Enhanced reactivity to malondialdehyde-modified proteins by systemic lupus erythematosus autoantibodies.
OBJECTIVE
Evaluation of the reactivity of autoantibodies of systemic lupus erythematosus (SLE) patients directed against malondialdehyde (MDA)-modified catalase, superoxide dismutase (SOD), and different Hep2 protein fractions (hydrophobic, hydrophilic, and nuclear).


METHODS
Thiol groups and MDA-protein adducts were first assessed among 65 SLE patients and 60 healthy controls. Then, the reactivities of SLE immunoglobulin (Ig)G autoantibodies towards MDA-modified and unmodified proteins were compared using a standard enzyme-linked immunosorbent assay (ELISA).


RESULTS
An increase in the levels of MDA-modified proteins and a decrease in the concentration of thiol groups among SLE patients (p < 0.05) were observed. IgG circulating autoantibodies in the sera of SLE patients exhibited a significant enhanced reactivity (p < 0.05) against catalase and SOD-modified proteins. The same data were observed in the different protein fractions extracted from cultured cells (p < 0.05).


CONCLUSIONS
These data reinforce the role of oxidative stress and especially lipid peroxidation products in the progression of SLE disease.
Ben Mansour
R
R
Unit of Biotechnology and Pathology, Higher Institute of Biotechnology of Sfax, Tunisia. riadhbm2004@yahoo.fr
Lassoued
S
S
Elgaied
A
A
Haddouk
S
S
Marzouk
S
S
Bahloul
Z
Z
Masmoudi
H
H
Attia
H
H
Aïfa
M S
MS
Fakhfakh
F
F
D000704:Analysis of Variance; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology*; D008315:Malondialdehyde / Q000276:immunology*; D011506:Proteins / Q000276:immunology*; D013482:Superoxide Dismutase / Q000276:immunology*
D001323:Autoantibodies; D011506:Proteins; D008315:Malondialdehyde; D013482:Superoxide Dismutase