ESTRADIOL MEASUREMENT IN WOMEN ON ORAL HORMONE REPLACEMENT THERAPY - THE VALIDITY OF COMMERCIAL TEST KITS

Four commercially available methods for the measurement of oestradiol were used to assay oestradiol concentrations in samples from women rec eiving oral hormone replacement therapy. Significant differences in re sults were found between samples that were measured direct and those s ubjected to an extraction procedure. There was considerable variabilit y in the extraction: direct ratio between methods, indicating that wit h some methods an extraction procedure should be performed before anal ysis on samples from women receiving oral hormone replacement therapy. Factors that account for discrepant results between methods probably include increased concentration of sex hormone binding globulin togeth er with cross-reacting metabolites and conjugates.