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Perazzio SF, Palmeira P, Moraes-Vasconcelos D, Rangel-Santos A, de Oliveira JB, Andrade LEC, Carneiro-Sampaio M. A Critical Review on the Standardization and Quality Assessment of Nonfunctional Laboratory Tests Frequently Used to Identify Inborn Errors of Immunity. Front Immunol 2021; 12:721289. [PMID: 34858394 PMCID: PMC8630704 DOI: 10.3389/fimmu.2021.721289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 10/05/2021] [Indexed: 12/24/2022] Open
Abstract
Inborn errors of immunity (IEI), which were previously termed primary immunodeficiency diseases, represent a large and growing heterogeneous group of diseases that are mostly monogenic. In addition to increased susceptibility to infections, other clinical phenotypes have recently been associated with IEI, such as autoimmune disorders, severe allergies, autoinflammatory disorders, benign lymphoproliferative diseases, and malignant manifestations. The IUIS 2019 classification comprises 430 distinct defects that, although rare individually, represent a group affecting a significant number of patients, with an overall prevalence of 1:1,200-2,000 in the general population. Early IEI diagnosis is critical for appropriate therapy and genetic counseling, however, this process is deeply dependent on accurate laboratory tests. Despite the striking importance of laboratory data for clinical immunologists, several IEI-relevant immunoassays still lack standardization, including standardized protocols, reference materials, and external quality assessment programs. Moreover, well-established reference values mostly remain to be determined, especially for early ages, when the most severe conditions manifest and diagnosis is critical for patient survival. In this article, we intend to approach the issue of standardization and quality control of the nonfunctional diagnostic tests used for IEI, focusing on those frequently utilized in clinical practice. Herein, we will focus on discussing the issues of nonfunctional immunoassays (flow cytometry, enzyme-linked immunosorbent assays, and turbidimetry/nephelometry, among others), as defined by the pure quantification of proteins or cell subsets without cell activation or cell culture-based methods.
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Affiliation(s)
- Sandro Félix Perazzio
- Division of Rheumatology, Universidade Federal de São Paulo, Sao Paulo, Brazil
- Immunology Division, Fleury Medicine and Health Laboratory, Sao Paulo, Brazil
| | - Patricia Palmeira
- Laboratório de Investigação Médica (LIM-36), Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo (FMUSP), Sao Paulo, Brazil
| | - Dewton Moraes-Vasconcelos
- Laboratório de Investigação Médica (LIM-56), Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo (FMUSP), Sao Paulo, Brazil
| | - Andréia Rangel-Santos
- Laboratório de Investigação Médica (LIM-36), Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo (FMUSP), Sao Paulo, Brazil
| | | | - Luis Eduardo Coelho Andrade
- Division of Rheumatology, Universidade Federal de São Paulo, Sao Paulo, Brazil
- Immunology Division, Fleury Medicine and Health Laboratory, Sao Paulo, Brazil
| | - Magda Carneiro-Sampaio
- Laboratório de Investigação Médica (LIM-36), Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo (FMUSP), Sao Paulo, Brazil
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Sao Paulo, Brazil
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Rhodes D, Carcelain G, Keeney M, Parizot C, Benjamins D, Genesta L, Zhang J, Rohrbach J, Lawrie D, Glencross DK. Assessment of the AQUIOS flow cytometer - An automated sample preparation system for CD4 lymphocyte PanLeucogating enumeration. Afr J Lab Med 2019; 8:804. [PMID: 31850159 PMCID: PMC6909423 DOI: 10.4102/ajlm.v8i1.804] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 03/18/2019] [Indexed: 11/16/2022] Open
Abstract
Background Flow cytometry has been the approach of choice for enumerating and documenting CD4-cell decline in HIV monitoring. Beckman Coulter has developed a single platform test for CD4+ T-cell lymphocyte count and percentage using PanLeucogating (PLG) technology on the automated AQUIOS flow cytometer (AQUIOS PLG). Objectives This study compared the performance of AQUIOS PLG with the Flowcare PLG method and performed a reference interval for comparison with those previously published. Methods The study was conducted between November 2014 and March 2015 at 5 different centres located in Canada; Paris, France; Lyon, France; the United States; and South Africa. Two-hundred and forty samples from HIV-positive adult and paediatric patients were used to compare the performances of AQUIOS PLG and Flowcare PLG on a FC500 flow cytometer (Flowcare PLG) in determining CD4+ absolute count and percentage. A reference interval was determined using 155 samples from healthy, non-HIV adults. Workflow was investigated testing 440 samples over 5 days. Results Mean absolute and relative count bias between AQUIOS PLG and Flowcare PLG was −41 cells/µL and −7.8%. Upward and downward misclassification at various CD4 thresholds was ≤ 2.4% and ≤ 11.1%. The 95% reference interval (2.5th – 97.5th) for the CD4+ count was 453–1534 cells/µL and the percentage was 30.5% – 63.4%. The workflow showed an average number of HIV samples tested as 17.5 per hour or 122.5 per 8-hour shift for one technician, including passing quality controls. Conclusion The AQUIOS PLG merges desirable aspects from conventional flow cytometer systems (high throughput, precision and accuracy, external quality assessment compatibility) with low technical operating skill requirements for automated, single platform systems.
