17-OH Progesterone, LC/MS

Methodology: 
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Performed: 
Monday - Friday
Use: 
This test is used to evaluate patients with congenital adrenal hyperplasia1 - 5 , as well as hirsutism and/or infertility 6. It is also used to assess or rule-out certain adrenal or ovarian tumors with endocrine activity7.
Specimen Requirements: 

Type: Serum

Container/Tube: Red-top tube or gel-barrier tube
  • If a red-top tube is used, transfer the separated serum to a plastic transport tube.

Sample Volume: 0.8 mL

Minimum Volume: 0.4 mL (Repeat testing is not possible with this specimen volume.)

Storage: Refrigerate specimens after collection.

Stability (collection to time of analysis/testing): 
  • Ambient: 6 days
  • Refrigerated: 7 days
  • Frozen: 2.6 years
  • Freeze/Thaw cycles: Stable (x9)
Rejection Criteria:
  • Citrate plasma specimen
  • Improper labeling
Reference Values: 

Reference Intervals

Premature Infants

26 to 28 weeks, day 4

124 − 841

31 to 35 weeks, day 4

26 − 568

Full-Term Infants

Day 3

0 − 77

Female:

1 to 11 months

13 − 106

Male:

1 to 11 months

Levels increase after the first week to peak values, ranging from 40 to 200 ng/dL, between 30 and 60 days. Values then decline to prepubertal range < 91 ng/dL.

Prepubertal Children

1 to 9 years

 

0 − 90

Tanner Stage

Male

Female

1

0 − 90

0 − 82

2

0 − 115

11 − 98

3

10 − 138

11 − 155

4

29 − 180

18 − 230

5

24 − 175

20 − 265

Adult Male

 

27 − 199

Adult Female

Follicular

 

15 − 70

Luteal

 

35 − 290

CPT Code (s): 
83498
Notes: 

UFHPL Test #: 28000

Congenital adrenal hyperplasia (CAH), is an autosomal recessive disorder affecting one of the enzymes required to synthesize cortisol from cholesterol in the adrenal gland.1-4 Diminished production of cortisol leads to increased pituitary secretion of ACTH via the negative feedback mechanism, which in turn causes hyperplasia of the adrenal cortex. Excess production of hormones proximal to the enzymatic defect gives rise to various clinical phenotypes. The clinical symptoms of CAH directly result from either the deficiencies in mineralocorticoid or glucocorticoid production or from the overproduction of precursors that are converted to androgens.1-4 There is a wide spectrum of clinical presentations, including a severely affected, "salt-wasting" form, a simple virilizing form with normal aldosterone production, and a mild "nonclassic" form that may be asymptomatic or may be associated with symptoms that may not be discovered until adulthood.1-5

The incidence of classic CAH ranges from 1:10,000 to 1:20,000 births1 but is more prevalent in some ethnic groups, particularly in remote geographic regions. The most common form of CAH occurs as the result of mutations in the CYP21A2 gene, which results in 21-hydroxylase deficiency (21-OHD).1 This enzyme converts 17-hydroxyprogesterone (17-OHP) to 11-deoxycortisol and progesterone to deoxycorticosterone, respective precursors for cortisol and aldosterone. In Caucasians, 21-OHD accounts for more than 90% of all cases, whereas 5% are caused by 11-hydroxylase deficiency and other enzyme deficiencies and clinical phenotypes are less common.1,4 In 21-OHD, reduced production of glucocorticoids can lead to adrenal crises with hypoglycemia and hypotension in the setting of an illness or physiological stress.2 Approximately 75% of classic CAH cases also suffer aldosterone deficiency with clinical symptoms that can include poor feeding and failure to thrive, vomiting, hyperkalemia, hyponatremia, dehydration, metabolic acidosis, and apathy.1-4 The excess 17-OHP and other unblocked precursors, pregnenolone and progesterone, are diverted in the adrenals to the production of dehydroepiandrosterone and androstenedione, which are then peripherally converted to testosterone.1,2 A key manifestation of this androgen overproduction is in utero virilization resulting in genital ambiguity in newborn females.1-4 In fact, 21-OHD is the most common cause of ambiguous genitalia in females.8 Males with 21-OHD appear normal at birth so the age at diagnosis in untreated boys varies according to the severity of disease.1-4 If unrecognized and left untreated, both girls and boys undergo rapid postnatal growth and sexual precocity as well as premature maturation of the growth plates, ultimately resulting in reduced final height.1-4

Neonatal screening and diagnosis of CAH is typically accomplished through the measurement of 17-OHP by immunoassay from filter paper (Guthrie) cards with subsequent confirmation in serum by liquid chromatography/tandem mass spectrometry (LC/MS-MS).5 In order to reduce the potential of false-negative results, the cutoff levels of neonatal 17-OHP screening assays are typically set so that approximately 1% of all tests are reported as positive. Given the low prevalence of CAH, only approximately one in every 100 neonates with a positive screening test will have CAH as confirmed by LC/MS-MS.1-5

