1Amira A Nasr, 2Shaymaa El-Mongy, 3Samia Nassar, 4Hanan A. Salem, 5Nahla E. El-Ashmawy
Departments of 1Medicine, 2,4Dermatology & Venereology, Faculty of Medicine, Mansoura University, and Departments of 3Dermatology & Venereology, Faculty of Medicine, and 5Biochemistry, Faculty of Pharmacy, Tanta University, Egypt
The role of apoptosis in the pathogenesis of systemic lupus erythematosus (SLE), has been suspected. One of the most inducers of apoptosis is the Fas (receptor / ligand) system. Nitric oxide (NO) plays a vital role in immunity. Apoptosis is an important mechanism by which NO may contribute to the pathogenesis of SLE. We tried to explore whether NO and Fas-ligand (Fas-L) expression by peripheral blood mononuclear cells (PBMC) is altered in SLE and interrelate this with other parameters of disease activity. Twenty nine SLE patients (16 lupus nephritis, 13 lupus non nephritis) and 20 healthy controls were the subjects of this work. Serum NO was determined by a colourimetric method. Fas-L mRNA expression was analyzed by RT-PCR. Fas-L expression was detected in unstimulated PBMC of 24 out of 29 SLE patients (82.76%), but in none of the control subjects. NO production was significantly higher in SLE patients compared to the controls [median (range)] 16.6 (14-38.8) nmol/ml versus 10.05 (9-19) nmol/ml, P<0.001. Fas-L optical density (OD) ratio was significantly higher in lupus nephritis patients versus lupus non nephritis patients [median (range)] 3 (0.77-4.7) versus 0.65 (0.3-0.9) P=0.001 and it was significantly correlated with NO production (r=0.612) (P<0.05). Significant +ve correlation was also found between Fas-L OD ratio, serum NO production and clinical and serological evidence of SLE disease activity. Fas-L expression and NO production were increased in SLE patients. This increase was in parallel to disease activity. It is concluded that, development of new therapeutic strategies that reduce Fas-L expression and NO production may constitute novel treatment remedies for SLE patients.