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Affiliation(s)
- Daniel Rhodes
- Clinical Affairs, Beckman Coulter Immunotech, Marseille, France
| | | | - Mike Keeney
- Lawson Health Research Institute, London Health Sciences Centre and St. Joseph's Health Care, Victoria Hospital, London, Ontario, Canada
| | | | | | | | - Jin Zhang
- Life Science Flow Cytometry, Beckman Coulter Incorporated, Miami, Florida, United States
| | - Justin Rohrbach
- Clinical affairs, Beckman Coulter Incorporated, Miami, Florida, United States
| | - Denise Lawrie
- National Health Laboratory Service, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa
| | - Deborah K Glencross
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,National Health Laboratory Services, Johannesburg, South Africa
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Kestens L, Mandy F. Issue Highlights - November 2017 (92:B6). CYTOMETRY PART B-CLINICAL CYTOMETRY 2018; 92:433-436. [PMID: 29077268 DOI: 10.1002/cyto.b.21599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Daniel Francois Venter W, Chersich MF, Majam M, Akpomiemie G, Arulappan N, Moorhouse M, Mashabane N, Glencross DK. CD4 cell count variability with repeat testing in South Africa: Should reporting include both absolute counts and ranges of plausible values? Int J STD AIDS 2018; 29:1048-1056. [PMID: 29749876 DOI: 10.1177/0956462418771768] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although eligibility for antiretroviral treatment is no longer based on CD4 thresholds, CD4 testing remains important. Variation in CD4 cell count complicates initiation of antibiotic prophylaxis, differential diagnoses and assessments of immunological recovery. Five hundred and fifty-three HIV-positive antiretroviral-naïve adults, recruited from inner-city clinics, had three serial CD4 cell count tests. Test 1 was mostly done in a laboratory network supporting primary care clinics, while Tests 2 and 3 were performed in a tertiary-level laboratory. Reproducibility was assessed through Bland-Altman limits of agreement and coefficients of variation. Participants, a mean age of 34 years and mostly female (57%), had a median 203 CD4 cells/μL (Test 1). Seventeen per cent classified as having advanced HIV disease (CD4 cell count < 200 cells/µL) on Test 1 had a CD4 cell count > 200 cells/µL on Tests 2 and 3. Mean differences between tests were <10 cells/µL for all comparisons. Limits of agreement for Tests 1 and 2 were -106.9 to 112.7 and coefficient of variation 15. Corresponding figures for Tests 2 and 3 were -88.2 to 103.4, and 13. Means of tests were similar, suggesting no systematic measurement differences, despite testing being done at different times. Variations were, however, considerable in many instances, though smaller in testing done in the same laboratory. CD4 cut-offs must not be applied rigidly, but rather constitute one amongst many factors used to guide patient care. Moreover, given the difficulties in determining whether CD4 changes are due to HIV disease, or other biological and laboratory factors, CD4 laboratory reports should include a range of plausible values, not only the absolute count.
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Affiliation(s)
- Willem Daniel Francois Venter
- 1 Wits Reproductive Health and HIV Institute (Wits RHI), Faculty of Health Sciences, University of the Witwatersrand, Braamfontein, Johannesburg, South Africa
| | - Matthew F Chersich
- 1 Wits Reproductive Health and HIV Institute (Wits RHI), Faculty of Health Sciences, University of the Witwatersrand, Braamfontein, Johannesburg, South Africa
| | - Mohammed Majam
- 1 Wits Reproductive Health and HIV Institute (Wits RHI), Faculty of Health Sciences, University of the Witwatersrand, Braamfontein, Johannesburg, South Africa
| | - Godspower Akpomiemie
- 1 Wits Reproductive Health and HIV Institute (Wits RHI), Faculty of Health Sciences, University of the Witwatersrand, Braamfontein, Johannesburg, South Africa
| | - Natasha Arulappan
- 1 Wits Reproductive Health and HIV Institute (Wits RHI), Faculty of Health Sciences, University of the Witwatersrand, Braamfontein, Johannesburg, South Africa
| | - Michelle Moorhouse
- 1 Wits Reproductive Health and HIV Institute (Wits RHI), Faculty of Health Sciences, University of the Witwatersrand, Braamfontein, Johannesburg, South Africa
| | - Nonkululeko Mashabane
- 1 Wits Reproductive Health and HIV Institute (Wits RHI), Faculty of Health Sciences, University of the Witwatersrand, Braamfontein, Johannesburg, South Africa
| | - Deborah K Glencross
- 2 Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and the National Health Laboratory Service, Johannesburg, South Africa
