Evaluation of automated immature granulocyte percentage by sysmex xn-3000 for predicting immature granulocyte in peripheral blood

Utility of automated immature granulocyte count for predicting myeloid cell series

Abstract

Immature granulocytes including promyelocyte, myelocyte, metamyelocyte and other myeloid series are premature white blood cells that are released from bone morrow during infection and inflammatory conditions. The presence of immature granulocytes in peripheral blood indicates leukopoiesis and may represent the earliest indicator of bone marrow stimulation by infection, inflammation, or any other stimuli. Recent studies have reported immature granulocyte percentage (%IG) by Sysmex hematology XN-3000 for predicting hematological diseases. However, the predictive value of %IG demonstrates immature granulocytes in peripheral blood smear that remains unclear and rarely used in hematological application in Thailand. In this study, we assessed the ability of this marker in guiding myeloid series differentiation. The pilot cohort study 145 samples were collected from clinical specimens of hematology laboratory unit at Saraburi Hospital. Compared with manual microscopic differentiation as a standard method and %IG of the automated hematology analyzer, the data were analyzed cutoff value, sensitivity and specificity using Receiver operating characteristic (ROC) curve. The cutoff valuer of %IG level greater than 3.95% (AUC = 0.971; 95% CI: 0.946 – 0.997) that illustrates the presence of in vivo immature granulocytes with exhibited sensitivity of 95.3% and specificity of 92.3%. Therefore, %IG level has high accuracy and specificity and used as an early marker for predicting immature granulocyte in peripheral blood. Moreover, this study may be helpful in guiding severe hematological diseases and supporting the value of the %IG parameter for further hematological application for immature granulocytes detection combined with daily routine peripheral blood smear.