Progesterone saliva analysis via a luminescence immunoassay

In-vitro-diagnostic quantitative determination of active free progesterone (a female hormone) in human saliva requires luminescence immunoassay. Measurements acquired by this device can be applied in the diagnosis and treatment of ovary disorders and can be used as an aid for the validation of ovulation.

  • Method — Luminescence immunoassay
  • Regulatory status — EU: CE, CDN: IVD
  • Substrate/isotope — Acridium based
  • Kit size — 12 x 8
  • Specimen/volumes — 20 µL saliva/without extraction
  • Incubation time — 1 x 4 hours, 1 x 10 minutes
  • Standard range — 10–1000 pg/mL

The female sex hormone, progesterone, is a C21-steroid and a precursor in the metabolism of other steroids. Progesterone is formed mostly in the corpus luteum of the ovaries, during the key part of pregnancy in the placenta and in very small quantities for the formation of other steroids in the adrenal cortex and the testes.

At the latter locations, progesterone is vital for the production of aldosterone, testosterone, cortisol and 17-b-estradiol. In the circulation, the key part of progesterone is bound to the sex hormone-binding globulin (SHBG), to the corticoid binding globulin (CBG, Transcortin) and to albumin. About 1% to 2% of progesterone flows as a free hormone in plasma.

Only this percentage signifies the active part in the regulation of the endocrine. The free hormone is discharged in equal quantities in saliva. It is presumed that enzymatic metabolization of portions of this hormone takes place in the saliva glands.

Progesterone is one key hormone involved in the endocrine regulation of the menstrual cycle. Following ovulation, progesterone is discharged by the corpus luteum that forms from the ovulated follicle in the ovaries. The progesterone level increases from the sixth to the eighth day following ovulation to a plateau. Along with estradiol, it hinders the release of FSH and LH in the pituitary gland by a negative feedback mechanism.

Progesterone is discharged into the circulation in a pulsating manner. Due to the lysis of the corpus luteum, the progesterone level reduces during the last three days of the menstrual cycle to a pre-ovulatory level. In pregnancy, starting at the eighth gestation week, the placenta turns into the major source of progesterone production in the second and third trimesters.

The progression of progesterone levels in the circulation is seen in its concentration in saliva. The most vital function of progesterone is to ready the female genital organs for potential implantation and to sustain the pregnancy.

The key effects of progesterone are to present the secretory phase of the endometrium, to subdue the contractions of the uterus, and to encourage the growth of mammary tissue, as well as other effects on women’s endocrine system and the metabolism.

Concerning physiology, the measurement of progesterone in the saliva is beneficial in monitoring the menstrual cycle to establish the time of ovulation and to evaluate the function of the corpus luteum, which becomes significant in the early stages of pregnancy.

As the rise and fall of the progesterone levels rely on specific situations as well, it is very convenient to obtain a hormone profile by recurrently collecting samples of saliva.