Researchers have developed a finger-prick blood sample device to detect
serious liver damage.
Researchers looking to make
tuberculosis (TB) and HIV treatment safer have developed a paper-based test for
drug-induced liver damage.
Standard treatments for TB such
as rifampicin and pyrazinamide can cause liver damage, particularly in people
co-infected with hepatitis B or C, which are common in Asia.
Similarly, patients can
experience liver damage if they are treated for HIV with commonly used
nevirapine-based drugs.
Yet clinicians in developing
countries rarely have easy access to tests for drug-induced liver injury, said
Nira Pollock, assistant professor of medicine at Harvard Medical School in the
United States.
US doctors routinely check for
high levels of chemical markers in blood that show if patients are developing
serious liver damage, and then adjust their medication accordingly.
Now, researchers have developed
and tested a stamp-sized paper device with channels and wells that mix, split,
and filter a finger-prick blood sample to detect these chemical markers.
The trial used existing blood
samples to compare the device to standard tests. It showed an overall accuracy
of more than 90 percent compared with the gold standard of 100 percent.
It takes just 15 minutes to get
the color changes that indicate normal, moderate, or high levels of liver
markers. The test also includes a control that confirms the test was accurate.
The estimated cost of each test
is just ten US cents, compared with upfront costs of thousands of dollars for
existing point-of-care mini laboratory devices.
Jason Rolland, senior director of
research from Diagnostics For All, which developed the technology, said the
test is cheap, easy to use, and portable, with no need for electricity or
instrumentation.
“It is designed to be used in a
rural clinic to support our mission in the developing world,” he added.
Usually liver function testing
for patients in rural areas requires samples to be sent to large hospitals, and
they can get lost en route, said Rolland. He added that drug-induced liver
damage rates are between ten and 25 percent in the developing world, compared
to around two percent of patients being treated for TB in the developed world.
Pollock coordinated the trial and
is liaising with the National Hospital for Tropical Diseases in Vietnam to
conduct field trials of the device in patients suffering from HIV.
If the test works as well in
patients, the researchers are hoping to have a commercial product in 2014.
Currently, Diagnostics for All is
able to manufacture 500 to 1,000 tests per day.
Commenting on the research,
Alison Grant, assistant professor of medicine at the London School of Hygiene
and Tropical Medicine, said the technology “could be very useful for patients
at high risk or thought to have liver damage.”
But she cautioned that not all
patients benefit from routine liver function testing, and WHO guidelines
recommend it only for patients at highest risk.
And the cost could be higher than
stated.
“Experience of other
point-of-care tests suggests that in addition to initial training, staff need
refresher training periodically to be sure they are using the test correctly,
and this support needs to be taken into account when estimating the true cost
of the test,” Grant added.
Rachel Mundy
The article can be found
at: Pollock NR et al. (2012) A
Paper-Based Multiplexed Transaminase Test for Low-Cost, Point-of-Care Liver
Function Testing.
Source: Science and
Development Network
No comments:
Post a Comment