Adults/infants/children 0.3–6.2 Adults > age 80 years Up to 10.0 Newborn by day 3 < 20.0 Newborn by day 10 < 10.0 Newborn by day 14 < 6.2 Example of Chemiluminescence Immunoassay Method—TSH Estimation Thyroglobulin Antibodies

 

Women Follicular phase 0.75–2.16 ng/mL

Luteinic phase 0.94–2.33 ng/mL

Men 0.60–1.85 ng/mL

PROGESTERONE

Normal Values (Units—ng/mL)

Males 0.4–0.9

Females

Follicular phase 0.40–1.7

Midluteal 4.9–18.8

Postmenopausal Up to–1.0

On oral contraceptive pills 0.34–0.92

Pregnant females

18–21 wk 53–76

22–25 wk 60–86

26–29 wk 71–133

30–33 wk 86–142

34–37 wk 104–175

38–41 wk 117–187

Measurement of serum progesterone have also been

used to check the effectiveness of ovulation induction, to

monitor progesterone replacement therapy and to detect

and evaluate patients at risk for abortion during the early

weeks of pregnancy, progesterone levels are increased

in luteal phase of menstrual cycle, luteal cysts of ovary,

ovarian tumors (e.g. arrhenoblastoma) and adrenal

tumors. While decreased levels of progesterone are seen in

conditions of amenorrhea, threatened abortion and fetal

death, toxemia of pregnancy and gonadal agenesis.

Values are Increased in

Adrenal hyperplasia (congenital males), corpus luteum

cyst, lipid ovarian tumors, molar pregnancy, ovarian

chorionepithelioma, ovarian neoplasms, placental tissue

(retained postparturition), precocious puberty and theca

lutein cysts. Drugs include adrenocortical hormones,

estrogens and progesterones.

Values are Decreased in

Adrenogenital syndrome, amenorrhea, anovular

menstruation, fetal abnormality or death, luteal

deficiency, menstrual abnormalities, ovarian failure,

panhypopituitarism, placental failure or insufficiency,

preeclampsia, Stein-Levinthal syndrome, threatened

abortion, toxemia of pregnancy, Turner’s syndrome,

and primary/secondary hypogonadism. Drugs include

ampicillin and ethinyl estradiol.

The Endocrine System 783

17-ALPHA-HYDROXYPROGESTERONE

Reference Values

The serum or plasma 17αOH progesterone values are

comprised in the following intervals:

Women Follicular phase 0.2–1.2 ng/mL

Luteinic phase 1.0–4.5 ng/mL

Menopause 0.2–0.8 ng/mL

Men 0.2–2.3 ng/mL

Children 0.2–0.9 ng/mL

Its measurement is of value in the diagnosis and measurement of congenital adrenal hyperplasia, hirsutism and

infertility. Circulating 17 alpha hydroxy progesterone

normally exhibits a diurnal variation similar to that of cortisol,

with higher values in the morning. Serum measurement

has been used in the differential diagnosis of hirsutism and

infertility where 21 hydrolase deficiency is suspected. Since

late-onset congenital adrenal hyperplasia can sometimes

mimic the polycystic ovary syndrome, untreated congenital

adrenal hyperplasia in newborn is usually associated with

markedly elevated 17 alpha hydroxy progesterone levels

ranging from 10 to 400 times the upper limit of the normal.

TOTAL TRI-IODOTHYRONINE (T3)

Expected Values for the T3 EIA Test System

(in ng/dL)

Expected Ranges (±2 SD) 69–202

Interpretation of Total T3 in ng/mL

Age ng/mL

Adults 0.60–2.3

Children

Cord blood 0.15–0.75

First 72 hours 0.32–2.16

7–14 days AVG–2.5

2–14 weeks 1.60–2.40

4–16 weeks 1.17–2.09

16–52 weeks 1.10–2.80

1–5 years 1.05–2.69

5–10 years 0.94–2.41

10–15 years 0.83–2.31

Free Tri-iodothyronine (FT3)

Interpretation

Several drugs are known to effect the binding of triiodothyronine to the thyroid hormone carrier proteins or

its metabolism to T3 and complicate the interpretation of

free T3 results.

Circulating autoantibodies to T3 and hormone-binding

inhibitors may interfere.

Heparin has been reported to have in vivo and in vitro

effects on free T3 concentration. Therefore, do not obtain

samples in which this anticoagulant has been used.

In severe nonthyroidal illness (NTI), the assessment of

thyroid status becomes very difficult. TSH measurements

are recommended to identify thyroid dysfunction.

Familial dysalbuminemic conditions may yield

erroneous results on direct free T3 assays.

“Not Intended for Newborn Screening.”

Expected Ranges of Values

Expected Values for the Free T3 EIA Test System (in pg/mL)

Adult Pregnancy

Expected ranges

(±2 SD) 1.4–4.2 1.8–4.2

T-Uptake

Interpretation

The T-uptake test is dependent upon a multiplicity of

factors: thyroid gland and its regulation, thyroxine binding

globulin (TBG) concentration, and the binding of the

thyroid hormones to TBG. Thus, the T-uptake test alone is

not sufficient to assess clinical status.

