Prolonged platelet hyperactivity after COVID-19 infection.

Platelet hyperactivity often occurs in patients with coronavirus disease 2019 (COVID-19). However, it remains unclear how long platelet hyperactivity lasts after the acute phase, owing to a lack of follow-up studies. To elucidate the course of platelet hyperactivity, we serially measured platelet activity in patients with COVID-19 up to 40 days after hospital admission using an easily assessable haematology analyser that semi-quantitates platelet clumps on a scattergram. Our results showed that platelet hyperactivity persisted for at least 40 days even after acute inflammation subsided in most patients with COVID-19, regardless of disease severity. Persistent platelet hyperactivity may contribute to thromboembolic complications in post-COVID-19 patients.

Evaluation of new haematology analyser, XN-31, for malaria detection in blood donors: A single-centre study from India.

BACKGROUND AND OBJECTIVES: Malaria continues to be a significant public health concern in India, with several regions experiencing endemicity and sporadic outbreaks. The prevalence of malaria in blood donors, in India, varies between 0.02% and 0.07%. Common techniques to screen for malaria, in blood donors and patients, include microscopic smear examination and rapid diagnostic tests (RDTs) based on antigen detection. The aim of this study was to evaluate a new fully automated analyser, XN-31, for malaria detection, as compared with current practice of using RDT. MATERIALS AND METHODS: Cross-sectional analytical study was conducted to evaluate clinical sensitivity and specificity of new automated analyser XN-31 among blood donors' samples and clinical samples (patients with suspicion of malaria) from outpatient clinic collected over between July 2021 and October 2022. No additional sample was drawn from blood donor or patient. All blood donors and patients' samples were processed by malaria rapid diagnostic test, thick-smear microscopy (MIC) and the haematology analyser XN-31. Any donor blood unit incriminated for malaria was discarded. Laboratory diagnosis using MIC was considered the 'gold standard' in the present study. Clinical sensitivity and specificity of XN-31 were compared with the gold standard. RESULTS: Fife thousand and five donor samples and 82 diagnostic samples were evaluated. While the clinical sensitivity and specificity for donor samples were 100%, they were 72.7% and 100% for diagnostic samples. CONCLUSION: Automated haematology analysers represent a promising solution, as they can deliver speedy and sensitive donor malaria screening assessments. This method also has the potential to be used for pre-transfusion malaria screening along with haemoglobin estimation.

Evaluation of the Sysmex XQ-320 three-part differential haematology analyser and its flagging capabilities.

BACKGROUND: Three-part differential (3PD) haematology analysers offer a quick, easy-to-use and economical way to acquire important information about a patient's physiology. In this study, we evaluated a new 3PD analyser, the Sysmex XQ-320, investigated its comparability with its predecessor (Sysmex XP-300) and the five-part differential analyser Sysmex XN-9000, and explored its flagging potential. METHODS: Analytical performance studies were conducted for repeatability, within-laboratory precision, between-day precision, carry-over and linearity with fresh blood and QC material. Method comparison was performed in 493 samples comparing XQ-320 with XP-300, using the XN-9000 as the gold standard. RESULTS: The XQ-320 excelled manufacturer's specifications in the analytical performance studies, except for MXD in within-laboratory and between-day precisions using the QC material level 1. The XQ-320 showed correlation values greater than 0.94 with XN-9000 for the majority of the 20 reportable parameters (MXD# 0.891, MXD% 0.898 and MCHC 0.849). Improvements over the XP-300 were observed in WBC in the leucocytopenic range (bias -0.038 vs. -0.097) and PLT (bias 2.568 vs. -7.877, intercept 3.880 vs. -8.845). Concordance between XQ-320 and XP-300 was 91.9% for the WBC histogram abnormal distribution flag and 95.3% for the PLT flag. Patterns of increased neutrophils and decreased mixed cells on the XQ-320 were observed in samples that raised a flag on XN-9000. CONCLUSION: The XQ-320 showed excellent analytical performance, and very good to excellent correlation with XN-9000 with improvements over XP-300. Flagging combined with parameter patterns identified additional suspected abnormal samples, thus making the XQ-320 an excellent solution for laboratories utilising 3PD analysers.

