74278-3
LaboratoryMycobacterium tuberculosis stimulated gamma interferon ESAT-6 Ag spot count [#] in Blood
Definition
The count of spots (0 to >20) in a patient's T cells that represent IFN-γ released in response to the presence of M. tuberculosis early secretory antigenic target-6 (ESAT-6) antigens. The spot count provides a measurement of the abundance of Mycobacterium tuberculosis sensitive effector T cells in the peripheral blood. This term is based on, but not limited in use to, Oxford Immunotec's T-SPOT.TB assay, used to diagnose M. tuberculosis. T-SPOT.TB assay uses enzyme-linked immunospot (ELISPOT) methodology to enumerate M. tuberculosis-sensitized T cells by capturing interferon-gamma (IFN-y) in the vicinity of T cells in the patient's whole blood. In the T-SPOT.TB assay, the test result is positive if [ESAT-6 (Panel A) - negative control spots] and/or [CFP10 (Panel B) - negative control spots] is greater than or equal to 8 spots. The test result is negative if both [Panel A - negative control] and/or [Panel B - negative control] is less than or equal to 4 spots.
LOINC 6-Axis Classification
Component
Mycobacterium tuberculosis stimulated gamma interferon.ESAT-6 Ag spot count
Property
Num
Time Aspect
Pt
System
Bld
Scale Type
Qn
Method Type
N/A
Details
Class
MICRO
Order/Observation
Both
Short Name
M TB IFN-g.ESAT-6 Ag Bld
Display Name
M. tuberculosis stim IFN-g ESAT-6 Ag spot count (Bld) [#]
Related Names
Frequently Asked Questions
What is LOINC code 74278-3?
LOINC code 74278-3 identifies "Mycobacterium tuberculosis stimulated gamma interferon ESAT-6 Ag spot count [#] in Blood". The count of spots (0 to >20) in a patient's T cells that represent IFN-γ released in response to the presence of M. tuberculosis early secretory antigenic target-6 (ESAT-6) antigens. The spot count provides a measurement of the abundance of Mycobacterium tuberculosis sensitive effector T cells in the peripheral blood. This term is based on, but not limited in use to, Oxford Immunotec's T-SPOT.TB assay, used to diagnose M. tuberculosis. T-SPOT.TB assay uses enzyme-linked immunospot (ELISPOT) methodology to enumerate M. tuberculosis-sensitized T cells by capturing interferon-gamma (IFN-y) in the vicinity of T cells in the patient's whole blood. In the T-SPOT.TB assay, the test result is positive if [ESAT-6 (Panel A) - negative control spots] and/or [CFP10 (Panel B) - negative control spots] is greater than or equal to 8 spots. The test result is negative if both [Panel A - negative control] and/or [Panel B - negative control] is less than or equal to 4 spots.
What does 74278-3 measure?
This code measures Mycobacterium tuberculosis stimulated gamma interferon.ESAT-6 Ag spot count in Bld. It belongs to the MICRO class in the LOINC classification.
What is LOINC?
LOINC (Logical Observation Identifiers Names and Codes) is a universal standard for identifying laboratory and clinical observations. It is maintained by the Regenstrief Institute and used worldwide for health data exchange.