Predictive value of the neutrophil-to-lymphocyte ratio and hemoglobin insystemic lupus erythematosus.

The aim of the present study was to evaluate the association of the neutrophil-to-lymphocyte ratio (NLR) and hemoglobin levels with disease activity in patients with systemic lupus erythematosus (SLE) and to explore their clinical significance in predicting SLE. The present study included 212 patients with SLE and 201 healthy controls. All the clinical characteristics were collected from their medical records. The results revealed that the NLR was elevated and the hemoglobin level was markedly decreased in the patients with SLE compared with the healthy controls. NLR was positively correlated with the SLE Disease Activity Index 2000 (SLEDAI-2K), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), whereas it was not correlated with C3 or C4. The hemoglobin level was negatively correlated with SLEDAI-2K, ESR and CRP and positively correlated with C3 and C4. In addition, NLR [EXP(B)=1.986; 95% confidence interval (CI), 1.432-2.753; P=0.001] and hemoglobin [EXP(B)=0.947; 95% CI, 0.929-0.965; P=0.001] were independent predictive factors of SLE. The optimal NLR cut-off value for predicting SLE was 2.075, with 71.14% sensitivity and 69.57% specificity, whereas the optimal hemoglobin cut-off value was 131.5 mg/l, with 75.79% sensitivity and 77.98% specificity. In addition, high NLR together with low hemoglobin levels and high NLR or low hemoglobin levels had increased positive predictive values (86.05 and 66.95, respectively). High NLR with low hemoglobin levels and high NLR or low hemoglobin levels also had higher sensitivity (64.91 and 92.40, respectively) and specificity (64.91 and 18.95, respectively), compared with high NLR alone or low hemoglobin alone. In conclusion, NLR and hemoglobin may reflect SLE disease activity and may be used as markers for predicting the outcome of SLE.