Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New TB test means quicker and easier diagnosis for patients

10.03.2008
A new blood test could enable doctors to rule out tuberculosis (TB) infection within days rather than weeks, according to a new study published this week in the journal Annals of Internal Medicine.

The study, by researchers from Imperial College London and the University of Oxford, shows that doctors can determine that a patient does not have tuberculosis with 99% accuracy when using the new blood test, ELISpot-Plus, in conjunction with a skin test known as tuberculin skin testing, already in use.

TB is difficult to diagnose because many of its symptoms, such as fever, fatigue, and loss of appetite, are also commonly found in many other conditions. The combination of ELISpot-Plus and tuberculin skin testing is able to rule out TB within 48 hours, providing a much quicker result than existing testing methods, for which results take up to several weeks.

The new test combination could prevent patients who do not have TB from being subjected to further lengthy TB tests, and allow doctors to begin investigating other explanations for such patients' symptoms.

The new study showed that ELISpot-Plus alone was accurately able to determine TB infection in 89% of cases and tuberculin skin testing alone was able to determine TB infection in 79% of cases. However, using both tests together was able to rule out TB infection with an accuracy of 99%.

The ELISpot-Plus test works by detecting signs of a particular response that occurs when the immune system encounters TB infection. The test looks for a type of protein known as interferon-Y. This is secreted by T cells in the immune system when they encounter antigens found in the bacterium mycobacterium tuberculosis, which causes most cases of TB.

The tuberculin skin test commonly gives falsely positive results if a patient has previously been vaccinated against TB, because vaccination causes a reaction in the immune system which looks very similar to its reaction against actual TB infection. ELISpot-Plus is able to distinguish TB infection from BCG vaccination because it uses special antigens that only pick out the T cells that are induced by TB infection, and not those induced by vaccination.

The new test is useful in determining a patient's TB status but the results are not able to accurately reveal whether a patient with TB has it the 'active' form, which causes symptoms, or the dormant 'latent' form, which does not. This means that patients with a positive result would need further testing. However, the new test combination should allow doctors to establish which patients require further TB testing and which do not.

At present, the 'gold standard' for confirming whether or not a patient has TB involves growing cultures from sputum samples from a patient and analysing these cultures to see if they contain traces of mycobacterium tuberculosis.

This means that patients being tested for TB need to stay in hospital for three days, undergoing invasive procedures, to obtain necessary samples. They then wait for several weeks for the results.

Professor Ajit Lalvani, from the National Heart and Lung Institute at Imperial College London, who led the study team, said: "Our new test could revolutionise the way we manage people with suspected TB. At the moment, it can take quite a long time to figure out whether or not a patient has the disease, because it can mimic many different conditions and present in many different ways.

"Our study shows that by using the new blood test, together with the old skin test, we could establish if someone does not have TB within two days of them coming in for tests, allowing doctors to focus on other possible diagnoses. If we cannot rule out TB, we can then refer them for further testing to confirm the diagnosis. Using this new system would allow us to treat patients much more quickly and effectively," added Professor Lalvani.

The ELISpot-Plus device is not yet licensed and they intend to make it available to as large a number of TB patients as possible, including those in the developing world who carry the largest burden of TB, through ethical commercialisation.

The study looked at 389 patients recruited at Northwick Park Hospital in London and Heartlands Hospital in Birmingham. The researchers compared the performance of tuberculin skin testing and two blood tests, ELISpot and ELISpot-Plus, both individually and used in combination, in diagnosing patients with suspected active TB. The study was funded by the Wellcome Trust, the Sir Halley Stewart Trust and the UK Department of Health.

Britain is the only country in Western Europe where TB is on the rise and London, which carries almost half the national burden, is Europe's TB capital. Professor Lalvani leads a new, specially created TB Task Force at Imperial College London and its Academic Health Science Centre, Imperial College Healthcare NHS Trust. The TB Task Force aims to develop and deploy effective new weapons in the battle against TB, both in London and globally, through cutting-edge scientific research.

Professor Steve Smith, the Principal of the Faculty of Medicine at Imperial College London and Chief Executive of Imperial College Healthcare NHS Trust, said: "Our new Academic Health Science Centre integrates healthcare services with teaching and research to take the world's best research from bench to bedside - giving patients quicker access to new medical advances. We established Professor Lalvani's department because we value his patient-centred research and care deeply about London's growing TB problem. The work of Professor Lalvani and his team is an excellent example of world-class research providing significant benefits for our patients".

Laura Gallagher | alfa
Further information:
http://www.imperial.ac.uk

More articles from Studies and Analyses:

nachricht Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland

nachricht Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>