Discovery of biomarkers found in highly-infectious patients raises hopes of new TB test. Credit: University of Southampton
Key points:
- Scientists identified 6 proteins that can be used to confirm TB in patients, even without symptoms.
- They hope the identification leads to a simple blood test to diagnose the condition and stop its unknowing spread.
- In the UK, TB cases increased to around 5,000 last year, and are expected to continue rising in 2024.
Scientists have taken a major step toward developing a blood test that could identify millions of people who spread tuberculosis unknowingly. They hope the findings will pave the way for a simple test that can diagnose and identify millions of people who spread tuberculosis unknowingly—about 10 million cases annually.
For the study, published in the Journal of Clinical Investigation, researchers studied proteins found in the blood of people with active TB in Africa and South America. They compared the biomarkers to those found in healthy people and patients with lung infections, identifying 118 proteins that differed significantly between the groups.
The team then narrowed these down to 6 proteins that can be used to distinguish contagious patients with TB from people in good health or with lung conditions.
“In our study, we combined a new measurement technique with deep mathematical analysis to identify these six new markers of TB disease,” said lead author Hannah Schiff, a respiratory expert at Southampton. “It could lead to a transformative alternative to diagnosing the condition—a simple test that detects proteins in the bloodstream whose levels differ between people with TB, healthy individuals, and those suffering from other respiratory illnesses.”
Schiff likened this prospective test to the lateral flows used during the COVID-19 pandemic.
“The new markers we discovered are truly exciting, but the important work now is to develop these into tests that can be used for the millions of people who are transmitting TB without knowing it,” said study co-director Diana Garay-Baquero. “As the COVID-19 pandemic confirmed, we ignore highly infectious airborne diseases at our peril.”
Researchers say as many as 3 million cases of TB were missed last year, mostly in developing countries. In the UK, cases increased to around 5,000 last year, and are expected to continue rising in 2024, according to the UK Health Security Agency.
“TB remains a global catastrophe because our efforts to control the spread are hindered by inadequate testing, which is slow and reliant on specialist equipment and labs,” said Schiff. “A third of people who get infected go undiagnosed and remain infectious.