Flagging performance of the Sysmex XN 2000 haematology analyser

A complete blood cell count that includes a differential count of white blood cells (WBCs) is an important test to detect hematology abnormalities and to monitor patients' disease status. Most hematology analyzers identify samples with suspect abnormal cells and report the results by pathology flags. The diagnostic ability of a flag is a function of the underlying technology, and the computerized algorithms designed to evaluate the data. Concerning the presence of blasts, the Sysmex XE and XN analyzers report the flag "Blasts?" and "Blasts/ Abn.Lympho?", respectively. On the XE analyzers, the flag "Blasts?" is derived by a cluster analysis of scatterplots from the differential (DIFF) and the immature myeloid information (IMI) channel. On the XN, the flag "Blasts/Abn Lympho?" is triggered based on information from the white blood cell differential channel (WDF channel). The flag "Blasts?" indicates the possible presence of myeloblasts, and the flag "Blasts/Abn Lympho?" indicates the possible presence of blasts not specified by lineage and/or abnormal lymphocytes. 1,2 Despite the continuous improvement of the hematology analyzers, the flags are subject to ambiguities that require further examination. Several Abstract Introduction: The aim of the present study was to evaluate the diagnostic ability of blast flags generated by Sysmex instruments (XE/XN) by comparing with immunophenotyping by flow cytometry (IFCM). Additionally, the ability of manual microscopy and CellaVision DM96 (pre-and reclassification) to predict the presence of "true" blasts was investigated. Methods: Blood samples (n = 240) with suspect pathology flags reported by the XE were collected from the daily workload and examined by the XN, by manual microscopy, by CellaVision DM96 and by IFCM (CytoDiff Panel). Results: The ROC analysis for blasts showed an area under the curve of 0.64 ("Blasts?") (XE), 0.57 ("Blasts/Abn Lympho?") (XN), 0.75 (CellaVision preclassification procedure), 0.78 (CellaVision reclassification procedure), and 0.81 (manual microscopy). The sensitivity of blast detection varied between the methods from 0.41 (XE) to 0.90 (XN), and the specificity varied from 0.17 (XN) to 0.95 (CellaVision reclassification). Conclusions:The CellaVision reclassification procedure has a diagnostic ability for predicting blasts close to that of manual microscopy. The blood smear methods show a notable number of false negative results. The Sysmex XN reported a higher rate of true positive blast flags than the XE. Taken together, the CytoDiff method could be a useful alternative to smear examination to correctly identify blasts. K E Y W O R D S blast flag, CellaVision, CytoDiff, flow cytometry, Sysmex hematology instruments | 339 EILERTSEN ET aL.

Section: Introductionmentioning

confidence: 99%

Evaluation of the detection of blasts by Sysmex hematology instruments, CellaVision DM96, and manual microscopy using flow cytometry as the confirmatory method

Eilertsen

Saether

Henriksson

et al. 2019

“…However, an accurate analytical performance of the automated systems and also flagging abilities to identify the abnormal cells should be evaluated routinely. In recent years, studies have demonstrated a good correlation between automated leukocyte differentials and manual microscopy, and high accuracy, good precision, and linearity and also accurate flagging for abnormal cells were reported with different analyzers …”

Section: Introductionmentioning

confidence: 99%

Comparison of performance and abnormal cell flagging of two automated hematology analyzers: Sysmex XN 3000 and Beckman Coulter DxH 800

Genç

Dervisoglu

Erdem

et al. 2017

“…In the XN series, detection of WBC abnormalities is based on a complex flagging algorithm guided by the information processing unit (IPU) software of the analyzer. The instrument can detect particular cell populations with an abnormal size, shape or position in the scattergrams 1,5,7,8,11,12 . Based on these findings, a Q ‐value is calculated.…”

Section: Methodsmentioning

confidence: 99%

“…In our laboratory, this XN series is composed of two XN‐10 and one XN‐20 modules, directly connected to a SP‐50–automated slidemaker‐stainer module and a DI‐60 digital cell imaging analyzer. Each XN module is equipped with a White Differentiation (WDF) channel, used for leukocyte differentiation and flagging for among which blast/abnormal lymphocytes, and the XN‐20 offers an additional White Progenitor Cell (WPC) channel that can differentiate between blasts and abnormal lymphocytes or can remove a false‐positive WDF flag in order to decrease manual microscopic review rate 1‐3 …”

Section: Introductionmentioning

confidence: 99%

“…Malignant lymphocytes and blasts both exhibit increased fluorescence compared with normal lymphocytes and can therefore hardly be distinguished by the WDF channel, resulting in the WBC "Suspect" flag "Blasts/Abnormal lymphocytes?" 1 . Reactive lymphocytes also show an increased RNA content and can therefore not always be differentiated from malignant lymphocytes, leading to the combined "Blasts/Abnormal lymphocytes?"…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The integration of Sysmex XN‐9100’ WPC channel reflex testing in the detection of reactive versus malignant blood samples

Blomme

Boeckx

Brusselmans

et al. 2020

Introduction Sysmex XN‐9100™ (Sysmex, Kobe, Japan) system has an optional White Progenitor Cell (WPC) channel. While the White Differentiation (WDF) channel reports a combined flag for blasts/abnormal lymphocytes, WPC channel specifies flagging into a separate flag for each cell type or removes the flag entirely. Aim of this study was to evaluate the added value of this WPC channel in the detection of malignant samples. Methods Routine blood samples analyzed on Sysmex XE‐5000 with flagging for either blasts, abnormal lymphocytes, or atypical lymphocytes (n = 630) were selected for testing on Sysmex XN‐9100, resulting in a reflex WPC analysis in 420 samples. All samples were microscopically evaluated with DI‐60 digital cell imaging analyzer. Results WPC reflex testing resulted in a suspect flag ("blasts" and/or "abnormal lymphocytes") in 334 samples, which was confirmed microscopically in 38% (128/334). In all true positive samples, WPC correctly classified the initial WDF flag in either "blasts" flag or "abnormal lymphocytes?" flag in 75%. Only 12% (50/420) of WDF "blasts/abnormal lymphocytes" positive samples became negative after WPC reflex testing. Subgroup analysis showed differences between the "pediatric" versus "adult" groups and the "hematological/chemotherapy" versus "nonhematological/nonchemotherapy" groups in specificity and smear reduction. Conclusion Overall, WPC reflex testing showed good sensitivity (99%); however, the specificity remains poor (29%). Using reflex WPC to the WDF channel resulted in a 12% reduction of the smear review rate. Although the WPC channel offers different interesting advantages, additional topics and a specific workflow should be applied to optimize the use of this channel.