An initiative that is developing a rapid and inexpensive test to analyze the immune system of people living with HIV/AIDS has received a $7.3 million grant from the Bill & Melinda Gates Foundation, it is announced. If successful, the test would improve healthcare workers' ability to determine the best treatment for their patients.
The CD4 Initiative at Imperial College London was established to develop an easy to use point-of-care test with a cost of around $2 that can measure the numbers of CD4+ T-cells in a person's blood, without using electronics or mechanical parts.
CD4+ T-cells are critical for a healthy functioning immune system and are slowly destroyed during the course of HIV infection. When the numbers of CD4+ T-cells in a person's blood drop, this makes them increasingly vulnerable to illness.
Healthcare workers rely on a CD4 count when making decisions about how HIV-positive patients should be treated and when they should begin antiretroviral therapy. The new test would enable patients to find out within minutes if they should begin antiretroviral treatment.
Imperial's academic and industrial partners in the CD4 Initiative have worked since 2007 to devise the new test. Teams from Beckman Coulter, Inc (USA), Macfarlane Burnet Institute (Australia) and Zyomyx, Inc (USA) have already developed three prototypes, one of which will be chosen to be manufactured and mass produced in 2010.
The new test will work with a finger-prick blood sample and will have a simple read-out. One of the new prototypes has a design similar to that of a home pregnancy test.
The majority of patients in the developing world do not currently have access to CD4 testing because it is expensive and requires specially trained operators. Where testing facilities exist, it is often too difficult for people in rural areas to reach them. For those who are tested, it can take weeks to obtain results.
"There has been a lot of progress increasing access to life-saving HIV drugs in the developing world, but the lack of access to essential diagnostic tests like a CD4 test is a major barrier to providing the best possible care," said Dr Hans-Georg Batz, Director of the CD4 Initiative from the Division of Medicine at Imperial College London.
"The majority of patients start anti-retroviral therapy based on symptoms alone. Research shows that if you wait until you're sick to start treatment, you have a much poorer outcome than if you start based on CD4 count. Our new test will have a huge positive impact for people living with HIV across the world."
Dr Steven Reid, the project manager for the CD4 Initiative at Imperial College London, added: "In resource-poor rural areas, patients sometimes have to walk miles to get to a clinic. Even if a traditional CD4 count is offered, the patients have to come back in a couple of weeks for the result. By then, some are too sick or cannot afford to return. For others, it may already be too late.
"The new test would eliminate the need to wait for treatment. As soon as a patient finds out that they are HIV positive, they could immediately find out if they need to start on antiretroviral therapy," added Dr Reid.
The CD4 Initiative is a multi-partner, international collaborative effort housed at Imperial College London. A 2005 grant of $8.6m from the Bill & Melinda Gates Foundation supported the first three years of the project.
The $7.3 million grant will support trials of the new test in developed and developing world countries, developing the manufacturing process, and initial production runs.