Monocyte counting: discrepancies in results obtained with different automated instruments.

Goossens, Willy; hove, Luc Van den; Verwilghen, R. L.

doi:10.1136/jcp.44.3.224

Cited by 38 publications

(39 citation statements)

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“…The hematology analyzer underestimated the monocyte counts with a bias of Ϫ179 monocytes/mm 3 . This is a large value, representing 35 to 40% of the total monocyte counts, as already reported for several hematology analyzers (14,19).…”

Section: Cd4mentioning

confidence: 60%

“…In our study, the CD45 analysis is combined with volumetric counting in order to generate absolute leukocyte differential counts. These parameters, when defined on hematological counters, can be error prone (3,19,33), and the monocyte counts are frequently underestimated (Table 3) (14,19). On the other hand, the monocyte counts obtained by CD45 gating and carefully confirmed by the CD14 monocytic marker expression (20) are more accurate.…”

Section: Discussionmentioning

confidence: 99%

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Affordable CD4 ⁺ -T-Cell Counting by Flow Cytometry: CD45 Gating for Volumetric Analysis

Jánossy

Jani

Bradley

et al. 2002

Clin Vaccine Immunol

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The flow cytometers that are currently supported by industry provide accurate CD4؉ -T-cell counts for monitoring human immunodeficiency virus disease but remain unaffordable for routine service work under resource-poor conditions. We therefore combined volumetric flow cytometry (measuring absolute lymphocyte counts in unit volumes of blood) and simpler protocols with generic monoclonal antibodies (MAbs) to increase cost efficiency. Volumetric absolute counts were generated using CD45/CD4 and CD45/CD8 MAb combinations in two parallel tubes. The percentage values for the various subsets were also determined within the leukocyte and lymphocyte populations utilizing a fully automated protocol. The levels of agreement between the newly developed method and the present industry standards, including both volumetric and bead-based systems using a full MAb panel for subset analysis, were tested by Bland-Altman analyses. The limits of agreement for CD4 counts generated by the volumetric methods using either CD45/CD4 (in a single tube) or the full Trio MAb panel (in three tubes) on the CytoronAbsolute flow cytometer were between ؊29 and ؉46 cells/mm 3 with very little bias for CD4 counts (in favor of the Trio method: ؉8 CD4 ؉ lymphocytes/mm 3 ; 0.38% of lymphocytes). The limits of agreement for absolute CD4 counts yielded by the volumetric CD45/CD4 method and the bead-based method were between ؊118 and ؉98 cells/mm 3 , again with a negligible bias (؊10 CD4 ؉ lymphocytes/mm 3 ). In the volumetric method using CD45/CD8, the strongly CD8 ؉ cells were gated and the levels of agreement with the full Trio showed a minor bias (in favor of the Trio; ؉40 CD8 ؉ cells/mm 3 ; 5.2% of lymphocytes) without a significant influence on CD4/CD8 ratios. One trained flow cytometrist was able to process 300 to 400 stained tubes per day. This workload extrapolates to a throughput of >30,000 samples per year if both CD45/CD4 and CD45/CD8 stainings are performed for each patient or a throughput of >60,000 samples if only CD45/CD4 counts are tested in a single tube. Thus, on the basis of the high efficiency and excellent agreement with the present industry standards, volumetric flow cytometers with automated gating protocols and autobiosamplers, complemented by generic CD45, CD4, and CD8 MAbs used in two-color immunofluorescence, represent the most suitable arrangements for large regional laboratories in resource-poor settings.Dedicated flow cytometers are designed to enumerate the absolute numbers and percentages of lymphocyte populations, such as subsets of T cells, B cells, and NK cells. In the clinical service for monitoring human immunodeficiency virus (HIV) disease, the primary aim is to deliver absolute CD4 ϩ -T-cell counts, and this is achieved with a remarkably high level of precision (9,24,26,29,30). Nevertheless, the various cytometric systems differ in complexity (9). It has recently been documented that routine CD4-T-cell enumeration can be simplified without compromising quality (13,18,32), leading to costeffective services for patie...

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Section: Cd4mentioning

confidence: 60%

Section: Discussionmentioning

confidence: 99%

Affordable CD4 ⁺ -T-Cell Counting by Flow Cytometry: CD45 Gating for Volumetric Analysis

Jánossy

Jani

Bradley

et al. 2002

Clin Vaccine Immunol

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“…Because of its high precision and objective results, flow cytometry using fluorescence-labeled mAbs is an efficient method of enumerating monocytes [24][25][26] and basophils 27,28 and has been proposed as an alternative reference method without the shortcomings of the manual differential count that also affect manual detection of left shift and enumeration of immature cells. 12,13,29 Investigators have therefore tried to find alternative flow cytometric methods for detecting neutrophil reaction.…”

Section: Discussionmentioning

confidence: 99%

“…[24][25][26][27] ' 31 Day-to-day precision was not assessed, because of lack of suitable control material. However, the stable MFI of the daily analyzed DNA-Check Beads (data not shown) and the precision reported for the mAb-based enumeration of monocytes 31 revealed high day-to-day precision of mAb-based flow cytometry.…”