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Coetzee LM, Glencross DK. Performance verification of the new fully automated Aquios flow cytometer PanLeucogate (PLG) platform for CD4-T-lymphocyte enumeration in South Africa. PLoS One 2017; 12:e0187456. [PMID: 29099874 PMCID: PMC5669480 DOI: 10.1371/journal.pone.0187456] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 10/22/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The National Health Laboratory Service (NHLS) offers wide-scale CD4 testing through a network of laboratories in South Africa. A new "load and go" cytometer (Aquios CL, Beckman Coulter), developed with a PLG protocol, was validated against the predicate PLG method on the Beckman Coulter FC500 MPL/CellMek platform. METHODS Remnant routine EDTA blood CD4 reference results were compared to results from two Aquios/PLG instruments (n = 205) and a further n = 1885 samples tested to assess daily testing capacity. Reproducibility was assessed using ImmunotrolTM and patient samples with low, medium, high CD4 counts. Data was analyzed using GraphPad software for general statistics and Bland-Altman (BA) analyses. The percentage similarity (%Sim) was used to measure the level of agreement (accuracy) of the new platform versus the predicate and variance (%SimCV) reported to indicate precision of difference to predicate. RESULTS 205 samples were tested with a CD4 count range of 2-1228 cells/μl (median 365cells/μl). BA analysis revealed an overall -40.5±44.0cells/μl bias (LOA of 126.8 to 45.8cells/μl) and %Sim showing good agreement and tight precision to predicate results (94.83±5.39% with %SimCV = 5.69%). Workflow analysis (n = 1885) showed similar outcomes 94.9±8.9% (CV of 9.4%) and 120 samples/day capacity. Excellent intra-instrument reproducibility was noted (%Sim 98.7±2.8% and %SimCV of 2.8%). 5-day reproducibility using internal quality control material (Immunotrol™) showed tight precision (reported %CV of 4.69 and 7.62 for Normal and Low material respectively) and instrument stability. CONCLUSION The Aquios/PLG CD4 testing platform showed clinically acceptable result reporting to existing predicate results, with good system stability and reproducibility with a slight negative but precise bias. This system can replace the faded XL cytometers in low- to medium volume CD4 testing laboratories, using the standardized testing protocol, with better staff utilization especially where technical skills are lacking. Central monitoring of on-board quality assessment data facilitates proactive maintenance and networked instrument performance monitoring.
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Affiliation(s)
- Lindi-Marie Coetzee
- Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- National Health Laboratory Service (NHLS), CD4 Unit, Charlotte Maxeke Hospital, Johannesburg, South Africa
- * E-mail:
| | - Deborah K. Glencross
- Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- National Health Laboratory Service (NHLS), CD4 Unit, Charlotte Maxeke Hospital, Johannesburg, South Africa
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Coetzee LM, Moodley K, Glencross DK. Performance Evaluation of the Becton Dickinson FACSPresto™ Near-Patient CD4 Instrument in a Laboratory and Typical Field Clinic Setting in South Africa. PLoS One 2016; 11:e0156266. [PMID: 27224025 PMCID: PMC4880207 DOI: 10.1371/journal.pone.0156266] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 05/11/2016] [Indexed: 12/27/2022] Open
Abstract
Background The BD-FACSPresto™ CD4 is a new, point-of-care (POC) instrument utilising finger-stick capillary blood sampling. This study evaluated its performance against predicate CD4 testing in South Africa. Methods Phase-I testing: HIV+ patient samples (n = 214) were analysed on the Presto™ under ideal laboratory conditions using venous blood. During Phase-II, 135 patients were capillary-bled for CD4 testing on FACSPresto™, performed according to manufacturer instruction. Comparative statistical analyses against predicate PLG/CD4 method and industry standards were done using GraphPad Prism 6. It included Bland-Altman with 95% limits of agreement (LOA) and percentage similarity with coefficient of variation (%CV) analyses for absolute CD4 count (cells/μl) and CD4 percentage of lymphocytes (CD4%). Results In Phase-I, 179/217 samples yielded reportable results with Presto™ using venous blood filled cartridges. Compared to predicate, a mean bias of 40.4±45.8 (LOA of -49.2 to 130.2) and %similarity (%CV) of 106.1%±7.75 (7.3%) was noted for CD4 absolute counts. In Phase-2 field study, 118/135 capillary-bled Presto™ samples resulted CD4 parameters. Compared to predicate, a mean bias of 50.2±92.8 (LOA of -131.7 to 232) with %similarity (%CV) 105%±10.8 (10.3%), and 2.87±2.7 (LOA of -8.2 to 2.5) with similarity of 94.7±6.5% (6.83%) noted for absolute CD4 and CD4% respectively. No significant clinical differences were indicated for either parameter using two sampling methods. Conclusion The Presto™ produced remarkable precision to predicate methods, irrespective of venous or capillary blood sampling. A consistent, clinically insignificant over-estimation (5–7%) of counts against PLG/CD4 and equivalency to FACSCount™ was noted. Further field studies are awaited to confirm longer-term use.
