An Evaluation of the Performance of Automated Blood Analysis System for Detecting Nucleated Red Blood Cells and Immature Granulocyte
Objective To analyze the reliability of SYSMEX XN-9100 automatic blood analysis system(XN-9100)for detecting nucleated red cells(NRBC)and immature granulocytes with manual microscopy as a standard and to further guide the re-examination of blood routine.Methods 1465 cases of NRBC＞0/100 white blood cells(WBC)and/or immature granulocytes＞0 were collected by XN-9100 tests.After smear staining,the number of NRBC and immature granulocytes was counted by artificial microscope.Microscopy was used as the gold standard to evaluate the correlation and consistency of NRBC and immature granulocytes counted by the instrument.Receiver operating characteristic(ROC)curve was plotted to evaluate the diagnostic efficacy of XN-9100 in detecting nucleated red cells and immature granulocytes.Results There was a positive correlation between the number of NRBC and the number of immature granulocytes detected by instrument and microscopy(R2=0.8631 and 0.7251).Blan-Altman analysis showed that the 95％confidence interval of NRBC ratio difference between instrumental method and microscopic method was-0.59±10.75/100 WBC,and 9 cases(0.61％)were outside the confidence interval,showing a good consistency.The 95％confidence interval of the difference between the percentage of immature granulocytes counted by instrument and microscopy was(0.87±4.98)％,and 56 cases(3.82％)were outside the agreement range.The number of NRBC and immature granulocytes counted by manual microscopy was used as the gold standard to draw the ROC curve,and the area under the curve was 0.70 and 0.84,respectively.The sensitivity(98.47％)and specificity(63.87％)of the instrument were the best when the counting result was ≥0.05 NRBC/100WBC,with a false negative 1.53％and false positive 36.13％.The sensitivity(85.87％)and specificity(88.60％)were the best when the ratio of counting immature granulocytes was set at ≥0.10％,with a false negative 14.13％and false positive 11.40％.Conclusion XN-9100 can rapidly detect the number of NRBC and immature granulocytes in peripheral blood,and has a high sensitivity for the detection of nucleated red cells but relatively low specificity,which needs to be further confirmed by microscopic examination before clinical report.The sensitivity and specificity of the detection of immature granulocytes are high,but the false negative is high.It is necessary to combine the scatter plot and alarm information to determine whether re-examination is necessary to prevent potential missed diagnosis.
Nucleated red blood cellImmature granulocyteMicroscope rule
万方数据
维普
