Unique Lessons From the Natural Progression of Rejection in Human Uterine Allografts.

Introduction: Uterus transplantation (UTx) is a novel treatment for absolute uterine infertility. Acute T cell–mediated rejection (TCMR) can be monitored only through serial cervical biopsies. Methods: This study, the first of its kind in human transplantation, evaluated clinical, serological, and pathophysiological manifestations of allograft rejection from immunosuppression withdrawal (ISW) to graft hysterectomy (Hx). Results: Following live birth, immunosuppression was abruptly withdrawn from six living‐donor UTx recipients. ISW occurred at a median of 7.4 weeks before graft Hx. Post‐ISW signs of rejection included: (1) discoloration of the cervix; (2) increased uterine size compared to day of ISW; (3) serological evidence of eosinophilia and progressive development of donor‐specific antibodies (DSA) or child‐specific antibodies (CSA); (4) histopathological evidence of TCMR in cervical biopsies preceding the development of antibodies in serum; and (5) C4d deposition in tissue before formation of DSA or CSA in all but two recipients. At graft Hx, endometrial glands were preferentially targeted for destruction over stroma while parametrial arteries displayed variable arteritis and fibrointimal hyperplasia. Conclusion: Recognition of the progression of uterine allograft rejection may be important for other human organ recipients and drive research on modulation of immunosuppression and the paradoxical relationship between adaptive cellular and humoral immunity in natural pregnancies. Trial Registration: ClinicalTrials.gov identifier: NCT02656550 [ABSTRACT FROM AUTHOR]