Standard medical treatment of CAH consists of oral glucocorticoid and mineralocorticoid administration in order to suppress adrenal androgens and to compensate for adrenal steroid deficiencies.1-5 Levels of 17-OHP, androstenedione, and plasma renin activity can be used to evaluate adequacy of therapy in conjunction with clinical signs and symptoms.8 A recent clinical practice guideline recommends monitoring treatment by measuring 17-OHP levels early in the morning and before medication.1 This guideline states that 17-OHP should not be completely normalized because of risk of iatrogenic Cushing's syndrome.1,8 The target 17-hydroxyprogesterone range suggested for children with CAH is 400-1200 ng/dL.8 Clinical factors dictate management of individual adults.8

In addition to the classic salt-wasting and simple virilizing forms of CAH, there is also a mild "nonclassic" form of CAH (NC-CAH), which may show variable degrees of postnatal androgen excess but is sometimes asymptomatic.1,2,8 NC-CAH is much more common than classic CAH, occurring in approximately 0.1% to 0.2% in the general Caucasian population but in as much as 2% in some populations, such as Ashkenazi Jews.1 NC-CAH presents with a wide spectrum of phenotypes due to the complexity of gene duplications, deletions, rearrangements, and compound heterozygotes that cause the condition.1 Like more severe forms of CAH, NC-CAH can present as salt-wasting and simple virilizing disease with growth acceleration, premature adrenarche, or menstrual abnormalities.2 NC-CAH is a relatively common cause of hyperandrogenic symptoms in women and has been implicated in between 2% and 5% of cases studied.9-11 The diagnosis of nonclassic CAH after infancy is accomplished by measuring an early morning baseline serum 17-OHP in symptomatic individuals.1-5,8 Measurement of other steroids after a cosyntropin stimulation can be used to differentiate 21-OHD from 11-hydroxylase and P450 oxidoreductase deficiencies and to make the diagnosis in borderline cases.1-5,8

Footnotes

  1. Speiser PW, Azziz R, Baskin LS, et al. A Summary of the Endocrine Society Clinical Practice Guideline on Congenital Adrenal Hyperplasia due to Steroid 21-Hydroxylase Deficiency. Int J Pediatr Endocrinol. 2010; 2010:494173. PubMed 20981249
  2. Dauber A, Kellogg M, Majzoub JA. Monitoring of therapy in congenital adrenal hyperplasia. Clin Chem. 2010 Aug; 56(8):1245-1251. PubMed 20558634
  3. Forest MG. Recent advances in the diagnosis and management of congenital adrenal hyperplasia due to 21-hydroxylase deficiency. Hum Reprod Update. 2004 Nov-Dec; 10(6):469-485. PubMed 15514016
  4. Riepe FG, Sippell WG. Recent advances in diagnosis, treatment, and outcome of congenital adrenal hyperplasia due to 21-hydroxylase deficiency. Rev Endocr Metab Disord., 2007 Dec; 8(4):349-363. PubMed 17885806
  5. Rauh M. Steroid measurement with LC-MS/MS in pediatric endocrinology. Mol Cell Endocrinol. 2009 Mar 25; 301(1-2):272-281. PubMed 19007847
  6. Chang RJ. A practical approach to the diagnosis of polycystic ovary syndrome. Am J Obstet Gynecol. 2004 Sep; 191(3):713-717. PubMed 15467530
  7. Dennedy MC, Smith D, O'Shea D, et al. Investigation of patients with atypical or severe hyperandrogenaemia including androgen-secreting ovarian teratoma. Eur J Endocrinol. 2010 Feb; 162(2):213-220. PubMed 19906851
  8. Merke DP. Approach to the adult with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. J Clin Endocrinol Metab. 2008 Mar; 93(3):653-660. PubMed 18326005
  9. Escobar-Morreale HF, Sanchón R, San Millán JL. A prospective study of the prevalence of nonclassical congenital adrenal hyperplasia among women presenting with hyperandrogenic symptoms and signs. J Clin Endocrinol Metab. 2008 Feb; 93(2):527-533. PubMed 18000084
  10. Martin KA, Chang RJ, Ehrmann DA, et al. Evaluation and treatment of hirsutism in premenopausal women: An Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2008 Apr; 93(4):1105-1120. PubMed 18252793
  11. Carmina E, Rosato F, Jannì A, Rizzo M, Longo RA.. Extensive clinical experience: Relative prevalence of different androgen excess disorders in 950 women referred because of clinical hyperandrogenism. J Clin Endocrinol Metab. 2006 Jan; 91(1):2-6. PubMed 16263820
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