The major goal of the paper is to compare these two tests.  CD4 count is the gold standard for determining when to start antiretroviral (ARV) therapy, but it is expensive.  CD4 cell counts are typically performed by flow cytometry, which is not available, and difficult to maintain in many resource-limited settings. [8]  Thus, the WHO has suggested TLC as a cheaper alternative for determining when to begin ARV therapy when CD4 counts are not available in resource-limited settings.

In order to complete this study, samples were sent off-site for flow cytometric analysis.