The flagging features of the Sysmex XN-10 analyser for detecting platelet clumps and the impacts of platelet clumps on complete blood count parameters.

OBJECTIVES: Platelet clumps present in anticoagulant specimens may generate a falsely decreased platelet count and lead to an incorrect diagnosis. A clear understanding of the ability of a haematology analyser (HA) to detect platelet clumps is important for routine work in the clinical laboratory. METHODS: Citrate-anticoagulated whole-blood samples were collected from various patients as a negative group. Adenosine diphosphate (ADP)-induced platelet aggregation was performed on those negative samples to mimic platelet-clump-containing (positive) samples. The 'platelet clumps' and 'platelet abnormal' flags generated by the Sysmex XN-10 instrument were used to assess the flagging performance of this HA and demonstrate its flagging features. The complete blood count (CBC) results of paired negative and positive samples were compared to evaluate the impact of platelet clumps on the CBC parameters. RESULTS: A total of 187 samples were eligible for this study. The total accuracy, sensitivity, and specificity of the platelet clumps flag were 0.786, 0.626, and 0.947, respectively. The total accuracy, sensitivity, and specificity of the platelet abnormal flag were 0.631, 0.348, and 0.914, respectively. A separate assessment focusing on the positive samples with low platelet counts showed that the total sensitivities of the platelet clumps and platelet abnormal flags were 0.801 and 1.000, respectively. Platelet clumps may interfere with the leukocyte count and with platelet and erythrocyte indices. CONCLUSIONS: Platelet clumps can influence not only platelet indices but also leukocyte and erythrocyte counts. The Sysmex XN-10 instrument is sensitive to positive samples with low platelet counts but insensitive to those with high platelet counts.

Residual red cells in blood components: A multisite study of fully automated enumeration using a hematology analyzer.

BACKGROUND: Manufacture of platelet concentrates (PCs) and plasma may fail to remove all residual red blood cells (rRBCs). Measuring rRBCs for compliance to guidelines has proven challenging, leading to an absence of a consensus methodology. Sysmex hematology analyzers with the Blood Bank mode (BB mode) analysis option offer the potential for automated rRBC counting. We therefore performed a two-site appraisal of the system. STUDY DESIGN AND METHODS: Performance characteristics were determined using platelet and plasma samples spiked with RBCs. Sample stability (n = 47) and the impact of sample type were also assessed. Components (platelets, n = 1474; plasma, n = 77) prepared using different routine manufacturing methods were tested to assess variation in rRBC concentration. RESULTS: Linearity studies up to 19 000 RBCs/µL demonstrated good correlation between expected and observed results (R2 ≥ 0.9731), and flow cytometric results also correlated well with BB mode (R2 = 0.9400). Precision analysis gave a limit of quantitation of 6 to 7 RBCs/µL, and carryover was 0.03%. Ethylenediaminetetraacetic acid and plain tube results were not significantly different (P ≥ 0.10), and samples were stable up to 24 hours. Apheresis PCs produced at two sites had lower rRBC concentrations (medians, 17 and 13 RBCs/µL) than those produced with the buffy coat method either manually (median, 681 RBCs/µL) or with the automated Terumo Automated Centrifuge and Separator Integration process (median, 81 RBCs/µL). All PCs failing visual inspection as having RBCs ≥4000 RBCs/µL were also detected by the BB mode. CONCLUSION: The BB mode had acceptable performance characteristics and has the potential for integration into a fully automated process control system for rRBC enumeration in plasma and PCs.

A Comparative Evaluation of Performance of Sysmex XN 3000 and Horiba Yumizen H2500 Automated Complete Blood Count Analysers.

