Advances in CD4 cell enumeration in resource-poor countries

Baum, Linda L.; Crowe, Suzanne; Landay, Alan

doi:10.1097/coh.0b013e3280ef6909

Cited by 11 publications

(9 citation statements)

References 38 publications

(35 reference statements)

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“…Both latter analyzers have proven their usefulness for validating absolute number-and percentage-based CD4 T cell counting in the field (16,25). These single platforms using only a flow cytometer and volumetric systems allow counting of CD4 T cells in a fixed volume, thus leading to a considerable reduction in the costs of CD4-positive T cell enumeration in comparison to microbead-based systems (2). In addition, the compact low-range single platforms Auto40 and CyFlow SL_3 are portable desktop flow cytometers that do not require optical alignment, can run on a 12-volt car battery, and can be connected to a laptop computer, suggesting their possible use in health care mobile units and thereby making CD4 T cell enumeration available in remote or hard-to-reach locations.…”

Section: Discussionmentioning

confidence: 99%

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Validation of a Single-Platform, Volumetric, CD45-Assisted PanLeucogating Auto40 Flow Cytometer To Determine the Absolute Number and Percentages of CD4 T Cells in Resource-Constrained Settings Using Cameroonian Patients' Samples

Mbopi-Kéou

Mion

Sagnia

et al. 2012

Clin. Vaccine Immunol.

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ABSTRACTThe study evaluated the single-platform, volumetric, CD45-assisted PanLeucogating Auto40 flow cytometer (Apogee Flow Systems Ltd., Hemel Hempstead, United Kingdom) for CD4 T cell numeration, compared to the reference FACSCalibur flow cytometer. Results of absolute counts and percentages of CD4 T cells by Auto40 and FACSCalibur of 234 tripotassium EDTA (K3-EDTA)-blood samples from 146 adults and 88 children (aged from 18 months to 5 years), living in Yaoundé, Cameroon, were highly correlated (r2= 0.97 andr2= 0.98, respectively). The mean absolute bias and relative bias between Apogee Auto40 and FACSCalibur absolute CD4 T cell counts were +9.6 cells/μl, with limits of agreement from −251 to 270 cells/μl, and +4.1%, with limits of agreement from −16.1 to 24.4%, respectively. The mean absolute bias and relative bias between Apogee Auto40 and FACSCalibur CD4 T cell results expressed as percentages were +0.05% CD4 (95% confidence interval [CI], −0.03 to 0.41), with limits of agreement from −6.0 to 5.9% CD4, and +1.0%, with limits of agreement from −32.3 to 34.4%, respectively. The Auto40 counting allowed identification of the majority of adults with CD4 T cell counts below 200 cells/μl (sensitivity, 87%; specificity, 98%) or below 350 cells/μl (sensitivity, 92%; specificity, 98%) and of children with CD4 T cell counts below 750 cells/μl (sensitivity, 82%; specificity, 98%) or below 25% CD4+(sensitivity, 96%; specificity, 99%). The Auto40 analyzer is a reliable alternative flow cytometer for CD4 T lymphocyte enumeration to be used in routine immunological monitoring according to the WHO recommendations for HIV-infected adults as well as children living in resource-constrained settings.

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Section: Discussionmentioning

confidence: 99%

“…Immunophenotyping using flow cytometry is the reference method for the enumeration of the CD4 marker on T lymphocytes (2). Initially, the use of a large panel of reagents and stringent gating techniques for full lymphocyte subset analysis was shown to be superfluous and expensive (17).…”

Section: Discussionmentioning

confidence: 99%

Validation of a Single-Platform, Volumetric, CD45-Assisted PanLeucogating Auto40 Flow Cytometer To Determine the Absolute Number and Percentages of CD4 T Cells in Resource-Constrained Settings Using Cameroonian Patients' Samples

Mbopi-Kéou

Mion

Sagnia

et al. 2012

Clin. Vaccine Immunol.

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“…Finally, CD4 T counting remains currently an important biological marker for antiretroviral treatment initiation and monitoring, while HIV-1 RNA load is not sufficiently available in the field. The speed of implementation of CD4 T lymphocyte count facilities has been unrivalled in recent years in resource-limited countries and has met challenges with technology selection, laboratory infrastructure development, human resource training, cost-effectiveness, instrument maintenance and ensuring testing access and quality [14, 31, 37]. However, most conventional benchtop flow cytometer systems used for enumeration of CD4 T lymphocyte counts are relatively complex, costly, technically demanding and the instruments used, need constant maintenance.…”

