Enzyme-linked immunosorbent assay measurements of antimüllerian hormone (AMH) in human blood are a composite of the uncleaved and bioactive cleaved forms of AMH

Abstract

Objective: To determine whether the Beckman Coulter antimüllerian hormone (AMH) Gen II enzyme-linked immunosorbent assay (ELISA) detects the uncleaved precursor (proAMH) and/or the active cleaved form (AMHN,C) of AMH.

Design: Technical investigation.

Setting: Community study.

Patient(s): Healthy boys and male and female adult volunteers.

Intervention(s): None.

Main outcome measure(s): Assay of AMH and Western blot analysis of captured forms of AMH.

Result(s): In blood, AMH in blood consists of both proAMH, the inactive uncleaved precursor, and AMHN,C, the enzyme-cleaved, receptor-competent form. The Gen II AMH ELISA detected both recombinant proAMH and AMHN,C. The noncovalent association of the two cleavage fragments of AMHN,C appears to be necessary for ELISA detection because recombinant free AMHC and AMHN were undetectable. Spike-recovery experiments showed that proAMH was not completely recovered from serum unless it was prediluted 1 hour before the assay.

Conclusion(s): The leading ELISA for AMH provides a composite value of two biologically distinct forms of AMH. It is not known whether proAMH and AMHN,C have identical relationships to ovarian reserve, antral follicle counts, or other aspects of ovarian function. Hence, future research into the physiology and clinical utility of AMH should consider the two forms separately.

Keywords: Immunoassay; ovarian reserve; prohormone cleavage; proprotein.