Malondialdehyde and Nitric Oxide Levels in Erythrocytes from Patients with Systemic Sclerosis

<i>Objective:</i> To investigate malondialdehyde (MDA) and nitric oxide (NO) levels in the erythrocytes from patients with systemic sclerosis (SSc). <i>Subjects and Methods:</i> Twenty-nine patients diagnosed as having SSc and 16 volunteer healthy subjects (as control group) participated in the study. Fasting blood samples were obtained from the patients and healthy subjects in anticoagulated tubes (with EDTA), and the erythrocytes were separated. The MDA and NO levels were measured in the erythrocyte sediments by the spectrophotometric method. <i>Results:</i> The levels of MDA and NO were elevated in the erythrocyte sediments of the patients as compared to those of the control group (1.037 ± 0.125 vs. 0.951 ± 0.114 µmol/g Hb, respectively, p = 0.047 for MDA, and 0.340 ± 0.071 vs. 0.209 ± 0.074 mmol/g Hb, respectively, p < 0.001 for NO). A weak positive correlation was also observed between MDA and NO levels (r = 0.30, p = 0.15 in the patient group, and r = 0.27, p = 0.49 in the control group). <i>Conclusions:</i> Our results show higher levels of MDA and NO in the erythrocytes of patients with SSc than normal subjects.