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Affiliation(s)
- Lindi-Marie Coetzee
- National Health Laboratory Service of South Africa (NHLS), Charlotte Maxeke Hospital, CD4 Laboratory, Parktown, Johannesburg, South Africa.,Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2198, Johannesburg, South Africa
| | - Keshendree Moodley
- Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2198, Johannesburg, South Africa
| | - Deborah Kim Glencross
- National Health Laboratory Service of South Africa (NHLS), Charlotte Maxeke Hospital, CD4 Laboratory, Parktown, Johannesburg, South Africa.,Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2198, Johannesburg, South Africa
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Scott LE, Campbell J, Westerman L, Kestens L, Vojnov L, Kohastsu L, Nkengasong J, Peter T, Stevens W. A meta-analysis of the performance of the Pima™ CD4 for point of care testing. BMC Med 2015; 13:168. [PMID: 26208867 PMCID: PMC4515022 DOI: 10.1186/s12916-015-0396-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The Alere point-of-care (POC) Pima™ CD4 analyzer allows for decentralized testing and expansion to testing antiretroviral therapy (ART) eligibility. A consortium conducted a pooled multi-data technical performance analysis of the Pima CD4. METHODS Primary data (11,803 paired observations) comprised 22 independent studies between 2009-2012 from the Caribbean, Asia, Sub-Saharan Africa, USA and Europe, using 6 laboratory-based reference technologies. Data were analyzed as categorical (including binary) and numerical (absolute) observations using a bivariate and/or univariate random effects model when appropriate. RESULTS At a median reference CD4 of 383 cells/μl the mean Pima CD4 bias is -23 cells/μl (average bias across all CD4 ranges is 10 % for venous and 15% for capillary testing). Sensitivity of the Pima CD4 is 93% (95% confidence interval [CI] 91.4% - 94.9%) at 350 cells/μl and 96% (CI 95.2% - 96.9%) at 500 cells/μl, with no significant difference between venous and capillary testing. Sensitivity reduced to 86% (CI 82% - 89%) at 100 cells/μl (for Cryptococcal antigen (CrAg) screening), with a significant difference between venous (88%, CI: 85% - 91%) and capillary (79%, CI: 73% - 84%) testing. Total CD4 misclassification is 2.3% cases at 100 cells/μl, 11.0% at 350 cells/μl and 9.5 % at 500 cells/μl, due to higher false positive rates which resulted in more patients identified for treatment. This increased by 1.2%, 2.8% and 1.8%, respectively, for capillary testing. There was no difference in Pima CD4 misclassification between the meta-analysis data and a population subset of HIV+ ART naïve individuals, nor in misclassification among operator cadres. The Pima CD4 was most similar to Beckman Coulter PanLeucogated CD4, Becton Dickinson FACSCalibur and FACSCount, and less similar to Partec CyFlow reference technologies. CONCLUSIONS The Pima CD4 may be recommended using venous-derived specimens for screening (100 cells/μl) for reflex CrAg screening and for HIV ART eligibility at 350 cells/μl and 500 cells/μl thresholds using both capillary and venous derived specimens. These meta-analysis findings add to the knowledge of acceptance criteria of the Pima CD4 and future POC tests, but implementation and impact will require full costing analysis.
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Affiliation(s)
- Lesley E Scott
- Department of Molecular Medicine and Haematology, Faculty of Health Science, School of Pathology, University of the Witwatersrand, 7 York Road Parktown, Johannesburg, South Africa.
| | | | | | - Luc Kestens
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium. .,Laboratory of Immunology, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
| | - Lara Vojnov
- Clinton Health Access Initiative, Boston, MA, USA.
| | | | | | - Trevor Peter
- Clinton Health Access Initiative, Boston, MA, USA.
| | - Wendy Stevens
- Department of Molecular Medicine and Haematology, Faculty of Health Science, School of Pathology, University of the Witwatersrand, 7 York Road Parktown, Johannesburg, South Africa. .,National Health Laboratory Service, Johannesburg, South Africa.
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Peeling RW, Sollis KA, Glover S, Crowe SM, Landay AL, Cheng B, Barnett D, Denny TN, Spira TJ, Stevens WS, Crowley S, Essajee S, Vitoria M, Ford N. CD4 enumeration technologies: a systematic review of test performance for determining eligibility for antiretroviral therapy. PLoS One 2015; 10:e0115019. [PMID: 25790185 PMCID: PMC4366094 DOI: 10.1371/journal.pone.0115019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 11/17/2014] [Indexed: 12/04/2022] Open
Abstract
Background Measurement of CD4+ T-lymphocytes (CD4) is a crucial parameter in the management of HIV patients, particularly in determining eligibility to initiate antiretroviral treatment (ART). A number of technologies exist for CD4 enumeration, with considerable variation in cost, complexity, and operational requirements. We conducted a systematic review of the performance of technologies for CD4 enumeration. Methods and Findings Studies were identified by searching electronic databases MEDLINE and EMBASE using a pre-defined search strategy. Data on test accuracy and precision included bias and limits of agreement with a reference standard, and misclassification probabilities around CD4 thresholds of 200 and 350 cells/μl over a clinically relevant range. The secondary outcome measure was test imprecision, expressed as % coefficient of variation. Thirty-two studies evaluating 15 CD4 technologies were included, of which less than half presented data on bias and misclassification compared to the same reference technology. At CD4 counts <350 cells/μl, bias ranged from -35.2 to +13.1 cells/μl while at counts >350 cells/μl, bias ranged from -70.7 to +47 cells/μl, compared to the BD FACSCount as a reference technology. Misclassification around the threshold of 350 cells/μl ranged from 1-29% for upward classification, resulting in under-treatment, and 7-68% for downward classification resulting in overtreatment. Less than half of these studies reported within laboratory precision or reproducibility of the CD4 values obtained. Conclusions A wide range of bias and percent misclassification around treatment thresholds were reported on the CD4 enumeration technologies included in this review, with few studies reporting assay precision. The lack of standardised methodology on test evaluation, including the use of different reference standards, is a barrier to assessing relative assay performance and could hinder the introduction of new point-of-care assays in countries where they are most needed.
