Objective: To investigate the role of polymorphisms of the glutathione S-transferase M1 (GSTM1) and GSTT1 genes in determining susceptibility to Sjögren's syndrome (SS) and autoantibody production.
Methods: Polymorphisms of the GSTM1 and GSTT1 genes in 106 Japanese patients with primary SS and in 143 healthy controls were analyzed by polymerase chain reaction.
Results: Frequency of the GSTM1 homozygous null genotype was significantly increased in SS patients compared with controls (57.5% versus 44.1%; P = 0.035). Moreover, a significantly greater frequency of SSA antibodies was found among SS patients with the GSTM1 null genotype than among those with the GSTM1 non-null genotype (P = 0.0013). Frequency of the GSTT1 polymorphism was not different between SS patients and controls.
Conclusion: The GSTM1 homozygous null genotype could be a genetic factor that determines susceptibility to SS and may be involved in SSA antibody production.