Estradiol, Sensitive
| Estradiol, Sensitive | | | |
| Number | | 140244 |
| CPT | | 82670 |
| Synonyms | | E2 ; Estradiol-17 Beta |
| Specimen | | Serum |
| Volume | | 0.8 mL |
| Minimum Volume | | 0.3 mL (Note: This volume does not allow for repeat testing.) |
| Container | | Red-top tube or gel-barrier tube |
| Collection | | If a red-top tube is used, transfer separated serum to a plastic transport tube. |
| Storage Instructions | | Refrigerate |
| Patient Preparation | | No isotopes administered 24 hours prior to venipuncture |
| Causes for Rejection | | Gross lipemia; recently administered isotopes |
| Reference Interval | | See table.1,2,3
Age
(y) | Male
(pg/mL) | Female
(pg/mL) | | 0-6 | 0-15 | 0-15 | | 7-10 | 0-15 | 0-70 | | 11-12 | 0-40 | 10-300 | | 13-15 | 0-45 | 10-300 | | >15 | 3-70 | See below | | Ovulating female: | | Follicular phase | 9-175 | | Luteal phase | 44-196 | | Periovulatory | 107-281 | | Oral contraceptives | 0-91 | | Postmenopausal female: | | Treated | 42-289 | | Untreated | 0-19 | | Tanner Stage | | I | 3-15 | 5-10 | | II | 3-10 | 5-115 | | III | 5-15 | 5-180 | | IV | 3-40 | 25-345 | | V | 15-45 | 25-410 |
|
| Use | | This sensitive estradiol assay is designed for the investigation of infertility, particularly in situations where low estradiol levels can be expected. The analytic range of the assay is appropriate for the assessment of the low levels of estradiol typically observed in men, prepubertal girls, and postmenopausal women. Estradiol levels are useful in the diagnosis of precocious puberty in females and along with gonadotropins can help establish the cause. Estradiol levels in the prepubertal range can help to confirm the diagnosis of delayed puberty in females. |
| Limitations | | Estradiol levels tend to fluctuate dramatically during the perimenopausal transition.4 There is significant overlap of the expected range in menopausal women with values observed during normal menstrual cycles. Estradiol results obtained with different assay methods cannot be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor serial patient results. |
| Methodology | | Radioimmunoassay (RIA) |
| Additional Information | | Estradiol is the primary reproductive hormone in nonpregnant women.5,6 This steroid hormone plays an important role in normal fetal development and in the development of secondary sexual characteristics in females. Estradiol influences the maturation and maintenance of the uterus during the normal menstrual cycle. Levels of estradiol steadily increase during the follicular phase of the menstrual cycle in association with the growth and development of the ovarian follicle. As the follicular phase proceeds, estradiol exerts a negative feedback control on the pituitary, resulting in a drop in FSH levels. Near the end of the follicular phase, there is a dramatic increase in estradiol levels. At this point, the feedback of estradiol on the hypothalamus becomes positive and produces the midcycle surge of LH which immediately precedes ovulation. After ovulation, estradiol levels initially fall abruptly, but then increase as the corpus luteum forms. At the end of the cycle, levels fall off in anticipation of the initiation of the next follicular phase. During pregnancy, the placenta produces estradiol. Estradiol levels are generally low in menopause due to diminished ovarian production. A small amount of estradiol is produced by the male testes.5,6 Elevated levels in males can lead to gynecomastia. Increased estradiol levels in males may be caused by increased body fat, resulting in enhanced peripheral aromatization of androgens. Levels in men can also be increased by excessive use of marijuana, alcohol, or prescribed drugs, including phenothiazines and spironolactone. Estradiol levels can also be dramatically elevated in germ cell tumors and tumors of a number of glands in both men and women. |
| Footnotes | | - Midgeon CJ, Berkovitz GD, and Fechner PY, “The Diagnosis of Pediatric Reproductive Disorders,” Biochemical Basis of Pediatric Disease, 2nd ed, Soldin SJ, Rifai N, and Hicks JMB, eds, Washington, DC: AACC Press, 1995, 243-70.
- Soldin SJ, Brugnara C, Gunter KC, et al, Pediatric Reference Ranges, 2nd ed, Washington, DC: AACC Press, 1997, 68.
- Tietz NW, ed, Clinical Guide to Laboratory Tests, 3rd ed, Philadelphia, PA: WB Saunders Co, 1995, 216.
- Burger HG, “Diagnostic Role of Follicle-Stimulating Hormone (FSH) Measurements During the Menopausal Transition - An Analysis of FSH, Oestradiol, and Inhibin,” Eur J Endocrinol, 1994, 130(1):38-42 (review).
- Gronowski AM and Landau-Levine M, “Reproductive Endocrine Function,” Tietz Textbook of Clinical Chemistry, 3rd ed, Burtis CA and Ashwood ER, eds, Philadelphia, PA: WB Saunders Co, 1999, 1601-41.
- Wheeler MJ, “Infertility,” The Immunoassay Handbook, Wild D, ed, Stockton Press, 1994, 366-78
|
|