New Rapid Blood Test for Tuberculosis

A rapid new blood test for tuberculosis (TB) can detect infection even in people with weak immune systems, including new-born babies, people with HIV, and transplant patients--people who are most vulnerable to developing TB.

The test, called T SPOT-TB, is designed to replace the tuberculin skin test, which takes three to seven days for results, is prone to false-positives and false-negatives, can scar the skin, and may be inconsistent in cases of BCG (Bacillus Calmette-Guerin) vaccination.
T SPOT-TB will enable doctors to reliably screen people who have been in contact with a TB sufferer, identifying and treating them before they actually develop the disease and become infectious, according to the developers.

TB infection induces a strong response by immune T cells. It is these T cells, in a small blood sample, that are detected by T SPOT-TB, which literally counts them as spots on a test plate. The test has been proven in 16 clinical studies, involving more than 4,000 people in 11 countries. In healthy unexposed controls, specificity was 99.9%. Sensitivity has been shown to be over 96%.

TB is currently out of control, causing three million deaths each year, more than any other infectious disease. Along with the increase in the number of cases, there has been a substantial increase in the number of strains of TB resistant to current treatments. The new test will enable more people to be diagnosed and treated while their infection is still dormant, thus preventing them from developing full-blown TB, which is highly contagious.

"The tools we use to diagnose TB are 50-100 years old; this disease has been neglected for decades,” observed Dr. Ajit Lalvani, of Oxford University (UK), who has led the development of the test over the past 10 years. "I am pleased that we have finally brought the benefits of modern scientific research to the front line to fight this age-old disease.”

The test is being commercialized by Oxford Immunotech (UK), an international clinical diagnostics company. The T-SPOT technology can be applied to diagnose and monitor any major disease driven by T cell response, noted the company. The test has recently been approved for sale in Europe.




Related Links:
Oxford Univ.
Oxford Immunotech