Granulocyte colony-stimulating factor as a checkpoint of the embryo invasive potential and endometrial receptivity

Granulocyte colony-stimulating factor (G-CSF) promotes proliferation, survival, and differentiation of myeloid-lineage cells, as well as normal hematopoietic cells. The immunomodulating effects of G-CSF, which consist in stimulating the Th2 biased type immune response, prevent the development of graft-versus-host disease (GvHD) and, as a special case of GvHD, are responsible for the embryo implantation into the endometrium after the embryo transfer. G-CSF stimulates subpopulations of neutrophils, which display anti-inflammatory properties and are involved in tissue regeneration. The increased secretion of annexin A1 and IL-10 ensures the anti-inflammatory and immunomodulating effects of neutrophils. This review article presents data from four meta-analyzes aimed to explore the efficiency of G-CSF on infertile women undergoing in vitro fertilization. These data demonstrate an increase in the embryo implantation rate and clinical pregnancy rate, which is provided by the change in the endometrial receptivity and/or the invasive potential of the developing embryo.