Performance comparison of two automated digital morphology analyzers for leukocyte differential in patients with malignant hematological diseases: Mindray MC-80 and Sysmex DI-60.

BACKGROUND: The MC-80 (Mindray, Shenzhen, China), a newly available artificial intelligence (AI)-based digital morphology analyzer, is the focus of this study. We aim to compare the leukocyte differential performance of the Mindray MC-80 with that of the Sysmex DI-60 and the gold standard, manual microscopy. METHODS: A total of 100 abnormal peripheral blood (PB) smears were compared across the MC-80, DI-60, and manual microscopy. Sensitivity, specificity, predictive value, and efficiency were calculated according to the Clinical and Laboratory Standards Institute (CLSI) EP12-A2 guidelines. Comparisons were made using Bland-Altman analysis and Passing-Bablok regression analysis. Additionally, within-run imprecision was evaluated using five samples, each with varying percentages of mature leukocytes and blasts, in accordance with CLSI EP05-A3 guidelines. RESULTS: The within-run coefficient of variation (%CV) of the MC-80 for most cell classes in the five samples was lower than that of the DI-60. Sensitivities for the MC-80 ranged from 98.2% for nucleated red blood cells (NRBC) to 28.6% for reactive lymphocytes. The DI-60's sensitivities varied between 100% for basophils and reactive lymphocytes, and 11.1% for metamyelocytes. Both analyzers demonstrated high specificity, negative predictive value, and efficiency, with over 90% for most cell classes. However, the DI-60 showed relatively lower specificity for lymphocytes (73.2%) and lower efficiency for blasts and lymphocytes (80.1% and 78.6%, respectively) compared with the MC-80. Bland-Altman analysis indicated that the absolute mean differences (%) ranged from 0.01 to 4.57 in MC-80 versus manual differential and 0.01 to 3.39 in DI-60 versus manual differential. After verification by technicians, both analyzers exhibited a very high correlation (r = 0.90-1.00) with the manual differential results in neutrophils, lymphocytes, and blasts. CONCLUSIONS: The Mindray MC-80 demonstrated good performance for leukocyte differential in PB smears, notably exhibiting higher sensitivity for blasts identification than the DI-60.

Differential white blood cell counts in rabbits: a comparison of the Advia 2120 and a manual method.

We evaluated the performance of the Advia 2120 (Siemens) differential leukocyte count (A-Diff) compared to the manual method (M-Diff) in rabbits. EDTA-anticoagulated blood samples collected for diagnostic purposes were analyzed within 6 h of collection. The M-Diff was performed blindly by 2 observers on blood smears by counting 200 cells. We initially included 117 samples; 25 samples were excluded because of suboptimal gating of leukocytes in the Advia peroxidase cytogram or poor blood smear quality. The correlation between the A-Diff and M-Diff was very high for heterophils (r = 0.924, p < 0.001) and lymphocytes (r = 0.903, p < 0.001), high for basophils (r = 0.823, p < 0.001), moderate for monocytes (r = 0.645, p < 0.001), and low for eosinophils (r = 0.336, p = 0.001). The Passing-Bablok regression analyses revealed a small-to-moderate constant error for lymphocytes and a slight constant error for basophils. Small proportional errors were detected for heterophils, lymphocytes, and eosinophils. The Bland-Altman analyses revealed that the Advia significantly underestimates heterophils and overestimates lymphocytes compared to M-Diff. The biases for the other leukocytes were minimal and likely clinical insignificant; however, our results, particularly for eosinophils, should be interpreted cautiously given the observed low percentages in our samples. Given the observed biases in heterophil and lymphocyte percentages in the Advia 2120 CBC results in rabbits, method-specific reference intervals should be used. The Advia can recognize leporine basophils. Evaluation of blood smears is still recommended to investigate abnormal results and erroneous cytograms reported by the Advia.

Daily monitoring of vaginal interleukin 6 as a predictor of intraamniotic inflammation after preterm premature rupture of membranes - a new method of sampling studied in a prospective multicenter trial.

