Recurrent miscarriage (RM) and recurrent implantation failure (RIF) are unsolved challenges in reproductive medicine. Whether RIF patients share the same risk factors as RM patients is a matter of debate. Besides clinical factors, immune alterations are discussed in both conditions. The scope of this study was to compare the prevalence of clinical and immunological risk factors in a large cohort of RM and RIF patients. Between 11/2011 and 02/2019, 613 RM and 185 RIF patients were included. A screening for anatomical malformations, endocrine, autoimmune, prothrombotic and parental chromosomal disorders was performed. The immune status was assessed using flow cytometry analysis of peripheral lymphocyte subpopulations and uterine natural killer cells (uNK cells) using immunohistochemistry. RM patients showed a higher rate of intrauterine adhesions and elevated antinuclear antibodies ≥ 1:160 (p < 0.05). A higher prevalence of submucous fibroids and increased factor VIII levels were observed in RIF patients (p < 0.05). The prevalence of an antiphospholipid syndrome (APLS) was low and did not differ between the two groups. RIF patients had higher numbers of peripheral regulatory T-cells (p < 0.05). Significant more RIF patients were diagnosed with elevated uNK cells (p < 0.05). Differences in clinical and immunological risk factors of RM and RIF patients reflect different entities. Lower Tregs in RM and higher uNK cells in RIF patients might be related to the previous exposure of the immune system to fetal cells. The low prevalence of an APLS indicates a potential overestimation of this factor in the pathophysiology of RM and RIF.

中文翻译：

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一个样？复发性植入失败和复发性流产的免疫学和临床风险因素不同。

复发性流产 (RM) 和复发性植入失败 (RIF) 是生殖医学中尚未解决的挑战。RIF 患者是否与 RM 患者具有相同的风险因素是一个有争议的问题。除了临床因素外，两种情况下都讨论了免疫改变。本研究的范围是在一大群 RM 和 RIF 患者中比较临床和免疫学危险因素的患病率。2011 年 11 月至 2019 年 2 月期间，包括 613 名 RM 和 185 名 RIF 患者。进行了解剖畸形、内分泌、自身免疫、血栓形成和父母染色体疾病的筛查。使用免疫组织化学对外周淋巴细胞亚群和子宫自然杀伤细胞 (uNK 细胞) 进行流式细胞术分析来评估免疫状态。RM 患者的宫腔粘连发生率较高，抗核抗体升高 ≥ 1:160 (p < 0.05)。在 RIF 患者中观察到较高的黏膜下肌瘤患病率和增加的因子 VIII 水平（p < 0.05）。抗磷脂综合征 (APLS) 的患病率很低，两组之间没有差异。RIF 患者的外周调节性 T 细胞数量较多（p < 0.05）。显着更多的 RIF 患者被诊断为 uNK 细胞升高（p < 0.05）。RM 和 RIF 患者临床和免疫学危险因素的差异反映了不同的实体。RM 中较低的 Tregs 和 RIF 患者中较高的 uNK 细胞可能与免疫系统先前暴露于胎儿细胞有关。