Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
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 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.
Specimen container paediatric:
Serum or EDTA plasma
Specimen container adult:
Serum or EDTA plasma
Minimum volume paediatric:
1 mL blood
Minimum volume adult:
1 mL blood
Special requirements:
Special Requirement: Ideally do not collect before 3 days of age. For diagnosis in neonates, samples should be taken prior to any steroid replacement.
Sample stability:
Unseparated: Same day
Separated: 5 days at 4-8°C, 1 year at -20°C
Transport requirements:
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. 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.
Reference ranges:
17-hydroxyprogesterone LC-MS/MS Reference Ranges (nmol/L):
| Age | Male | Female |
| < 1yr | <7.5 | <7.5 |
| 1-9 | <3 | <3 |
| 10+ | <6.2 | <6.8 |
Factors affecting result:
Prematurity, acute illness/stress may increase 17OHP in infants.