A tissue specific magnetic resonance contrast agent, Gd-AMH, for diagnosis of stromal endometriosis lesions: a phase I study.

The anti-mullerian hormone (AMH) is a homodimeric glycoprotein member of the transforming growth factor ß (TGF-ß) superfamily, is secreted by Sertoli cells in the embryonic testes and is responsible of the regression of the mullerian duct. The physiological functions of this protein remain largely unknown, and its expression in human tissues has yet to be completely determined. Firstly, we analyzed AMH expression in human tissues by immunohistochemistry. AMH was distributed in many organs, although with different tissue and cell localization and various expression levels; we also demonstrated strong AMH expression in endometriosis tissues. Secondly, we demonstrated the ability of an anti-AMH antibody, labeled with gadiolinium, to be directly detected by magnetic resonance in small endometriosis lesions (5 mm in diameter) in vivo in a mouse model. In conclusion, our data suggest that based on its expression pattern, AMH may serve to maintain physiological cellular homeostasis in different human tissues and organs. Moreover, it is strongly expressed in endometriosis lesions as a selective tissue specific contrast agent for in vivo detection of stromal endometriosis lesions. The potential significance of these findings could be further validated in a clinical setting.