The role of apoptotic proteins in patients with systemic lupus erythematosis.

Lymphocytes and granulocytes from healthy donors and SLE patients were used to investigate the role of Fas/FasL system in the pathogenesis of systemic lupus erythematosus (SLE). Determination of lymphocyte subpopulations was carried out by flowcytometry. Fas and FasL expression in lymphocytes and granulocytes were measured by immunofluorescence. Apoptotic cells were measured by TUNEL assay. sFas in the plasma was measured by ELISA. Thirty five normal blood donors and 45 SLE patients were selected for this study. This study was carried out between 2005 and 2007. The number of peripheral leukocytes undergoing apoptosis in SLE patients was greater than those of healthy donors. The degree of DNA damage in lymphocytes and granulocytes of SLE patients was much higher than those of healthy donors (P < 0.05 & P < 0.5, respectively). Additionally, a positive relationship was seen between the level of apoptotic lymphocytes'and the dosage of prednisolone used for treatment of SLE (r = 0.6). The level of Fas and FasL expression on different lymphocyte subpopulations increased depending on the activity of the disease (P < 0.5 & P < 0.05, respectively). There was an inverse correlation between the sFas and the stage of disease. Finally, we have demonstrated a relationship between the titre of autoantibodies and the degree of DNA damage in lymphocytes and granulocytes (r = 0.7 & r = 0.6, respectively). In conclusion, Fas and FasL are likely to play an important role in the pathogenesis of SLE. The real value may be used as a predictor for the activity of disease as well.