Plasma nitric oxide and oxidized LDL levels in systemic lupus erythematosus (SLE)

Abstract

Abstract Background: Systemic lupus erythematosus (SLE) is an autoimmune disease with different clinical manifestations. The inflammatory and oxidative modification reactions are the most important events associated with cardiovascular complications of SLE patients. The aim of this study was to investigate the nitric oxide (NO) and the oxidized low-density lipoprotein (Ox-LDL) levels in order to explain the role of oxidized particles in development of clinical manifestations. Methods: A total of 80 subjects, SLE patients (n=40) and healthy controls (n=40), were recruited and matched regarding to age, gender, and body mass index (BMI). The biochemical parameters were measured using routine laboratory methods. The plasma Ox-LDL and NO levels were assayed with ELISA and colorimetric techniques, respectively. Results: The plasma NO level was significantly high in SLE patients (33.03±18.09 μmol/mL) in comparison to healthy controls (15.25±11.54 μmol/mL). In contrast, the total and normalized (Ox-LDL/LDL) plasma Ox-LDL values were low in SLE patients (p=0.2 and p<0.05, respectively). A linear negative correlation was also observed between the plasma Ox-LDL and NO levels (r=0.25, p<0.05). Multiple logistic regression analysis showed the critical role of NO on Ox-LDL level. Moreover, the disease activity and medications did not relate to the plasma Ox-LDL level (p>0.5). Conclusions: The results showed that the excess NO prevents the oxidation of LDL particles so that the inflammatory events in comparison to oxidative modifications may be most involved in clinical complications of SLE patients.