Neutrophil-to-lymphocyte ratio in systemic lupus erythematosus is influenced by steroids and may not completely reflect the disease activity

Objectives: Neutrophil-to-lymphocyte ratio (NLR) has emerged as an important parameter in inflammatory network andcould pave the way for newer treatment strategies in systemic lupus erythematosus (SLE). The study evaluated NLR as apredictor of disease activity in SLE and attempted to relate the factors influencing the NLR.Methods: The study included 117 SLE patients fulfilling the systemic lupus international collaborating clinics/AmericanCollege of Rheumatology (SLICC/ACR) criteria (2010). The subjects were classified into mild, moderate, and severesystemic lupus erythematosus disease activity index 2000 (SLEDAI 2K) groups and compared. NLR values were classifiedas ≤2, >2–4 and >4 groups and its relationship with study variables was evaluated by Notched box-and-Whisker plots,Spearman correlation and Mountain plot. ROC and multiple linear regression were used to verify discriminatory abilityand factors influencing NLR respectively.Results: Approximately 24% (n=28) of patients each had mild and moderate SLEDAI disease activities, and 52.14% (n=61)had severe activity. Patients with severe disease activity were significantly younger (31.69±10.09 years) and were onmore immunosuppressants/DMARDs. The patients in the >4 NLR group had significantly elevated total leucocyte count(TLC) 5560 (3360-11480) cells/mm3 and CRP 4.46 (0.3-48.2) mg/L and more patients were on steroid therapy. The >2-4NLR group had moderate inverse correlation with SLEDAI. NLR, ESR, CRP, and C3 did not show agreement with SLEDAI.The NLR was associated with CRP and steroid usage and could not discriminate disease severity.Conclusion: The relationship of the NLR with SLEDAI was not consistent. NLR was associated with CRP and steroid use.NLR as a marker of inflammation or as a predictor of SLE disease activity needs further investigation.