RESEARCH ARTICLE
Validation of Microcapillary Flow Cytometry for Community-Based CD4+ T Lymphocyte Enumeration in Remote Burkina Faso
Cybèle A Renault1, *, Arouna Traore 3, Rhoderick N Machekano 2, 4, Dennis M Israelski 1, 2, 3, 5
Article Information
Identifiers and Pagination:
Year: 2010Volume: 4
First Page: 171
Last Page: 175
Publisher ID: TOAIDJ-4-171
DOI: 10.2174/1874613601004010171
Article History:
Received Date: 21/10/2009Revision Received Date: 16/8/2010
Acceptance Date: 15/9/2010
Electronic publication date: 30/12/2010
Collection year: 2010
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited
Abstract
Background
CD4+ T lymphocyte enumeration plays a critical role in the initiation and monitoring of HIV-infected patients on antiretroviral therapy. There is an urgent need for low-cost CD4+ enumeration technologies, particularly for use in dry, dusty climates characteristic of many small cities in Sub-Saharan Africa
Design
Cross-sectional study
Methods
Blood samples from 98 HIV-infected patients followed in a community HIV clinic in Ouahigouya, Burkina Faso were obtained for routine CD4+ T lymphocyte count monitoring. The blood samples were divided into two aliquots, on which parallel CD4+ measurements were performed using microcapillary (Guava EasyCD4) and dedicated (Becton Dickinson FACSCount) CD4+ enumeration systems. Spearman rank correlation coefficient was calculated, and the sensitivity, specificity and positive predictive value (PPV) for EasyCD4 <200 cells/µL were determined compared to the reference standard FACSCount CD4 <200 cells/µL
Results
Mean CD4 counts for the EasyCD4 and FACSCount were 313.75 cells/µL and 303.47 cells/µL, respectively. The Spearman rank correlation coefficient was 0.92 (p<0.001). Median values using EasyCD4 were higher than those with the FACSCount (p=0.004). For a CD4<350 cells/uL, sensitivity of the EasyCD4 was 93.9% (95%CI 85.2-98.3%), specificity was 90.6% (95% CI 75.0-98.0%), and PPV was 95.4% (95%CI 87.1-99.0%)
Conclusion
Use of the EasyCD4 system was feasible and highly accurate in the harsh conditions of this remote city in Sub-Saharan Africa, demonstrating acceptable sensitivity and specificity compared to a standard operating system. Microcapillary flow cytometry offers a cost-effective alternative for community-based, point-of-care CD4+ testing and could play a substantial role in scaling up HIV care in remote, resource-limited settings
