Improved Blood Test for TB Launched

Tuberculosis (TB) is a contagious bacterial infection spread primarily by coughing of patients with the active pulmonary form of the disease. In 2015, it was estimated that there were 10.4 million new cases of active TB worldwide and 1.8 million deaths from TB.

In latent tuberculosis infection (LTBI), the bacterium infects a person but produces no symptoms unless it progresses to the active disease. On a global basis, approximately one out of three people are estimated to have latent TB infection, and about 5%-10% of those individuals, if untreated, will progress to active tuberculosis at some point.


Screening of high-risk individuals and treatment for LTBI play an important role in tuberculosis control efforts in the USA and many European countries, as well as in other developed and emerging markets around the world. A fourth generation blood test kit for tuberculosis has been launched and will be available in the USA from October 9, 2017. The novel CD4/CD8 design delivers most comprehensive evaluation of patients’ immune response to tuberculosis infection.

The QuantiFERON-TB Gold Plus (QFT-Plus, Qiagen., Hilden, Germany) advances the science of TB testing with innovative antigens that measure the cell-mediated immune response to tuberculosis infection from both CD4+ and CD8+ T cells, providing a broader assessment of TB infection. CD8+ T cells have been shown to play an important role in Mycobacterium tuberculosis immunity. Published evidence underlines the future potential of CD8+ T cells for distinguishing active from latent TB, discerning recent versus old infections, detecting TB in certain populations such as human immunodeficiency virus (HIV) co-infection and young children, as well as assessing one's response to TB treatment. No other test is optimized for both CD4 and CD8 T cell responses.

Masae Kawamura, MD, Senior Director, TB Medical and Scientific Affairs, at QIAGEN, said, “The proprietary CD4+/CD8+ T cell technology of QFT-Plus has the potential to provide important insights for high-risk patients such as contacts exposed to active TB or HIV-positive persons while maintaining high specificity. In the USA, test accuracy has never been more important as the country aggressively fights to end tuberculosis through recent policy-driven expansion of targeted testing and preventive treatment. It is currently estimated that 93% of the TB disease in the USA comes from the 13 million-person reservoir of latent TB infection.”