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.
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.
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.
The GSTM1 homozygous null genotype could be a genetic factor that determines susceptibility to SS and may be involved in SSA antibody production.