A research team, led by an Indian researcher at Imperial College London has developed a new blood test that can detect tuberculosis (TB) infection within few days rather than weeks.
Professor Ajit Lalvani, from the National Heart and
Lung Institute at Imperial College London and his colleagues have revealed that
the new blood test ELISpot-Plus, combined with a skin test known as tuberculin
skin testing, can determine that a patient does not have tuberculosis with 99
percent accuracy within 48 hours.
The ELISpot-Plus test detects a particular response that
occurs once the immune system stumble upon TB infection. It searches for a
protein known as interferon-Y that is secreted by T cells in the immune system.
ELISpot-Plus alone was accurately able to determine TB
infection in 89 percent of cases while tuberculin skin testing alone could
determine TB infection in 79 percent cases.
The study showed that using both tests together could
rule out TB infection with an accuracy of 99 percent.
"Our study shows that by using the new blood
test, together with the old skin test, we could establish if someone does not
have TB within two days of them coming in for tests, allowing doctors to focus
on other possible diagnoses," said Professor Lalvani.
"If we cannot rule out TB, we can then refer them for
further testing to confirm the diagnosis. Using this new system would allow us
to treat patients much more quickly and effectively," he added.
The new test combination would be able to prevent
patients who do not have TB from being subjected to further lengthy TB tests
and can allow doctors to establish which patients require further TB testing
and which do not.