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Assays / Hormones
/ Steroid Profile (urine)
Urinary steroid profiling by high resolution gas chromatography
provides a composite picture of adrenal function. Oestrogen and
aldosterone metabolites are not detected under normal circumstances.
Steroid metabolism in newborn infants is markedly different from
that in children and adults. In the newborn infant a urinary steroid
profile avoids difficulties in interpreting results derived by other
techniques which may be subject to interference from unusual steroids
present at this time of life.
Clinical use
1. Disorders of adrenal steroid biosynthesis
2. 46XY disorders of sex differentiation (DSD,Male pseudohermaphroditism)
3. Steroid-producing tumours.
4. Steroid sulphatase deficiency.
5. Congenital adrenal hypoplasia.
6. Premature adrenarche / precocious puberty.
7. Adrenal suppression (exogenous steroids).
Applications
1. Disorders of adrenal steroid biosynthesis
(a) Virilisation of a newborn female
Congenital adrenal hyperplasia (CAH) due to:
-21-hydroxylase deficiency
-11 beta-hydroxylase deficiency
-3 beta-hydroxysteroid dehydrogenase deficiency
Characteristic profiles are found after day 3 of life for each
type. CAH requires life-long treatment and a steroid profile is
desirable on any patient with a suspected inborn error of steroid
metabolism to clarify the nature of the steroids in excess.
(b) Hypertension
-17 alpha-hydroxylase
deficiency
-11 beta-hydroxylase deficiency
17 alpha-hydroxylase deficiency is rarely detected in childhood
and more usually presents in phenotypic females with delayed puberty,
primary infertility, amenorrhoea and hypertension. 11 beta-hydroxylase
deficiency may present at birth but also may present in later life
with hypertension.
-11 beta-hydroxysteroid dehydrogenase deficiency
11 beta-hydroxysteroid dehydrogenase deficiency (or apparent mineralocorticoid
excess syndrome ) presents with severe hypertension usually in childhood.
(c) Salt-loss
- CAH due to 21-hydroxylase deficiency
- CAH due to 3 beta-hydroxysteroid dehydrogenase/isomerase deficiency
- Pseudohypoaldosteronism
- Defects of aldosterone biosynthesis
- Lipoid adrenal hyperplasia
2. 46XY DSD (formerly known as Male pseudohermaphroditism)
In an incompletely virilised male, a steroid profile is of limited
use in the newborn period for the diagnosis of disorders of testosterone
production or metabolism. If the boy is older than 3 months a defect
of 5 alpha-reductase is revealed
by the finding of low ratio of 5 alpha- to 5 beta- reduced metabolites
of cortisol. In a pubertal child, the defect is also clearly reflected
in the distribution of androgen metabolites.
17 beta-hydroxysteroid dehydrogenase
deficiency and other causes of low testosterone production are not
detected by urine steroid profile analysis but genetic testing can
be used in those cases with high index of suspicion.
3. Steroid-producing tumours
Adrenal tumours may secrete hormones (e.g. cortisol, androgens,
11-deoxycorticosterone), inactive steroids (16a-hydroxy DHA or pregnenolone)
or be non-functional (no steroid production by the tumour). It is
useful to have a profile before surgery so that recurrence can be
monitored.Gonadal tumours may result in increased plasma sex steroid
concentrations but usually do not change the urine steroid profile.
4. Steroid sulphatase deficiency.
In pregnancy this condition is characterised by increased excretion
of androgen sulphates and reduced excretion of oestriol in maternal
urine.
5. Congenital adrenal hypoplasia.
There are two types distinguishable by the urine steroid profile.
In the anencephalic type, no fetal adrenal steroids are found in
newborn infant urine. In the miniature adult type all steroids are
found, but at low levels.
6. Premature adrenarche/ precocious puberty.
Premature adrenarche is characterised by high excretion rates of
metabolites of cortisol and androgen for age and body size. When
there are signs of virilisation one also needs to consider the possibility
of CAH, most commonly the 21-hydroxylase defect or an adrenal tumour.
Adrenal tumours may secrete DHA or 11b-hydroxy-androstenedione.
7. Adrenal suppression.
Steroid metabolites may be suppressed in subjects receiving exogenous
glucocorticoids.
Patient Preparation
In cases of ambiguous genitalia it is important to obtain a karyotype.
If the patient has hypertension, plasma renin activity and plasma
aldosterone concentrations should be checked before considering
steroid profile analysis.
A 24h urine collection with no preservative is ideal. Random samples
may be acceptable for the identification of inborn errors of steroid
metabolism.
Endogenous cortisol production cannot usefully be examined if hydrocortisone
or cortisone acetate is being given. If glucocorticoid treatment
is essential, dexamethasone is preferred since dexamethasone metabolites
do not interfere in the assay. A depot Synacthen test can be used
to assess adrenal function during dexamethasone treatment.
For diagnosis of the cause (other than 21-hydroxylase deficiency)
of salt-loss in a neonate, salt intake and mineralocorticoid treatment
should be reduced as much as possible.
Sample Preparation
Record the 24h urine volume. Transfer 40 mL of urine preferably
to two 20 mL Sterilin plastic bottles with plastic lids. Do not
overfill the bottles and stand them upright if freezing prior to
dispatch. Do not use Parafilm on the inside of the lid. Record on
the SAS request form the 24 h volume or duration of the collection,
age and sex of the patient, clinical details and any relevant treatment.
Reference ranges
The SAS Laboratory will provide appropriate reference data and an
interpretation of results based on relevant biochemical and clinical
information.
Centres offering this assay
London (King's),
London (UCLH).
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