Dehydroepiandrosterone Sulphate (DHEA-S), plasma or serum

Alternate test name

DHA, DHEA, DHEAS

Lab area

Clinical Biochemistry - General

Method and equipment

Equipment : Roche Cobas Pro e801

Method : Competition principle. Total duration of assay: 18 minutes.
▪ 1st incubation: By incubating the sample (9 µL) with a DHEA‑S‑specific biotinylated antibody, an immunocomplex is formed, the amount of which is dependent upon the analyte concentration in the sample.
▪ 2nd incubation: After addition of streptavidin-coated microparticles and a DHEA‑S derivative labeled with a ruthenium complex, the still‑vacant sites of the biotinylated antibodies become occupied, with formation of an antibody‑hapten complex. The entire complex becomes bound to the solid phase via interaction of biotin and streptavidin.
▪ The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Unbound substances are then removed with ProCell II M. Application of a voltage to the electrode then induces chemiluminescent emission which is measured by a photomultiplier. Results are determined via a calibration curve which is instrument specifically generated by 2‑point calibration and a master curve provided
via the cobas link.

Expected turn-around time

STAT/Urgent: 4 hours Routine: 24 hours

Specimen type

Serum, Plasma Lithium Heparin

Specimen requirements

150 uL

Storage and transportation

Frozen

Shipping information

The Hospital for Sick Children

Rapid Response Laboratory

555 University Avenue, Room 3642

Toronto, ON

Canada

M5G 1X8

Phone: 416-813-7200

Toll Free: 1-855-381-3212

Hours: 7 days/week, 24 hours/day

Requisition

Dehydroepiandrosterone Sulphate (DHEA-S), plasma or serum - requisition

Background and clinical significance

Dehydroepiandrosterone sulfate (DHEA-S) is the most abundant adrenal androgen and also functions as a neurosteroid that is produced by the adrenal cortex. DHEA-S is an excellent indicator of adrenal androgen production. DHEA-S exhibits only weak androgenic activity but can be metabolized to more active androgens such as testosterone and androstenedione. Serum concentrations decline with age and can serve as a prognostic factor in both critical illnesses and breast cancer progression. Elevated levels of DHEA-S are found in the plasma of patients with adrenal tumors or congenital adrenal hyperplasia. DHEA-S may also be slightly elevated in patients with polycystic ovaries. Tumors in men that produce hCG may lead to increased levels of testicular DHEA-S.