The free thyroxine index (FTI), which is the product of

the T-uptake ratio and the total thyroxine concentration,

has gained wide clinical acceptance as a more accurate

assessment of thyroid status. The FTI value compensates

for any condition or drug, such as pregnancy or estrogens,

which alters the TBG and the T4 levels but does not change

the thyrometabolic status. A table of interfering drugs

and conditions which affect the T-uptake test has been

compiled by the Journal of the American Association of

Clinical Chemists.

Expected Ranges of Values

Expected Values for the T-uptake EIA Test System

Thyroid Status Percent

T-uptake

T-ratio

Euthyroid 25–35 0.83–1.17

Hypothyroid or TBG

(Excess binding)

less than 25 less than 0.83

Hyperthyroid or TBG

(Reduced binding)

greater than 35 greater than 1.17

784 Concise Book of Medical Laboratory Technology: Methods and Interpretations Total Thyroxine (T4)

Interpretation

Total serum thyroxine concentration is dependent upon

a multiplicity of factors: thyroid gland function and its

regulation, thyroxine-binding globulin (TBG) concentration,

and the binding of thyroxine to TBG. Thus, total thyroxine

concentration alone is not sufficient to assess clinical status.

Total serum thyroxine values may be elevated under

conditions, such as pregnancy or administration of

oral contraceptives. A T3 uptake test may be performed

to estimate the relative TBG concentration in order to

determine if the elevated T4 is caused by TBG variation.

A decrease in total thyroxine values is found with proteinwasting diseases, certain liver diseases and administration of

testosterone, diphenylhydantoin or salicylates.

“Not intended for newborn screening.”

Expected Range of Values

Expected Values for the T4 EIA Test System (in µg/dL)

Male Female*

Expected Ranges (±2 SD) 4.4–10.8 4.8–11.6

*Normal patients with high TBG levels were not excluded except if

pregnant

Normal Values (µg/dL)

Age

Adults 5.0–12.0

Pregnant > 14 weeks 9.1–14.0

Elderly (> 60 years)

Female 5.5–10.5

Male 5.0–10.0

Children

Cord blood

First 72 hours 7.4–13.0

7–14 days 11.8–22.6

4–16 weeks 9.8–16.6

4–12 months 7.2–14.4

1–5 years 7.8–16.5

5–10 years 7.3–15.0

6.4–13.3

10–15 years 5.6–11.7

Panic levels

Thyroid storm possible > 20.0

Myxedema possible < 2.0

Free Thyroxine (FT4)

Interpretation

Total serum thyroxine concentration is dependent upon

a multiplicity of factors: thyroid gland function and its

regulation, thyroxine-binding globulin (TBG) concentration,

and the binding of thyroxine to TBG. Thus, total thyroxine

concentration alone is not sufficient to assess clinical

status.

Total serum thyroxine values may be elevated under

conditions such as pregnancy or administration of oral

contraceptives. A T3 uptake test may be performed to

estimate the relative TBG concentration in order to

determine if the elevated T4 is caused by TBG variation.

A decrease in total thyroxine values is found with

protein-wasting diseases, certain liver diseases and

administration of testosterone, diphenylhydantoin or

salicylates.

“Not intended for newborn screening.”

Expected Range of Values

Expected values for the free T4 EIA test system (in ng/dL)

Adult Pregnancy

Expected Ranges (±2S. D.) 0.8-2.0 0.8-2.2

Thyrotropin (TSH)

Interpretation

Serum thyrotropin concentration is dependent upon a

multiplicity of factors: hypothalamus gland function,

thyroid gland function, and the responsiveness of pituitary

to TRH. Thus, thyrotropin concentration alone is not

sufficient to assess clinical status.

Serum thyrotropin values may be elevated by pharmacological intervention. Domperiodone, amiodazon, iodide,

phenobarbital, and phenytoin have been reported to

increase TSH levels.

A decrease in thyrotropin values has been reported

with the administration of propranolol, methimazol,

dopamine and d-thyroxine.

Genetic variations or degradation of intact TSH into

subunits may affect the binding characteristics of the

antibodies and influence the final result. Such samples

normally exhibit different results among various assay

systems due to the reactivity of the antibodies involved.

“Not intended for newborn screening.”

The Endocrine System 785

Expected Ranges of Values

Expected values for the TSH IEMA test system

(in µlU/ mL)

Low normal range 0.39

High normal range 6.16

Normal Values (µIU/ mL)

Age

Adults/infants/children 0.3–6.2

Adults > age 80 years Up to 10.0

Newborn by day 3 < 20.0

Newborn by day 10 < 10.0

Newborn by day 14 < 6.2

Example of Chemiluminescence Immunoassay

Method—TSH Estimation Thyroglobulin Antibodies

Interpretation

The presence of autoantibodies to Tg is confirmed

when the serum level exceeds 125 lU/mL. The clinical

significance of the result, coupled with antithyroid

peroxidase activity, should be used in evaluating the

thyroid condition. However, clinical inferences should not

be solely based on this test but rather as an adjunct to the

clinical manifestations of the patient and other relevant

tests.