Association of Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR) to disease activity in Filipino lupus patients

ABSTRACT

Background@#Systemic lupus erythematosus (SLE) is a chronic, multisystem, autoimmune disease characterized by autoantibody production, immune complex deposition and excessive pro-infl ammatory cytokine production due to an aberrant and dysfunctional immune system. Disease activity markers for SLE are helpful in the management and prognostication of the disease. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been studied as a novel infl ammatory marker and prognostic markers for cardiovascular diseases, infl ammatory disorders and malignancies.@*Objective@#The aim of the study is to investigate the association of NLR and PLR to disease activity of Filipino patients with SLE.@*Methods@#This is a cross-sectional study done through a retrospective chart review of 135 Filipino SLE patients divided into two groups. Group 1 (SLEDAI-2K score of <3) had 64 patients who were in low disease activity/remission and group 2 (SLEDAI2K score of ≥3) had 71 patients who were in active disease. Clinical characteristics and disease activity parameters (C3, anti-dsDNA, ESR) and NLR and PLR were compared in the two groups. Correlations of NLR and PLR with established clinical and laboratory disease activity markers of SLE (C3, anti-dsDNA, SLEDAI-2K scores) were analyzed.@*Results@#The group 2 or those with active disease had signifi cantly 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 signifi cantly higher in patients with lupus nephritis. NLR was positively correlated with anti-dsDNA (r = +0.490, p-value of <0.001) and SLEDAI-2K scores (r = +0.496, p-value of <0.001). NLR was negatively correlated with C3 (r = -0.336, p-value of <0.001). 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). PLR was also negatively correlated with C3 levels (r = -0.215, p-value 0.012). Using the ROC curve analysis, the cut-off values in predicting active disease in SLE were 1.968 (sensitivity 77.5%, specifi city 75%) for NLR and 144.53 (sensitivity 63.4%, specifi city 60%) for PLR. The cut-off values in predicting lupus nephritis were 2.121 (sensitivity 73.1%, specifi city 60%) for NLR and 167.0 (sensitivity 65.4%, specifi city 68%) for PLR.@*Conclusions@#NLR and PLR were signifi cantly higher among Filipino SLE patients with active disease including lupus nephritis refl ecting active infl ammation. NLR and PLR correlated well with established disease activity markers for SLE namely C3, anti-dsDNA, and SLEDAI-2K scores. NLR and PLR could be a useful and convenient disease activity marker for SLE patients.