OBJECTIVES: (A) To introduce a new technique for vaginal fluid sampling (biocompatible synthetic fiber sponge) and (B) evaluate the collected vaginal fluid interleukine-6 (IL-6vag)-concentration as a new diagnostic tool for daily monitoring of intrauterine inflammation after preterm premature rupture of membranes (PPROM). Secondary objectives were to compare the potential to predict an intrauterine inflammation with established inflammation parameters (e.g., maternal white blood cell count). METHODS: This prospective clinical case-control diagnostic accuracy multicenter study was performed with women after PPROM (gestational age 24.0/7 - 34.0/7 weeks). Sampling of vaginal fluid was performed once daily. IL-6vag was determined by electrochemiluminescence-immunoassay-kit. Neonatal outcome and placental histology results were used to retrospectively allocate the cohort into two subgroups: 1) inflammation and 2) no inflammation (controls). RESULTS: A total of 37 cases were included in the final analysis. (A): Measurement of IL-6 was successful in 86% of 172 vaginal fluid samples. (B): Median concentration of IL-6vag in the last vaginal fluid sample before delivery was significantly higher within the inflammation group (17,085 pg/mL) compared to the controls (1,888 pg/mL; p=0.01). By Youden's index an optimal cut-off for prediction an intrauterine inflammation was: 6,417 pg/mL. Two days before delivery, in contrast to all other parameters IL-6vag remained the only parameter with a sufficient AUC of 0.877, p<0.001, 95%CI [0.670-1.000]. CONCLUSIONS: This study established a new technique for vaginal fluid sampling, which permits assessment of IL-6vag concentration noninvasively in clinical daily routine monitoring.

COMPARISON OF THREE ANALYZERS FOR ASSESSING COMPLETE BLOOD COUNTS IN NONHUMAN PRIMATES.

Diagnostic hematology can prove challenging to the exotic animal practitioner presented with a nonhuman primate patient. Few point-of-care automated cell counters are calibrated for primate samples. Twenty-one samples from 17 nonhuman primates presented to an exotic animal practice were analyzed. Samples were run on both canine and feline settings on each of two veterinary point-of-care analyzers: one that assays by impedance technology, and one that assays by laser flow cytometry. Samples were also sent to a reference laboratory to be assayed on an analyzer that performs simultaneous impedance and laser measurements of blood cells and has been calibrated for use in nonhuman primates. Fourteen analytes were assessed for each sample on each machine. Manual hematocrits and total white blood cell counts were also performed on 16 of the samples. Statistical analysis indicated some variance between individual parameters, but overall correlation was acceptable.

Evaluation and comparison of the new Mindray BC-6200 hematology analyzer with ADVIA 2120i.

BACKGROUND: The Mindray BC-6200 is a new automatic hematology analyzer that quantifies the parameters of blood morphology and leukocyte differential in five populations (5-Diff). The aim of the study was to evaluate the BC-6200 and compare it with the Siemens ADVIA 2120i analyzer. MATERIALS AND METHODS: The comparison between BC-6200 and ADVIA 2120i analyzers was performed using 390 whole blood samples collected on K3 EDTA. For the BC-6200, the carryover effect, precision, and linearity were evaluated. 138 samples were used to assess the sensitivity and flag ability, suggesting the presence of abnormal cells such as blasts, immature granulocytes, or atypical lymphocytes. Flagging results were compared with microscopic evaluation of blood smears. RESULTS: The BC-6200 analyzer showed a high correlation (r ≥ .97) with ADVIA 2120i for most of the compared parameters except RDW (r = .8350), MPV (r = .7634), Mon# (r = .8366), Baso# (r = .9205), and NRBC (r = .3768). The BC-6200 had better correlation with microscopic evaluation for NRBC (r = .8902) compared with ADVIA 2120i (r = .5677). The BC-6200 has shown high efficiency for flagging blasts (80.4%), immature granulocytes (80.5%), and atypical lymphocytes (69.0%). CONCLUSION: The new Mindray BC-6200 hematology analyzer provides high measurements precision and good correlation with ADVIA 2120i for most of the morphology and 5-diff parameters.

Diagnóstico Laboratorial para COVID-19: aspectos operacionais e processamento dos testes

O próximo Debate Virtual do Conass, nesta sexta-feira (31), às 17 horas irá tratar dos testes da Covid-19 – quais os tipos, quando e quais devem ser usados, como ser aplicados, como fazer a leitura do resultado, entre outros aspectos relevantes deste instrumento fundamental para o enfrentamento e controle da pandemia do novo coronavírus.

