Is there a place for immunomodulation in assisted reproduction techniques?

Granulocyte colony-stimulating factor in reproductive-related disease: Function, regulation and therapeutic effect

Granulocyte colony-stimulating factor (G-CSF) is one of the cytokines which plays important roles in embryo implantation and normal pregnancy. At the maternal-fetal interface, G-CSF can be synthesized by multiple cells, and participates in regulation of trophoblast development, endometrial decidualization, placental metabolism and angiogenesis. Moreover, as an important medium of intercellular communication, G-CSF has also been shown to exert key roles in crosstalk between cellular components at the maternal-fetal interface. Recently, our study demonstrated that G-CSF derived from M2 macrophage could promote trophoblasts invasion and migration through activating PI3K/AKT/Erk1/2 pathway, thereby involving in normal pregnancy program. Herein, we will summarize the role and regulation of G-CSF in normal pregnancy and reproductive-related disease, and the clinical applications of G-CSF in patients undergoing in vitro fertilization with thin endometrium, repeated implantation failure, and women suffered with recurrent spontaneous abortion.

Treatment of G-CSF in unexplained, repeated implantation failure: A systematic review and meta-analysis

BACKGROUD

Repeated implantation failure (RIF) is a stressful situation for subfertile women undergoing in vitro fertilisation (IVF) treatment and caregivers. Granulocyte-colony stimulating factor (G-CSF) seems to play an important role in assisted reproductive techniques. However, it is currently unknown whether G-CSF is effective in improving results for patients with RIF.

OBJECTIVE

To describe and summarize current evidence of the effect of the granulocyte colony stimulating factor (G-CSF) in treating RIF.

METHOD

Relevant scientific literature was thoroughly searched by computer in domestic and foreign database from the inceptions to November 2019. And relevant randomized controlled trials (RCTs) assessing the efficacy of G-CSF in unexplained RIF were included. The meta-analysis was conducted by Stata 12. 0 software, and we estimated relative risks (RRs) and associated 95 % confidence intervals (CIs) of G-CSF on implantation rate (IR), the clinical pregnancy rate (CPR), the abortion rate (AR) in patients with unexplained RIF using fixed-effect model. Besides, Subgroup analysis was performed according to the different administration methods.

RESULT

A total of eleven articles were included for the final meta-analysis with sample sizes ranging from 13 to 107 patients. The G-CSF was associated with an increased IR [RR = 2.346, 95 %CI (1.615-3.409), I2 = 0. 0%] and CPR [RR = 1.910, 95 %CI (1.562-2.337), I2 = 0.0 %] in patients with unexplained RIF. When further stratified by the method of administration, the subgroup analysis revealed that both intrauterine injection and subcutaneous injection are capable of improving IR[subcutaneous injection:RR = 2.400, 95 %CI (1. 268-4. 542), I2 = 0.0 %; intrauterine injection:RR = 2.317, 95 %CI (1.462-3.673), I2 = 0.0 %] and CPR[subcutaneous injection: RR = 2. 022, 95 %CI (1.443-2.832), I2 = 0. 0%; intrauterine injeciton: RR = 1.848, 95 %CI (1.438-2.376), I2 = 0. 0%]. G-CSF was not associated with AR in patients with unexplained RIF [RR = 2.092, 95 %CI (0.815-5.369), I2 = 0.0 %].

CONCLUSION

The current evidence support G-CSF's positive effect on the implantation rate and clinical pregnancy rate of patients with unexplained RIF, especially when administrated by subcutaneous injection. There is no conclusive evidence for the association between G-CSF and the abortion rate. Moreover, few of the included articles reported side effects of G-CSF, so its safety remains to be investigated.Thus, future research should evaluate.

Alloimmune and Autoimmune Background in Recurrent Pregnancy Loss - Successful Immunotherapy by Intravenous Immunoglobulin

PROBLEM

Immunotherapies [leukocyte immunization, intravenous immunoglobulin (IVIG)] introduced to treat women with recurrent spontaneous abortions (RSA) have still controversial results in most clinical trials. A selection of these patients would be advantageous for higher efficacy.

METHOD OF STUDY

A complex immunological panel assay was offered to patients with reproductive failure without any other known cause. We focused here on the cellular immunological parameters.

RESULTS

High cytotoxic T lymphocyte precursor frequency and cell-mediated cytotoxic activity and a rather high natural killer cell activity were found in alloimmune RSA patients. Thirty-two patients were investigated by immunological assays and in 78% of the women an alloimmune background could be defined. The efficacy of IVIG treatment was 96% in this group.

CONCLUSIONS

The novel cellular immunological assays proved to be favourable for the indication of RSA patients and showed the usefulness of this selection process for effective immunotherapy.

T cells in normal pregnancy and recurrent pregnancy loss

This review focuses on the possible role of T cells in successful pregnancy and in unexplained recurrent abortion. The functions exhibited by Th1 and Th2 cells have suggested, perhaps in a simplistic way, that Th1-type cytokines, which promote allograft rejection, may compromise pregnancy, whereas the Th2-type cytokines, by inhibiting Th1 responses, promote allograft tolerance and therefore may improve fetal survival. However, Th1 cytokines are not always detrimental for pregnancy development. Th1 cytokines, depending on their time of expression, stage of gestation and relative concentrations, could have a positive role in successful pregnancy. Other cytokines (LIF, M-CSF) produced by T cells seem to be important for the maintenance of pregnancy. Hormones present in the microenvironment of the decidual T cells could be responsible, at least in part, for the cytokine profile of the T cells. Indeed, progesterone is a potent inducer of Th2-type cytokines (e.g. IL-4 and IL-5), LIF and M-CSF production by T cells, whereas relaxin induces T cells to produce IFNgamma. Of course, the success of pregnancy depends on many mechanisms induced by different type of cells. Th2 cells could be one of these.