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Zijenah LS, Kadzirange G, Madzime S, et al. Affordable flow cytometry for enumeration of absolute CD4+ T-lymphocytes to identify subtype C HIV-1 infected adults requiring antiretroviral therapy (ART) and monitoring response to ART in a resource-limited setting. J Transl Med. 2006;4:33doi: 10.1186/1479-5876-4-33.
Zijenah, L. S., Kadzirange, G., Madzime, S., Borok, M., Mudiwa, C., Tobaiwa, O., Mucheche, M., Rusakaniko, S., & Katzenstein, D. A. (2006). Affordable flow cytometry for enumeration of absolute CD4+ T-lymphocytes to identify subtype C HIV-1 infected adults requiring antiretroviral therapy (ART) and monitoring response to ART in a resource-limited setting. Journal of translational medicine, 433. https://doi.org/10.1186/1479-5876-4-33
Zijenah, Lynn S, et al. "Affordable flow cytometry for enumeration of absolute CD4+ T-lymphocytes to identify subtype C HIV-1 infected adults requiring antiretroviral therapy (ART) and monitoring response to ART in a resource-limited setting." Journal of translational medicine vol. 4 (2006): 33. doi: https://doi.org/10.1186/1479-5876-4-33
Zijenah LS, Kadzirange G, Madzime S, Borok M, Mudiwa C, Tobaiwa O, Mucheche M, Rusakaniko S, Katzenstein DA. Affordable flow cytometry for enumeration of absolute CD4+ T-lymphocytes to identify subtype C HIV-1 infected adults requiring antiretroviral therapy (ART) and monitoring response to ART in a resource-limited setting. J Transl Med. 2006 Aug 14;4:33. doi: 10.1186/1479-5876-4-33. PMID: 16907973; PMCID: PMC1586214.
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J Transl Med. 2006 Aug 14;4:33. doi: 10.1186/1479-5876-4-33.

Affordable flow cytometry for enumeration of absolute CD4+ T-lymphocytes to identify subtype C HIV-1 infected adults requiring antiretroviral therapy (ART) and monitoring response to ART in a resource-limited setting.

Journal of translational medicine

Lynn S Zijenah, Gerard Kadzirange, Simon Madzime, Margaret Borok, Chiedza Mudiwa, Ocean Tobaiwa, Mary Mucheche, Simbarashe Rusakaniko, David A Katzenstein

Affiliations

  1. Department of Immunology, College of Health Sciences University of Zimbabwe, Harare, Zimbabwe. [email protected]

PMID: 16907973 PMCID: PMC1586214 DOI: 10.1186/1479-5876-4-33

Abstract

BACKGROUND: The World Health Organization (WHO)'s "3 x 5 program" has spurred efforts to place 3 million people on combination antiretroviral therapy (ART) for treatment of AIDS in resource-limited countries. Paradoxically, the cost of CD4+ T-lymphocyte count essential for decision-making to commence HIV positive adults on ART as well as for monitoring responses to ART remains unaffordable in most resource-limited countries. Thus, low-cost methods for enumerating CD4+ T-lymphocyte are urgently needed.

OBJECTIVE: To evaluate Cyflow cytometry (Cyflow SL, Partec, Munster, Germany) for enumeration of absolute CD4+ T-lymphocyte in subtype C HIV-1 seropositive subjects using FACSCount (Becton and Dickinson, Immunocytometry Systems, San Jose, CA, USA) as the "predicate method".

METHODS: A total of 150 HIV-1 seropositive subjects were included in the evaluation exercise. Fifty-eight specimens were collected from pregnant HIV-1 seropositive women (subtype C drug resistance study). Twenty-seven specimens were collected from women and their spouses with AIDS followed in a Duke ART study to assess the immunologic and virologic responses to generic ART, comprising Stavudine, Lamivudine and Nevirapine (Stalanev, Varichem Labs, Harare, Zimbabwe). Sixty-five specimens were collected from AIDS patients enrolled in an ongoing Kaposi Sarcoma (KS) study to investigate impact of ART on KS progression. Enumeration of CD4+ T-lymphocytes using FACSCount is routinely conducted for all the three studies. The Medical Research Council of Zimbabwe and Medicines Control Authority of Zimbabwe approved the studies. Whole blood was collected in EDTA vacutainer tubes and aliquoted into two tubes (200 microL in each). CD4+ T-lymphocyte counts were enumerated using a Cyflow counter, in the Department of Immunology and a FACSCount in the Department of Obstetrics and Gynaecology within 6 hours of phlebotomy following manufacturers' instructions.

RESULTS: Using linear regression analysis, there was a very strong correlation (R = 0.991) between the overall CD4+ T-lymphocyte counts obtained by FACSCount and those obtained by Cyflow. When data analysis was stratified by study groups, there was a strong correlation between the FACSCount and Cyflow CD4+ T-lymphocyte counts from subjects in the three independent studies; Subtype C resistance (R2 = 0.987), Duke ART (R2 = 0.980) and KS (R2 = 0.994), Table 1. Using Bland-Altman plots, the overall, absolute CD4+ T lymphocytes obtained by the two methods were in excellent agreement (mean difference 1.21, 95% Confidence Interval {CI): -2.1 to 3.3). For the 0-250 CD4+ T-lymphocytes range, the CD4 counts obtained using FACSCount were also in good agreement with those obtained using Cyflow counter (mean difference = 2.6 cells/microL, 95% CI: -1.1 to 6.3). Similarly, in the 251-500 (mean difference 1.0, cells/microL, 95% CI: -3.7 to 5.6) and the 501-1200 (mean difference = 0.29 cells/microL, 95% CI: -8.1 to 8.7) CD4 T-lymphocytes range, good agreement was observed.

CONCLUSION: The Cyflow counter is as accurate as the FACSCount in enumerating absolute CD4+ T-lymphocytes in the range 1-1200 cells/muL. Cyflow cytometry is relatively affordable, easy to use technology that is useful not only in identifying HIV seropositive individuals who require ART but also for monitoring immunologic responses to ART.

References

  1. J Immunol Methods. 1996 Sep 9;195(1-2):103-12 - PubMed
  2. Clin Diagn Lab Immunol. 2000 May;7(3):333-5 - PubMed
  3. Clin Diagn Lab Immunol. 2005 Dec;12(12):1416-24 - PubMed
  4. Cytometry. 2000 Dec 15;42(6):327-46 - PubMed
  5. Lancet. 1986 Feb 8;1(8476):307-10 - PubMed
  6. Br J Haematol. 2000 Dec;111(4):1198-208 - PubMed
  7. Br J Haematol. 1999 Sep;106(4):1059-62 - PubMed
  8. AIDS. 2003 Oct 17;17(15):2201-8 - PubMed
  9. Clin Diagn Lab Immunol. 2005 Jan;12(1):224-7 - PubMed
  10. AIDS Anal Afr. 2000 Feb-Mar;10(5):2 - PubMed
  11. Trans R Soc Trop Med Hyg. 2006 Oct;100(10):980-5 - PubMed
  12. J Acquir Immune Defic Syndr. 2005 May 1;39(1):32-7 - PubMed
  13. Antivir Ther. 2004 Jun;9(3):395-405 - PubMed

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