Modern automated laboratory haematology analysers use various methods to measure different haematological parameters. These parameters are useful in the diagnostic and clinical interpretation of patient symptoms. So, it is very important to compare the performance of different analysers measuring the same parameter. Hence, a comparison of complete blood counts analysed by Sysmex XN 3000 and Horiba Yumizen H2500 was performed. Total 296 EDTA anti-coagulated blood samples were processed in both the analysers in duplicate within 4 h of collection. The white blood cell count, red blood cell count, erythrocyte indices, differential leukocyte count, platelet count and platelet indices and reticulocyte count were compared. A good level of correlation and agreement between different parameters were obtained. A strong correlation was observed (r > 0.9) between Sysmex XN 3000 and Yumizen H2500 for WBC (0.997), RBC (0.997), Haemoglobin (0.999), haematocrit (0.974), MCV (0.902), MCH (0.99),, platelet count by impedance (0.989), mean platelet volume (0.954), plateletcrit (0.971), platelet distribution width (PDW) (0.916), neutrophils (0.997), lymphocytes (0.989), monocytes (0.943), and eosinophils (0.991) counts. A moderate correlation was observed for RDW-CV (0.75). The basophils count showed poor correlation (r < 0.5) possibly because of sample selection with mostly low basophils count. An acceptable bias was observed for most of the parameters like WBC, RBC, Haemoglobin, Haematocrit, platelet counts, neutrophils, lymphocytes, eosinophils and monocytes. The studied instruments ensured satisfactory interchangeability except for few parameters, thus facilitate substitution of one analyser by another without affecting the clinical decision making.

Verification of a 6-part differential haematology analyser Siemens Advia 2120i.

Introduction: The aim of this study was to perform a comprehensive verification of a 6-part differential haematology analyser Siemens Advia 2120i (Erlangen, Germany), prior to its routine implementation. Materials and methods: Our verification protocol included: precision (within- and between-run), estimated bias (%) as measure of trueness, which was calculated from observed and manufacturers' declared value, analytical measuring interval (AMI), carryover, confirmation of a limit of blank (LoB), determination of a limit of detection (LoD) and limit of quantitation (LoQ). The K2 ethylenediaminetetraacetic acid (EDTA) patients' leftover samples were used for verification of analyser Advia 2021i. Acceptance criteria were based on manufacturer technical specifications (Siemens), 2016 state-of-the-art criteria (Vis and Huisman), and EFLM Biological Variation Database. Results: The within- and between-run precision were acceptable for all parameters and the lowest coefficients of variation were observed for mean corpuscular volume (MCV) (0.3% and 0.6%, respectively). Estimated bias was within the acceptance criteria for all parameters except for MCV (the estimated bias was 2.2% (acceptance criteria 2.0%). AMI was confirmed for all tested parameters (r > 0.99). The carryover estimates ranged from 0.1% for platelet count (Plt) to 0.6% for red blood cell count and were within the manufacturers' specifications (≤ 1%). Manufacturers' claims for LoB were confirmed for leukocytes, erythrocytes, haemoglobin, and platelets. The estimated LoD and LoQ were 0.05 x109/L and 0.1 x109/L for white blood cell count, while for Plt values were 2 x109/L and 3 x109/L, respectively. Conclusions: Analytical performance of the Siemens Advia 2120i meets predefined quality goals and is suitable for routine use in a clinical laboratory.

Technological features of blast identification in the cerebrospinal fluid: A systematic review of flow cytometry and laboratory haematology methods.

