Fas gene polymorphisms in systemic lupus erythematosus and serum levels of some apoptosis-related molecules.

The frequency of the Fas gene polymorphism at positions-1377 G/A and -670 A/G in 249 patients with systemic lupus erythematosus (SLE) and 212 healthy controls were investigated using the allele-specific polymerase chain reaction. On evaluation of genotype and allelic distributions at position -670, no significant difference was observed between patients and controls. At position -1377, the GG genotype and G allele was higher in the patient group than in the control group (p < 0.036). The haplotype frequencies showed a significant difference between patients and controls (p = 0.045). The association of these polymorphisms and Fas and Fas ligand serum levels and also anti-SSA/Ro and anti-SSB/La antibodies were studied in a second cohort of SLE patients. Soluble Fas and Fas ligand levels were both significantly higher in the patient group compared with controls (p = 0.001), but they showed no significant association with the studied polymorphisms. Anti-SSA/Ro and anti-SSB/La were not correlated with soluble Fas and Fas lignad levels, but patients with the -670GG genotype showed lower amounts of anti-SSB/La in their serum. In conclusion, results of this study imply that Fas promoter polymorphisms might contribute to individual susceptibility to SLE and influence the anti-SSB/La autoantibody response in patients.