HIV Monitoring Reasearch Progress

Why Count CD4 Cells?

Most HIV-infected people don't develop AIDS right away, because their immune systems can keep the virus in check for months and sometimes years. In general, doctors don't recommend that infected people start taking HIV medications while their immune system is still healthy. Doctors know whether or not a patient's immune system is healthy by measuring the "CD4 count." This is the number of CD4 cells in a sample of blood. CD4 cells, also called CD4+ T cells, are a type of white blood cell that fights infection. HIV destroys CD4 cells, weakening the body's immune system and ultimately causing AIDS. CD4 counts should be determined before a patient receives antiretroviral therapy and then measured regularly while the patient is on therapy.

Why Develop New Technology?

Most technology available to count CD4 cells is large, expensive and difficult to operate. These tools are therefore unsuitable for many low-income countries. Our research goal is to develop a device that meets the following criteria:

• counts CD4 cells at a lower cost than existing flow cytometry technology
• portable to allow health-care workers to access patients in remote areas
• simple, "push of a button" operation such that healthcare worker training is minimal

Research Accomplishments

• Constructed a bench-top prototype for counting CD4 cells that has the potential to be less expensive and is easier to use than existing technology
• Constructed a flow cell prototype for counting CD4 cells that has the potential to be less expensive and is easier to use than existing technology
• Validated the prototype system against the existing technology in Botswana using HIV patient samples from 61 adults and six children
• Demonstrated reliable results (CD4 cell count) comparable to the existing technology
• Initiated the development of a miniaturized, portable device for counting CD4 cells
• Initiated the development of a disposable microfluidic cartridge for counting CD4 cells
• Licensed the UT technology to LabNow, Inc. (Austin, TX) for commercialization

Current Activities

We are currently working with LabNow, Inc. and its partners to translate our research prototypes into a practical diagnostic system that will be accessible and affordable for use in important global health care settings.

External Links

World Health Organization CD4 Enumeration

The World Health Organization's specific review of CD4 counting technologies.

The Well Project's information on CD4 counts

Find Diagnostics: organization focused on affordable diagnostics for infectious diseases worldwide.

The Forum for Collaborative HIV Research, a consortium with an advocacy and funding role for HIV/AIDS research priorities, including low-cost CD4 and viral load tests

Project Inform

Bill and Melinda Gates Foundation

Doris Duke Charitable Foundation