Next-Generation Blood Test for Latent TB Submitted to FDA

The 4th-generation test, QFT-Plus, adds proprietary CD8 antigens and workflow improvements that allow for even more efficient implementation, especially in large-scale TB screening programs. These include a single-tube blood collection option, as well as the current use of the unique "assay in collection tube" design that allows for immediate stimulation of the blood sample.

“We are very encouraged by the positive adoption and favorable early data for the fourth generation of QuantiFERON, and the role our test plays in the fight against TB. [QFT-Plus] is the only latent TB test on the pathway to evaluation by the World Health Organization (WHO), and we are excited that this new generation will soon be available in the United States. Bringing new insights for physicians to manage their patients and offering more efficiency to public health agencies are important hallmarks of QFT-Plus,” said Dr. Masae Kawamura, MD, senior director of Medical and Scientific Affairs, TB Diagnostics, QIAGEN, “TB is both a global and mobile disease, greatly impacting the United States.”

Six independent peer-reviewed publications to date have supported the performance of QFT-Plus, and additional studies are currently underway in 22 countries involving more than 30,000 patients. The first studies include comparisons on sensitivity in active TB and close contacts, as well as on laboratory precision and correlation to flow cytometry.

The transition to the 4th generation test comes amid a series of new recommendations that will broaden the use of IGRAs in the US. In December 2016, a task force supported by the American Thoracic Society (ATS), the US Centers for Disease Control and Prevention (CDC), and the Infectious Diseases Society of America, published new evidence-based guidelines recommending the use of IGRA tests in wider groups of people at risk for TB infection. This followed recommendations by the US Preventive Services Task Force (USPSTF) in September 2016 that primary-care physicians should screen adult patients in groups at high risk for latent TB infection.

Both the USPSTF and new ATS/CDC recommendations referred to QuantiFERON-TB Gold as one of two FDA-approved IGRAs, preferable in certain patient groups to the century-old tuberculin skin test (TST). The ATS/CDC recommendations also highlighted the expert committee’s rationale for expanded IGRA use based on the accuracy of IGRAs to minimize the risk of unnecessary TB treatment and related drug toxicity issues.

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 1 in 3 people are estimated to have LTBI, and about 5-10% of those individuals, if untreated, will likely progress to active tuberculosis at some point. Screening of high-risk individuals and treatment for LTBI already play an important role in tuberculosis control efforts in several countries.

QFT-Plus involves Qiagen’s QuantiFERON technology, which can provide objective information on the activity of cell-mediated functions of the immune system by measuring the release of interferon-gamma in response to specific antigens or proteins contained in whole blood samples through a simple, highly automated process. It is in particular unique in its ability to detect presymptomatic infections and risks that cannot be discovered using standard diagnostic technologies.