Portable HIV Test

A new technology that provides a complete HIV test and T-cell count in less than 20 minutes could revolutionize how the disease is diagnosed in remote parts of the world. 

The study detailing the device, published today in Science Translational Medicine, comes just 24 hours after the release of a report showing that antiretroviral therapy (ART) has saved 2.8 million years of life in South Africa since 2004. Using what the authors say are conservative estimates, computer simulations predicted that an additional 15.1 million years of life will be be saved by 2030 among those receiving the costly treatment in the sub-Saharan nation.

That report, published in the Journal of Infectious Diseases, didn't take into account the advantages of a device like the one described in today's study. A handheld version of the tool is expected to be developed within the next few years, making it easier to deploy to remote regions. With just a single drop of blood, the device can provide a total CD4-CD8 profile, which measures the types of white blood cells present in the body and offers a more complete measure of immune system function.

The test can quickly determine whether a person is eligible to begin the lifesaving ART treatment, even if they are not yet aware that they have the disease. The World Health Organization (WHO) recommends beginning ART when a person's T-cell count falls below 500. T-cells, including CD4 and CD8 cells, are helper cells that boost the immune system. 

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How Does It Work?

Currently small enough to place on a table, the HIV testing device uses electricity to count and classify T-cells. Essentially, it's a lab on a microchip. Its developers hope to make the device widely available for clinical use within the next three years.

“Other technologies use optics that are generally more costly, fragile, and bulky,” Nicholas Watkins, one of the study's authors, told Healthline. 

Watkins, a research scientist at Nabsys Inc. in Providence, R.I., said that the device is sturdier and less expensive than existing technologies. The traditional method is like “a portable CD player versus an mp3 player that is solid state with all electrical components,” he said.

Dr. Michael April, lead author of the ART study in South Africa, told Healthline that both developments pack a one-two punch for quashing HIV in under-served areas.

Having a portable tool available to rapidly assess HIV could allow doctors in places like South Africa to better monitor the progression of the disease. This could lead to quicker deployment of second-line treatment. 

“Access to second-line ART has a huge impact if it's universally available,” said April, of the San Antonio Uniformed Services Health Education Consortium.

According to 2012 UNAIDS estimates, about 18 percent of people in South Africa ages 15 to 49 have HIV. About one-third of those infected with HIV are eligible for ART but don't receive it. April said that the scope of the problem in South Africa adds to the staggering number of life-years saved by ART.

“We're finally starting to have a lot of success,” April said of battling HIV worldwide. “It's finally starting to look like we're stemming the tide a little bit and really starting to make some great progress.”

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Rashid Bashir, an author of the study on the testing device, said that the technology could also be useful in remote or limited-resource areas in the U.S. Bashir, a professor at the University of Illinois, said that it could be used to measure all different cell types, and could have many other applications for diagnosing and monitoring disease. 

A New Way to Calculate Cancer Survival

Also today, a paper published in Science Translational Medicine reports that a new device can digitally count a type of T-cell that can help predict how long ovarian cancer patients will live: the tumor-infiltrating lymphocyte (TIL).

Although a higher count of TILs is thought to be associated with longer survival, they are also found in metastasized tumors, which are removed during surgery. This creates a paradox, according to Franck Pagès, a French researcher who wrote an accompanying article in the medical journal.

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Jason Bielas, a cancer researcher at the University of Washington, says that his device scans a T-cell's DNA, which is like a “barcode,” revealing a wealth of information. He said that it will be useful as personalized medicine—treatments specially tailored to a patient—becomes more common.

Although not portable like Watkins' device, he hopes to see it used one day in clinical settings.