Thyroid and Parathyroid Hormone Laboratory

Question 1

The most useful test for assessing thyroid function

Answer 1

THYROID-STIMULATING HORMONE

Question 2

immunometric assays effectively screen for
hyperthyroidism

Answer 2

Second-generation TSH

Question 3

chemiluminometric assays give fewer false-negative
results and more accurately distinguish between
euthyroidism and hyperthyroidism

Answer 3

Third-generation TSH

Question 4

chemiluminometric assays give fewer false-negative
results and more accurately distinguish between
euthyroidism and hyperthyroidism

Answer 4

Third-generation TSH

Question 5

exists providing a 10-fold increase in sensitivity
compared to third-generation assays

it is used primarily for research purposes

Answer 5

Fourth-generation assay

Question 6

reference range for s-TSH

Answer 6

s 0.3–4.2 mIU/L

Question 7

Measured by chemiluminometric assay or similar
immunometric technique

Answer 7

THYROXINE (T4)

Question 8

reference range for T4

Answer 8

0.4–4.0 mIU/L

Question 9

composed of both bound and free fractions

Answer 9

TRIIODOTHYRONINE (T3)

Question 10

reference range for total T3

Answer 10

80–200 ng/dL

Question 11

It is used as a second-line test after TSH in the evaluation of
suspected thyroid disorders and when used in conjunction with
TSH

Answer 11

FREE THYROXINE (FT4)

Question 12

FT3 levels may be required to evaluate clinically euthyroid
patients who have an altered distribution of thyroid binding
proteins as seen during ____________ or in patients with
__________________.

Answer 12

pregnancy
dysalbuminemia

Question 13

Reference range for FT3

Answer 13

2.8–4.4 pg/mL

Question 14

LOW FREE T4
LOW TSH

Answer 14

Secondary
hypothyroidism

Question 15

NORMAL FREE T4, LOW TSH

Answer 15

Subclinical
hyperthyroidism

Question 16

NORMAL FREE T4
LOW TSH

Answer 16

Subclinical
hyperthyroidism

Question 17

HIGH FREE T4
LOW TSH

Answer 17

Primary
hyperthyroidism

Question 18

LOW FREE T4
Normaal TSH

Answer 18

Secondary
hypothyroidism

Question 19

NORMAL FREE T4
Normaal TSH

Answer 19

Normal

Question 20

HIGH FREE T4
Normaal TSH

Answer 20

Secondary
hyperthyroidism

Question 21

NORMAL FREE T4
Highl TSH

Answer 21

Subacute
hypothyroidism

Question 22

LOW FREE T4
Highl TSH

Answer 22

Primary
hypothyroidism

Question 23

NORMAL FREE T4
Highl TSH

Answer 23

Subclinical
hypothyroidism

Question 24

HIGH FREE T4
Highl TSH

Answer 24

Secondary
hyperthyroidism

Question 25

Anti-Tg autoantibodies are most commonly associated with
_____________?

Answer 25

hashimoto’s thyroiditis

Question 26

reference range for thyroglobulin antibodies

Answer 26

s <4.0 IU/mL

Question 27

the most sensitive test for detecting autoimmune thyroid diseases including Hashimoto’s thyroiditis and Graves’ disease

Answer 27

THYROPEROXIDASE ANTIBODY

Question 28

reference range for TPO autoantibodies

Answer 28

s <9.0 IU/mL

Question 29

Most closely associated with disease pathogenesis

Answer 29

THYROTROPIN RECEPTOR ANTIBODY

Question 30

THYROTROPIN RECEPTOR ANTIBODY also known as___________________ or______________?

Answer 30

Long-acting thyroid stimulator (LATS) or thyroid-stimulating immunoglobulins
(TSI)

Question 31

reference range for TRAb

Answer 31

≤1.75 IU/L

Question 32

Common PTH assays use a _______________ in which two
antibodies bind to specific sites on the PTH molecule

Answer 32

sandwich technique

Question 33

solid phase antibody binds to the

Answer 33

e C-terminal end

Question 34

Signal antibody binds

Answer 34

N-terminal ends

Question 35

Measures the entire 1 to 84 PTH
sequence.

Answer 35

SANDWICH ELISA or electrochemiluminescent PTH
(intact, whole)

Question 36

This assay detects biologically active PTH
by its ability to induce formation of cAMP

Answer 36

CAP ASSAY

Question 37

There is no crossreactivity. Therefore, PTH
levels are low in subjects with cancers
producing PTHrP.

Answer 37

PTHRrP ASSAYS and PTH ASSAYS

Question 38

Test used for specimens obtained from parathyroid tumors.

Answer 38

Fine needle aspiration or needle biopsy