CLINICAL SIGNIFICANCE OF SOLUBLE SERUM FAS AND APO1/FAS GENE POLYMORPHISM (RS1800682) -670A>G IN SYSTEMIC LUPUS ERYTHEMATOSUS.

Systemic lupus erythematosus (SLE) is a complex genetically autoimmune disease with poorly understood pathogenesis. Lupus nephritis ( LN) is one of the most serious complications of SLE. Abnormalities of apoptosis may be involved in the development of autoimmune disorders Abnormal FAS-mediated apoptosis is one of the susceptibility factors in development of SLE. Promoter variants in the APO-1/Fas gene have been studied in SLE and other autoimmune diseases. Aim:The present case control study was conducted to detect the possible association APO1/FAS-670A>G gene polymorphism with susceptibility to SLE andLupus nephritis (LN)and detect an association between the SNP and disease activity. In addition, investigate the possible relation between the polymorphism and s FAS levels and their possible association with of lupus nephritis. .Patients and Methods: fiftySLEpatients and 44 healthy control subjects were included in the study.SFas levels were detected by ELISA. PCR-RFLP was used to detect APO1/FAS-670A>G gene polymorphism. Lupus nephritis patients had proteinuria higher than 0.5g/24 hours .SLEDAI score was used to assess disease activity status in SLE and LN patients. Results:SFas levels were significantly higher in SLE compared to healthy control subjects (P<0.001). SLE patients with moderate SLE disease activity group followed by severe activity had higher sFas levels compared to low activity group (P=0.022).The heterozygous AG genotype of APO1/FAS-670A>G gene polymorphism was significantly higher in SLE patients compared to control group (P=0.029 ).There was a non- significant association between APO1/FAS-670A>G gene polymorphism and LN patients (P=0.326). There was a statistically significant positive correlation between sFas levels and SLEDAI score in patients carrying the AG genotype. Conclusion: Our results suggests a possible genetic association between increased risk of SLE and APO1/FAS-670A>G gene polymorphism.in addition we suggest a possible relation between sFas levels and SLE activity status.