Association of Neutrophil-to-Lymphocyte Ratio With Inflammation and Erythropoietin Resistance in Chronic Dialysis Patients

Abstract

Background: Neutrophil-to-lymphocyte ratio (NLR) was widely studied as a prognostic marker in various medical and surgical specialties, but its significance in nephrology is not yet established. Objective: We evaluated its accuracy as an inflammation biomarker in a dialysis population. Design setting: Single-center retrospective study. Patients: The records of all 550 patients who were treated with hemodialysis (HD) or peritoneal dialysis (PD) from September 2008 to March 2011 were included. Measurements: NLR was calculated from the monthly complete blood count. Methods: Association between NLR and markers of inflammation (C-reactive protein [CRP], serum albumin, and erythropoietin resistance index [ERI]) was measured using Spearman coefficient. Results: In total, 120 patients were eligible for the correlation analyses. We found a positive correlation between NLR and CRP (all patients: r = 0.45, P < .001; HD: r = 0.47, P < .001; PD: r = 0.48, P = .13). NLR and albumin were inversely correlated ( r = −0.51, P < .001). Finally, high NLR was associated with a nonsignificant increased ERI, but we have not demonstrated a direct correlation. Limitations: CRP and albumin are not measured routinely and were ordered for a specific clinical reason leading to an indication bias. Also, no relationship with clinical outcome was established. Conclusions: NLR seems to be a good inflammatory biomarker in dialysis in addition to being easily available. However, controlled studies should be conducted to properly assess and validate NLR levels that would be clinically significant and relevant, as well as its prognostic significance and utility in a clinical setting.