Neutrophils-to-lymphocyte and platelet-to-lymphocyte ratio and Systemic Lupus erythematosus activity: a cross-sectional study in Brazilian patients

Background: To identify disease activity in Systemic Lupus Erythematosus (SLE) is important to choose the correct treatment. Neutrophil /Lymphocyte (N/L) and Platelet/ Lymphocyte (P/L) ratio have been considered to reflect inflammatory status in several situations. In this study, we aimed to evaluate the association of N/L and P/L with SLE disease activity. Methods: This is a crosssectional study of 189 SLE patients for disease activity for SLEDAI-2K (SLE Disease activity index), ESR (erythrocyte sedimentation rate), CRP (C reactive protein) and hemogram with N/L and P/L ratio. Results: N/L ratio demonstrated correlation with SLEDAI (rho=0.24; p=0.0009) ESR (rho =0.17; p=0.02) and CRP (rho=0.23; p=0,004); P/L correlated with SLEDAI (rho=0.21; p=0.003), CRP (rho=0.26; p=0.001), ESR (rho=0.23; p=0.003) and levels of anti-dsDNA (rho=0.29; p=0.02) and had a negative correlation with hemoglobin (rho= -0.27; p=0.0001). A cut-off of 2.28 in N/L ratio had sensitivity of 68.6% and specificity of 68.2% for active disease; a cut-off of 124.1 in P/L ratio had sensitivity of 82.9 and specificity of 41.1% for active SLE. Conclusions: N/L and P/L ratio are useful in the evaluation of SLE disease activity.