Newcastle Laboratories

17-alpha-Hydroxyprogesterone, serum

Clinical Background:

17-α-hydroxyprogesterone (17OHP) is a biosynthetic precursor of cortisol and thus of adrenal origin in males and females. In females there is an additional, though small, contribution from the ovar...

17-α-hydroxyprogesterone (17OHP) is a biosynthetic precursor of cortisol and thus of adrenal origin in males and females. In females there is an additional, though small, contribution from the ovary. Furthermore the amount of 17OHP secreted by the ovary varies throughout the menstrual cycle. Blood levels are higher in the luteal phase than in the follicular phase. Serum levels of 17OHP are raised when there is impairment in the 21- and 11a-hydroxylation steps through to cortisol. Diagnosis of classical congenital adrenal hyperplasia (CCAH) due to these defects (most commonly 21-hydroxylase deficiency) may be made by measuring 17OHP levels in serum/plasma. 17OHP levels may also be used to monitor glucocorticoid therapy in patients with CCAH. Newborns with CCAH may present with ambiguous genitalia (in females) or salt-wasting adrenal crisis, typically 2-3 weeks after birth. These adrenal crises are life-threatening.
Milder defects in 21-hydroxylase may lead to non-classcial CAH (NCCAH), also known as late-onset CAH. Female patients with NCCAH may present with a PCOS-like phenotype, with hirsuitism and/or menstrual irregularities. NCCAH may also be associated with early puberty.

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Test Details

  • Discipline:

    Biochemistry

    Biochemistry

  • Specimen Container Adult:

    Serum-SST

    Serum-SST

  • Specimen Container Paediatric:

    Serum-SST

    Serum-SST

  • Minimum Volume Adult:

    2 mL blood

    2 mL blood

  • Minimum Volume Paediatric:

    1 mL blood

    1 mL blood

  • Special Requirement:

    Do not collect before 3d of age, preferably 5d. For diagnosis in neonates, samples should be taken prior to any steroid replacement.

     

    Do not collect before 3d of age, preferably 5d. For diagnosis in neonates, samples should be taken prior to any steroid replacement.

     

  • Sample Stability:

    Unseparated: Same day
    Separated: 7 days at 4-8°C, 1 month at -20°C

    Unseparated: Same day
    Separated: 7 days at 4-8°C, 1 month at -20°C

  • Transport Requirements:

    Ambient

    Ambient

  • Interpretation:

    Untreated individuals with CCAH due to 21-hydroxylase deficiency have very high serum/plasma 17OHP concentrations (usually >100 nmol/L). Androstenedione is also highly elevated. In order to confirm...

    Untreated individuals with CCAH due to 21-hydroxylase deficiency have very high serum/plasma 17OHP concentrations (usually >100 nmol/L). Androstenedione is also highly elevated. In order to confirm a diagnosis of 21-hydroxylase deficiency it is recommended that a urine steroid profile is requested. Non-specific elevations in 17OHP can occur in neonates due to prematurity, low birth weight, or stress.

    In NCCAH 17OHP concentrations may be elevated (usually <100 nmol/L), but are within the reference range in some cases. Measurement of 17OHP after synacthen stimulation is therefore required in some cases to exclude or diagnose NCCAH. An exaggerated increase in 17OHP concentrations in response to synacthen is observed in NCCAH.

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  • Reference Ranges:

    Infants less than 1 year: <9 nmol/L
    Adult male: 1.9 - 6.5 nmol/L
    Adult female Follicular Phase: 1.0 - 4.5 nmol/L
    Adult female Luteal Phase: 0.8 - 8.8 nmol/L

    Infants less than 1 year: <9 nmol/L
    Adult male: 1.9 - 6.5 nmol/L
    Adult female Follicular Phase: 1.0 - 4.5 nmol/L
    Adult female Luteal Phase: 0.8 - 8.8 nmol/L

  • Factors Affecting Result:

    In very young infants interference from sulphated steroids may increase measured 17OHP concentrations. Regular spironolactone therapy may increase measured 17OHP concentrations.
    N.B. Heterophilic a...

    In very young infants interference from sulphated steroids may increase measured 17OHP concentrations. Regular spironolactone therapy may increase measured 17OHP concentrations.
    N.B. Heterophilic antibodies can interfere with immunoassays.

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  • Routine Contact Name:

    Duty Biochemist

  • Routine Telephone:

    Freeman: 0191 244 8889

    RVI: 0191 282 9719

    Freeman: 0191 244 8889

    RVI: 0191 282 9719

  • Routine Email:

  • Specialist Test:

    Yes

    Yes

  • Specialist Contact Name:

    Endocrine Lab

    Endocrine Lab

  • Specialist Telephone:

    0191 282 4025

    0191 282 4025

Availability:

Available during full access hours.
Assayed weekly.
Site of analysis: RVI

May be available urgently after discussion with the Duty Biochemist

Turn Around:

Within 2 weeks

Send To:

Department of Blood Sciences

Level 3
Leazes Wing
Royal Victoria Infirmary
Queen Victoria Road
Newcastle upon Tyne
NE1 4LP

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