The Relationship between Erythrocyte Sedimentation Rate and Erythrocyte Sedimentation/Red Blood Cell Ratio and Disease Activity in Systemic Lupus Erythematosus.

Background: The treatment options of systemic lupus erythematosus (SLE) patients in active and inactive phases are very different clinically, and the prognosis of patients with active SLE is much worse than inactive patients. However, the present indicators for diagnosis of SLE in activity are limited and inefficient. Methods: Three hundred thirty patients with SLE were included. All patients are classified as SLEDAI (systemic lupus erythematosus disease activity index) > 4 as active and SLEDAI <= 4 as inactive. The linear correlation between variables was assessed by Pearson's correlation analysis. The difference between parameters in active and inactive patients was evaluated by the Mann-Whitney U test. The evaluation capacity of erythrocyte sedimentation/red blood cell (ERR) and red blood cell/albumin ratio (RAR) on SLE activity was determined by bivariate regression analysis. Sensitivity and specificity are assessed by receiver operating characteristic curve (ROC). Results: Compared with the inactive SLE, ESR (52.97 +/- 35.66 vs. 32.38 +/- 29.16 p < 0.001), ERR (15.40 +/- 12.41 vs. 8.19 +/- 8.10 p < 0.001) and RAR (0.13 +/- 0.10 vs. 0.11 +/- 0.20 p = 0.038) are all elevated in active SLE (52.97 +/- 35.66 vs. 32.38 +/- 29.16 p < 0.001). ERR shows better correlation than RAR with ESR (p < 0.001 vs. p = 0.911). Patients with active SLE exhibited higher SLEDAI than those with inactive SLE (8.67 +/- 2.67 vs. 3.27 +/- 1.36, p < 0.001). According to ROC analysis, when ESR levels > 58.5 and ERR levels > 13.18, the sensitivity is 37.6% and 45.2%, the specificity is 83.0% and 83.2%. Conclusions: ESR and ERR are potential indicators for diagnosis of active and inactive SLE.