A new approach for diagnosing hematological malignancies using monocytosis workflow optimization and abnormal lymphocyte/blast flag of Sysmex XN series of blood count analyzers.

INTRODUCTION: Monocytosis Workflow Optimization rule set has been developed by using mono-dysplasia-score to determine reactive monocytosis and prevent unnecessary blood smear of these patients and for detection of chronic myelomonocytic leukemia cases during complete blood count. In our study, we aimed to examine the contribution of Monocytosis Workflow Optimization rule set. METHODS: Adult patients with monocyte count ≥1.0 103 /µL and monocyte percentage ≥10% were included in our study. Blood smears were made from the samples in our laboratory. These smears were examined and patients were divided into two groups as reactive monocytosis or hematological malignancy. The groups were compared in terms of Monocytosis Workflow Optimization rule set and device flags. RESULTS: Twenty-one patients had hematological malignancies of 155 patients who were included in our study. Monocytosis Workflow Optimization rule set suggested performing blood smear in 19 of the patients with hematological malignancy, and evaluated two patients as reactive monocytosis with 90.5% sensitivity and 76.9% specificity. There was an "abnormal lymphocyte/ blast" flag in 90.5% of patients with hematological malignancies and in patients whose Monocytosis Workflow Optimization rule set defined as reactive monocytosis and it was found that sensitivity and negative predictive value reached 100%. CONCLUSION: Automated validation support systems and softwares developed especially for these systems make it possible to classify patients with their non-specific findings, as a result both contributing to the reduction of laboratory workload and costs and assisting laboratory specialists and clinicians with adding value to laboratory results.

Estimation of white blood cell and platelet counts in ovine blood smears, and a comparison with the ADVIA 120 hematology analyzer.

BACKGROUND: Manual evaluation of blood cell counts on stained blood films is a common procedure in resource-limited laboratories of farm animal clinics. Moreover, settings for sheep blood cell counts are not provided on most veterinary hematology analyzers. OBJECTIVES: We aimed to (a) compare the results of white blood cell (WBC) counts evaluated microscopically on ovine blood smears with those obtained by the ADVIA 120 hematology analyzer and validate appropriate correction factors for the manual technique; and (b) assess the two suggested factors to calculate platelet counts on blood smears in sheep. METHODS: The blood samples of 57 sheep were used to generate a regression equation between the average WBC count per field and the WBC count determined using the ADVIA 120 analyzer. Thirty-one new ovine samples were used to assess the agreement between the calculated WBC counts based on a generated equation and those obtained by the analyzer using the Passing-Bablok test and Bland-Altman plots. Similarly, agreements between platelet counts using two different factors for platelet calculation were assessed using the Bland-Altman plot. RESULTS: The average bias of calculated WBC counts was 0.4%, with precision and accuracy being over 95%. Regarding calculated platelet counts, Bland-Altman plots revealed a bias of 26.4% and 1.4% when the average number of platelets per field was multiplied by 15 000 and 20 000, respectively. CONCLUSIONS: Microscopic WBC counting in ovine blood is a reliable alternative to automated analyses using the generated equation. A better agreement between the two methods was observed when a factor of 20 000 was used to calculate platelet counts in ovine blood smears.

Performance of a Nageotte hemocytometer method and a flow cytometric assay for residual leukocyte quantification in leukoreduced canine packed red blood cells.