BACKGROUND: Involvement of the central nervous system (CNS) by acute leukemias (ALs) has important implications for risk stratification and disease outcome. The clinical laboratory plays an essential role in assessment of cerebrospinal fluid (CSF) specimens from patients with ALs at initial diagnosis, at the end of treatment, and when CNS involvement is clinically suspected. The two challenges for the laboratory are 1) to accurately provide a cell count of the CSF and 2) to successfully distinguish blasts from other cell types. These tasks are classically performed using manual techniques, which suffer from suboptimal turnaround time, imprecision, and inconsistent inter-operator performance. Technological innovations in flow cytometry and hematology analyzer technology have provided useful complements and/or alternatives to conventional manual techniques. AIMS: We performed a PRISMA-compliant systematic review to address the medical literature regarding the development and current state of the art of CSF blast identification using flow cytometry and laboratory hematology technologies. MATERIALS AND METHODS: We searched the peer reviewed medical literature using MEDLINE (PubMed interface), Web of Science, and Embase using the keywords "CSF or cerebrospinal" AND "blasts(s)". RESULTS: 108 articles were suitable for inclusion in our systematic review. These articles covered 1) clinical rationale for CSF blast identification; 2) morphology-based CSF blast identification; 3) the role of flow cytometry; 4) use of hematology analyzers for CSF blast identification; and 5) quality issues. 9 /L, which is much lower than the original machine count and platelet transfusion was warranted. DISCUSSION: 1) Clinical laboratory testing plays a central role in risk stratification and clinical management of patients with acute leukemias, most clearly in pediatric ALs; 2) studies focused on other patient populations, including adults and patients with AML are less prevalent in the literature; 3) improvements in instrumentation may provide better performance for the classification of CSF specimens. CONCLUSION: Current challenges include: 1) more precisely characterizing the natural history of AL involvement of the CNS, 2) improvements in automated cell count technology of low cellularity specimens, 3) defining the role of flow MRD testing of CSF specimens and 4) improved recognition of specimen quality by clinicians and laboratory personnel.

Usefulness of the lymphocyte positional parameters in the Sysmex XN haematology analyser in lymphoproliferative disorders and mononucleosis syndrome.

INTRODUCTION: The lymphocyte positional parameters included in Sysmex XN have been suggested as useful means to differentiate lymphoproliferative disorders (LPD), mononucleosis syndrome (MNS) and other lymphocytoses. METHODS: We evaluated Sysmex XN analysers, which supply 6 lymphocyte positional parameters that can be measured in the WDF scattergram: LY-X, LY-Y, LY-Z, LY-WX, LY-WY and LY-WZ. RESULTS: We collected 301 samples from normal controls, polyclonal lymphocytosis, MNS and LPD. MNS and monoclonal expansion of T granular lymphocyte (T-GL) diagnostic groups accumulated higher numbers of significant differences in the mean values in comparison with the other groups. We propose a new algorithm that can differentiate T-GL cases from other diagnostic groups with an SE of 67.5%, an SP of 98.2%, a PPV of 87.1% and an NPV of 94.3%. Another algorithm showed its efficiency to differentiate MNS cases from other diagnostic groups with an SE of 63.6%, an SP of 97.5%, a PPV of 70.0% and an NPV of 96.7%. In 38.5% of all cases, the analyser did not generate any morphologic flag. Abnormal results in lymphocyte positional parameters were useful to detect 72.5% of these samples. CONCLUSION: The lymphocyte positional parameters provided by Sysmex XN analysers are useful to differentiate expansions of T-GLs from other LPD and to differentiate MNS cases from other diagnostic groups. In addition, these parameters are very useful for detecting changes in the lymphocytes that make it necessary to review blood smears in samples without morphological flagging.

From XE-2100 to XN-9000, from SIS Standard to GFHC recommendations for slide review: potential impact on review rate and turnaround time.

In 2014, we moved from XE-2100 with Standard SIS rules to XN-9000 with GFHC recommendations for slide review. The aim of our study was to evaluate the potential impact of the new Sysmex® automation with implementation of GFHC rules on our review rate, turnaround time (TAT), workload and on CD34+ stem cells enumeration. We conducted a retrospective observational study from September 2013 through August 2014, in CHU Dinant Godinne UCL Namur. With the GFHC recommendations and the new Sysmex® automation, we significantly reduced our review rate by nearly 30% considering all units (35.8% vs 25.9%), and up to 73% when excluding oncology haematology department (17.5% vs 4.7%). We also noticed significantly shorter TAT for CBC measurement (median for routine samples: 76.4 vs 56.8 minutes, p < 0.0001; urgent samples: 18.9 vs 15.2 minutes, p = 0.023), slide review (median: 54.9 vs 36.4 minutes, p < 0.0001) and CD34+ enumeration performed on peripheral blood samples (p < 0.001) and on apheresis samples (p = 0.026). In conclusion, GFHC recommendations implemented on the new Sysmex® XN-9000 resulted in a significant reduction in review rate and in TAT. This is particularly of interest for the clinicians with subsequent potential faster patient management.

