17-Hydroxyprogesterone, Serum
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Reference ranges of serum 17-hydroxyprogesterone (17-OHPG) are as follows [1, 2, 3] :
Cord blood: 1000-3000 ng/dL
Newborns: < 630 ng/dL (> 630 ng/dL may be seen in preterm infants, but > 1000 ng/dL is uncommon)
Prepubertal males: < 110 ng/dL
Adult males: < 220 ng/dL
Prepubertal females: < 100 ng/dL
Follicular (in females): < 80 ng/dL
Luteal (in females): < 285 ng/dL
Postmenopausal females: < 51 ng/dL
Levels of 17-hydroxyprogesterone vary throughout the day. In women, they also vary during the different phases of the menstrual cycle. No special preparation is required for this test. [4]
For newborn screening, a random sample is collected via a heel stick 48 hours after birth. A value greater than 5,000 ng/dL is a hallmark of congenital adrenal hyperplasia (CAH). [4]
Beyond infancy, it is best to collect the sample in the early morning, because levels of 17-hydroxyprogesterone vary in accordance with the circadian rhythm. In menstruating women, obtain the sample in the follicular phase. [4]
The specimen type is serum. Acceptable containers are lavender- (EDTA), pink- (K2EDTA), or green-topped (sodium or lithium heparin) tubes.
After the blood sample is collected, serum is separated. For specimen preparation, transfer 0.5 mL of serum or plasma to a standard transport tube (minimum of 0.3 mL). The stability of the collection after separation from cells at ambient temperature is 48 hours; when refrigerated, 1 week; and when frozen, 6 months to 2 years.
Grossly hemolyzed specimens are unacceptable for processing and are rejected. Most labs also reject specimens received at room temperature; hence, the specimen is transported either refrigerated or frozen.
Liquid chromatography-tandem mass spectrometry (LC-MS) is currently used for the measurement of the 17-hydroxyprogesterone level. Conventionally, hormone measurements have been measured using radioimmunoassays, but those can be problematic due to interference with similar steroid compounds.
17-hydroxyprogesterone (17-OHPG) is produced primarily in the adrenal cortex, placenta, and to some degree in the gonads (the testes and the corpus luteum of the ovary). It is an intermediate product in the synthesis of cortisol and androgens.
The level of 17-hydroxyprogesterone becomes elevated when two enzymes in the synthesis of cortisol are defective (21-hydroxylase, 11β-hydroxylase), leading to CAH.
The 17-hydroxyprogesterone test is routinely ordered as a part of newborn screening to detect CAH. In over 90% of patients, CAH results from homozygous or compound heterozygous mutations in the cytochrome P-450 C21 (CYP21A2) gene, causing 21-hydroxylase deficiency. All 50 US states and several other countries have instituted newborn screening by measurement of serum 17-hydroxyprogesterone. [5] Prenatal diagnosis is now possible by chorionic villous sampling.
Measurement of 17-hydroxyprogesterone in the blood may also be used to aid in the diagnosis of late-onset CAH in females with hirsutism and irregular menses. If a 17-hydroxyprogesterone test result is abnormal, a corticotropin-stimulation test should be ordered as a confirmatory test in CAH.
In cases of genital ambiguity, a karyotype test may be ordered as a follow-up test to detect chromosomal disorders, as well as to help differentiate the sex of the baby and determine appropriate treatment.
Burris CA, Ashwood ER, Burns DE. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 5th ed. St. Louis, Mo: Elsevier Saunders; 2012.
McPherson RA, Pincus MR. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. Philadelphia, Pa: Elsevier Saunders; 2017.
Wallach J. Interpretation of Diagnostic Tests. 10th ed. New York, NY: Little Brown & Co; 2015.
Rey RA, Houk CP, Witchel S, Lee PA. Disorders of sex development. Gardner DG, Shoback D, eds. Greenspan’s Basic & Clinical Endocrinology. 10th ed. New York, NY: McGraw-Hill Education; 2018. 526-30. [Full Text].
Bartz S, Barker JM, Kappy MS, Kelsey M, Travers SH, Zeitler PS. Endocrine disorders. Hay WW Jr, Levin MJ, Deterding RR, Abzug MJ, eds. Current Diagnosis & Treatment: Pediatrics. 24th ed. New York, NY: McGraw-Hill Education; 2018. [Full Text].
Muhammad Bader Hammami, MD Fellow in Inflammatory Bowel Disease, St Louis University School of Medicine
Disclosure: Nothing to disclose.
Puspalatha Sajja, MD Fellow, Department of Endocrinology, Albert Einstein Medical Center
Disclosure: Nothing to disclose.
Catherine Anastasopoulou, MD, PhD, FACE Associate Professor of Medicine, Sidney Kimmel Medical College of Thomas Jefferson University; Attending Endocrinologist, Department of Medicine, Albert Einstein Medical Center
Catherine Anastasopoulou, MD, PhD, FACE is a member of the following medical societies: American Association of Clinical Endocrinologists, American Society for Bone and Mineral Research, Endocrine Society, Philadelphia Endocrine Society
Disclosure: Nothing to disclose.
Eric B Staros, MD Associate Professor of Pathology, St Louis University School of Medicine; Director of Clinical Laboratories, Director of Cytopathology, Department of Pathology, St Louis University Hospital
Eric B Staros, MD is a member of the following medical societies: American Medical Association, American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology
Disclosure: Nothing to disclose.
17-Hydroxyprogesterone, Serum
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