Overview: TB Platinum Interferon-Gamma Release Assay TestIntroduction: The TB Platinum Interferon-Gamma Release Assay Test measures interferon gamma to diagnose latent tuberculosis, preventing active TB. Aligned with 2023 CDC guidelines, it uses immunoassays for high specificity, supporting infection screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in immunology for patients with suspected latent tuberculosis.
Other Names: TB Platinum IGRA Assay, QuantiFERON-TB Gold Test.
FDA Status: FDA-approved test, meeting immunology standards for diagnostic accuracy.
Historical Milestone: IGRA testing began in the 2000s with tuberculosis research. Immunoassay methods improved in the 2010s, enhancing diagnostic precision.
Purpose: Measures interferon gamma to diagnose latent tuberculosis, guides treatment, and prevents active TB.
Test Parameters: 1. Interferon Gamma Release 2. TB Antigen Response
Pretest Condition: No fasting required. Collect whole blood in special IGRA tubes. Report history of TB exposure or symptoms.
Specimen: Whole Blood (special IGRA tube, 2-5 mL). Transport in a biohazard container.
Sample Stability at Room Temperature: 24 hours
Sample Stability at Refrigeration: 48 hours
Sample Stability at Frozen: Not frozen
Medical History: Document TB exposure, cough, or history of tuberculosis. Include current medications, especially immunosuppressants.
Consent: Written consent required, detailing the tests purpose, latent tuberculosis implications, and risks of sample collection.
Procedural Considerations: Uses enzyme-linked immunosorbent assay (ELISA) to measure interferon gamma release in response to TB antigens. Results are available in 1-2 days, supporting clinical decisions. Performed in laboratories, often for latent TB diagnosis.
Factors Affecting Result Accuracy: Improper sample handling or immunosuppression can affect results. Recent TB exposure may yield false negatives.
Clinical Significance: Positive IGRA confirms latent tuberculosis, guiding preventive therapy. Negative results may require TST or chest X-ray.
Specialist Consultation: Consult an infectious disease specialist or pulmonologist for result interpretation and treatment planning.
Additional Supporting Tests: Tuberculin skin test (TST), chest X-ray, or sputum AFB to confirm TB diagnosis.
Test Limitations: Non-specific for active vs. latent TB; clinical correlation is needed. Sample quality affects sensitivity.
References: CDC Tuberculosis Guidelines, 2023; Clinical Infectious Diseases, Lewinsohn DM, 2022.
