QuantiFERON®-TB Gold Plus (Client Incubated)
Also known as: Interferon-gamma Release Assay (IGRA) for Mycobacterium tuberculosis, QFT-Plus
Use
QuantiFERON-TB Gold Plus is an in vitro diagnostic test using a peptide cocktail of CD4+ and CD8+ T cell antigens to stimulate cells in heparinized whole blood. Detection of interferon-gamma by enzyme-linked immunosorbent assay (ELISA) is used to identify in vitro responses to these peptide antigens that are associated with Mycobacterium tuberculosis infection. QuantiFERON-TB Gold Plus is an indirect test for M. tuberculosis infection (including disease) and is intended for use in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations.
Special Instructions
This test is time-sensitive, requiring incubation at 37°C for 16 to 24 hours prior to transport to LabCorp. Specimens must be received in the laboratory within 70 hours post-incubation, and no more than 94 hours from collection. Follow collection times based on logistic considerations between the incubating location and LabCorp.
Limitations
A negative QuantiFERON-TB Gold Plus result does not exclude Mycobacterium tuberculosis infection or tuberculosis disease due to potential false negatives related to infection stage, co-morbid conditions affecting immune function, and improper blood collection handling or assay performance. Heterophile antibodies or non-specific interferon-gamma production from other inflammatory conditions may mask specific responses. A positive result should not solely determine infection and needs further medical evaluation for active tuberculosis disease.
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 71775-1
- 8251-1
- 64084-7
- 88517-8
- 71776-9
- 71774-4
- 71773-6
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
1 mL x four tubes in QuantiFERON-TB Gold Plus kit
Minimum Volume
1 mL x four tubes in QuantiFERON-TB Gold Plus kit
Container
QuantiFERON®-TB Gold Plus collection kit
Collection Instructions
Blood collection tubes should be at room temperature at the time of collection. Follow instructions included with draw kit. Use a needle and holder (not a butterfly) for collection. Fill tubes to the black fill line; replace any underfilled/overfilled tubes.
Storage Instructions
Before incubation, maintain specimen at room temperature; stability for incubation is within 16 hours of collection. After incubation, maintain at room temperature (17°C to 27°C). Do not centrifuge, refrigerate, or ship on ice.
Causes for Rejection
Rejection includes grossly hemolyzed, icteric, or lipemic samples, expired tubes, centrifuged/refrigerated/frozen specimens, specimens >94 hours old, receipt of three tube kits, under-filled/over-filled tubes, insufficient plasma.