Fas promoter-670 polymorphism is associated with development of anti-RNP antibodies in systemic lupus erythematosus

Objective. To evaluate whether the polymorphism of Fas promoter -670 is ass ociated with susceptibility to systemic lupus erythematosus (SLE) and rheum atoid arthritis (RA) and their clinical features. Methods. A polymerase chain reaction of a genomic DNA-restriction fragment length polymorphism was used to determine genotypes of the Fas promoter -67 0 in 87 patients with SLE, 87 with RA, and 87 healthy controls. A second co hort of SLE patients (n=85) was included. Clinical manifestations were anal yzed in each patient and correlated with the genotypes. Results. The genotype distribution of the Fas promoter -670 did not differ between patients with SLE and control subjects (AA. GA, GG genotypes 31. 54 , 15% vs 30, 55, 15% controls. respectively: chi-squared = 0.03, 2 df, p=0. 99) and between RA patients and controls (AA, GA, GG genotypes 38, 44, 18% vs 30, 55, 15% controls, respectively, chi-squared = 2.30, 2 df, p=0.32). R egarding the clinical status of lupus patients according to Fas promoter -6 70 genotypes, there was no significant difference in age at onset, anti-dsD NA titer, C3, C4 level. renal involvement. number of American College of Rh eumatology (ACR) criteria met, SLE Disease Activity Index, SLE Internationa l Collaborating Clinics/ACR Damage Index, or autoantibody profiles. However , the frequency of anti-RNP antibody was significantly different in the AA, GA, and GG groups (71, 25, 30%; chi-squared = 13.29. 2 df, p=0.001). To co nfirm this finding, the Fas promoter -670 genotype was examined in a second cohort of SLE patients (n=85). The result in the second cohort replicated the association shown in the first. In patients with RA, there was no signi ficant difference in clinical and laboratory findings according to the Fas promoter -670 genotypes. Conclusion. Our data suggest that the Fas promoter -670 polymorphism is ass ociated with development of anti-RNP antibodies in SLE.