CHRC, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, 1169-056 Lisboa, Portugal.
Immunology Department, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, 1169-056 Lisboa, Portugal.
Int J Mol Sci. 2022 Dec 2;23(23):15200. doi: 10.3390/ijms232315200.
Recurrent pregnancy loss (RPL) affects 1-2% of women and is defined as having experienced two or more failed pregnancies. In almost 50% of cases, the causes are idiopathic (IRPL), but increasing evidence has suggested an immunological cause. B cells are known to provide crucial support for a successful pregnancy outcome. However, their involvement in the mechanisms underlying IRPL is still unclear. This systematic review and meta-analysis aimed to comprehensively summarise the existing evidence regarding the levels and profiles of B cells in IRPL. An extensive computerized search in PubMed/Medline, Embase, Scopus, and Web of Science databases was performed with no imposed limits. Two reviewers independently screened all retrieved studies, extracted all the data, and assessed the methodological quality. Disagreements were resolved by a third reviewer. From a total of 1125 retrieved studies, 19 studies were included in the systematic review, and 8 studies were quantitatively analysed. We highlight a potential association between women with IRPL and increased levels of endometrial B cells. In addition, the flow cytometry technique seems to be preferred over immunohistochemistry for identifying those differences, while further studies are necessary to clarify the role of B cells as an immunological risk factor for RPL.
复发性妊娠丢失 (RPL) 影响 1-2%的女性，定义为经历过两次或更多次失败的妊娠。在近 50%的病例中，原因是特发性的 (IRPL)，但越来越多的证据表明存在免疫原因。B 细胞已知为成功妊娠结局提供了至关重要的支持。然而，它们在 IRPL 潜在机制中的作用仍不清楚。本系统评价和荟萃分析旨在全面总结关于 IRPL 中 B 细胞水平和特征的现有证据。在 PubMed/Medline、Embase、Scopus 和 Web of Science 数据库中进行了广泛的计算机检索，没有施加任何限制。两名评审员独立筛选所有检索到的研究，提取所有数据，并评估方法学质量。分歧由第三名评审员解决。从总共检索到的 1125 项研究中，有 19 项研究被纳入系统评价，有 8 项研究进行了定量分析。我们强调了 IRPL 女性与子宫内膜 B 细胞水平升高之间可能存在的关联。此外，流式细胞术技术似乎比免疫组织化学更适合识别这些差异，而进一步的研究则有必要阐明 B 细胞作为 RPL 免疫风险因素的作用。
