The ratio of superoxide dismutase to standard deviation of erythrocyte distribution width as a predictor of systemic lupus erythematosus

BACKGROUND: To explore the clinical value of the serum superoxide dismutase‐to‐standard deviation of erythrocyte distribution width ratio (SRSR) in systemic lupus erythematosus (SLE). METHODS: A total of 222 SLE patients from the Rheumatology and Immunology Department in the Second Affiliated Hospital of Chongqing Medical University from January 2017 to April 2019 were collected as the experimental group, and a total of 202 healthy physical examiners were extracted as the control group. Neutrophil‐to‐lymphocyte ratio (NLR), superoxide dismutase‐to‐standard deviation of erythrocyte distribution width ratio (SRSR), and platelet‐to‐lymphocyte ratio (PLR) were calculated from the collected data and then compared the level of the above three indexes between the two groups. In addition, we analyzed the association between SRSR and clinically relevant indicators. RESULTS: We found that the SRSR of SLE patients was significantly lower than healthy control group, by analyzing the receiver operating characteristic (ROC) curve; it revealed that the SRSR had higher specificity and sensitivity than either superoxide dismutase (SOD) or standard deviation of erythrocyte distribution width (RDW‐SD) alone. The area under the curve (AUC) for SRSR was significantly larger than either SOD or RDW‐SD alone, and the AUC for SRSR was also larger than NLR and PLR. And it was found that SRSR was independently correlated with SLE disease activity through multiple linear regression analysis. CONCLUSION: SRSR is a useful biomarker for the diagnosis of SLE, and it is of great significance in the clinical application.