AMHconverter: an online tool for converting results between the different anti-Müllerian hormone assays of Roche Elecsys®, Beckman Access, and Kangrun.

Background: The anti-Müllerian hormone (AMH) is gaining attention as a key factor in determining ovarian reserve and polycystic ovarian syndrome, and its clinical applications are becoming more widespread worldwide. Objective: To identify the most accurate formula for converting AMH assay results between different platforms, so that the developed AMH converter can be used to reduce the need for multiple AMH tests at different hospitals. Methods: Assuming that the Beckman Access, Kangrun, and Roche Elecsys® AMH assays fit a linear relationship from the lowest to the highest concentration (a global relationship), we used Passing-Bablok regression to determine the conversion equation between each two assays. When the relationship between two AMH assays was a local one, spline regression was used. Bland-Altman plots were drawn to check systemic bias and heterogeneity of variance across different ranges of values. The fitting effects of the models were evaluated using the squared coefficient of determination (r2), adjusted r2, root mean square error (RMSE), Akaike information criterion (AIC), and corrected AIC. Results: The coefficient of variance for multiple controls in the Kangrun, Roche, and Beckman assays was lower than 5%, and the bias of multiple controls was lower than 7%. A global linear relationship was observed between the Kangrun and Roche assays, with the intercept being zero, for which Passing-Bablok regression was employed for data conversion between the two platforms. For the other two pairs of platforms, i.e., Roche and Kangrun or Beckman and Kangrun, spline regression was applied, with the intercepts not including zero. The six corresponding formulas were developed into an online AMH converter (http://121.43.113.123:8006/). Conclusion: This is the first time Passing-Bablok plus spline regression has been used to convert AMH concentrations from one assay to another. The formulas have been developed into an online tool, which makes them convenient to use in practical applications.

A sensitive HPLC-DMS/MS/MS method for multiplex analysis of androgens in human serum without derivatization and its application to PCOS patients.

Both classical androgens and 11-oxygenated androgens play important roles in polycystic ovarian syndrome (PCOS). Therefore, high-quality measurements of androgens are very important. In the present study, a highly sensitive and specific method was developed and validated for the simultaneous determination of three classical androgens and five 11-oxygenated androgens in human serum, using a high- performance liquid chromatography-differential mobility spectrometry tandem mass spectrometry (HPLC-DMS/MS/MS). Serum samples were extracted with the mixture of ethyl acetate/tert-butyl methyl ether (1/1, v/v) prior to analysis with the HPLC-DMS/MS/MS system. Stable isotopes were used as the internal standards. Separation was performed on a Poroshell SB C18 column (150 × 2.1 mm, 2.7 µm), with a differential mobility spectrometry (DMS) component, which was used to enhance the resolution. The gradient mobile phase consisted of acetonitrile and ammonium formate buffer with 0.1 % formic acid in both solvents. The sensitivity of the majority of the androgens was improved following addition of the DMS component. Under the optimal conditions, the trace amount of the target androgens in the serum was quantified accurately. The lower limit of quantification of the different analytes ranged from 0.05 to 0.2 ng/mL. The method was validated prior to its application to the assay of the clinical samples.