ANEMIA :PROMISING ONE MINUTE POINT OF CARE TEST
A simple point-of-care
testing device for anemia could provide more rapid diagnosis of the common
blood disorder and allow inexpensive at-home self-monitoring of persons with
chronic forms of the disease.
The disposable
self-testing device analyzes a single droplet of blood using a chemical reagent
that produces visible color changes corresponding to different levels of
anemia. The basic test produces results in about 60 seconds and requires no
electrical power. A companion smartphone application can automatically
correlate the visual results to specific blood hemoglobin levels.
By allowing rapid
diagnosis and more convenient monitoring of patients with chronic anemia, the
device could help patients receive treatment before the disease becomes severe,
potentially heading off emergency room visits and hospitalizations. Anemia,
which affects two billion people worldwide, is now diagnosed and monitored
using blood tests done with costly test equipment maintained in hospitals,
clinics or commercial laboratories.
Because of its
simplicity and ability to deliver results without electricity, the device could
also be used in resource-poor nations.
A paper describing
the device and comparing its sensitivity to gold-standard anemia testing was
published August 30 in The Journal of Clinical
Investigation. Development of the test has been supported by the
FDA-funded Atlantic Pediatric Device Consortium, the Georgia Research Alliance,
Children's Healthcare of Atlanta, the Georgia Center of Innovation for
Manufacturing and the Global Center for Medical Innovation.
"Our goal is to
get this device into patients' hands so they can diagnose and monitor anemia
themselves," said Dr. Wilbur Lam, senior author of the paper and a
physician in the Aflac Cancer and Blood Disorders Center at Children's
Healthcare of Atlanta and the Department of Pediatrics at the Emory University
School of Medicine. "Patients could use this device in a way that's very
similar to how diabetics use glucose-monitoring devices, but this will be even
simpler because this is a visual-based test that doesn't require an additional
electrical device to analyze the results."
The test device was
developed in a collaboration of Emory University, Children's Healthcare of
Atlanta and the Georgia Institute of Technology -- all based in Atlanta. It
grew out of a 2011 undergraduate senior design project in the Wallace H.
Coulter Department of Biomedical Engineering at Georgia Tech and Emory
University. In 2013, it was among the winners of Georgia Tech's InVenture
Prize, an innovation competition for undergraduate students, and won first
place in the Ideas to SERVE Competition in Georgia Tech's Scheller College of
Business.
Using a two-piece
prototype device, the test works this way: A patient sticks a finger with a
lance similar to those used by diabetics to produce a droplet of blood. The
device's cap, a small vial, is then touched to the droplet, drawing in a
precise amount of blood using capillary action. The cap containing the blood
sample is then placed onto the body of the clear plastic test kit, which
contains the chemical reagent. After the cap is closed, the device is briefly
shaken to mix the blood and reagent.
"When the
capillary is filled, we have a very precise volume of blood, about five
microliters, which is less than a droplet -- much less than what is required by
other anemia tests," explained Erika Tyburski, the paper's first author
and leader of the undergraduate team that developed the device.
Blood hemoglobin
then serves as a catalyst for a reduction-oxidation reaction that takes place
in the device. After about 45 seconds, the reaction is complete and the patient
sees a color ranging from green-blue to red, indicating the degree of anemia.
A label on the
device helps with interpretation of the color, or the device could be
photographed with a smartphone running an application written by Georgia Tech
undergraduate student Alex Weiss and graduate student William Stoy. The app
automatically correlates the color to a specific hemoglobin level, and could
one day be used to report the data to a physician.
To evaluate
sensitivity and specificity of the device, Tyburski studied blood taken from
238 patients, some of them children at Children's Healthcare of Atlanta and the
others adults at Emory University's Winship Cancer Institute. Each blood sample
was tested four times using the device, and the results were compared to
reports provided by conventional hematology analyzers.
The work showed that
the results of the one-minute test were consistent with those of the
conventional analysis. The smartphone app produced the best results for
measuring severe anemia.
"The test
doesn't require a skilled technician or a draw of venous blood and you see the
results immediately," said Lam, who is also an assistant professor in the
Coulter Department of Biomedical Engineering. "We think this is an
empowering system, both for the general public and for our patients."
Tyburski and Lam
have teamed up with two other partners and worked with Emory's Office of
Technology Transfer to launch a startup company, Sanguina, to commercialize the
test, which will be known as AnemoCheck™. The test ultimately will require
approval from the FDA. The team also plans to study how the test may be applied
to specific diseases, such as sickle cell anemia -- which is common in Georgia.
The device could be
on pharmacy shelves sometime in 2016, where it might help people like Tyburski,
who has suffered mild anemia most of her life. "If I'd had this when I was
kid, I could have avoided some trips to the emergency room when I passed out in
gym class," she said.
About a third of the
population is at risk for anemia, which can cause neurocognitive deficits in
children, organ failure and less serious effects such as chronic fatigue.
Women, children, the elderly and those with chronic conditions such as kidney
disease are more likely to suffer from anemia.
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