Background The neutrophil-to-lymphocyte ratio (NLR) is known to be associated with a poor outcome in patients with chronic kidney disease (CKD). Several studies have reported that NLR is closely related to the presence and activity of systemic lupus erythematosus (SLE). However, little is known about the prognostic role of NLR in patients with lupus nephritis (LN). Thus, the aim of this study was to determine whether NLR can predict progression to CKD in LN patients.

Methods We enrolled 175 LN patients with available clinical data at the time of renal biopsy from the longitudinal SLE cohort. We divided LN patients into three groups based on NLR levels (T1, < 2.43; T2, 2.43–4.75; T3, > 4.75), and compared their demographic, clinical, histological and laboratory findings, and long-term prognosis among the groups. Univariate and multivariable Cox proportional hazard regression models were used to identify independent risk factors for CKD in LN patients.

Results Patients in the highest NLR tertile were older and had a higher SLEDAI score, lower eGFR, and higher white blood cell and platelet counts than those in the lowest tertile. During a mean follow-up of 100.8 ± 65.6 months, development of CKD and end-stage renal disease (ESRD) was more frequent in patients in the highest tertile (p < 0.001, p = 0.026). Finally, the highest NLR tertile was associated with an increased risk of development of CKD (adjusted hazard ratio (HR) = 2.972, 95% CI (1.429–6.182)).

Conclusions Our results demonstrated that a higher NLR in LN patients had higher disease activity and showed more rapid decline of kidney function from the onset of LN. Therefore, NLR can be used as a prognostic marker for predicting CKD and and ESRD in LN patients.