• CD16;
  • CD56;
  • CD69;
  • natural killer cells;
  • recurrent spontaneous abortion;
  • T lymphocytes

Problem  Determination of subpopulations of T lymphocytes, natural killer (NK) and activation status, in peripheral blood during the mid-luteal phase from patients with unexplained recurrent spontaneous abortion (RSA).

Method of study  Peripheral blood samples from non-pregnant women with RSA and normal multiparous were taken and evaluated for subpopulations of T lymphocytes: CD4, CD8, (‘naive-like’ and ‘memory-like’), TCR receptor (αβ and γδ), activation status by CD69+surface or intracellular/CD3+, and NK cells (CD16+/CD56dim/CD3, CD16+/CD56 bright/CD3, CD69+surface or intracellular/CD56+/CD3 cells).

Results  The evaluation of T lymphocytes only showed an increase in the expression of CD69 (surface and intracellular) in the RSA group. Additionally, we observed an increase in the total NK cells, CD56+ NK cells percentages, CD56dim NK cells and CD69 NK cells in RSA group.

Conclusion  These observations support the concept that immunological activation of T lymphocytes and NK cells could be involved in peripheral blood during the mid-luteal phase in patients with unexplained RSA.