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ORIGINAL RESEARCH article

Front. Immunol.

Sec. Immunological Tolerance and Regulation

Volume 16 - 2025 | doi: 10.3389/fimmu.2025.1628337

Decoding Neutrophil Extracellular Traps and Key Gene Drivers in Unexplained Pregnancy Loss

Provisionally accepted
Hui  DingHui Ding1,2,3Lu  ZhangLu Zhang1,3Wei  YangWei Yang1,3Yu  LiuYu Liu1Chao  WangChao Wang1Li  LiuLi Liu4Cheng  LiCheng Li1,3Liyuan  PanLiyuan Pan1,3Lin  ChenLin Chen1,3Meimei  LiuMeimei Liu1,3*
  • 1The Second Affiliated Hospital of Harbin Medical University, Harbin, China
  • 2Zhoukou central hospital, Zhoukou, China
  • 3Habin medical university, Harbin, China
  • 4Harbin Red Cross Central Hospital, Harbin, China

The final, formatted version of the article will be published soon.

Background: Recurrent pregnancy loss (RPL) represents a critical reproductive health concern, with nearly half of RPL cases lacking clinically identifiable etiologies, termed unexplained RPL (uRPL). Neutrophil extracellular traps (NETs), released by activated neutrophils, have been implicated in the pathogenesis and progression of various reproductive disorders. However, the relationship between NETs and uRPL remains poorly characterized. Methods: This study enrolled 34 patients with uRPL and 30 healthy controls. Serum NETs biomarkers (MPO-DNA, citH3) were quantified via ELISA. Decidual tissues underwent histopathology (H&E), immunohistochemistry, and transcriptomics (6uRPL vs. 5 controls). Machine learning identified key NETs-related differentially expressed genes, validated by Western blotting. Immune cell infiltration and gene-immune correlations were assessed bioinformatically. Results: uRPL patients exhibited elevated serum NETs biomarkers (MPO-DNA, citH3; p<0.01) and increased decidual neutrophil infiltration. Immunohistochemistry confirmed upregulated MPO and citH3 in uRPL (p<0.01). Transcriptomics identified four key DE-NRGs (C3AR1, ITGAM, ITGB2, LYZ), validated at the protein level (p<0.05). Immune profiling revealed increased CD8+ T cells, M2 macrophages, and neutrophils, alongside reduced CD4+ memory T cells, follicular helper T cells, and monocytes in uRPL. All DE-NRGs correlated positively with M2 macrophages (r>0.6) and negatively with follicular helper T cells and monocytes (r<-0.5). LYZ also correlated with neutrophils (r>0.5). A nomogram incorporating DE-NRGs demonstrated robust diagnostic accuracy (AUC>0.85). Conclusion: This study establishes a novel link between NETs and the pathogenesis of uRPL. It highlights the abnormal activation of C3AR1, ITGAM, ITGB2, and LYZ, along with M2 macrophage polarization, as crucial factors in decidual immune dysregulation. These findings suggest that NETs could serve as therapeutic targets, while DE-NRGs may act as potential biomarkers for uRPL.

Keywords: neutrophil extracellular traps (NETs), Unexplained recurrentpregnancy loss(uRPL), immune microenvironment, machine learning algorithms, Decidual inflammation

Received: 14 May 2025; Accepted: 18 Aug 2025.

Copyright: © 2025 Ding, Zhang, Yang, Liu, Wang, Liu, Li, Pan, Chen and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Meimei Liu, The Second Affiliated Hospital of Harbin Medical University, Harbin, China

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