Increased levels of autoantibodies against catalase and superoxide dismutase associated with oxidative stress in patients with rheumatoid arthritis and systemic lupus erythematosus

Objective: To evaluate the level of autoantibodies against superoxide dismutase (SOD) and catalase (CAT) in the sera of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) Tunisian patients, to study the oxidative profile among the same patients and to establish a correlation between the two parameters in order to understand the role of each one in the genesis of the two diseases.Method: Using a standard enzyme‐linked immunosorbent assay (ELISA), the levels of immunoglobulin G (IgG) and IgM directed against CAT and SOD in the sera of 39 RA patients, 40 SLE patients, and 50 control healthy individuals were evaluated. The oxidative/antioxidative profile was tested by measuring serum malondialdehyde (MDA), conjugated dienes (CD), CAT activity, and SOD activity.Results: Our data showed increased levels of IgG antibodies (Ab) against CAT in both groups of patients (p<0.05) compared to control subjects. However, the SLE patients displayed an increased level of anti‐SOD IgG (p<0.05). In all patients...