Siemens IMMULITE 1000 Thyroglobulin Manual Del Usuario página 2

®
IMMULITE /IMMULITE
English
Intended Use: For in vitro diagnostic use
with the IMMULITE and IMMULITE 1000
Analyzers — for the quantitative
measurement of thyroglobulin in serum or
heparinized plasma, as an aid in
monitoring patients who have undergone
thyroidectomy.
Catalog Number: LKTY1 (100 tests)
Test Code: TG Color: Dark Gray
The presence of autoantibodies
against thyroglobulin (anti-TG) can
interfere with the determination of
thyroglobulin in serum. Anti-TG
antibodies can be quantitated by using
the IMMULITE Anti-TG Ab kit
(LKTG1).
When monitoring patients over time,
TG values obtained with different
methods cannot be used
interchangeably due to the differences
in methods and reagent specificity.
The laboratory should provide the
physician with the method identity
along with the result. Serial serum TG
measurements should be made with
the same method.
Summary and Explanation
Thyroglobulin (TG) is a heterogeneous
iodoglycoprotein which has a molecular
mass of approximately 660,000 daltons.
Thyroglobulin is normally synthesized in
the follicular cells of the thyroid gland,
under the influence of thyrotropin, and
represents the precursor to thyroxine and
the other iodothyronines.
The expected upper limit of normal for
circulating thyroglobulin is approximately
40 to 60 ng/mL, with a median of
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5 to 10 ng/mL. Somewhat higher values
are encountered in newborns
during the third trimester of pregnancy.
Thyroglobulin levels also tend to be
elevated in regions of endemic goiter.
The major clinical applications for
measurement of this prohormone derive
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2,12
7,10
and
IMMULITE/IMMULITE 1000 Thyroglobulin (PILKTY-24, 2015-04-30)
1000 Thyroglobulin
from the fact that functioning thyroid tissue
appears to be the only source of
circulating thyroglobulin. Accordingly,
thyroglobulin determinations have been
widely used to complement radioiodine
scanning and other techniques (such as
ultrasound or immunohistochemical
staining) as an aid in identifying the
presence or absence of functioning thyroid
tissue, or an increase in such tissue
relative to an individually established
baseline. The differential diagnosis of
congenital hypothyroidism is a well-
established context of use for this
application of serum thyroglobulin
measurement.
Congenital Hypothyroidism:
Thyroglobulin determinations have been
used, sometimes in conjunction with
ultrasound and radioiodine scanning, to
help clarify the type of thyroid defect in
previously diagnosed congenital
3,4,6,7,10,13
hypothyroidism.
undetectable thyroglobulin levels are
expected in infants born without thyroid
tissue (thyroid agenesis), whereas higher,
but widely varying levels are generally
encountered in infants with hypoplastic
thyroid glands, ectopic thyroid tissue,
dyshormonogenic goiter, congenital TBG
deficiency or transient hypothyroidism.
Other Applications: Thyroglobulin
measurements may also be of value in
helping to distinguish subacute thyroiditis
from thyrotoxicosis caused by covert
administration of thyroid hormones. In the
latter event, low levels of thyroglobulin are
expected due to thyroid hormone
suppression of thyrotropin.
Principle of the Procedure
IMMULITE/IMMULITE 1000 Thyroglobulin
is a solid-phase, chemiluminescent
immunometric assay.
Incubation Cycles: 1 × 60 minutes
Specimen Collection
EDTA should not be used as an
anticoagulant.
The use of an ultracentrifuge is
recommended to clear lipemic samples.
Very low or
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