A multi-institutional study of renal outcomes and renal-related pregnancy outcomes in uterus transplant recipients

Inhibition of NFAT promotes loss of tissue resident uterine natural killer cells and attendant pregnancy complications in humans

Uterine natural killer cells (uNKs) are a tissue resident lymphocyte population that are critical for pregnancy success. Although mouse models have demonstrated that NK deficiency results in abnormal placentation and poor pregnancy outcomes, the generalizability of this knowledge to humans remains unclear. Here we identify uterus transplant (UTx) recipients as a human population with reduced endometrial NK cells and altered pregnancy phenotypes. We further show that the NK reduction in UTx is due to impaired transcriptional programming of NK tissue residency due to blockade of the transcription factor nuclear factor of activated T cells (NFAT). NFAT-dependent genes played a role in multiple molecular circuits governing tissue residency in uNKs, including early residency programs involving AP-1 transcription factors as well as TGFβ-mediated upregulation of surface integrins. Collectively, our data identify a previously undescribed role for NFAT in uterine NK tissue residency and provide novel mechanistic insights into the biologic basis of pregnancy complications due to alteration of tissue resident NK subsets in humans.

One Sentence Summary

Role of NFAT in uterine NK cell tissue residency.

Living-Donor Uterus Transplantation: A Clinical Review

Uterus transplantation (UTx) is currently the only available treatment for absolute uterine factor infertility. More than 90 uterus transplantations have been performed worldwide, mostly from living donors. Living-donor (LD) UTx is a challenging surgical procedure since it poses ethical issues, and it is a high-risk and invasive surgery with higher hysterectomy-related risks compared to conventional hysterectomy. A total of 59 living-donor hysterectomies have been reported in the literature, including 35 performed with a laparotomic approach, 20 with a robotic approach and 4 with a laparoscopic approach. The mean donor age was 45.6 ± 9.1 years, and 22 were unrelated with the recipients, 34 were emotionally related (27 mothers, 5 sisters, 2 mother's sisters). The mean recipient age was 28.8 ± 4.5 years. Mayer-Rokitansky-Küster-Hauser syndrome was the most common indication for uterus transplant. Robotic living-donor hysterectomy had the longest operative time but resulted in a lower blood loss and postoperative stay compared to laparotomic and laparoscopic approaches. Twenty-nine births from LD-UTx have been reported, four after robotic living-donor hysterectomy and twenty-five after a laparotomic procedure. UTx is now an effective treatment for women with UFI. While living-donor UTx in some cases may be considered an experimental procedure, it offers the extraordinary possibility to give women the opportunity to have a pregnancy. Many efforts should be made to reduce the potential risks for donors, including the use of mini-invasive techniques, and the efficacy of UTx in the recipients, giving the potential harm of immunosuppression in a recipient of a non-life-saving organ.

Miracles of science: Birth after uterus transplantation

AIM

The concept of regaining childbearing ability via uterus transplantation (UTx) motivates many infertile women to pursue giving birth to their own children. This article provides insight into maternal and neonatal outcomes of the procedure globally and facilitates quality of care in related medical fields.

METHODS

The authors searched ISI Web of Science, MEDLINE, non-PubMed-indexed journals, and common search engines to identify peer-review publications and unpublished sources in scientific reference databases.

RESULTS

The feasibility of the procedure has been proven with 46 healthy children in 88 procedures so far. Success relies upon dedicated teamwork involving transplantation surgery, obstetrics and reproductive medicine, neonatology, pediatrics, psychology, and bioethics. However, challenges exist owing to donor, recipient, and fetus. Fetal growth in genetically foreign uterine allograft with altered feto-maternal interface and vascular anatomy, immunosuppressive exposure, lack of graft innervation leading to "unable-to-feel" uterine contractions and conception via assisted reproductive technology create notable risks during pregnancy. Significant portion of women are complicated by at least one or more obstetric problems. Preeclampsia, gestational hypertension and diabetes mellitus, elevated kidney indices, and preterm delivery are common complications.

CONCLUSIONS

UTx has short- and long-term satisfying outcome. Advancements in the post-transplant management would undoubtedly lead this experimental procedure into mainstream clinical practice in the near future. However, both women and children of UTx need special consideration due to prematurity-related neonatal problems and the long-term effects of transplant pregnancy. Notable health risks for the recipient and fetus should be discussed with potential candidates for UTx.

Long-term Course of Kidney Function in Uterus Transplant Recipients Under Treatment With Tacrolimus and After Transplantectomy: Results of the First Clinical Cohort

Background

Chronic kidney disease is common after non-renal solid organ transplantation, mainly secondary to calcineurin inhibitors toxicity. Uterus transplantation (UTx) is an innovative treatment for women with absolute uterine factor infertility. UTx is exclusive because it is transient with the absence of lifelong immunosuppression and is performed in young healthy participants. Therefore, UTx provides a unique setting for evaluating the effect of time-limited calcineurin inhibitors treatment on recipients' kidney function.

Methods

In the first UTx cohort worldwide, we studied kidney function using estimated glomerular filtration rate (eGFR) in 7 women over a median follow-up of 121 (119-126) mo.

Results

Median eGFR (mL/min/1.73 m2) of the cohort was 113 at UTx, which declined to 74 during month 3, 71 at months 10-12, 76 at hysterectomy (HE), and 83 at last follow-up. Median duration of tacrolimus exposure was 52 (22-83) mo, and median trough levels (µg/L) were 10 during month 3 and 5.8 at HE. Between UTx and month 3, decline in kidney function was observed in all 7 participants with a median eGFR slope for the whole cohort of -24 mL/min/1.73 m2, which declined further by -4 mL/min/1.73 m2 until months 10-12. Thereafter, eGFR slope improved in 3 participants, remained stable in 3, and worsened in 1 until HE/tacrolimus discontinuation, after which it improved in 2. Eventually, between UTx and last follow-up, 4 of 7 participants had a decline in their eGFR, the median annual eGFR slope being negative at -1.9 mL/min/1.73 m2/y for the whole group.

Conclusions

Kidney function declined in all recipients early after UTx followed by a persistent long-term decrease in majority, despite transplantectomy and discontinuation of immunosuppression. Thus, UTx may incur an increased risk of chronic kidney disease even in this young and healthy population, highlighting the importance of close surveillance of kidney function and minimization of tacrolimus exposure.