Association of Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR) to Disease Activity in Filipino Lupus Patients

Abstract

Background: Disease activity markers for systemic lupus erythematosus (SLE) are helpful in the management and prognostication of the disease. Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been studied as novel inflammatory and prognostic markers for cardiovascular diseases, inflammatory disorders, and malignancies. Objective: The aim of the study is to investigate the association of NLR and PLR to disease activity of Filipino SLE patients. Methods: This is a cross-sectional study done through a retrospective chart review of 135 Filipino SLE patients divided into 2 groups. Group 1 had 64 patients who were in low disease activity/remission and Group 2 had 71 patients who were in active disease. Clinical characteristics and disease activity parameters and NLR and PLR were compared in the two groups. Correlations of NLR and PLR with established clinical and laboratory markers of SLE (C3, anti-dsDNA, SLEDAI-2K scores) were analyzed. Results: Group 2 had significantly higher NLR (2.947 ± 1.756 vs. 1.868 ± 0.832, p-value of < 0.001) and PLR (205.9 ± 122.2 vs. 140.2 ± 53.0, p-value of < 0.001) levels compared to Group 1. NLR and PLR values were also significantly higher in patients with lupus nephritis. NLR was positively correlated with anti-dsDNA (r = +0.490, p-value < 0.001) and SLEDAI-2K scores (r = +0.496, p-value < 0.001) and was negatively correlated with C3. PLR was also positively correlated with anti-dsDNA (r = +0.301, p-value of < 0.001) and SLEDAI-2K scores (r = +0.369, p-value < 0.001). Using ROC curve analysis, the cut-off values in predicting active disease in SLE were 1.968 (sensitivity 77.5%, specificity 75%) for NLR and 144.53 (sensitivity 63.4%, specificity 60%) for PLR. Conclusions: NLR and PLR were significantly higher among Filipino SLE patients with active disease including lupus nephritis. NLR and PLR correlated well with established disease activity markers for SLE. NLR and PLR could be a useful and convenient disease activity marker for SLE.