Association of peripheral natural killer cell percentage with age, body mass index, serum anti- Müllerian hormone, various autoantibodies, and thrombophilia-related markers in women undergoing in vitro fertilization.

OBJECTIVE

This study aimed to assess associations between the peripheral natural killer (pNK) cell percentage and women's age, body mass index (BMI), serum anti-Müllerian hormone (AMH), autoantibodies, and thrombophilia-related markers among infertile women undergoing in vitro fertilization (IVF).

METHODS

We enrolled 91 infertile Korean women (mean age 37.7 years [range, 26 to 48]) whose pNK cell percentage was measured either before IVF (22 women) or after ≥1 failed embryo transfer (ET) (69 women) between May 2017 and November 2022 at a single university hospital. Levels of antiphospholipid antibodies, thyroid-stimulating hormone (TSH), anti-thyroglobulin, anti-microsome, anti-nuclear antibodies, antithrombin III, protein C, and protein S were measured. Serum AMH was tested within 1 year of the pNK cell measurement.

RESULTS

The mean pNK cell percentage was 16.69%±7.60%, and 68 women (74.7%) had pNK ≥12%. Univariate analysis of five continuous variables (age, BMI, AMH, TSH, and number of failed ETs) showed that the pNK percentage was negatively associated with BMI (r=-0.213, p=0.043) and AMH (r=-0.213, p=0.049). Among 11 autoantibodies/markers, only β2-glycoprotein 1 immunoglobulin G (IgG) antibody was associated with a difference in pNK percentage (9.75%±4.72% in 4 positive vs. 17.63%±7.77% in 76 negative women, p=0.022). In a multivariate analysis of BMI, AMH, and β2-glycoprotein 1 IgG positivity, AMH (B=-0.249, p=0.028) was significantly negatively associated with the pNK percentage.

CONCLUSION

The percentage of pNK cells is closely associated with serum AMH levels.