The QuantiFERON ® -TB Gold assay detects CMI responses in-vitro
to tuberculosis infection by measuring interferon-gamma (IFN-G)
harvested in plasma from whole blood incubated with the M. tuberculosis-specific
antigens, ESAT-6 & CFP-10.
he QuantiFERON ® -TB Gold test is performed in two stages.
In the first stage, aliquots of heparinised whole blood are incubated
with ESAT-6, CFP-10, T cell mitogen (PHA) and negative control
antigens. Following a 16 to 24 hour incubation, the plasma is
harvested.
In the second stage, the amount of IFN-? in the plasma samples
is quantified by enzyme-linked immunosorbent assay (ELISA). Results
for test samples are reported in International Units relative
to a recombinant human IFN- ? standard preparation.
An IFN-G response to either ESAT-6 or CFP-10 above the test cut-off
is considered indicative of M. tuberculosis infection.
This test should be considered as an alternative to the Mantoux
test, but has the advantages that it can be used to detect latent
TB infection in patients who have been vaccinated with BCG and
have a positive Mantoux test. It can also be used when a Mantoux
test is contraindicated.
Please note this test is primarily intended to detect latent infection
with M. tuberculosis, but not for the diagnosis and management
of active tuberculosis. Should active TB be suspected, culture
(and/or PCR testing) of appropriate clinical specimens is still
necessary for a definitive diagnosis.
This assay will not detect infection with M. bovis BCG
strains used for vaccination or immunotherapy.
Specimen collection advice:
Gently mix the heparin blood tube (minimum 5mL venous blood) by
inverting the tube several times to dissolve the heparin, and
transport to the laboratory at ambient temperature (22°C ±
5°C). Do not refrigerate or freeze the specimen.
NB: Blood should be incubated with stimulation antigens as soon
as possible (within 10 hours) after collection. Specimens should
reach the laboratory by no later than 4pm Monday to Friday. Specimens
arriving after hours may be rejected.
Please contact the laboratory for advice if there is likely to
be any delay in specimen transport on 93422670.
For further information on this test and result interpretation,
test limitations & references, please see the attached .pdf
file (tbgold.pdf)
This package insert has been posted with the permission of
Cellestis
