MO277THE RATIO OF NEUTROPHIL TO LYMPHOCYTE AS A POTENTIAL MARKER OF CLINICOPATHOLOGICAL ACTIVITY FOR SYSTEMIC LUPUS ERYTHEMATOSUS
Abstract Background and Aims The ratio of neutrophils to lymphocytes (NLR) is a novel inflammatory factor that is elevated in systemic lupus erythematosus (SLE) and related to disease activity. However, the relationship between NLR and renal pathological manifestations in patients with lupus nephritis (LN) has not been studied. Method In this retrospective study, 240 SLE patients were recruited. 186 patients with renal involvement and 124 LN patients underwent renal biopsy. In the meanwhile, control groups included 125 chronic kidney disease (CKD) patients and 125 healthy volunteers. Patients with SLE disease activity 2000 (SLEDAI-2K) >9 and ≤ 9 were defined as severely active and mildly active, respectively. Clinical parameters and pathological data were collected. The correlations between NLR and clinicopathological features were analyzed. Results The NLR of SLE group was significantly higher than that of the sex-age matched control groups. Patients with nephritis had higher NLR levels than those without nephritis [2.88(1.81,4.32) vs. 2.43(1.55,3.90), P=0.044; Figure 1]. Increased NLR was observed in severely active group compared to mildly active group [3.00(1.84,4.28) vs.2.36(1.61,3.51), P=0.020; Figure 1]. NLR was significantly positively related with SLEDAI score (r=0.131, P=0.043), Renal SLEDAI score (r=0.173, P=0.023), C-reactive protein (CRP; r=0.213, P=0.002), 24-hour urine protein (r=0.274, P<0.001; Figure 2A), renal activity index (AI; r=0.192, P=0.033), cellular crescents (r=0.274, P=0.006) and tubular atrophy (r=0.226, P=0.011), and negatively correlated with serum albumin (r=-0.187, P=0.004; Figure 2A). Based on the receiver operating characteristic (ROC) curve, the best NLR cut-off value to predict severe activity and cellular crescents was 2.19 and 3.16, respectively. The ability of NLR to differentiate severely active from mildly active SLE was stronger than CRP and weaker than C3 (Figure 3A). The ability of NLR to predict cellular crescents was better than C3, but not superior to SLEDAI and RSLEDAI. Interestingly, the ROC fitted by NLR and RSLEDAI had a higher AUC and sensitivity [AUC=0.75(0.66,0.84), sensitivity=82.6%, specificity=63.6%; Figure 3B]. Conclusion NLR was a non-invasive and potential inflammatory factor to evaluate clinical and renal pathological activity in patients with SLE.