TY - JOUR
T1 - A microchip CD4 counting method for HIV monitoring in resource-poor settings
AU - Rodriguez, William R.
AU - Christodoulides, Nicolaos
AU - Floriano, Pierre N.
AU - Graham, Susan
AU - Mohanty, Sanghamitra
AU - Dixon, Meredith
AU - Hsiang, Mina
AU - Peter, Trevor
AU - Zavahir, Shabnam
AU - Thior, Ibou
AU - Romanovicz, Dwight
AU - Bernard, Bruce
AU - Goodey, Adrian P.
AU - Walker, Bruce D.
AU - McDevitt, John T.
PY - 2005
Y1 - 2005
N2 - Background: More than 35 million people in developing countries are living with HIV infection. An enormous global effort is now underway to bring antiretroviral treatment to at least 3 million of those infected. While drug prices have dropped considerably, the cost and technical complexity of laboratory tests essential for the management of HIV disease, such as CD4 cell counts, remain prohibitive. New, simple, and affordable methods for measuring CD4 cells that can be implemented in resource-scarce settings are urgently needed. Methods and Findings: Here we describe the development of a prototype for a simple, rapid, and affordable method for counting CD4 lymphocytes. Microliter volumes of blood without further sample preparation are stained with fluorescent antibodies, captured on a membrane within a miniaturized flow cell and imaged through microscope optics with the type of charge-coupled device developed for digital camera technology. An associated computer algorithm converts the raw digital image into absolute CD4 counts and CD4 percentages in real time. The accuracy of this prototype system was validated through testing in the United States and Botswana, and showed close agreement with standard flow cytometry (r = 0.95) over a range of absolute CD4 counts, and the ability to discriminate clinically relevant CD4 count thresholds with high sensitivity and specificity. Conclusion: Advances in the adaptation of new technologies to biomedical detection systems, such as the one described here, promise to make complex diagnostics for HIV and other infectious diseases a practical global reality.
AB - Background: More than 35 million people in developing countries are living with HIV infection. An enormous global effort is now underway to bring antiretroviral treatment to at least 3 million of those infected. While drug prices have dropped considerably, the cost and technical complexity of laboratory tests essential for the management of HIV disease, such as CD4 cell counts, remain prohibitive. New, simple, and affordable methods for measuring CD4 cells that can be implemented in resource-scarce settings are urgently needed. Methods and Findings: Here we describe the development of a prototype for a simple, rapid, and affordable method for counting CD4 lymphocytes. Microliter volumes of blood without further sample preparation are stained with fluorescent antibodies, captured on a membrane within a miniaturized flow cell and imaged through microscope optics with the type of charge-coupled device developed for digital camera technology. An associated computer algorithm converts the raw digital image into absolute CD4 counts and CD4 percentages in real time. The accuracy of this prototype system was validated through testing in the United States and Botswana, and showed close agreement with standard flow cytometry (r = 0.95) over a range of absolute CD4 counts, and the ability to discriminate clinically relevant CD4 count thresholds with high sensitivity and specificity. Conclusion: Advances in the adaptation of new technologies to biomedical detection systems, such as the one described here, promise to make complex diagnostics for HIV and other infectious diseases a practical global reality.
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U2 - 10.1371/journal.pmed.0020182
DO - 10.1371/journal.pmed.0020182
M3 - Article
C2 - 16013921
AN - SCOPUS:33846567457
SN - 1549-1277
VL - 2
SP - 663
EP - 672
JO - PLoS Medicine
JF - PLoS Medicine
IS - 7
ER -