الوصف
Inhibins are members of the TGF-β superfamily of growth factors. Inhibin A consists of two partially homologous disulphide – linked subunits, α and β. FSH regulation appears to be a major biological
role for inhibin A and B, antagonising the effect of activin. Inhibin A levels are low during early to mid-follicular phase but increase around the time of the pre-ovulatory gonadotropin surges. Inhibin A levels remain elevated through the majority of the luteal phase, then decrease in synchrony with declining progesterone just prior to the luteal-follicular phase transition. During pregnancy, inhibin A rises 12 days after ovulation as a result of hCG stimulation of the placenta and corpus luteum, peaks at approximately 42 days, then, falls slightly thereafter. In pregnancy, inhibin A is produced by the placenta.
دواعي الإستعمال
Inhibin A levels demonstrate a two-fold increase in the second trimester in Down’s syndrome pregnancies as compared to normal pregnancies, thus, making Inhibin A a clinically important and useful test. The inclusion of inhibin A in prenatal screening in addition to α- fetoprotein, β-hCG, and maternal age, increases the Down’s syndrome detection rate to 75% from 53%. Inhibin A and B measurements are used as markers of follicle development. During pregnancy, it is used as a marker of gestational diseases or foetal distress and for Down’s syndrome risk assessment in the second trimester. Inhibin A levels are significantly elevated in sera of women with granulosa cell tumours and is used for the early detection of the disease and monitoring its recurrence after surgery. Inhibin A is also elevated in mucinous-borderline carcinoma and occasionally elevated in serous carcinoma.
نوع العينة والكمية والشروط
1 مل من المصل محفوظة بدرجة حرارة الغرفة
إحتياطات خاصة
Transport sample at room temperature.
المعدل الطبيعي
Early follicular (0-4 day of LMP): 5.46 - 28.16 pg/mL Mid follicular (5-10 day of LMP): 7.87 - 34.54 pg/mL Late follicular (11-13 day of LMP): 19.49 - 102.28 pg/mL Mid Cycle (Day of ovulation): 49.92 - 155.48 pg/mL Early Luteal (15-17 day of LMP): 35.93 - 132.68 pg/mL Mid Luteal (18-25 day of LMP):13.15 - 159.55 pg/mL Late Luteal (26-28 day of LMP): 7.28 - 89.95 pg/mL IVF peak level: 354.2-1690 pg/mL PCOS Ovulatory: 5.65-15.99 pg/mL Postmenopause: < 1.00-3.88 pg/mL