This process analyzes blood samples to detect immune responses specific to Mycobacterium tuberculosis, the bacteria causing tuberculosis (TB). The test measures the release of interferon-gamma (IFN-) from certain white blood cells when exposed to TB-specific antigens. By quantifying IFN- levels, clinicians can determine if an individual has been infected with TB. For example, a positive result indicates exposure, while a negative result suggests no infection. A borderline result may indicate an indeterminate response and often requires further investigation.
Accurate and timely diagnosis of TB infection is crucial for effective disease management and public health control. This method offers several advantages over the traditional tuberculin skin test (TST), including enhanced specificity, eliminating the influence of prior BCG vaccination or exposure to non-tuberculous mycobacteria. Additionally, results are available more quickly, allowing for prompt initiation of treatment if necessary. The development and implementation of this modern blood test have significantly advanced TB diagnostics globally, improving the capacity to identify both latent and active infections.