Comparison of the Cytodiff flow cytometric leucocyte differential count system with the Sysmex XE-2100 and Beckman Coulter UniCel DxH 800.

INTRODUCTION

Routine automated haematology analysers categorize leucocytes into five types. The Cytodiff (Beckman Coulter) is a 16-part leucocyte differential analysis system that uses six markers and five colours. We compared leucocyte differential counts obtained by the Cytodiff with five-part differential counts obtained by routine automated haematology analysers.

METHODS

We collected 477 EDTA blood samples from healthy individuals and patients with malignancies, sepsis and multi-organ failure. Leucocyte differential counts were simultaneously analysed by a Cytodiff multiparametric flow cytometric system and the XE-2100 (Sysmex) and UniCel DxH 800 (Beckman Coulter) automated haematology analysers. Regression and correlation analyses were performed between the different systems.

RESULTS

Our Cytodiff results were well correlated with those produced using the DxH 800 and XE-2100 analysers except for monocytes and basophils. The correlations were poorer for leukopenic than for nonleukopenic samples. For most samples, Cytodiff obtained a higher correlation with manual counts according to a case analysis; however, in several samples, the Cytodiff generated false decreases in monocyte levels and false increases in basophil levels.

CONCLUSION

The Cytodiff may have an advantage, as it could sensitively detect blasts and immature granulocytes. Additionally, it was less labour-intensive than manual counting, and therefore, the Cytodiff might be useful for differential counts.