Evaluation of immature granulocyte determination and establishment of its reference range

Objective To investigate the immature granulocyte(IG) count determination by the automated hematology analyzer in clinical application and establish a normal reference range of IG of our laboratory by Sysmex XE-2100 automated hematology analyzer.Methods A clinical sample was determined successively for 20 times to ensure the intra-batch precision;2 quality controls were determined successively for 20 days to ensure the inter-batch precision.The IG counts of 101 specimens were determined by the Sysmex XE-2100 hematology analyzer and flow cytometry respectively,and the results were compared to evaluate the correlation.883 whole blood specimens were determined and classified by the Sysmex XE-2100 hematology analyzer and manual microscopy respectively,and the results were compared to evaluate the consistency.766 healthy subjects were determined by the Sysmex XE-2100 automated hematology analyzer for determining the IG count and establishing the reference range.Results The intra-batch coefficients of variation(CV) of absolute IG counts of high,medium and low precision values were 4.78%,5.35% and 13.06% respectively.The intra-batch CVs of IG% were 3.82%,6.03% and 14.54% respectively.The inter-batch CVs of absolute IG counts of high and low values were 4.38% and 5.13% respectively.The inter-batch CVs of IG% were 4.3% and 5.1% respectively.All of them were within the tolerance limit(15%).The correlation coefficient(r) between Sysmex XE-2100 hematology analyzer and flow cytometry was 0.916,and that between Sysmex XE-2100 hematology analyzer and manual microscopy was 0.890 3.There was no significant difference between different ages(P0.05),but not between male and female(P0.05).IG reference ranges were established regardless of age.The absolute IG count reference range for male was(0,0.04×109/L),and for female it was(0,0.02×109/L).The IG% reference range for male was(0,0.5%),and for female it was(0,0.4%).Conclusions Hematology analyzer can be used for IG count and provide data for diagnosis and therapy monitoring.Every clinical laboratory should establish its own reference range of IG count.