Sysmex Journal International
Comparison of Automated Immature Granulocyte ( IG ) Count on Sysmex XE-2100 Analyser with Manual Microscopy
Frankie IP＊１ and Yi NING＊２
*1 Haematology SEALS Randwick
*2 Sysmex Singapore
The enumeration of immature granulocytes ( IG ) is routinely done by morphologists counting 100 cells on a stained blood film by visual microscopy. This is highly labour intensive, time consuming, imprecise and also subject to personal bias. With the introduction of the Sysmex XE-2100 analyser and the XE pro and XE IG Master software packages ( Sysmex Corp., Kobe, Japan ), it is now possible to enumerate immature granulocytes automatically using fluorescence flow cytometry technique.
The present study evaluated the efficiency and accuracy of the automated IG counts
( Sysmex XE-2100 ) against manual visual microscopy ( NCCLS H20-A protocol ). 244 routine samples with automated IG counts > 2.0% were included in the study. Statistical analysis showed good agreement between the two methods. For IG counts without the asterisk flag ( low reliability flag ), the correlation is r=0.81; for IG counts with the asterisk flag, the correlation is r=0.67. Overall ( combining the two groups with and without the asterisk flags ), the correlation is r=0.72.
In our study, we have shown that the extended differential counts including the IG counts from the Sysmex XE-2100 can significantly reduce the number of manual differentials performed in a haematology laboratory. However there is a need for education of the clinicians for the meaning of automated immature granulocyte counts ( combined counts of metamyelocytes, myelocytes and promyelocytes ) before automated IG counts can become acceptable and reportable in routine doctors' reports. In addition, reference intervals for IG counts should be established.
Automated Immature Granulocyte Counts, IG Counts, Sysmex XE-2100, Manual Differential Count, Extended Differential Count