OBJECTIVE: To evaluate the performances of a manual Nageotte hemocytometer method and commercial fluorescent bead-based flow cytometric assay for quantifying [rWBC] in leukoreduced canine packed red blood cell (pRBC) units. DESIGN: Prospective study. Five, commercially purchased, double leukoreduced canine pRBC units were spiked with canine leukocytes to create 6 pRBC standards with the following [rWBC]: < 0.1, 0.375, 1.5, 3.0, 6.0, and 24.0 WBC/µL. [rWBC] of each pRBC standard was measured with the Nageotte hemocytometer and flow cytometric techniques. Limit of detection (LoD), linearity, and bias were determined for each method. For each standard, accuracy and precision were calculated; the cumulative accuracy and mean precision for measurements between the LoD and 24.0 WBC/µL were also determined. SETTING: University veterinary blood bank and clinical pathology laboratory. MEASUREMENTS AND MAIN RESULTS: The Nageotte hemocytometer method had an LoD = 1.48 WBC/µL, inadequate linearity (R2  = 0.92), and a significant negative proportional bias (slope best-fit line = 0.52 ± 0.03). Between [rWBC] 1.5-24 WBC/µL, the technique demonstrated poor cumulative accuracy (6.7%) but acceptable mean precision (17.3%). Relative to a 2 rWBC/µL threshold, at 1.5 WBC/µL the method was inaccurate (6.7%) with acceptable precision (16.6%). The flow cytometric assay had an LoD = 1.3 WBC/µL, acceptable linearity (R2  = 0.99), and a mild positive proportional bias (slope best-fit line = 1.11 ± 0.01). The technique had acceptable cumulative accuracy (80%) and mean precision (10.7%) for measuring [rWBC] between 1.5 and 24 WBC/µL. At 1.5 WBC/µL, this method was acceptably accurate (86.7%) and precise (16.0%). CONCLUSIONS: The flow cytometric assay demonstrated acceptable performance for quantification of [rWBC] in leukoreduced canine pRBC units. The Nageotte hemocytometer method should be used cautiously due to poor accuracy and significant negative bias.

[Mastering the analytical process of the Complete Blood Count: how and why?] / Maîtrise du processus analytique de la Numération Formule Sanguine : comment et pourquoi ?

This is a prospective study realized at the level of the hematology department and blood transfusion center of the University Hospital Center (CHU) of Dr Ben Badis of Constantine and spread out over a period of one year (from January 1st to December 31st). The work focused on the analytical processes mastery of the NFS needs a compulsory step concerning technical and organizational laboratory skills respecting the ISO 15189 laws going through a mastery of support processes (humain resourses, informatics, materials, documents, management) indispensable for the good function of analytic proceedings, a performance evaluation of the hematology analyzer Advia (2120 I and II and 560) and quality control management (intern, extern). The analytic performance evaluation of Advia gives reliable results reproductible and stable for use of the routine automatisation good inter-machine correlation and laboratory performance in terms of the quality extern evaluation with military hospital laboratory.

Evaluation of the HemoCue WBC DIFF in leukopenic patient samples.

BACKGROUND: White blood cell (WBC) counts are used to monitor bone marrow function and to screen for infections. The HemoCue WBC DIFF Point-Of-Care (POC) instrument classifies WBCs through cell image recognition. To evaluate its suitability for monitoring cancer patients, we examined its performance in samples from patient with leukopenia and in samples containing nRBC. METHODS: Sysmex samples with WBCs 0.05-3.40 × 109 /L were examined on the HemoCue WBC DIFF, and the correlations between the instruments were assessed by Deming regression for total WBC, neutrophils, and lymphocytes. The theoretical CV% (CVt), calculated from number of cells counted by the HemoCue WBC DIFF, was used to determine the statistical error of the WBC counts. The interference of nRBC was also evaluated. RESULTS: The counting variation was primarily the source of statistical error in the lower counts with an imprecision between 3.8-9.2% for total WBC (0.56-2.29 ×109 /L), 8.7-14.3% for neutrophils (0.36-1.33 ×109 /L) and 9.8-15.1% for lymphocytes (0.35-0.89 ×109 /L). The correlation coefficient was between 0.658 and 0.986-poorest for lymphocytes. The total WBC count on the HemoCue WBC DIFF was significantly increased in nRBC samples due to lymphocyte count overestimation, and not by other WBCs. CONCLUSIONS: The HemoCue WBC DIFF provided reliable and accurate counts of total WBC, neutrophil, and lymphocyte in leukopenic samples. Until POC instruments that can perform an accurate complete blood count are available, the HemoCue WBC DIFF can be used to assist physicians in making decisions in situations of postchemotherapy leukopenia and neutropenia.

The use of a hematology analyzer with a new generation of software as an alternative to flow cytometry for enumerating residual white blood cells in blood components.

