Siemens IMMULITE 1000 Thyroglobulin Manual Del Usuario página 6

Intraassay Precision (Within-Run):
Statistics were calculated for samples
from the results of 20 replicates in a single
run. (See "Intraassay Precision" table.)
Interassay Precision (Run-to-Run):
Statistics were calculated for samples
assayed in 20 different runs. (See
"Interassay Precision" table.)
Linearity: Samples were assayed under
various dilutions. (See "Linearity" table for
representative data.)
Recovery: Samples spiked 1 to 19 with
three thyroglobulin solutions (1,440, 3,100
and 5,720 ng/mL) were assayed. (See
"Recovery" table for representative data.)
Bilirubin: Presence of bilirubin in
concentrations up to 200 mg/L has no
effect on results, within the precision of the
assay.
Hemolysis: Presence of packed red blood
cells in concentrations up to 30 µL/mL has
no effect on results, within the precision of
the assay.
Lipemia: Presence of triglycerides in
concentrations up to 3,000 mg/dL has no
effect on results, within the precision of the
assay.
Specificity: The assay is specific for
thyroglobulin, with no detectable
crossreactivity to alpha-fetoprotein (AFP),
FSH, TSH, diiodothyronine (T2),
triiodothyronine (T3), or thyroxine (T4).
(See "Specificity" table.)
Alternate Sample Type: To assess the
effect of alternate sample types, blood
was collected from 20 volunteers into plain
and heparinized tubes. Equal volumes of
the matched samples were spiked with
various concentrations of thyroglobulin, to
obtain values throughout the calibration
range of the assay, and then assayed by
the IMMULITE Thyroglobulin procedure.
By linear regression:
(Heparin) = 0.93 (Serum) + 0.52 ng/mL
r = 0.989
Means:
7.7 ng/mL (Serum)
7.3 ng/mL (Heparin)
EDTA: Samples (n = 11) were collected
into plain and EDTA vacutainer tubes.
(EDTA) = 0.83 (Serum) – 10.8 ng/mL
r = 0.829
Means:
179 ng/mL (Serum)
137 ng/mL (EDTA)
6
The results show that EDTA plasma
should not be used in the IMMULITE
Thyroglobulin procedure.
Method Comparison: The assay was
compared to a commercially available
indirect solid phase enzyme immunometric
assay for thyroglobulin (Kit A) on
150 samples from patients with
Hashimoto's disease, Graves' disease,
patients who had undergone
thyroidectomy, as well as euthyroid
individuals. The thyroglobulin
concentrations of these patients covered
the entire calibration range of the assay.
The data are tabulated in reference to the
respective assays' suggested cutoffs.
55
Kit A ng/mL
 50 ng/mL 10
50 ng/mL
9
Agreement: 94.0%
95% Confidence Limits for Relative Sensitivity
and Specificity, respectively: 69.2% – 100% and
88.2% – 97.0%,
Clinical Performance: A clinical study at
a university medical center in the
midwestern United States included
56 thyroid disease patients (41 females
and 15 males, with an age range from
20 to 72 years) who provided from
2 to 6 serial specimens in the course of
their treatments that included partial,
subtotal or total thyroidectomy, and other
medical interventions. The results of this
study showed that IMMULITE
Thyroglobulin measurements were
consistent with the thyroid disease
conditions of these patients.
References
1) Bodlaender P, et al. Sensitive
radioimmunological screening test for anti-
thyroglobulin autoantibodies. Clin Chem
1978;24:272-4. 2) Cody V. Thyroglobulin and
thyroid hormone synthesis. Endocr Res
1984;10:73-88. 3) Czernichow P, et al. Plasma
thyroglobulin measurements help determine the
type of thyroid defect in congenital
hypothyroidism. J Clin Endocrinol Metab
1983;56242-5. 4) Dammacco F, et al. Serum
thyroglobulin and thyroid ultrasound studies in
infants with congenital hypothyroidism. J Pediat
1985;106:451-3. 5) Feldt-Rasmussen U. Serum
thyroglobulin and thyroglobulin autoantibodies in
thyroid diseases. Allergy 1983;38:369-87.
6) Gons MH, et al. Concentration of plasma
IMMULITE/IMMULITE 1000 Thyroglobulin (PILKTY-24, 2015-04-30)
IMMULITE Thyroglobulin
55
Relative Relative
Sensitivity Specificity
ng/mL
0
100% 93.6%
131