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Affiliation(s)
- Rosanna W. Peeling
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, England
- * E-mail:
| | - Kimberly A. Sollis
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, England
| | - Sarah Glover
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, England
| | - Suzanne M. Crowe
- Centre for Biomedical Research, Burnet Institute, Melbourne, 3004, Victoria, Australia
| | - Alan L. Landay
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, IL, 60612, United States of America
| | - Ben Cheng
- Pangaea Global AIDS Foundation, Oakland, CA, 94607, United States of America
| | - David Barnett
- UK NEQAS for Leucocyte Immunophenotyping, Sheffield, S10 2QD, England
| | - Thomas N. Denny
- Duke Human Vaccine Institute and Center for HIV/AIDS, Immunology and Virology Quality Assessment Center, Durham, NC, 27710, United States of America
| | - Thomas J. Spira
- Division of AIDS, STD, &TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30333, United States of America
| | | | - Siobhan Crowley
- Director Health Programs, ELMA Philanthropies, New York, NY, United States of America
| | - Shaffiq Essajee
- Clinton Health Access Initiative, Boston, MA, 02127, United States of America
| | | | - Nathan Ford
- World Health Organization, Geneva, Switzerland
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WHO multicenter evaluation of FACSCount CD4 and Pima CD4 T-cell count systems: instrument performance and misclassification of HIV-infected patients. J Acquir Immune Defic Syndr 2014; 66:e98-107. [PMID: 24853304 PMCID: PMC4149645 DOI: 10.1097/qai.0000000000000214] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND CD4⁺ T-cell counts are used to screen and follow-up HIV-infected patients during treatment. As part of the World Health Organization prequalification program of diagnostics, we conducted an independent multicenter evaluation of the FACSCount CD4 and the Pima CD4, using the FACSCalibur as reference method. METHODS A total of 440 paired capillary and venous blood samples were collected from HIV-infected patients attending the HIV outpatient clinic in Antwerp, Belgium, and the HIV care and treatment center in Dar es Salam, Tanzania. Capillary blood was run on Pima analyzer, whereas venous blood was analyzed on FACSCount, Pima, and FACSCalibur instruments. Precision and agreement between methods were assessed. RESULTS The FACSCount CD4 results were in agreement with the FACSCalibur results with relative bias of 0.4% and 3.1% on absolute CD4 counts and an absolute bias of -0.6% and -1.1% on CD4% in Antwerp and Dar es Salam, respectively. The Pima CD4 results were in agreement with the FACSCalibur results with relative bias of -4.1% and -9.4% using venous blood and of -9.5% and -0.9% using capillary blood in Antwerp and Dar es Salam, respectively. At the threshold of 350 cells per microliter, the FACSCount CD4 and Pima CD4 using venous and capillary blood misclassified 7%, 9%, and 13% of patients, respectively. CONCLUSIONS The FACSCount CD4 provides reliable CD4 counts and CD4% and is suitable for monitoring adult and pediatric HIV patients in moderate-volume settings. The Pima CD4 is more suitable for screening eligible adult HIV patients for antiretroviral treatment initiation in low-volume laboratories.
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Piyasena ME, Graves SW. The intersection of flow cytometry with microfluidics and microfabrication. LAB ON A CHIP 2014; 14:1044-59. [PMID: 24488050 PMCID: PMC4077616 DOI: 10.1039/c3lc51152a] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A modern flow cytometer can analyze and sort particles on a one by one basis at rates of 50,000 particles per second. Flow cytometers can also measure as many as 17 channels of fluorescence, several angles of scattered light, and other non-optical parameters such as particle impedance. More specialized flow cytometers can provide even greater analysis power, such as single molecule detection, imaging, and full spectral collection, at reduced rates. These capabilities have made flow cytometers an invaluable tool for numerous applications including cellular immunophenotyping, CD4+ T-cell counting, multiplex microsphere analysis, high-throughput screening, and rare cell analysis and sorting. Many bio-analytical techniques have been influenced by the advent of microfluidics as a component in analytical tools and flow cytometry is no exception. Here we detail the functions and uses of a modern flow cytometer, review the recent and historical contributions of microfluidics and microfabricated devices to field of flow cytometry, examine current application areas, and suggest opportunities for the synergistic application of microfabrication approaches to modern flow cytometry.
