T-SPOT.TB is a type of ELISPOT

ELISPOT

The Enzyme-linked immunosorbent spot assay is a common method for monitoring immune responses in humans and animals. It was developed by Cecil Czerkinsky in 1983....

 assay used for tuberculosis diagnosis

Tuberculosis diagnosis

Tuberculosis is diagnosed by finding Mycobacterium tuberculosis bacteria in a clinical specimen taken from the patient. While other investigations may strongly suggest tuberculosis as the diagnosis, they cannot confirm it.-Diagnosis:...

. It is available in most European countries, the United States as well as various other territories. It was developed by researchers at the University of Oxford in England. It counts the number of effector T cells, white blood cell

White blood cell

White blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...

s that produce gamma interferon, in a sample of blood. This gives an overall measurement of the antigen

Antigen

An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...

 load on the immune system, which can reveal the presence of subclinical disease. Because this does not rely on production of a reliable antibody

Antibody

An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...

 response or recoverable pathogen

Pathogen

A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...

, the technique can be used to detect conditions such as latent tuberculosis

Latent tuberculosis

Also called latent tuberculosis infection, latent TB or LTBI.Latent tuberculosis is where a patient is infected with Mycobacterium tuberculosis, but does not have active tuberculosis disease. Patients with latent tuberculosis are not infectious, and it is not possible to get TB from someone with...

. This technique is especially useful because it is much faster (results within 24 hours) than the previous methods and more accurate (the previous skin test would result in positive if a person doesn't have TB but has had the vaccine before or if has come into contact with the mycobacterium before). This allows physicians to treat and control the disease much better.

In one study in Germany, 70 out of 72 patients with confirmed TB infection were T-SPOT.TB positive, indicating a sensitivity of 97.2%.

T-SPOT.TB is a diagnostic test manufactured by Oxford Immunotec Ltd. in the UK
www.oxfordimmunotec.com