William Rodriguez and colleagues now report a new way of counting CD4 cells that is cheaper and easier than the current state-of-the-art technology. As they describe in the July issue of the international medical journal PLoS Medicine, their prototype performed well when tested on real-life samples, mostly from adult patients. Its reliability was as good as the existing counters in the range of counts where CD4 numbers are most critical to inform treatment decisions. A fully portable handheld model is now under development. After some modest training, such a tool should allow a variety of health care workers in remote areas to accurately analyze the CD4 status of HIV infected patients locally.
In an accompanying Perspective article, Zvi Bentwich (of Hebrew University in Jerusalem) argues that "the absence of tools to measure CD4 counts clearly jeopardizes the success of recently launched global campaigns to fight AIDS". While acknowledging that several issues remain to be resolved before the assay can become a widely used tool in resource-poor settings, Bentwich states "the authors of this study should be commended for addressing an extremely important issue and developing this novel approach for counting CD4 in patients with HIV."