The Role of NK Cells in Recurrent Miscarriage (Abortion)

Recurrent miscarriage is an early pregnancy complication that affects about 1–3% of couples. There are specific characteristics of natural killer (NK) cells associated with miscarriage. In patients with recurrent miscarriage, a lack of inhibition of decidua natural killer cells can be observed, which leads to a more activated state and presentation of NK cell dim that is characterized by higher levels of pro-inflammatory cytokines and cytotoxicity effect. In peripheral blood, a dysfunctional cytokine production by natural killer cells has been also reported, with an increase of interferon-γ levels and a decrease of interleukin-4. Accordingly, there are different population of NK cells such as dim and bright. The lack of balance between these populations can lead to miscarriage. Using flow cytometry, we can detect these populations and propose the treatment too.