Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) were useful markers in assessment of inflammatory response and disease activity in SLE patients

OBJECTIVE: Although there have been extensive investigations on neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and mean platelet volume (MPV) in many diseases, their roles in systemic lupus erythematosus (SLE) remain unclear. The purpose of the present study was to evaluate NLR, PLR, and MPV levels in adult SLE patients and explore their clinical significance. METHODS: A retrospective study involving 154 adult SLE patients and 151 healthy controls was performed. All clinical characteristics of the SLE patients were extracted from their medical records. NLR, PLR, and MPV levels between SLE patients and healthy controls were compared, and correlations between these indexes and clinical characteristics were analyzed. RESULTS: Increased NLR, PLR, and MPV were observed in SLE patients. NLR was positively correlated with C-reaction protein (r = 0.509, p < 0.01), erythrocyte sedimentation rate (r = 0.610, p < 0.01), and SLE Disease Activity Index (SLEDAI) scores (r = 0.471, p < 0.01). PLR was positively correlated with SLEDAI scores (r = 0.44, p < 0.01). SLE patients with nephritis had higher NLR and PLR levels than those without nephritis (p < 0.01, p = 0.03). In addition, an NLR level of 2.065 was determined as predictive cut-off value of SLE (sensitivity 74.7%, specificity 77.5%, AUC = 0.828). Multiple regression analysis suggested that NLR was independently associated with SLE disease activity. CONCLUSIONS: NLR and PLR could reflect inflammatory response and disease activity in SLE patients.