Objective: To investigate the role of polymorphisms of the glutathione S-transferase M1 (GSTM1), GSTT1, and GSTP1 genes in determining susceptibility to rheumatoid arthritis (RA) and association with the clinical features.
Methods: Polymorphisms of the GSTM1, GSTT1, and GSTP1 genes in 108 Japanese patients with RA and in 143 healthy controls were analyzed by polymerase chain reaction (PCR) or PCR-restriction fragment length polymorphism.
Results: The frequency of the GSTM1 null genotype was significantly higher among RA patients than among control subjects (60.2% and 44.1%, respectively. P = 0.011). Moreover, the female patients with GSTM1 homozygous null genotype showed significantly higher serum MMP-3 level than the female patients with non-null genotype (P = 0.030). Frequencies of the GSTT1 and GSTP1 gene polymorphism were not different between RA patients and controls.
Conclusion: The GSTM1 homozygous null genotype could be a genetic factor that determines susceptibility to RA and may have influence on the disease process.