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Affiliation(s)
- Menake E. Piyasena
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM USA
- Department of Chemistry, New Mexico Tech, Socorro, NM USA
| | - Steven W. Graves
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM USA
- Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, NM USA, FAX: 15052771979; TEL:15052772043
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Feasibility of performing multiple point of care testing for HIV anti-retroviral treatment initiation and monitoring from multiple or single fingersticks. PLoS One 2013; 8:e85265. [PMID: 24376873 PMCID: PMC3869909 DOI: 10.1371/journal.pone.0085265] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 11/25/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Point of Care testing (POCT) provides on-site, rapid, accessible results. With current South African anti-retroviral treatment guidelines, up to 4 fingersticks /patient/clinic visit could be required if utilizing POC. We determined the feasibility and accuracy of a nurse performing multiple POCT on multiple fingersticks followed by simplification of the process by performance of multiple POC on a single fingerstick. METHOD AND FINDINGS Random HIV positive adult patients presenting at a HIV treatment clinic in South Africa, for ART initiation/ monitoring, were approached to participate in the study between April-June 2012. Phase I: n=150 patients approached for multiple POCT on multiple fingersticks. Phase II: n=150 patients approached for multiple POCT on a single fingerstick. The following POC tests were performed by a dedicated nurse: PIMA (CD4), HemoCue (hemoglobin), Reflotron (alanine aminotransferase, creatinine). A venepuncture specimen was taken for predicate laboratory methodology. Normal laboratory ranges and Royal College of Pathologists Australasia (RCPA) allowable differences were used as guidelines for comparison. In 67% of participants, ≥3 tests were requested per visit. All POCT were accurate but ranged in variability. Phase I: Hemoglobin was accurate (3.2%CV) while CD4, alanine aminotransferase and creatinine showed increased variability (16.3%CV; 9.3%CV; 12.9%CV respectively). PIMA generated a misclassification of 12.4%. Phase II: Hemoglobin, alanine aminotransferase and creatinine showed good accuracy (3.2%CV, 8.7%CV, 6.4%CV respectively) with increased variability on CD4 (12.4%CV) but low clinical misclassification (4.1%). No trends were observed for the sequence in which POC was performed on a single fingerstick. Overall, PIMA CD4 generated the highest error rate (16-19%). CONCLUSIONS Multiple POCT for ART initiation and/or monitoring can be performed practically by a dedicated nurse on multiple fingersticks. The process is as accurate as predicate methodology and can be simplified using a single fingerstick.
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Performance of the PointCare NOW system for CD4 counting in HIV patients based on five independent evaluations. PLoS One 2012; 7:e41166. [PMID: 22912668 PMCID: PMC3415398 DOI: 10.1371/journal.pone.0041166] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 06/02/2012] [Indexed: 11/19/2022] Open
Abstract
Introduction Point-of-care (POC) CD4 testing can improve access to treatment by enabling decentralization and reducing patient loss-to-follow-up. As new POC CD4 technologies become available, their performance should be assessed before widespread deployment. This study reports the findings of five independent evaluations of the PointCare NOW CD4 system. Materials/Methods Evaluations were conducted in Southern Africa (Mozambique, South Africa) and North America (Canada, USA). 492 blood samples (55 from HIV-negative blood donors and 437 from HIV-infected patients, including 20 children aged between 12 and 59 months) were tested with both the PointCare NOW and reference flow cytometry instruments. Assessment of bias, precision and levels of clinical misclassification for absolute and percent CD4 count was conducted. Results PointCare NOW significantly overestimated CD4 absolute counts with a mean relative bias of +35.0%. Bias was greater in samples with CD4 counts below ≤350cells/µl (+51.3%) than in the CD4 >350cells/µl stratum (15.1%). Bias in CD4% had a similar trend with an overall relative mean bias of +25.6% and a larger bias for low CD4 stratum (+40.2%) than the higher CD4 stratum (+5.8%). Relative bias for CD4% in children was −6.8%. In terms of repeatability, PointCare NOW had a coefficient of variation of 11%. Using a threshold of 350cells/µl, only 47% of patients who qualified for antiretroviral therapy with reference CD4 testing, would have been eligible for treatment with PointCare NOW test results. This was 39% using a 200cells/µl threshold. Agreement with infant samples was higher, with 90% qualifying at a 25% eligibility threshold. Conclusion The performance of the PointCare NOW instrument for absolute and percent CD4 enumeration was inadequate for HIV clinical management in adults. In children, the small sample size was not large enough to draw a conclusion. This study also highlights the importance of independent evaluation of new diagnostic technology platforms before deployment.
