Normal Reference Ranges
Adult
Negative Qualitative
Pediatric
Negative Qualitative
Clinical Significance
Interferon-Gamma Release Assay (IGRA). Highly specific test for TB infection; not affected by prior BCG vaccination, unlike the tuberculin skin test (TST).
Causes of High
- Latent Tuberculosis Infection (LTBI)
- Active Tuberculosis infection
Causes of Low
- No TB infection