HWN Suggests

Weighing Gold or Counting Spots Which Is More Sensitive to Diagnose Latent Tuberculosis Infection?

Both tests detect IFN-γ produced by memory T cells that recognize Mycobacterium tuberculosis proteins that are absent in M. bovis bacille Calmette-Guérin (BCG). Vaccination with BCG does not yield false-positive results... I believe that the T-SPOT.TB test should be used for persons in whom cell-mediated immunity may be depressed. For immunocompetent persons, either IFN-γ–based test can be used. Clinical laboratories are likely to prefer the QuantiFERON-TB Gold test because it is simpler to perform than the T-SPOT.TB test.

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Articles of Interest

Clinical data for the T-SPOT.TB test

The T-SPOT.TB test is based on the in vitro ELISPOT assay developed at the University of Oxford, UK. This pioneering technology has been described in over 700 peer-reviewed publications showing the test’s excellent performance in a wide variety of clinical and epidemiological settings.

Clinical effect of T-SPOT.TB test for the diagnosis of tuberculosis

In conclusion, T-SPOT.TB test proved to be valuable for distinguishing between LTBI, active TB and old TB. In addition, a higher spot number level was observed in the active TB patient group, but T-SPOT.TB test showed low specificity for the diagnosis of different active TB subtypes.

Diagnostic Efficacy of T-SPOT.TB for Active Tuberculosis in Adult: A Retrospective Study

As for using T-SPOT.TB test to diagnose active tuberculosis, increased threshold could significantly elevate the diagnosis accordance. And we suggest that the threshold of T-SPOT.TB could be increased to 40sfu for diagnosing ATB. Attention should be paid when diagnose ATB in population with obsolescent tuberculosis, smoking history, diabetes and advanced age, for the risk of false-positive.

T-Spot TB

Every TB test result is a ‘moment of truth’. If it’s positive, then you’ve begun the process of fighting it. You can protect the patient and the wider community from a deadly risk. If it’s negative, there may be no need for powerful antibiotics – and the patient is cleared to live and work closely with others. With so much at stake, positive or negative, what’s vital is getting a result people can trust.

T-SPOT.TB Interferon-γ Release Assay Performance in Healthcare Worker Screening at Nineteen U.S. Hospitals

The high concordance and test completion rates in this study suggest that the T-SPOT.TB test is a reliable tool for healthcare worker serial screening. As expected, the observed positivity rates were lower compared with the tuberculin skin test, likely reflecting the higher specificity of this test. Furthermore, the observed rates of conversion were low and significantly correlated with the geographic incidence of tuberculosis. Our findings suggest that the T-SPOT.TB test is an accurate and reliable way to screen healthcare workers.

The TB test for physicians

Whether you are a primary care physician, rheumatologist or other specialist, physicians face the challenge of finding a tuberculosis (TB) test that is reliable with all patients, even those with weakened immune systems – the immunocompromised. In fact, many adults have been told that they are immunocompromised, which can result in an inaccurate TB result. That is why you need a TB test that is accurate across patient populations.

To Your Good Health: Positive T-SPOT test brings result of latent tuberculosis

The T-SPOT, like the QuantiFERON-TB Gold, is a blood test to look for tuberculosis infection... Both blood tests (these work by measuring the response of T cells to tuberculosis proteins) are more accurate than the TB skin test. Blood tests have the advantage of only coming in once, as opposed to the skin test where you need to have the test read by a clinician in 48 to 72 hours. The blood test is more than 95% specific, meaning it's extremely likely that you have latent infection and extremely unlikely to be a false positive. One disadvantage is that the blood test is much more expensive than the skin test. --