A new sensor technology developed by researchers at the University of Illinois at Urbana-Champaign and collaborators at Daktari Diagnostics can diagnose HIV/AIDS using just a drop of blood. The device could provide less costly, easy-to-use, immediate disease diagnostics, especially useful in remote areas of the world and locations with limited resources.
This small, disposable biochip can count CD4+/CD8+ T cells quickly and accurately for HIV diagnosis. Developed by the research group of Rashid Bashir, professor and head of the Department of Bioengineering at Illinois, the device uses a microfluidic biochip, a miniaturized chip designed to process fluids and sense the cells electronically. It works similar to a common blood sugar test, where a patient can put a drop of blood on a strip and insert the strip into a handheld reader to get a blood glucose result. In this case, the strip is a biochip inside of a cartridge, where white blood cells are captured in a microfluidic chamber coated with proteins.
The portable device provides information on the number of white blood cells and CD4+ T cells (immune cells that get destroyed when a patient is infected with the HIV virus) are in a drop of blood. Clinical diagnoses of AIDS are based on when CD4 cells get below 200-350 cells per microliter of whole blood.
Results of the research have been published in the latest issue of the journal Science Translational Medicine. According to the paper’s first co-authors, Nicholas Watkins and Umer Hassan, the approach can detect sub-populations of white blood cells, such as CD4+ and CD8+ T cells, and it can count white blood cells just as accurately as more complex time-consuming approaches using cell counting technologies that require larger volumes of blood. And, by using the CD4/CD8 ratio, doctors may obtain a more complete “picture” of HIV infection.
The group is working on miniaturizing the setup to make the technology handheld, as well as designing a cartridge that can be mass-produced. The biochip also could be used in many other situations where white blood cell counts are needed.