BACKGROUND: Leukoreduction of blood components was implemented to reduce transfusion-associated risks. The detection level for residual white blood cells (rWBCs) required to demonstrate leukoreduction was originally considered too low for hematology analyzers. Developments enabling cell counts in body fluids have, however, renewed interest in rWBC counting. An assessment of Sysmex XN hematology analyzers with software offering automated rWBC enumeration intended for use on blood components was performed. STUDY DESIGN AND METHODS: Performance characteristics were determined using platelet, red blood cell (RBC), and plasma samples spiked with WBCs. Subsequently, components (platelets, n = 1367; and plasma, n = 80) were tested and results compared with flow cytometry, to monitor leukoreduction efficiency to a level of less than 1 × 106 /unit. Components identified by flow cytometry as having poor leukoreduction, exceeding this limit, were also tested (platelets, n = 3; and RBCs, n = 10). RESULTS: Linearity studies up to 32 WBCs/µL showed good correlation between observed and expected results (R2 > 0.9996). Precision analysis gave an average limit of quantitation of 2 WBCs/µL with coefficients of variation less than 20%. Average carryover was 0.1%. Plain sample tubes were a source of aberrant results with routine components. Using ethylenediaminetetraacetic acid tubes the analyzer gave results greater than 1 × 106 /unit in 2.7% of cases compared with 1.4% by flow cytometry, but overall results were within specification, with more than 90% of components having rWBC values below the limit. All incidences of poor leukoreduction, with flow cytometry results greater than 13 rWBCs/µL were correctly identified, with an excellent correlation between results (R2 = 0.9818). CONCLUSION: The analyzer demonstrated acceptable performance characteristics for enumeration of rWBCs; consequently, additional multisite evaluations are warranted.

Patient self-testing of white blood cell count and differentiation: A study of feasibility and measurement performance in a population of Danish cancer patients.

OBJECTIVE: Patients in anticancer treatment with a known side effect of neutropenia are monitored closely with laboratory measurements of white blood cell count (WBC) and differentiation. This study sought to evaluate measurement properties and feasibility of patients' self-testing using a point-of-care testing (POCT) device. METHODS: A prospective feasibility and measurement study comparing the standard measurement of cancer patients' WBC and neutrophil count with POCT measurements. The study included 60 outpatients and 22 inpatients from a department of oncology at a university hospital. RESULTS: Patients successfully conducted 106 measurements using the POCT device. 46% of the patients were >70 years. Weighted Deming regression analysis showed minimal yet significant proportional bias between methods, with POCT increasingly underestimating both total WBC and neutrophils compared with the standard method the higher the count. Over 90% of patients reported they were willing and considered themselves able to use the POCT device at home. CONCLUSIONS: The instrument can be used for self-testing of post-anticancer leukopenia and has sufficient measurement precision for patient risk stratification. Patients are able and willing to conduct measurements including when in a situation of acute illness. Further studies are needed to confirm safety and value within patients' own home.

CD71 improves delineation of PNH type III, PNH type II, and normal immature RBCS in patients with paroxysmal nocturnal hemoglobinuria.

BACKGROUND: The diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) relies on flow cytometric demonstration of loss of glycosyl-phosphatidyl inositol (GPI)-anchored proteins from red blood cells (RBC) and white blood cells (WBC). High-sensitivity multiparameter assays have been developed to detect loss of GPI-linked structures on PNH neutrophils and monocytes. High-sensitivity assays to detect PNH phenotypes in RBCs have also been developed that rely on the loss of GPI-linked CD59 on CD235a-gated mature RBCs. The latter is used to delineate PNH Type III (total loss of CD59) and PNH Type II RBCs (partial loss of CD59) from normal (Type I) RBCs. However, it is often very difficult to delineate these subsets, especially in patients with large PNH clones who continue to receive RBC transfusions, even while on eculizumab therapy. METHODS: We have added allophycocyanin (APC)-conjugated CD71 to the existing CD235aFITC/CD59PE RBC assay allowing simultaneous delineation and quantification of PNH Type III and Type II immature RBCs (iRBCs). RESULTS: We analyzed 24 medium to large-clone PNH samples (>10% PNH WBC clone size) for PNH Neutrophil, PNH Monocyte, Type III and Type II PNH iRBCs, and where possible, Type III and Type II PNH RBCs. The ability to delineate PNH Type III, Type II, and Type I iRBCs was more objective compared to that in mature RBCs. Additionally, total PNH iRBC clone sizes were very similar to PNH WBC clone sizes. CONCLUSIONS: Addition of CD71 significantly improves the ability to analyze PNH clone sizes in the RBC lineage, regardless of patient hemolytic and/or transfusion status.

