Arsène Mekinian, Kamila Kolanska, Sofiane Bendifallah, Nathalie Chabbert-Buffet, Emile Daraï, Christine Bergeron, Geoffroy Canlorbe, Selim Aractingi, J. Varinot, Perrine Capmas, Martin Koskas, Service Gynécologie-Obstétrique et Médecine de la reproduction [Hôpital Tenon], Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Sorbonne Université (SU), Centre de Recherche Saint-Antoine (CR Saint-Antoine), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Service d’Anatomopathologie [CHU Tenon], Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-CHU Tenon [APHP], Sorbonne Université (SU), Service de chirurgie gynécologique et mammaire [CHU Pitié-Salpêtrière], Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-CHU Pitié-Salpêtrière [APHP], Service Chirurgie Plastique et de Cancérologie Mammaire [CHU Pitié-Salpêtrière], Service de Médecine Interne [CHU Saint-Antoine], Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-CHU Saint-Antoine [APHP], AP-HP Hôpital Bicêtre (Le Kremlin-Bicêtre), CIC - CHU Bichat, Institut National de la Santé et de la Recherche Médicale (INSERM), Service de Gynécologie-Obstétrique [CHU Tenon], Université Paris Descartes - Paris 5 (UPD5), Gynécologie-obstétrique et médecine de la reproduction - Maternité [CHU Tenon], CHU Tenon [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Saint-Antoine [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Tenon [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Service de Chirurgie et Cancérologie Gynécologique et Mammaire [CHU Pitié-Salpêtrière], CHU Pitié-Salpêtrière [AP-HP], CHU Saint-Antoine [AP-HP], and Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP]
International audience; RESEARCH QUESTION: What are the effects of ulipristal acetate (UPA) on the expression of endometrial proliferation and maturation markers?DESIGN: A total of 45 endometrium-containing blocks of hysterectomy samples from non-menopausal women with a diagnosis of moderate to severe symptoms of uterine fibroids: 14 women operated on at the end of a 3-month course of UPA; four women who had discontinued UPA treatment 1-12 months before surgery; 27 control unexposed samples (14 in the proliferative and 13 in the secretory phase). Immunohistochemical staining of Ki67, vascular endothelial growth factor-receptor 2 (VEGFR2), oestradiol receptor, progesterone receptor, interleukin-15 (IL-15), indoleamin-2,3-dioxygenase (IDO) and C-C motif chemokine ligand-2 (CCL2) markers were analysed in both endometrial compartments and layers.RESULTS: Under UPA, oestradiol receptor and progesterone receptor expression is similar to the proliferative phase in both layers, although with a decrease in cell proliferation. IL-15, IDO and CCL2 expressions are similar to the proliferative phase, suggesting a progesterone-antagonist effect of UPA. VEGFR2 staining suggests a trend to a mixed agonist-antagonist effect. No significant difference is observed in the post-UPA proliferative phase group compared with the control group in both layers of the endometrium.CONCLUSION: The effect of 3-month UPA treatment is mostly progesterone receptor antagonist-like. After treatment is discontinued, there are no signs of any long-term effects of this molecule on endometrial proliferation and maturation. Therefore, UPA may be administered to women willing to conceive in the short term without consequences for further implantation.