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One-dimensional acoustic standing waves in rectangular channels for flow cytometry. Methods 2012; 57:259-71. [DOI: 10.1016/j.ymeth.2012.02.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 02/22/2012] [Accepted: 02/23/2012] [Indexed: 11/21/2022] Open
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Butterfield LH, Palucka AK, Britten CM, Dhodapkar MV, Håkansson L, Janetzki S, Kawakami Y, Kleen TO, Lee PP, Maccalli C, Maecker HT, Maino VC, Maio M, Malyguine A, Masucci G, Pawelec G, Potter DM, Rivoltini L, Salazar LG, Schendel DJ, Slingluff CL, Song W, Stroncek DF, Tahara H, Thurin M, Trinchieri G, van Der Burg SH, Whiteside TL, Wigginton JM, Marincola F, Khleif S, Fox BA, Disis ML. Recommendations from the iSBTc-SITC/FDA/NCI Workshop on Immunotherapy Biomarkers. Clin Cancer Res 2011; 17:3064-76. [PMID: 21558394 DOI: 10.1158/1078-0432.ccr-10-2234] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To facilitate development of innovative immunotherapy approaches, especially for treatment concepts exploiting the potential benefits of personalized therapy, there is a need to develop and validate tools to identify patients who can benefit from immunotherapy. Despite substantial effort, we do not yet know which parameters of antitumor immunity to measure and which assays are optimal for those measurements. EXPERIMENTAL DESIGN The iSBTc-SITC (International Society for Biological Therapy of Cancer-Society for Immunotherapy of Cancer), FDA (Food and Drug Administration), and NCI (National Cancer Institute) partnered to address these issues for immunotherapy of cancer. Here, we review the major challenges, give examples of approaches and solutions, and present our recommendations. RESULTS AND CONCLUSIONS Although specific immune parameters and assays are not yet validated, we recommend following standardized (accurate, precise, and reproducible) protocols and use of functional assays for the primary immunologic readouts of a trial; consideration of central laboratories for immune monitoring of large, multi-institutional trials; and standardized testing of several phenotypic and functional potential potency assays specific to any cellular product. When reporting results, the full QA (quality assessment)/QC (quality control) should be conducted and selected examples of truly representative raw data and assay performance characteristics should be included. Finally, to promote broader analysis of multiple aspects of immunity, and gather data on variability, we recommend that in addition to cells and serum, RNA and DNA samples be banked (under standardized conditions) for later testing. We also recommend that sufficient blood be drawn to allow for planned testing of the primary hypothesis being addressed in the trial, and that additional baseline and posttreatment blood is banked for testing novel hypotheses (or generating new hypotheses) that arise in the field.
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Affiliation(s)
- Lisa H Butterfield
- Department of Medicine, University of Pittsburgh, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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Chan C, Lin L, Frelinger J, Hérbert V, Gagnon D, Landry C, Sékaly RP, Enzor J, Staats J, Weinhold KJ, Jaimes M, West M. Optimization of a highly standardized carboxyfluorescein succinimidyl ester flow cytometry panel and gating strategy design using discriminative information measure evaluation. Cytometry A 2011; 77:1126-36. [PMID: 21053294 DOI: 10.1002/cyto.a.20987] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The design of a panel to identify target cell subsets in flow cytometry can be difficult when specific markers unique to each cell subset do not exist, and a combination of parameters must be used to identify target cells of interest and exclude irrelevant events. Thus, the ability to objectively measure the contribution of a parameter or group of parameters toward target cell identification independent of any gating strategy could be very helpful for both panel design and gating strategy design. In this article, we propose a discriminative information measure evaluation (DIME) based on statistical mixture modeling; DIME is a numerical measure of the contribution of different parameters towards discriminating a target cell subset from all the others derived from the fitted posterior distribution of a Gaussian mixture model. Informally, DIME measures the "usefulness" of each parameter for identifying a target cell subset. We show how DIME provides an objective basis for inclusion or exclusion of specific parameters in a panel, and how ranked sets of such parameters can be used to optimize gating strategies. An illustrative example of the application of DIME to streamline the gating strategy for a highly standardized carboxyfluorescein succinimidyl ester (CFSE) assay is described.
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Affiliation(s)
- Cliburn Chan
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC 27710, USA.
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Frelinger J, Ottinger J, Gouttefangeas C, Chan C. Modeling flow cytometry data for cancer vaccine immune monitoring. Cancer Immunol Immunother 2010; 59:1435-41. [PMID: 20563720 PMCID: PMC2892609 DOI: 10.1007/s00262-010-0883-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 06/09/2010] [Indexed: 11/30/2022]
Abstract
Flow cytometry (FCM) is widely used in cancer research for diagnosis, detection of minimal residual disease, as well as immune monitoring and profiling following immunotherapy. In all these applications, the challenge is to detect extremely rare cell subsets while avoiding spurious positive events. To achieve this objective, it helps to be able to analyze FCM data using multiple markers simultaneously, since the additional information provided often helps to minimize the number of false positive and false negative events, hence increasing both sensitivity and specificity. However, with manual gating, at most two markers can be examined in a single dot plot, and a sequential strategy is often used. As the sequential strategy discards events that fall outside preceding gates at each stage, the effectiveness of the strategy is difficult to evaluate without laborious and painstaking back-gating. Model-based analysis is a promising computational technique that works using information from all marker dimensions simultaneously, and offers an alternative approach to flow analysis that can usefully complement manual gating in the design of optimal gating strategies. Results from model-based analysis will be illustrated with examples from FCM assays commonly used in cancer immunotherapy laboratories.
