Sysmex Journal International
2002Vol.12 No.2
OriginalEvaluation of the Automated Immature Granulocyte Count ( IG ) on Sysmex XE-2100 Automated Haematology Analyser vs. Visual Microscopy ( NCCLS H20-A )
AUTHOR(S)
Th WEILAND＊１, H KALKMAN＊２, and H HEIHN＊１
*1 Central Laboratory, c/o Barmbek General Hospital
Institute for Laboratory Medicine, Medical Microbiology and Hospital Hygiene
*2 Sysmex Europe GmbH
SUMMARY
The presence of immature granulocytes ( IG ) in peripheral blood is potentially important information indicating enhanced bone marrow activation. The quantification of immature granulocytes is routinely done by visual microscopy, which is a labour intensive and time consuming task. New software releases "XE Pro" and "IG Master" for the Sysmex XE-2100 automated haematology analyzer allow simple, fast and inexpensive quantification of promyelocytes, myelocytes and metamyelocytes summarized in the " IG count ", as claimed by the manufacturer.
The present study evaluated the agreement of the XE-2100 IG count with visual microscopy ( NCCLS H20-A ) in 246 routine blood samples containing more than 0.1 x103 /uL IG as reported by the automated analyser. Passing-Bablock regression and correlation analysis showed very good agreement ( r=0.900 ) between the two methods. A subset of pre-term and neonatal samples showed similarly good results ( r=0.884 ). The IG count performed noticeably better in this study than with the previous XE-2100 software packages as reported in the literature. Band forms are not included in the IG count, though the absolute values of the automated counts tend to be slightly higher than those obtained by microscopy.
There is need for clinical studies on the performance of the automated IG count in routine patient care and generally accepted reference ranges in normal and diseased subjects have yet to be established.
KEY WORDS
Hematology, Automated Hematology Analyzer, XE-2100, Differential Leucocyte Count, Immature Granulocytes, Method Comparison, NCCLS H20-A