Cytological examination of cerebrospinal fluid: Sysmex UF-1000i versus optical microscopy.

We evaluated the body fluid module on Sysmex UF-1000i (UF-1000i-BF) for analysis of white blood cell (WBC) and red blood cell (RBC) in cerebrospinal fluid. We collected 93 cerebrospinal fluid samples and compared the results of the UF-1000i-BF mode with the Fast-Read 102 disposable counting cell. Results shows a good correlation between the UF-1000i and the microscopic examination. The concordance percentage is 99.06% for white blood cells and 85.18% for red blood cells. The UF-1000i-BF mode offers rapid and reliable total WBC and RBC counts for initial screening of cerebrospinal fluid, and can improve the workflow in a routine laboratory.

False-positive of blood culture instrument: leukocytosis, overfilled vials or defective position?

Continuous monitoring of the performances of blood culture instrument can be based on the indicators proposed by the QUAMIC. Of these, the analytic performance indicator evaluates the rate of false-positive vials. False-positives vials can be reported by the device in case of leukocytosis or when vials are overfilled. In our laboratory, we record prospectively in our software all false positive vials as well as the position used for their incubation. These data are analyzed at least twice a year. For the first half of 2016, this strategy allowed us to identify a defective position. We then evaluated the impact of this anomaly as very weak. The one-year follow-up after the position repair confirmed a correction of the problem. Thus, traceability of positions reporting unexplained false-positive vials (i.e. neither due to leukocytosis nor overfilled vials) can allow laboratories to identify a defective position. This survey, if done prospectively, is simple to perform and not time-consuming. It could usefully complement the analytical performance indicator based on the false-positive rate.

Spurious Low WBC Count from Sysmex XN3000: a Case Report.

BACKGROUND: We present a case of spurious low WBC count in a liver transplant patient. The patient is a 56-year-old man with liver cancer. METHODS: His routine blood test revealed a decrease in WBC count: 0.03 x 109/L compared to 19.30 x 109/L before. The WBCs in the blood smear appeared higher than that reported by the XN without any aggregation. We diluted the blood sample to 1:7 with the DCL of the XN. RESULTS: The diluted result matches the blood smear. CONCLUSIONS: Dilution mode may be a good choice when there is WNR and WDF discordance, and a smear must be reviewed.

Can the 72-hour rule based on "Blast/Abn Lymph" flag on Sysmex XN-10 optimize the workflow in hematology laboratory?

Despite the continuing improvement of automated blood cell counters, confirmation by blood smear examination remains the gold standard in case of anomalies. With a constant goal of standardisation, different experts committees (e.g. the French-speaking cellular hematology group (Groupe francophone d'hématologie cellulaire, GFHC and the ISLH International society for laboratory hematology) recently published criteria for microscopic analysis of blood smears. Cornet et al. evaluated the application of those criteria and propose to suppress any review for 72 hours when a "Blast/Abn lymph" flag is triggered for a sample with no abnormal cell on the microscopic review. The aims of our study were to retrospectively evaluate whether this 72-hour rule adequately operates and whether it is possible to extend the arbitrary 72-hour timeframe to 96h and 144h. To achieve this goal, 40,688 blood samples were collected from three French-speaking hospitals. 1,548 samples presented an isolated "Blast/Abn lymph" flag. Only 221 samples presented the application of the 72-hour rule at least once for our study period. We were able to extend this rule to 144 hours for 10 samples of them. All blood smears for which the rule was applied were verified and there was no abnormal cell on smears at 72 and 144 hours. In conclusion, the 72-hour rule derived from the GFHC's criteria is secure and reduces the slide review rate and thus the production costs and the turnaround time of hemogram results. Further investigations could confirm that its extension to 144 hours is also adequate.