-
Views
-
Cite
Cite
EUGENIA ROSEMBERG, Immunoreactivity of Standards and Reference Preparations Used in the Radioimmunoassay of Follicle-Stimulating and Luteinizing Hormones in Serum, The Journal of Clinical Endocrinology & Metabolism, Volume 48, Issue 1, 1 January 1979, Pages 163–166, https://doi.org/10.1210/jcem-48-1-163
- Share Icon Share
Abstract
The Second International Reference Preparation of human menopausal gonadotropin (2nd IRP-HMG) and the National Pituitary Agency reference preparation LER 907 have been widely used to measure circulating levels of human FSH and LH by RIA in human serum. As the 2nd IRP-HMG has been replaced by the First International Standard for human urinary FSH and LH (1st IS), it was considered advisable to study the immunoreactivity of these preparations under our laboratory conditions.
In both the FSH and LH RIA systems employed, the three preparations elicited parallel dose-response curves. In the LH assay, the immunoreractivity of 1 mlU 1st IS equaled that of 1 mlU 2nd IRP-HMG and that of 3.6 ng LER 907. In the FSH assay, the immunoreactivity of 1 mlU 1st IS equaled that of 1 mlU 2nd IRP-HMG and that of 23 ng LER 907. Parallelism does not assure identity between the substances in test serum and the reference preparations used. Indeed, not only are these three preparations not identical to each other, but they are not identical to circulating endogenous human FSH and human LH. Therefore, in order to improve the likelihood of agreement of results from one laboratory to another, and from time to time in the same laboratory, measurement of circulating levels of FSH and LH carried out with presently available reference preparations should be performed under appropriate quality control conditions utilizing well characterized test reagents. In order to provide some measure of comparability among different laboratories, it is recommended that the immunoreactivity of these preparations be reported in equivalent unitage (i.e., micrograms of LER 907 and milliinternational units of either 2nd IRP-HMG or 1st IS)