Aid in the detection of latent disease among persons at increased risk for tuberculosis (TB). Positive predictive value is less in low-risk populations. May be used in persons who have received BCG vaccine.
Orderable SIM Number(s)
QUANTIFERON TB GOLD (LAB10118)
Synonyms
Quantiferon-TB Gold in Tube
Interferon-Gamma Release Assay for Tuberculosis
Latent Tuberculosis Infection (LTBI)
QFT & M TB
QFT-G & M.tuberculosis
QFT-TB
Quantiferon Mitogen and NIL
QuantiFERON-TB Gold In Tube & Mycobacterium tuberculosis Antibody
QuantiFERON-TB Gold Plus, 4-Tube
LAB10118
Collect
QuantiFERON-TB Gold Plus (Standard) 4-Tube Collection Kit (Lawson #622433). Contact Aspirus Reference Laboratory for collection kit.
Collection Instructions:
If drawing with needle, to leave the tubes on the needle for 2-3 seconds once the tube appears to have completed filling.
Recommendation is to draw with a syringe and 1 ml transferred to each of the tubes.
If drawing with butterfly, a “purge” tube should be used to ensure that the tubing is filled prior to the Q-gold tubes.
Fill to between black marks on each tube label (1ml of blood). DO NOT UNDER- or OVER-FILL.
Specimens may remain ambient for up to 16 hours after collection before being placed in an incubator.
Specimen Preparation
Transport plasma in the original containers. (Min: 0.8 mL per container)
Storage/Transport Temperature
Sample processing includes specific incubation and centrifuge timing. Choose one of the following two options for submitting to Aspirus Reference Laboratory:
NOT Processed
Samples MUST be delivered to the Aspirus Reference Laboratory within 16 hours of collection at Room Temperature.
Processed
Samples are incubated for 16 to 24 hours at 37 degrees C and then spun for 15 minutes at 2000-3000 RCF (g). Samples must be sent to ARL refrigerated. ***Indicate that samples have been incubated and spun***
Unacceptable Conditions
Whole Blood
Under-filled (<1ml) or Over-filled (>1ml) tubes
Interferon gamma release is measured for specimens from each of the four collection tubes. A qualitative result (Negative, Positive, or Equivocal) is based on interpretation of the four values, NIL, MITOGEN minus NIL (MITOGEN-NIL), TB1 minus NIL (TB1-NIL), and TB2 minus NIL (TB2-NIL). The NIL value represents nonspecific reactivity produced by the patient specimen. The MITOGEN-NIL value serves as the positive control for the patient specimen, demonstrating successful lymphocyte activity. The TB1-NIL tube specifically detects CD4+ lymphocyte reactivity, specifically stimulated by the TB1 antigens. The TB2-NIL tube detects both CD4+ and CD8+ lymphocyte reactivity, stimulated by TB2 antigens. An overall Negative result does not completely rule out TB infection.
A false-positive result in the absence of other clinical evidence of TB infection is not uncommon. Refer to: Updated Guidelines for Using Interferon Gamma Release Assays to Detect Mycobacterium tuberculosis Infection --- United States, 2010 http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5905a1.htm, for more information concerning test performance in low-prevalence populations and use in occupational screening.
CPT Codes
86480
Billable SIM Number(s)
331504
LOINC
71776-9
74774-4
64084-7
88517-8
71773-6
Overview
Ordering Recommendations
Aid in the detection of latent disease among persons at increased risk for tuberculosis (TB). Positive predictive value is less in low-risk populations. May be used in persons who have received BCG vaccine.
Orderable SIM Number(s)
QUANTIFERON TB GOLD (LAB10118)
Synonyms
Quantiferon-TB Gold in Tube
Interferon-Gamma Release Assay for Tuberculosis
Latent Tuberculosis Infection (LTBI)
QFT & M TB
QFT-G & M.tuberculosis
QFT-TB
Quantiferon Mitogen and NIL
QuantiFERON-TB Gold In Tube & Mycobacterium tuberculosis Antibody
QuantiFERON-TB Gold Plus, 4-Tube
LAB10118
Specimen
Collect
QuantiFERON-TB Gold Plus (Standard) 4-Tube Collection Kit (Lawson #622433). Contact Aspirus Reference Laboratory for collection kit.
Collection Instructions:
If drawing with needle, to leave the tubes on the needle for 2-3 seconds once the tube appears to have completed filling.
Recommendation is to draw with a syringe and 1 ml transferred to each of the tubes.
If drawing with butterfly, a “purge” tube should be used to ensure that the tubing is filled prior to the Q-gold tubes.
Fill to between black marks on each tube label (1ml of blood). DO NOT UNDER- or OVER-FILL.
Specimens may remain ambient for up to 16 hours after collection before being placed in an incubator.
Specimen Preparation
Transport plasma in the original containers. (Min: 0.8 mL per container)
Storage/Transport Temperature
Sample processing includes specific incubation and centrifuge timing. Choose one of the following two options for submitting to Aspirus Reference Laboratory:
NOT Processed
Samples MUST be delivered to the Aspirus Reference Laboratory within 16 hours of collection at Room Temperature.
Processed
Samples are incubated for 16 to 24 hours at 37 degrees C and then spun for 15 minutes at 2000-3000 RCF (g). Samples must be sent to ARL refrigerated. ***Indicate that samples have been incubated and spun***
Unacceptable Conditions
Whole Blood
Under-filled (<1ml) or Over-filled (>1ml) tubes
Interferon gamma release is measured for specimens from each of the four collection tubes. A qualitative result (Negative, Positive, or Equivocal) is based on interpretation of the four values, NIL, MITOGEN minus NIL (MITOGEN-NIL), TB1 minus NIL (TB1-NIL), and TB2 minus NIL (TB2-NIL). The NIL value represents nonspecific reactivity produced by the patient specimen. The MITOGEN-NIL value serves as the positive control for the patient specimen, demonstrating successful lymphocyte activity. The TB1-NIL tube specifically detects CD4+ lymphocyte reactivity, specifically stimulated by the TB1 antigens. The TB2-NIL tube detects both CD4+ and CD8+ lymphocyte reactivity, stimulated by TB2 antigens. An overall Negative result does not completely rule out TB infection.
A false-positive result in the absence of other clinical evidence of TB infection is not uncommon. Refer to: Updated Guidelines for Using Interferon Gamma Release Assays to Detect Mycobacterium tuberculosis Infection --- United States, 2010 http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5905a1.htm, for more information concerning test performance in low-prevalence populations and use in occupational screening.