Section: Discussionmentioning

confidence: 99%

Performance evaluation of the touchscreen-based Muse™ Auto CD4/CD4% single-platform system for CD4 T cell numeration in absolute number and in percentage using blood samples from children and adult patients living in the Central African Republic

et al. 2016

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BackgroundThe new microcapillary and fluorescence-based EC IVD-qualified Muse™ Auto CD4/CD4% single-platform assay (EMD Millipore Corporation, Merck Life Sciences, KGaA, Darmstadt, Germany) for CD4 T cell numeration in absolute number and in percentage was evaluated using Central African patients’ samples compared against the reference EC IVD-qualified BD FACSCount (Becton–Dickinson, USA) flow cytometer.MethodsEDTA-blood samples from 124 adults, 10 adolescents, 13 children and 3 infants were tested in parallel at 2 reference laboratories in Bangui.ResultsThe Muse™ technique was highly reproducible, with low intra- and inter-run variabilities less than 15%. CD4 T cell counts of Muse™ and BD FACSCount in absolute number and percentage were highly correlated (r2 = 0.99 and 0.98, respectively). The mean absolute bias between Muse™ and BD FACSCount cells in absolute number and percentage were −5.91 cells/µl (95% CI −20.90 to 9.08) with limits of agreement from −77.50 to 202.40 cells/µl, and +1.69 %CD4 (95% CI ±1.29 to +2.09), respectively. The percentages of outliers outside the limits of agreement were nearly similar in absolute number (8%) and percentage (10%). CD4 T cell counting by Muse™ allowed identifying the majority of individuals with CD4 T cell <200, <350 or <750 cells/µl corresponding to the relevant thresholds of therapeutic care, with sensitivities of 95.5–100% and specificities of 83.9–100%.ConclusionsThe Muse™ Auto CD4/CD4% Assay analyzer is a reliable alternative flow cytometer for CD4 T lymphocyte enumeration to be used in routine immunological monitoring according to World Health Organization recommendations in HIV-infected adults as well as children living in resource-constrained settings.

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“…Immunophenotyping by flow cytometry is the reference method for the enumeration of the CD4 marker on T lymphocytes [31]. Initially, the use of large panel of reagents and stringent gating techniques for full lymphocyte subset analysis has been shown to be superfluous and expensive [32].…”

Section: Discussionmentioning

confidence: 99%

Single-platform, volumetric, CD45-assisted pan-leucogating flow cytometry for CD4 T lymphocytes monitoring of HIV infection according to the WHO recommendations for resource-constrained settings

Koyalta¹,

Jenabian

Nadjiouroum

et al. 2013

BMC Res Notes

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BackgroundValidation of new affordable CD4 T cell measurement technologies is crucial specifically in resource-poor countries for antiretroviral treatment eligibility and immunologic CD4 monitoring of HIV-infected patients.MethodsThe absolute and percentage CD4 T cell counts of 258 HIV-1-infected blood samples (182 adults and 76 children), living in N’Djamena, Chad, were performed by single-platform, volumetric, CD45-assisted pan-leucogating Auto40 flow cytometer (Apogee Flow Systems Ltd, Hemel Hempstead, UK) comparing to the FACSCalibur flow cytometer as a reference method.ResultsAbsolute and percentage CD4 T cell counts obtained by Auto40 and FACSCalibur of 258 HIV-1-infected blood samples were highly correlated (r = 0.99 and r = 0.96, respectively). The mean absolute bias and percent bias between Apogee Auto40 and FACSCalibur absolute CD4 T cell counts, were −9.4 cells/μl with limits of agreement from −15 to 93 cells/μl, and +2.0% with limits of agreement from −0.9 to 4.9%, respectively. The mean of absolute bias and percent bias between Apogee Auto40 and FACSCalibur of CD4 percentage results were +0.4% (95% CI: -0.02 – 0.86) with limits of agreement from −2.4 to 0.3%, and +3.0% with limits of agreement from −6.6 to 0.6%, respectively. The Auto40 counting allowed to identify the majority of adults with CD4 T cells below 200 cells/μl (sensitivity: 89%; specificity: 99%) or below 350 cells/μl (sensitivity: 94%; specificity:98%); and of children below 750 cells/μl (sensitivity: 99%; specificity: 96%) or below 25% CD4+ (sensitivity: 94%; specificity: 98%).ConclusionThe Auto40 analyzer is an alternative flow cytometer for CD4 T lymphocyte enumeration to be used in routine for immunological monitoring according to the current WHO recommendations in HIV-infected adults as well as children living in resource-constrained settings like Chad.

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Advances in CD4 cell enumeration in resource-poor countries

Cited by 11 publications

References 38 publications

Validation of a Single-Platform, Volumetric, CD45-Assisted PanLeucogating Auto40 Flow Cytometer To Determine the Absolute Number and Percentages of CD4 T Cells in Resource-Constrained Settings Using Cameroonian Patients' Samples

Validation of a Single-Platform, Volumetric, CD45-Assisted PanLeucogating Auto40 Flow Cytometer To Determine the Absolute Number and Percentages of CD4 T Cells in Resource-Constrained Settings Using Cameroonian Patients' Samples

Performance evaluation of the touchscreen-based Muse™ Auto CD4/CD4% single-platform system for CD4 T cell numeration in absolute number and in percentage using blood samples from children and adult patients living in the Central African Republic

Single-platform, volumetric, CD45-assisted pan-leucogating flow cytometry for CD4 T lymphocytes monitoring of HIV infection according to the WHO recommendations for resource-constrained settings

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