Evaluation of Dynabeads and Cytospheres Compared With Flow Cytometry to Enumerate CD41 T Cells in HIV-Infected Ugandans on Antiretroviral Therapy

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dc.creatorLutwama, Fred
dc.creatorSerwadda, Ronnie
dc.creatorMayanja-Kizza, Harriet
dc.creatorShihab, Hasan M.
dc.creatorRonald, Allan
dc.creatorKamya, Moses R.
dc.creatorThomas, David
dc.creatorJohnson, Elizabeth
dc.creatorQuinn, Thomas C.
dc.creatorMoore, Richard D.
dc.creatorSpacek, Lisa A.
dc.date2011-12-30T19:06:24Z
dc.date2011-12-30T19:06:24Z
dc.date2008-07-01
dc.date.accessioned2018-09-04T12:32:17Z
dc.date.available2018-09-04T12:32:17Z
dc.descriptionCorrespondence to: Lisa A. Spacek, MD, PhD, Assistant Professor, Division of Infectious Diseases, Johns Hopkins Medical Institutions, 1830 East Monument Street, Room 421, Baltimore, MD 21287 (e-mail: lspacek@ jhmi.edu).
dc.descriptionBackground: Laboratory-based monitoring of antiretroviral therapy is essential but adds a significant cost to HIV care. The World Health Organization 2006 guidelines support the use of CD4 lymphocyte count (CD4) to define treatment failure in resource-limited settings. Methods: We compared CD4 obtained on replicate samples from 497 HIV-positive Ugandans (before and during ART) followed for 18 months by 2 manual bead–based assays, Dynabeads (Dynal Biotech), and Cytospheres (Beckman Coulter) with those generated by flow cytometry at the Infectious Diseases Institute in Kampala, Uganda. Results: We tested 1671 samples (123 before ART) with Dynabeads and 1444 samples (91 before ART) with Cytospheres. Mean CD4 was 231 cells/mm3 (SD, 139) and 239 cells/mm3 (SD, 140) by Dynabeads and flow cytometry, respectively. Mean CD4 was 186 cells/mm3 (SD, 101) and 242 cells/mm3 (SD, 136) by Cytospheres and flow cytometry, respectively. The mean difference in CD4 count by flow cytometry versus Dynabeads were 8.8 cells/mm3 (SD, 76.0) and versus Cytospheres were 56.8 cells/mm3 (SD, 85.8). The limits of agreement were 2140.9 to 158.4 cells/mm3 for Dynabeads and 2112.2 to 225.8 cells/mm3 for Cytospheres. Linear regression analysis showed higher correlation between flow cytometry and Dynabeads (r = 0.85, r2 = 0.73, slope = 0.85, intercept = 28) compared with the correlation between flow cytometry and Cytospheres (r = 0.78, r2 = 0.60, slope = 0.58, intercept = 45). Area under the receiver operating characteristics curve to predict CD4 ,200 cells/mm3 was 0.928 for Dynabeads and 0.886 for Cytospheres. Conclusion: Although Dynabeads and Cytospheres both underestimated CD4 lymphocyte count compared with flow cytometry, in resource-limited settings with low daily throughput, manual bead– based assays may provide a less expensive alternative to flow cytometry.
dc.identifierLutwama F. et al. (2008). Evaluation of Dynabeads and Cytospheres Compared With Flow Cytometry to Enumerate CD41 T Cells in HIV-Infected Ugandans on Antiretroviral Therapy. Journal of Acquired Immune Deficiency Syndromes, 48(3):297-303
dc.identifier1525-4135
dc.identifier1944-7884
dc.identifierhttp://hdl.handle.net/10570/283
dc.identifier.urihttp://hdl.handle.net/10570/283
dc.languageen
dc.publisherLippincott Williams & Wilkins.
dc.subjectCD4 lymphocyte counts
dc.subjectHIV-1 viral load
dc.subjectMonitoring and evaluation
dc.subjectAntiretroviral therapy
dc.subjectResource-limited setting
dc.subjectUganda
dc.titleEvaluation of Dynabeads and Cytospheres Compared With Flow Cytometry to Enumerate CD41 T Cells in HIV-Infected Ugandans on Antiretroviral Therapy
dc.typeJournal article, peer reviewed
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