Immature granulocytes as biomarkers of inflammation in children with predialysis chronic kidney disease

Abstract

Background: Chronic inflammation in patients with predialysis chronic kidney disease (CKD) is quite common. We aimed to investigate the relationship of the percentage of immature granulocytes (IG%) and immature granulocyte count (IGC) with inflammation in children with predialysis CKD.

Methods: The data from children with stage 2-4 CKD and a control group of healthy children were evaluated retrospectively. A highly-sensitive C-reactive protein (hs-CRP) level above 5 mg/dL was considered the presence of inflammation. The IGCs were calculated in the white cell differential channel of the Sysmex XN-9000 using the fluorescent flow cytometry method. The IG% was expressed as percentage of total leucocyte concentration.

Results: The data from 57 patients (30 stage 2 CKD, 15 stage 3 CKD, 12 stage 4 CKD) and 46 controls were analyzed. hs-CRP levels, IG%, IGC, white blood cell (WBC) and neutrophil counts, and neutrophil-to-lymphocyte ratio (NLR) were higher in patients than the control group (p < 0.000, p < 0.000, p < 0.000, p = 0.001, p = 0.002, p < 0.000, respectively). Both IG% and IGC were positively correlated with hs-CRP, WBC and neutrophil counts, and NLR (r = 0.485, p < 0.000; r = 0.379, p = 0.004; r = 0.543, p < 0.000; r = 0.628, p < 0.000 for IG%; r = 0.379, p = 0.004; r = 0.351, p = 0.007; r = 0.525, p < 0.000; r = 0.601, p < 0.000 for IGC, respectively). A ROC analysis of the relationship between IGC, IG%, and inflammation showed IGC and IG% had predictive value for the presence of inflammation (cut-off value: 0.035 × 10⁶/mL, AUC: 0.799 ± 0.061, sensitivity: 74.2%, specifity: 63%, p < 0.001 for IGC; cut-off value: 0.45%, AUC: 0.838 ± 0.056, sensitivity: 70.8%, specifity: 67.3%, p = 0.001 for IG%).

Conclusions: Immature granulocytes may be used as a biomarker of inflammation in children with predialysis CKD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Keywords: Children; Immature granulocytes; Inflammation; Predialysis chronic kidney disease.