Comparison of the Cytodiff flow cytometric leucocyte differential count system with the Sysmex XE-2100 and Beckman Coulter UniCel DxH 800 BORAE G. PARK, CHAN-JEOUNG PARK, SUE KIM, CHAN-HEE YOON, DUCK-HEE KIM, SEONGSOO JANG, HYUN-SOOK CHI Department of Laboratory Medicine, University of Ulsan and Asan Medical Center, Seoul, Korea Correspondence: Chan-Jeoung Park, Department of Laboratory Medicine, University of Ulsan and Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea. Tel.: +82 2 3010 4508 Fax: +82 2 478 0884 E-mail: cjpark@amc.seoul.kr doi:10.1111/j.1751-553X.2012.01439.x Received 26 October 2011; accepted for publication 2 May 2012 Keywords Cytodiff, leucocyte differential count, XE-2100, DxH 800 SUMMARY 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 rou- tine automated haematology analysers. Methods: We collected 477 EDTA blood samples from healthy indi- viduals and patients with malignancies, sepsis and multi-organ fail- ure. 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 pro- duced using the DxH 800 and XE-2100 analysers except for mono- cytes 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 sensi- tively detect blasts and immature granulocytes. Additionally, it was less labour-intensive than manual counting, and therefore, the Cytodiff might be useful for differential counts. INTRODUCTION Automated haematology analysers are useful for making leucocyte differential counts, but they can categorize leucocytes into only five types [1–3]. More- over, most of these analysers are poor at recognizing abnormal leucocytes, making the manual microscopic review of stained blood smears necessary in about © 2012 Blackwell Publishing Ltd, Int J Lab Hematol 1 ORIGINAL ARTICLE INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY International Journal of Laboratory Hematology The Official journal of the International Society for Laboratory Hematology