Urinary 1-OHPG levels were measured by synchronous fluorescence spectroscopy after immunoaffinity purification using monoclonal antibody 8E11. Erythrocyte GPA variant frequency (NN or NO) was assessed in MN heterozygotes with a flow cytometric assay. The GSTM1 and GSTT1 genotypes were assessed by a multiplex polymerase chain reaction (PCR) method. Urinary 1-OHPG levels were higher in workers handling industrial wastes than in those with presumed lower exposure to PAHs. An increase was seen in GPA variant frequency levels with increase in urinary 1-OHPG levels. When this association was evaluated by GSTM1 genotype status, the association between GPA mutation and urinary 1-OHPG levels was stronger in individuals with GSTM1 genotype. These results suggest that the association between urinary 1-OHPG and GPA mutation might be modulated by the GSTM1 genotype.