Peripheral blood natural killer cell proportion and ovarian function in women with recurrent implantation failure

Abstract

Current knowledge of the association between peripheral natural killer (NK) cell proportion and ovarian function in reproductive-age women is limited. We explored the association between NK cell proportion and ovarian function in women who underwent in-vitro fertilization (IVF) treatment. This was a retrospective cohort study using the data of 20–44-year-old women with recurrent implantation failure (RIF) who were tested for NK cell proportion and anti-Müllerian hormone (AMH). Indicators of ovarian function included AMH, observed-to-(age-appropriate) reference AMH ratio, high FSH, peak E₂ and total number of oocytes during the first IVF cycle following the test. We used different model specification controlling for women’s age, and body mass index. Among a total of 936 women, majority showed lower AMH compared to age-appropriate level. Average NK cell proportion was 13.5 ± 5.7%. Number of oocytes showed positive association with NK cell (ß = 0.040, p = .025). In the subgroup with NK ≥ 18%, NK cell proportion was negatively associated with AMH (−0.106, p = .012), AMH ratio (−0.049, p = .014) and number of oocytes (−0.021, p < .001) while the associations with others remain close to null. High NK cell proportion may be harmful to ovarian reserve or function.

Chinese abstract

目前对育龄女性外周血NK细胞比例与卵巢功能之间关系的认识是有限的。我们探讨了在接受体外受精（IVF）治疗的妇女中NK细胞比例和卵巢功能之间的关系。这是一项回顾性队列研究, 对20-44岁反复种植失败（RIF）的女性进行NK细胞比例和抗苗勒勒激素（AMH）检测。卵巢功能指标包括：AMH、观察到的与年龄相符的参考AMH比率、高FSH、E2峰、检测第一个体外受精周期的卵母细胞总数。我们应用了不同的模型规范控制女性年龄和体重指数。在总共936名妇女中, 大多数妇女的抗苗勒率低于相应年龄的水平。平均NK细胞比例为13.5±5.7%。卵母细胞数与NK细胞呈正相关(ß=0.040, p=.025)。在NK细胞比例为≥18%的亚组中, NK细胞比例与AMH呈负相关 (-0.106, p= .012), AMH比率（-0.049, p=.014）与卵母细胞数（-0.021, p < .001）之间的相关性接近于零。高NK细胞比例可能对卵巢储备或功能造成损害。

Keywords:

• Natural killer cells
• anti-Müllerian hormone
• estradiol
• recurrent implantation failure

Disclosure statement

The authors report no conflicts of interest.

Additional information

Funding

This work was supported by the National Research Foundation of Korea grant (NRF-2016R1D1A1B03933410 and 2018R1D1A1B07048821) funded by the Korean Government.