Glutathione S-transferases GSTM1 and GSTT1 polymorphisms and asbestosis

Objective: In a nested case-control study, the authors investigated whether the deletion polymorphism of glutathione S-transferases GSTM1 and GSTT1 represents a risk factor for the development of asbestosis. Methods: In total, 262 cases with asbestosis and 265 controls, selected from a cohort of 2080 workers occupationally exposed to asbestos, were genotyped for GSTM1 and GSTT1-null alleles. Cumulative exposure for each subject was available. Results: Asbestosis was associated with cumulative exposure (odds ratio [OR] = 3.21, confidence interval [CI] 2.43-4.23) and GSTT1-null genotype (OR = 0.61, CI 0.40-0.94), but not with GSTM1-null genotype (OR = 1.01, CI 0.71-1.43). The risk of GSTM1-null and GSTT1-null genotype for asbestosis did not change after adjustment by cumulative exposure, smoking, gender, and age. Conclusions: An important finding of this study is that GSTT1 gene deletion might have a protective effect on the development of asbestosis.