NK and T Cell Subtypes in the Endometrium of Patients with Recurrent Pregnancy Loss and Recurrent Implantation Failure: Implications for Pregnancy Success

Anne-Sophie Braun; Kilian Vomstein; Elisabeth Reiser; Susanne Tollinger; Christiana Kyvelidou; Katharina Feil; Bettina Toth

doi:10.3390/jcm12175585

NK and T Cell Subtypes in the Endometrium of Patients with Recurrent Pregnancy Loss and Recurrent Implantation Failure: Implications for Pregnancy Success

J Clin Med. 2023 Aug 27;12(17):5585. doi: 10.3390/jcm12175585.

Authors

Anne-Sophie Braun¹, Kilian Vomstein^{1

2

3}, Elisabeth Reiser¹, Susanne Tollinger¹, Christiana Kyvelidou¹, Katharina Feil¹, Bettina Toth¹

Affiliations

¹ Department of Gynecological Endocrinology and Reproductive Medicine, Medical University of Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria.
² Department of Obstetrics and Gynecology, The Fertility Clinic, Copenhagen University Hospital, Hvidovre, Kettegård Allé 30, 2650 Hvidovre, Denmark.
³ Recurrent Pregnancy Loss Unit, Copenhagen University Hospital (Rigshospitalet and Hvidovre Hospital), 2100 Copenhagen, Denmark.

Abstract

Background: RPL and RIF are challenges in reproductive medicine. The immune system plays a pivotal role in endometrial receptivity, successful implantation, and pregnancy complications. Immunological changes have been associated with RPL and RIF. Understanding immune dysregulation especially in NK and T cell subtypes may lead to better diagnostic concepts and treatments. From July 2019 to August 2020 patients with RPL and RIF underwent a standardized diagnostic procedure including endometrial biopsies. Immune cell analysis was performed using flow cytometry. Patients were contacted in March 2023 and interviewed concerning their pregnancy outcomes following diagnostics.

Results: Out of 68 patients undergoing endometrial biopsies, 49 patients were finally included. Live birth rates were high with 72% in RPL and 86% in RIF. Immune cell analysis revealed that patients with RPL had more cytotoxic CD56^dimCD16^high cells, while RIF patients had more CD56⁺ uNK cells. RPL patients with pregnancy complications showed increased NKT cell percentages.

Conclusion: Our findings suggest specific immune changes in RPL and RIF patients, offering potential therapeutic targets. Tailored immunotherapy based on endometrial immunophenotyping might be an option, but further research is needed.

Keywords: endometrium; immunophenotype; miscarriage; reproductive immunology; uterine NK cells.

Grants and funding

P 33249/FWF_/Austrian Science Fund FWF/Austria