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

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 × 10 6 /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. Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information