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.