In a retrospective, single-center study, investigators compared 158 patients with systemic lupus erythematosus (SLE)—subgrouped as active (SLE Disease Activity Index [SLEDAI] > 10; n=95) or low activity (SLEDAI ≤ 10; n=63)—with 105 age- and sex-matched healthy controls. Primary markers were neutrophil-to-lymphocyte ratio (NLR) and CD40, alongside routine labs. Compared with controls, the SLE group had significantly higher NLR, CD40, C-reactive protein (CRP), red blood cell distribution width (RDW), and monocyte-to-lymphocyte ratio (MLR), and lower lymphocytes, C3/C4, white blood cell count (WBC), hemoglobin (Hb), and immunoglobulin M (IgM) (all P<0.05). In multivariable logistic regression, NLR, CD40, lymphocyte count, C3, C4, IgG, IgM, WBC, Hb, RDW, MLR, and CRP remained independently associated with SLE. Diagnostic performance was high for NLR (AUC 0.917; cutoff 2.68; sensitivity 81.0%; specificity 92.4%) and CD40 (AUC 0.907; cutoff 6.94; sensitivity 76.6%; specificity 91.4%); CRP (AUC 0.797), RDW (0.784), and MLR (0.783) showed moderate value.
Within SLE, active disease showed higher NLR (mean ~6.9 vs 4.0) and CD40 (~11.6 vs 7.1) than low activity, with strong discrimination of activity for NLR (AUC 0.902; cutoff 5.31; sensitivity 87.3%; specificity 79.0%) and CD40 (AUC 0.904; cutoff 9.88; sensitivity 96.8%; specificity 76.8%). Both NLR and CD40 correlated positively with SLEDAI, CRP, RDW, and MLR (all P<0.001), supporting their roles as inflammatory and activity biomarkers.
Reference: Wang J, Zhang R, Guo Y, Zhai X, Liu J. Neutrophil-to-lymphocyte ratio and CD40 as diagnostic biomarkers for systemic lupus erythematosus and its disease activity. Am J Transl Res. 2025 Sep;17(9):7519-7529. doi: 10.62347/OBNZ4495.