Section: Precisionmentioning

confidence: 99%

Value of Neutrophil CD16 Expression for Detection of Left Shift and Acute-Phase Response

et al. 1997

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Fey RIII (CD16) expression of neutrophil granulocytes was measured in 156 patients by means of fluorescence-labeled antibodies with a flow cytometer. Results were compared with (1) 400-cell manual differential count; (2) left shift flagging on hematology analyzers; (3) absolute neutrophil count; and (4) acute-phase protein levels. Asynchrony was noted between neutrophil CD16 expression and microscopically defined neutrophil stage, particularly in heavily left-shifted samples, which made it impossible to reliably enumerate immature neutrophils on the basis of CD16 expression. According to receiver operating characteristics, the absolute count of CD16-negative neutrophils was highly discriminatory for detection of left shift, with an area under the curve (AUC) of 0.842 ± 0.03 (SE) and maximum efficiency of 81% ± 3%, but absolute neutrophil count was not significantly inferior (0.821 ± 0.03 and 76% ± 3%).Some investigators question the clinical value of detection of left shift or band cells.1-5 ; others consider left shift a valuable sign for a neutrophil reaction, particularly in neonatal or pediatric patients, who may not demonstrate an increase in total neutrophil count or a humoral response of acute-phase proteins.6-8 However, both automated and manual methods of detecting left shift have serious shortcomings. Most hematology analyzers report flags designed to indicate left shift, but instrument evaluations have shown the efficiency of the flagging algorithms to be insufficient, 9,10 especially for detection of band cells.11 Lack of an adequate reference method for enumeration of band cells or immature granulocytes is one problem. Manual differential counting is characterized by high imprecision, subjectivity of the examiner, and varying definition of band cells.2,4 ' 5,12 Even after uniform band identification criteria were defined, band results remained poorly reproducible. 13 In an effort to find alternative methods toFrom the Central Laboratory, Wilhelminenspital, Vienna, Austria.M a n u s c r i p t submitted April 2, 1996; revision accepted September 4,1996.Address reprint requests to Dr Hubl: Central Laboratory, Wilhelminenspital, Montleartstrasse 37, A-1171 Vienna, Austria.STKS and SE9000 flagging demonstrated efficiency of 76% ± 3% and 81% ± 3%, respectively. For detection of acute-phase response, absolute neutrophil count (AUC, 0.836 ± 0.04; maximum efficiency, 80% ± 4%) outperformed both quantitative neutrophil CD16 expression (0.760 ± 0.05; 75% ± 4%) and absolute CD16-negative neutrophil count (0.757 ± 0.05; 71% ± 4%); absolute band count performed similarly (0.853 ± 0.04; 79% ± 4%) and showed high efficiency at high sensitivity and specificity. Efficiency of analyzer flagging for detection of acute-phase response was not superior to absolute neutrophil count (STKS, 77% ± 4%; SE9000, 78% ± 4%). In conclusion, the diagnostic value of measuring neutrophil CD16 expression was generally similar to that of less complicated analytes.

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“…Identification of monocytes by blood cell counters, flow cytometry, and microscopic means is difficult and controversial, especially when abnormal cells are present [15] (which are not always of a monocytic lineage). The observation of weak/poor correlation for monocyte counts has been observed regularly in previous instrument evaluations [16,17]. For this set of clinically abnormal samples, discrepant results were also occasionally observed for, neutrophils and lymphocytes.…”

Section: Discussionmentioning

confidence: 67%

Evaluation of the Sysmex XN‐550, a Novel Compact Haematology analyser from the XN‐L^® series, compared to the XN‐20 system

Tailor¹,

Ij²,

Mellick³

et al. 2017

Int J Lab Hematology

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IntroductionThe XN-550 is a new, automated, compact, haematology analyser designed to generate a full blood count with a standard 5-part white blood cell differential and an immature granulocyte count, reticulocyte and optical platelet counts. The aim of the study was to evaluate the performance of the XN-550 and compare it to the established XN-20 system. MethodsWe evaluated the basic parameter and special measurement channels of the XN-550, using the XN-20 (which has a similar operating system), as a reference analyser. Precision, carryover and throughput evaluations were performed. In addition a total of 202 samples including normal controls and various pathological samples were studied for comparability. ResultsGood correlations with the reference analyser were obtained for all parameters expect basophils. The XN-550 offers impedance and optical platelet counts and the latter showed a better correlation and less scatter, than the impedance count and was comparable to the XN-20 fluorescent count at platelet counts ≤40x10 9 /L. Precision was good and no significant carryover was detected. ConclusionsThe XN-550 was simple and easy to use, while maintaining the good diagnostic sensitivity seen with high range systems such as the XN-20, making this compact device suitable for near-patient services and smaller satellite laboratories.

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Monocyte counting: discrepancies in results obtained with different automated instruments.

Cited by 38 publications

References 2 publications

Affordable CD4 ⁺ -T-Cell Counting by Flow Cytometry: CD45 Gating for Volumetric Analysis

Affordable CD4 ⁺ -T-Cell Counting by Flow Cytometry: CD45 Gating for Volumetric Analysis

Value of Neutrophil CD16 Expression for Detection of Left Shift and Acute-Phase Response

Evaluation of the Sysmex XN‐550, a Novel Compact Haematology analyser from the XN‐L^® series, compared to the XN‐20 system

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Monocyte counting: discrepancies in results obtained with different automated instruments.

Cited by 38 publications

References 2 publications

Affordable CD4 + -T-Cell Counting by Flow Cytometry: CD45 Gating for Volumetric Analysis

Affordable CD4 + -T-Cell Counting by Flow Cytometry: CD45 Gating for Volumetric Analysis

Value of Neutrophil CD16 Expression for Detection of Left Shift and Acute-Phase Response

Evaluation of the Sysmex XN‐550, a Novel Compact Haematology analyser from the XN‐L® series, compared to the XN‐20 system

Contact Info

Product

Resources

About

Affordable CD4 ⁺ -T-Cell Counting by Flow Cytometry: CD45 Gating for Volumetric Analysis

Affordable CD4 ⁺ -T-Cell Counting by Flow Cytometry: CD45 Gating for Volumetric Analysis

Evaluation of the Sysmex XN‐550, a Novel Compact Haematology analyser from the XN‐L^® series, compared to the XN‐20 system