Clinical Utility of Blood Cell Histogram Interpretation.

An automated haematology analyser provides blood cell histograms by plotting the sizes of different blood cells on X-axis and their relative number on Y-axis. Histogram interpretation needs careful analysis of Red Blood Cell (RBC), White Blood Cell (WBC) and platelet distribution curves. Histogram analysis is often a neglected part of the automated haemogram which if interpreted well, has significant potential to provide diagnostically relevant information even before higher level investigations are ordered.

Comparative Diagnostic Performance of the Granulocyte and Neutrophil Counts.

OBJECTIVES: Use of point-of-care testing is increasing, however many haematology analysers can only determine granulocyte count without further differentiation into neutrophils, eosinophils and basophils. Since the diagnosis of life-threatening neutropenia in cancer patients requires a distinct neutrophil count, this study aimed to determine the comparative performance between the neutrophil and granulocyte count. DESIGN AND METHODS: A database of 508 646 venous full blood count results measured on a laboratory reference analyser was mined from a large oncology unit. The relationship between granulocyte and neutrophil counts was assessed. Multinomial logistic regression was used to classify results into neutropenia grades using an equivalent granulocyte count. RESULTS: Granulocyte to neutrophil count correlation was 0.997. The accuracy for classification into neutropenia grades using the derived equivalent granulocyte count ranges was 96.4%. Identification of results with a neutrophil count <1.5×109 cells/L using an equivalent granulocyte count of <1.69×109 cells/L resulted in sensitivity, specificity, positive and negative predictive values of 98.0%, 99.5%, 97.8% and 99.5%, respectively. CONCLUSIONS: These results describe the relationship between granulocyte and neutrophil counts, measured on a laboratory analyser, in a large population of patients with malignancies and receiving anti-cancer therapies. However, this relationship must be established using a point of care testing system with a three-part differential count before considering the possibility that a granulocyte count can guide clinical decisions in the absence of a definitive neutrophil count, to reduce the frequency and severity of neutropenic complications in patients receiving cancer treatments.

Flagging performance of the Sysmex XN2000 haematology analyser.

INTRODUCTION: With the introduction of the Sysmex XN haematology analyser, the white blood cell differentiation channel (WDF) and abnormal cell detection channel (WPC) have been added with algorithms for flagging blasts and abnormal or atypical lymphocytes. METHODS: In this study, 2011 samples were evaluated on a Sysmex XN2000 analyser and microscopically reviewed using a CellaVision DM96 digital microscope. RESULTS: A reference group of apparently healthy blood donors (n = 262) demonstrated in only three samples a positive suspect flag, which could not be confirmed microscopically. Positive WBC suspect flags were demonstrated in 3% of the 2011 samples. From the 55 samples with positive WBC suspect flags, an automatic reflex test was performed within the WPC. The WPC reflex test resulted in 10× Blast?, 15× Abnormal lymph? and 15× Atypical lymph? flags, which could be confirmed microscopically in 33% of these cases. A negative flagging was demonstrated in 15 cases. Microscopic evaluation demonstrated no abnormalities in these 15 cases. However, laboratory technicians also reported the presence of abnormal lymphocytes in 158 samples without an Abnormal lymph? flag. CONCLUSION: In conclusion, the combined use of WDF and WPC resulted in a reduction of approximately 25% of the number blood smears. As a result of the various techniques for light microscopy and haemocytometry, the adequacy of the XN flagging for abnormal and atypical lymphocytes cannot be established with certainty. To improve the quality of the reported results, it is recommended that laboratory technicians incorporate the haemocytometry results and the flagging information in the microscopic slide review.

Diagnostic efficiency of the Sysmex XN WPC channel for the reduction of blood smears.

