Date: 2015-02-11
Type of information: Publication of results in a medical journal
phase:
Announcement: publication of results in the Lancet
Company: Qiagen (The Netherlands)
Product: QuantiFERON-TB Gold (QFT®)
Action
mechanism: QFT uses a peptide cocktail simulating ESAT-6, CFP-10, and TB7.7(p4) proteins to stimulate cells in heparinized whole blood. Detection of IFNγ by ELISA is used to identify in vitro responses to these peptide antigens, which are associated with M. tuberculosis infection.
Disease: tuberculosis
Therapeutic area: Infectious diseases
Country: China
Trial details:
Latest
news: * On February 11, 2015, Qiagen announced that groundbreaking clinical data published in The Lancet showed that reliance on the 100-year-old tuberculin skin test has significantly overestimated latent tuberculosis infections in China, while results in the same patients using its QuantiFERON-TB Gold (QFT®) provided a far better understanding of disease burden. Results from the pivotal study, done by researchers at the Chinese Academy of Medical Sciences and Peking Union Medical College in Beijing, found a far lower prevalence rate of latent TB as measured using QuantiFERON TB Gold than with the skin test (TST). The higher false positive rate created by the TST test – first developed and described by the German physician Felix Mendel in 1908 – is due to several factors including the use of the BCG vaccination in this country since the 1950s which has had only a very limited impact on reducing TB burden. The results in particular showed a far lower overall TB infection rate of 18.8% measured by QFT compared to 28% using the TST in China, which has been estimated to have one million new cases of TB every year, more than any country except India. The study – the largest-ever prospective multi-center study in China comparing diagnostics for latent tuberculosis infections – screened more than 21,000 people and aimed to identify at-risk populations to target for screening at the community level. Given the new information on lower prevalence rates in China based on these study results, the study authors wrote that community-based preventive interventions for those with latent TB may be practical for individuals at risk for developing active TB. The report in The Lancet presents the baseline phase of China’s first large-scale, multi-center study of the epidemiology of latent tuberculosis infection. The comparison study of more than 21,000 patients allowed detailed analysis of demographics and risk factors, along with robust comparisons within subgroups. The study’s follow-up phase is now underway, and patients with LTBI will be evaluated for rates of disease and associated risks. Generally, up to 10% of people with latent TB infection will develop active, contagious TB disease at some point. The overall TB infection rate was 18.8% measured by QFT compared to 28% by TST. Unlike the TST, positive rates of QFT were not related to prior Bacille Calmette-Guérin (BCG) vaccination, but correlated with background active TB and suspect rates, as well as known risks for TB. BCG vaccination is recommended by the WHO as a matter of TB control policy to newborns in many countries, including China.
