General HealthPCOS/PCOD

Hormones to Check for in a PCOD Profile Test

A PCOD Profile test helps to assess the function and level of various hormones in the body. The hormones in a PCOD profile test include:

Follicle Stimulating Hormone and Luteinizing Hormone

FSH (Follicle-Stimulating Hormone) and LH (Luteinizing Hormone) are called gonadotropins. They are composed of alpha and beta polypeptide chains where each chain is attached to a carbohydrate substitute moiety. The molecular weight of LH – 40,000Da and FSH – 25,000Da.

The secretion of LH and FSH is regulated by a single hypothalamic releasing factor, LH/FSHRH i.e. luteinizing hormone/follicle stimulating hormone releasing hormone. Both these hormones influence the function and maturation of the testes and ovary.

Luteinizing hormone (LH)

In normal state, LH causes ovulation by releasing the ovum from the ovarian follicle (previously matured under the influence of FSH in females). The ruptured follicle forms the corpus luteum, which then secretes both estradiol and progesterone. The corpus luteum is regulated by LH.

In context with PCOD, elevated LH values are observed in women with amenorrhea caused by ovarian failure. High values are also associated with primary dysfunction and low values with secondary (pituitary or hypothalamic) failure.

Reference LH normal range: 6-30 mIU/ml

Laboratory test– Serum LH is detected by the ELISA method.

PRINCIPLE: The LH ELISA test kit is a sandwich ELISA method in which one anti-LH antibody is coated in microtiter wells and another mouse monoclonal anti-LH antibody is present in the antibody-enzyme (HRP) conjugate solution. The test sample allowed to react with these antibodies is sandwiched between solid phase and enzyme-linked antibodies. After adding TMB substrate and stop solution, a yellow color is seen and measured at 450nm spectrophotometrically. The LH concentration is directly proportional to the color intensity of the test sample.

Follicle stimulating hormone (FSH)

It is synthesised in adenohypophysis that promotes follicular growth, prepares the follicle for the action of LH and induces release of LH to enhance the release of estrogens. FSH concentration increase at puberty. High values of FSH with peak order of 10 fold or more over basal levels are observed just before the time of ovulation.

Reference FSH normal range :4- 30 uIU/ml and 40-250 uIU/ml (postmenopausal)

Clinical significance: Increased serum FSH values are seen in menopause and decreased values may be seen in hypogonadism and PCOD.

Laboratory test – Serum FSH is determined by using ELISA method similar as serum LH determination. Non-hemolysed, non-icteric and non-lipemic fasting serum sample is required.

Prolactin

Prolactin(PRL) is a lactogenic hormone secreted by the pituitary lactotroph cells of the adenohypophysis. It stimulates and sustains lactation in post-partum mammals. PRL is composed of 199 amino acids and has a molecular weight of 23,000 Da. PRL circulates in the blood in monomeric, dimeric and polymeric forms.

Monomeric form appears to be most active and demonstrates the highest response to TRH. During pregnancy, the PRL content of lactotroph cells are increased due to elevated estrogen levels. Hyperprolactemia is the most common hypothalamic pituitary disorder encountered in clinical endocrinology.

Determining serum prolactin: Determining serum prolactin is important in diagnosing and managing hypothalamic and pituitary tumors. It is also an important marker to check for in women with amenorrhea (which may cause PCOD). The ELISA method is used to determine serum prolactin. Fasting serum specimen is required which can be stored at 2-8 degree Celsius for a week.

Reference PRL normal range :6-22 ng/ml

Testosterone

Testosterone is a steroid androgen hormone which is primarily secreted by the ovaries in females. Testicular androgens are synthesised in the interstitial tissue by the Leydig cells. Androgenic effects of testosterone in men include sex organs maturation, scrotum formation in the foetus and at puberty, deepening of the voice and axillary hair growth. The lack of testosterone leads to hypogonadism i.e. at puberty, secondary sex characteristics fail to develop due to impaired secretion of the gonadotropins,

Determining serum testosterone: Testosterone circulates in blood as a free form, or weakly bound with albumin or tightly bound with specific globulin. Free and weakly bound forms of testosterone are biologically active, while the tightly bound form with globulin is inactive.

An ELISA test helps in the detecting serum testosterone. Fasting serum is a preferred specimen. Since this specimen is subject to diurnal variation reaching peak concentration between 4 am to 8 am, it is better to use morning specimens.

Reference testosterone normal range: 0.52 nmol/L – 2.43 nmol/L

Thyroid stimulating hormone (TSH)

The thyrotrope cells of the anterior pituitary gland synthesises and secretes the Thyroid Stimulating Hormone which regulates the function of the thyroid gland. TSH is a glycoprotein that consists of two subunits, the alpha and the beta subunit. The alpha subunit is identical to that of hCG, LH and FSH. The beta subunit is specific to TSH and determines its function. Molecular weight of TSH is 30,000Da.

TSH stimulates the thyroid gland to secrete T3 and T4. The thyrotropin releasing hormone (TRH) from the hypothalamus controls TSH production. TRH is transported to the anterior pituitary gland via the superior hypophyseal artery where it regulates TSH release.

T3 and T4 levels in the blood affects the pituitary production of TSH. When T3 and T4 levels are low, TSH production increases. Similarly when T3 and T4 levels are high, TSH production decreases. This creates a regulatory negative feedback loop.

Determining serum TSH: High TSH values occurs in primary hypothyroidism. Low TSH may occur in primary hyperthyroidism, in secondary (pituitary-related) or in tertiary hypothyroidism (hypothalamus-related). Detecting serum TSH will help to avoid undertreatment of primary hypothyroidism and overtreatment of hypothyroidism.

Reference normal TSH range: Adult: 0-10 uIU/ml; Neonates : less than 25 mIU/ml, by 3rd day after birth.

PRINCIPLE: TSH determination is a solid phase immunoradiometric assay (IRMA) test based on monoclonal and polyclonal anti-TSH antibodies. One I125-labelled anti-TSH polyclonal antibody is present in the liquid phase, and the monoclonal anti-TSH antibodies are immobilized to the wall of a polystyrene tube.

In the procedure-TSH in patient’s serum is captured between the immobilised monoclonal anti-TSH antibodies and the radiolabelled polyclonal anti-TSH tracer. The tube is then decanted to remove the unbound I125 labelled anti-TSH antibody.

The TSH concentration is directly proportional to the radioactivity present in the tube after washing. The radioactivity is counted via a gamma counter. The TSH concentration is obtained by comparing the patient’s count per minute (CPM) against calibrated values (by using a standard graph).

Author

Yash Batra

Show More

Related Articles

Leave a Reply

Back to top button