WHO/BS/2016.2292 WHO International Collaborative Study of the Proposed 4th IS for Prolactin, Human

Overview

The World Health Organization (WHO) Expert Committee on Biological Standardization (ECBS) has recognized (2015) the need for a replacement International Standard (IS) for prolactin for the calibration of immunoassays to measure prolactin in human serum and plasma. We report here, the calibration of a candidate standard for prolactin by immunoassay in terms of the current, 3rd IS for Prolactin, human, 84/500, by an international collaborative study carried out by ten laboratories in seven countries. The unweighted geometric mean of the laboratory estimates of the prolactin immunoreactivity of the candidate standard, coded 83/573, is 67.2 mIU per ampoule (GCV = 8.1%, n=18) in terms of the current standard 84/500. The results of this study also indicate that the candidate standard appears sufficiently stable, on the basis of a thermally accelerated degradation study, to serve as an IS. The study included an assessment of the impact of the new standard on the routine measurement of prolactin in human serum samples. Nine of the ten laboratories contributed data during the collaborative study through the concomitant measurement of the prolactin content of sixteen human serum samples. The results suggest that the candidate standard is suitable for the continued calibration of immunoassay methods for the measurement of prolactin.

Therefore, it is proposed that the candidate preparation in ampoules coded, 83/573 is established as the 4 th IS for prolactin, human, for immunoassay with an assigned content of 67 mIU per ampoule.