Evaluation of immature granulocyte percentage and count in pediatric nephrotic syndrome.

Objective: The importance of immature granulocytes (IGs) in most infectious and inflammatory diseases has been highlighted. This study aimed to determine the clinical usability and importance of changes in the peripheral complete blood count profile, including IG percentage (IG%) and IG count (IG#), during the relapse and remission phases in pediatric nephrotic syndrome (NS) patients.

Methods: This retrospective observational study was performed at a tertiary care hospital between February 2020 and August 2022. Demographic characteristics and laboratory parameters were recorded. The IG count and IG% were measured using an automated hematological analyzer.

Results: IG% and IG# were both higher during the relapse phase of NS than during the remission phase (0.29% ± 0.14%, versus 0.23% ± 0.14%, p = 0.037 and 0.027 ± 0.015 × 10³/µL, versus 0.018 ± 0.014 × 10³/µL, p = 0.005, respectively). The neutrophil to lymphocyte ratio (NLR), platelet (PLT), white blood cell (WBC), and neutrophil counts had a strong positive correlation with IG# (r = 0.397, p < 0.001; r = 0.352, p < 0.001; r = 0.622, p < 0.001; r = 0.660, p < 0.001, respectively). The NLR, PLT, WBC, and neutrophil counts had a strong positive correlation with IG% (r = 0.348, p < 0.001; r = 0.187, p = 0.039; r = 0.303, p = 0.001; r = 0.426, p < 0.001, respectively). Receiver operating characteristic curve analysis showed that IG# had the best AUC value of 0.69 (95% CI: 0.58-0.77; p = 0.001) for the relapse phase of NS with a cutoff value of 0.025 × 10³/µL (sensitivity: 81.0%, specificity: 78.1%).

Conclusions: It is probable that a high level of immature granulocyte count has a positive correlation for NS relapse in pediatric patients. The IG % and IG# can be used together as biomarkers of inflammation in pediatric NS relapse.