LOINC Code 74279-1: Gamma interferon negative control spot count (Bld) [#]

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Gamma interferon.negative control spot count. It is commonly used with the system or sample type Bld.

When is it used?

• Used in lab systems, EHRs, and clinical data exchange.
• May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
• Status: ACTIVE
• Order vs observation: Both

What it does not mean

• The code identifies the observation or test, not the actual result.

Key facts

• Gamma interferon negative control spot count [#] in Blood
• Gamma interferon.negative control spot count
• The count of negative control spots (0 to >20) in a patient's T cells incubated without M. tuberculosis antigens (ESAT-6, CFP10). This term is created for, 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 test, a typical result is expected to have few to no spots in the negative (nil) control and 20 or more spots in the positive control (Mitogen stimulated). A negative control spot count of >10 is considered invalid.
• Blood; Cnt; Count; ID; IFN; IGNF neg cntrl; IGNF neg control; Infectious Disease; InfectiousDisease; Lung; Microbiology; NEG; Number; Point in time; Pulmonary; Pulmonology; QNT; Quan; Quant; Quantitative; Random; Respiratory; WB; Whole blood

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Frequently asked questions