NLR and PLR as Available and Inexpensive markers for Evaluation of Subclinical Inflammation in patients with Chronic Kidney Disease

Abstract

Chronic kidney disease (CKD) is associated with high morbidity and increased cardiovascular mortality. Chronic inflammation was found to be correlated with cardiovascular disease (CVD) in CKD population. High-sensitivity C-reactive protein (hs-CRP), is one of biomarkers of subclinical inflammation, and widely used as an independent predictor of cardiovascular risk. Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) were introduced as potential markers for evaluation of inflammation in several diseases. However, there are a few studies in CKD patients. We aimed to evaluate the relationship of NLR and PLR with hs-CRP levels in Syrian patients with CKD. The study included 100 CKD patients in stages 3 to 5 seen at Tishreen University Hospital, and 22 subjects served as control. CKD patients were divided into two groups, according to the presence or absence of inflammation, based on the high-sensitivity C-reactive protein (hs-CRP) cut off value of 3 mg/l. Blood samples were collected for blood count and hs-CRP levels determination. hs-CRP concentration was measured by immunoturbidimetry assay kit. NLR and PLR were calculated based on the absolute number of neutrophils, lymphocytes and platelets. We used the SPSS 25.0 program for the statistical analysis. Probability (P) value<0.05 was considered statistically significant. NLR as well as PLR and hs-CRP levels were significantly higher in all CKD groups compared to control subjects (p<0.05, for all). NLR and PLR values were significantly different between CKD groups with and without inflammation (for both, p<0.001). Both NLR and PLR were positively correlated with hs-CRP (r=0.50, p<0.001 for NLR; r=0.43, p<0.001 for PLR) in CKD patients. The best cutoff point for NLR to detect inflammation was ≥3.06, with 70% sensitivity and 81.1% specificity. For PLR, the cut off was ≥144.78, with 59% sensitivity and 73% specificity. There was no significant difference between the area under the NLR and PLR curve (0.77 vs. 0.70, p=0.19) for this population. Our findings suggests that NLR and PLR are available, simple and less expensive methods that could be used as markers of inflammation in CKD patients instead of hs-CRP.