The Association among Antioxidant Enzymes, Autoantibodies, and Disease Severity Score in Systemic Lupus Erythematosus: Comparison of Neuropsychiatric and Nonneuropsychiatric Groups

Table 3

Correlation among oxidative stress markers, antibodies, and diseases severity scores in SLE.

Variables		Biomarker of antioxidants
		Glutathione	SOD-rbc	GPX-rbc
SLEDAI	Correlation coefficient	−0.295	0.017	0.123
	P value	0.113	0.929	0.519
C3	Correlation coefficient	0.177	0.086	0.083
	P value	0.35	0.651	0.663
C4	Correlation coefficient	−0.08	0.073	0.008
	P value	0.673	0.701	0.968
a-dsDNA	Correlation coefficient	0.02	0.119	0.247
	P value	0.917	0.54	0.197
a-U1RNP	Correlation coefficient	−0.588**	−0.451	−0.409
	P value	0.008	0.053	0.147
a-Sm	Correlation coefficient	−0.506*	−0.269	−0.291
	P value	0.027	0.265	0.314
a-rib p	Correlation coefficient	−0.490*	−0.348	0.184
	P value	0.028	0.132	0.437
CRP	Correlation coefficient	0.236	−0.315	0.191
	P value	0.268	0.134	0.371

∗P < 0.05; **P < 0.01.
r, correlation coefficient; SLEDAI, systemic lupus erythematosus disease activity index; C3, complement 3; C4 complement 4; a-dsDNA, anti-double strand DNA; a-rib p, antiribosomal p; a-U1RNP, anti-U1 ribonucleoprotein; CRP, c-reactive protein; SOD-rbc, superoxide dismutase activity on red blood cell; GPX-rbc, glutathione peroxidase activity on red blood cell
The a-u1rnp (P = 0.019) was the only autoantibody that significantly negatively correlated with glutathione peroxidase activity on red blood cell (GPX-rbc) among neuropsychiatric SLE subgroups.