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Affiliation(s)
- Jacob Frelinger
- Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA
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Janossy G, Mandy F. Translational medicine as implementation science in the field of monitoring HIV and TB. New concepts emanating from resource-poor countries. CYTOMETRY PART B-CLINICAL CYTOMETRY 2010; 78:183-7. [DOI: 10.1002/cyto.b.20527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Naivar MA, Wilder ME, Habbersett RC, Woods TA, Sebba DS, Nolan JP, Graves SW. Development of small and inexpensive digital data acquisition systems using a microcontroller-based approach. Cytometry A 2010; 75:979-89. [PMID: 19852060 DOI: 10.1002/cyto.a.20814] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fully digital data acquisition systems for use in flow cytometry provide excellent flexibility and precision. Here, we demonstrate the development of a low cost, small, and low power digital flow cytometry data acquisition system using a single microcontroller chip with an integrated analog to digital converter (ADC). Our demonstration system uses a commercially available evaluation board making the system simple to integrate into a flow cytometer. We have evaluated this system using calibration microspheres analyzed on commercial, slow-flow, and CCD-based flow cytometers. In our evaluations, our demonstration data system clearly resolves all eight peaks of a Rainbow microsphere set on both a slow-flow flow cytometer and a retrofitted BD FACScalibur, which indicates it has the sensitivity and resolution required for most flow cytometry applications. It is also capable of millisecond time resolution, full waveform collection, and selective triggering of data collection from a CCD camera. The capability of our demonstration system suggests that the use of microcontrollers for flow cytometry digital data-acquisition will be increasingly valuable for extending the life of older cytometers and provides a compelling data-system design approach for low-cost, portable flow cytometers.
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Affiliation(s)
- Mark A Naivar
- The National Flow Cytometry Resource, Biosciences Division, Los Alamos National Laboratory, Los Alamos, NM 87131-0001, USA.
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Plate MM, Louzao R, Steele PM, Greengrass V, Morris LM, Lewis J, Barnett D, Warrino D, Hearps AC, Denny T, Crowe SM. Evaluation of the Blood Stabilizers TransFix™ and Cyto-Chex®BCT for Low-Cost CD4 T-Cell Methodologies. Viral Immunol 2009; 22:329-32. [DOI: 10.1089/vim.2009.0027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Megan M. Plate
- AIDS Pathogenesis and Clinical Research Program, Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Raul Louzao
- Duke Human Vaccine Institute and Center for HIV/AIDS Vaccine Immunology, Research Park, Durham, North Carolina
| | - Pauline M. Steele
- AIDS Pathogenesis and Clinical Research Program, Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Vicki Greengrass
- AIDS Pathogenesis and Clinical Research Program, Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Lisa M. Morris
- AIDS Pathogenesis and Clinical Research Program, Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Jenny Lewis
- Centre for International Health, Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - David Barnett
- United Kingdom National External Quality Assessment Service (UK NEQAS) for Leukocyte Immunophenotyping, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | | | - Anna C. Hearps
- AIDS Pathogenesis and Clinical Research Program, Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Thomas Denny
- Duke Human Vaccine Institute and Center for HIV/AIDS Vaccine Immunology, Research Park, Durham, North Carolina
| | - Suzanne M. Crowe
- AIDS Pathogenesis and Clinical Research Program, Burnet Institute for Medical Research and Public Health, Melbourne, Australia
- Department of Medicine, Monash University, Melbourne, Australia
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Abstract
The ability to rapidly identify immune cell subsets such as CD4 cells, which became possible around the same time as the onset of the HIV/AIDS pandemic, was one of the greatest advances in clinical and diagnostic immunology. The evolution of this global pandemic and the subsequent development of treatment strategies to prolong the life of infected individuals mean that it is now more crucial than ever that we develop affordable, reliable and accurate methods for the enumeration of CD4 cells. Here, we provide an overview of the historical developments in CD4 enumeration technologies that are related to HIV infection, and summarize the current technological challenges that must be overcome to meet the needs of those living with HIV infection.
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Affiliation(s)
- David Barnett
- UK NEQAS for Leukocyte Immunophenotyping, Rutledge Mews, 3 Southbourne Road, Sheffield, S10 2QN UK.
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Stevens W, Gelman R, Glencross DK, Scott LE, Crowe SM, Spira T. Evaluating new CD4 enumeration technologies for resource-constrained countries. Nat Rev Microbiol 2008; 6:S29-38. [PMID: 22745957 DOI: 10.1038/nrmicro2000] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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