BACKGROUND: Several small studies showed that the WPC (white precursor cell) channel in the Sysmex haematology analyser for leukocyte differentiation analysis leads to a significant reduction of microscopic blood smears. We determined the added value of the WPC channel for blood smear reduction in a large teaching hospital and whether this reduction was cost-effective and save. METHODS: Retrospectively, for 7850 leukocyte differentiation orders the percentage of samples resulting in a WPC analysis and the outcomes of the WPC analysis were analysed and compared with the blood smear results. RESULTS: WPC analysis resulted in a 12% reduction of blood smears, which is much lower than observed in other studies. This means 3-4bloodsmears/day less of a total of 28smears/day at the expense of missing 14 patient samples with pathology (blasts or abnormal lymphocytes) in a 9weeks period. The estimated total costs of WPC analysis per year was more than the reduction in costs due to less blood smear reviews. CONCLUSIONS: In a large teaching hospital, the small reduction in blood smears by the WPC channel does not outweigh the costs and the slight reduction in sensitivity for pathology.

Performance evaluation of the automated nucleated red blood cell enumeration on Sysmex XN analyser.

INTRODUCTION: Presence of peripheral blood nucleated red blood cell (NRBC) is associated with pathological conditions and leads to the overestimation of white blood cell count in automated haematology analysers (HA). The authors evaluated NRBC enumeration by a new HA Sysmex XN (XN) to demonstrate the precision and comparability to manual count (MC) at the various NRBC values. METHODS: Specimens with initially NRBC positive were included. For precision assessment, 8 levels of NRBCs were repeatedly analysed. For comparison study, 234 specimens were analysed by both XN and MC. RESULTS: For precision study, the percentage of coefficient of variation ranged from 14% to 45.6% and 1.2% to 4.4% for MC and XN, respectively. For comparison study between XN and MC, NRBCs ranged from 0% to 612.5%. Regression analysis demonstrated an r(2) of 0.98. The mean bias of 14.1% with 95% limits of agreement between -48.76% and 76.95% was found. The NRBC counts from XN appeared to be more in accordance with MC when the NRBCs were lower than 200% with the concordance rate of 94.2%. CONCLUSION: The automated NRBC enumeration by XN was precise and could replace the traditional MC, especially for the specimens with NRBCs lower than 200%.

Determining the stability of complete blood count parameters in stored blood samples using the SYSMEX XE-5000 automated haematology analyser.

INTRODUCTION: In this study, changes that occur in various blood parameters as determined by the Sysmex XE-5000 analyser upon storage of blood samples for 72 h were investigated. METHODS: Blood specimens (200) were processed through the SYSMEX XE-5000 haematology analyser within 4 h of collection. Each specimen was distributed into two aliquots and one stored at 4 °C and the other at room temperature (25 ± 1 °C). Both stored aliquots were retested after 24, 48 and 72 h. The mean, mean per cent change and mean absolute difference between the value at 4 h and each time point for all parameters were calculated. RESULTS: Among CBC parameters tested, the white cell count, red cell count and haemoglobin levels were found to be stable for up to 72 h. The mean cell volume and haematocrit changed significantly following 24-h storage at room temperature. Reticulocytes were stable for 72 h under both storage conditions. Among the differential parameters, results of the monocyte count displayed significant change after 24-h storage at room temperature. CONCLUSION: The data presented suggest that clinically reliable results for some CBC parameters can be obtained from specimens that are stored at 4 °C for up to 72 h.

ICSH guidelines for the evaluation of blood cell analysers including those used for differential leucocyte and reticulocyte counting.

This revision is intended to update the 1994 ICSH guidelines. It is based on those guidelines but is updated to include new methods, such as digital image analysis for blood cells, a flow cytometric method intended to replace the reference manual 400 cell differential, and numerous new cell indices not identified morphologically are introduced. Haematology analysers are becoming increasingly complex and with technological advancements in instrumentation with more and more quantitative parameters are being reported in the complete blood count. It is imperative therefore that before an instrument is used for testing patient samples, it must undergo an evaluation by an organization or laboratory independent of the manufacturer. The evaluation should demonstrate the performance, advantages and limitations of instruments and methods. These evaluations may be performed by an accredited haematology laboratory where the results are published in a peer-reviewed journal and compared with the validations performed by the manufacturer. A less extensive validation/transference of the equipment or method should be performed by the local laboratory on instruments prior to reporting of results.