Warnings And Precautions - Siemens Coat-A-Count TSH IRMA Manual Del Usuario

Coat-A-Count
English
Intended Use: Coat-A-Count TSH IRMA
is an immunoradiometric assay designed
for the quantitative measurement of
thyroid stimulating hormone (thyrotropin,
TSH) in serum. It is intended strictly for in
vitro diagnostic use as an aid in the
assessment of thyroid status.
Catalog Numbers: IKTS1 (100 tubes),
IKTS5 (500 tubes), IKTSX (1000 tubes)
The 100-tube kit contains less
than 20 microcuries
(740 kilobecquerels) of
125
radioactive I-polyclonal anti-TSH; the
500-tube kit contains less than
100 microcuries (3,700 kilobecquerels);
and the 1,000-tube kit contains less than
200 microcuries (7,400 kilobecquerels).
Summary and Explanation of
the Test
Thyroid stimulating hormone (thyrotropin,
TSH) is a pituitary hormone which,
through its action on the thyroid gland,
plays a major role in maintaining normal
circulating levels of the iodothyronines, T4
and T3. TSH is controlled by negative
feedback from circulating T4 and T3, and
by the hypothalamic hormone TRH
(thyrotropin releasing hormone).
In primary hypothyroidism, where there is
impaired production of thyroid hormones,
the TSH level is typically highly elevated.
In secondary or tertiary hypothyroidism, on
the other hand, where thyroid hormone
production is low as a consequence of
pituitary or hypothalamic lesions, the TSH
level is usually low. In hyperthyroidism, the
TSH level is typically suppressed to
subnormal levels. Less often, this
condition may result from hyperstimulation
of the thyroid, due to hypothalamic or
pituitary lesions, in which case the TSH
level is usually increased.
Measurement of circulating TSH has been
used as a primary test for differential
diagnosis of hypothyroidism
aid in monitoring the adequacy of thyroid
hormone replacement therapy.
2
®
TSH IRMA
19
and as an
18
Research studies have found that the
apparently healthy patients with TSH
>2.0 µIU/mL have increased risk to
develop thyroid diseases in the next 20
years. It has been suggested that it is
likely that the upper limit of the serum TSH
euthyroid reference range will be reduced
to 2.5 µIU/mL because >95% of rigorously
screened normal euthyroid volunteers
have serum TSH values between 0.4 and
22
2.5 µIU/mL.
Principle of the Procedure
Coat-A-Count TSH IRMA is a solid-phase
immunoradiometric assay based on
monoclonal and polyclonal anti-TSH
125
antibodies: one I-labeled anti-TSH
polyclonal antibody in liquid phase, and
monoclonal anti-TSH antibodies
immobilized to the wall of a polystyrene
tube. In the procedure:
TSH is captured between monoclonal
anti-TSH antibodies immobilized on the
inside surface of the polystyrene tube and
the radiolabeled polyclonal anti-TSH
tracer.
125
Unbound I-labeled anti-TSH antibody is
removed by decanting the reaction mixture
and washing the tube; this reduces
nonspecific binding to a very low level,
and ensures excellent low-end precision.
The TSH concentration is directly
proportional to the radioactivity present in
the tube after the wash step. The
radioactivity is counted using a gamma
counter, after which the concentration of
TSH in the patient sample is obtained by
comparing the patient counts-per-minute
with those obtained for the set of
calibrators provided.
Reagents to Pipet: 1
Total Incubation Time: 2 Hours
Total Counts at Iodination:
approximately 200,000 cpm

Warnings and Precautions

For in vitro diagnostic use.
Reagents: Store at 2–8°C in a refrigerator
designated for incoming radioactive
materials. Dispose of in accordance with
applicable laws.
Coat-A-Count TSH IRMA (PIIKTS-8, 2010-11-04)