Intrauterine CRH-treated PBMC in repeated implantation failure

Uterine infusion strategies for infertile patients with recurrent implantation failure: a systematic review and network meta-analysis

BACKGROUND

Intra-uterine infusion treatments were reported to be beneficial to embryo implantation and pregnancy outcomes, and considered as potential therapies for infertile patients with recurrent implantation failure (RIF). Nevertheless, their efficiencies were controversial and there lack of consensus on which intrauterine treatment is the most effective.

METHODS

All prospective trials (in Chinese or English) were searched in Databases PubMed, Cochrane, Web of Science, and CNKI from July 2013 to July 2023. We included studies that investigated various uterine infusions, including chorionic gonadotropin, granulocyte colony-stimulating factor, monocytes, platelet-rich plasma, etc. during IVF treatment and reported subsequent pregnancy outcomes.

RESULTS

We finally included 56 researches, including 40 randomized controlled trials, 14 non-randomized controlled trials, and 3 prospective cohort studies. This study included a total of 11 uterine perfusion methods: Placebo, Human Chorionic Gonadotropin (HCG), Granulocyte Colony-Stimulating Factor (G-CSF), platelet-rich plasma (PRP), Peripheral Blood Mononuclear Cell (PBMC), Growth hormone (GH), dexamethasone (DEX), Embryo culture supernatant (ESC), PRP combined with G-CSF (PRP + G-CSF), RPR combined with subcutaneous injection of G-CSF (RPR + G-CSFsc), G-CSF combined with subcutaneous injection of AXaIU (G-CSF + AXaIUsc). Intrauterine infusion of HCG, PBMC, G-CSF, and PRP significantly improves pregnancy outcomes in patients with repeated implantation failure compared with blank controls or placebo, and PRP improved the clinical pregnancy and live birth most. GH and ESC infusion might improve the pregnancy outcomes, but uterine infusion of DEX was shown with high miscarriage. The combination therapy did not show a significant advantage over the mono-therapy.

CONCLUSIONS

Intrauterine infusion of HCG, PBMC, G-CSF, and PRP are promising strategies for improving pregnancy outcomes for infertile patients with recurrent implantation failure. Among these treatments, PRP may be the best. More researches are required to explore the effect of drug combinations and less commonly used drugs as well.

TRIAL REGISTRATION

Our study was registered in PROSPERO and the ID was CRD42023467188.

Title: Repeated implantation failure is associated with increased Th17/Treg cell ratio, during the secretory phase of the human endometrium

Repeated implantation failure (RIF) is a significant limiting factor in assisted reproduction. Chronic endometrial inflammation has been noted in RIF women, therefore we sought to investigate the potential association of endometrial Th17/Treg ratio and endometrial inflammation in these cases. Endometrial pipelle biopsies were obtained from volunteers, 29 women with RIF (failure to achieve pregnancy following at least 3 transfers of high-grade embryos in IVF-cycles) and 27 fertile women (at least one child) in total, at the secretory phase of the menstrual cycle. Using tissues from 17 fertile and 18 RIF endometrial samples, stromal and immune cells were isolated and flow cytometry analysis was performed to determine Th17 and CD4+ CD25high FOXP3+ cell populations in endometrial stromal cell suspensions. Another group of tissues from 10 fertile and 11 RIF samples were used for mRNA expression levels of Treg and Th17-cell transcription factors, FOXP3 and RORγt respectively. Endometrial inflammatory mediators' mRNA expression was also analyzed. A statistically significant increase in protein flow cytometry analysis of Th17/Treg ratio (p ≤ 0.05) as well as a reduction in absolute Treg cells in the endometrium (p ≤ 0.05) was noted in women with RIF. Additionally, RNA analysis on the same set of women indicated RORγt/FOXP3 significantly increased in women with RIF compared to fertile ones (p ≤ 0.05). Finally, women with RIF exhibited significantly (p ≤ 0.05) elevated mRNA levels of pro-inflammatory mediators (ΤΝF-a, ΙL-6, IL-8 and CCl2). Women with RIF exhibit elevated Th17/Treg ratio, mostly due to endometrial Treg depletion, as well as a pro-inflammatory state in the endometrium.

Endometrium Immunomodulation to Prevent Recurrent Implantation Failure in Assisted Reproductive Technology

After more than four decades of assisted reproductive technology (ART) practice worldwide, today more than 60% of women undergoing in vitro fertilization (IVF) treatments fail to become pregnant after the first embryo transfer and nearly 20% of patients are suffering from unexplained recurrent implantation failures (RIFs) and repeated pregnancy loss (RPL). The literature reported different causes of RIF–RPL, mainly multifactorial, endometrial and idiopathic. RIF remains a black box because of the complicated categorization and causes of this physio-pathological dysregulation of implantation and pregnancy process after ovarian stimulation. Many options were suggested as solutions to treat RIF–RPL with controversial results on their usefulness. In this article, we reviewed different possible therapeutic options to improve implantation rates and clinical outcomes. Based on our experience we believe that endometrium immunomodulation after intrauterine insemination of activated autologous peripheral blood mononuclear cells (PBMCs) or platelet-rich plasma (PRP) can be a promising therapeutic solution. On the other hand, peripheral lymphocyte balance typing, specific cytokines and interleukins profiling can be proposed as predictive biomarkers of implantation before embryo transfer.

Effect of human peripheral blood mononuclear cells (hPBMCs) on mouse endometrial cell proliferation: a potential therapeutics for endometrial regeneration

OBJECTIVES

The persistently thin endometrium is a major cause of repeated implantation failure; however, there is no definite treatment for it yet. This study aimed to confirm the potential of human peripheral blood mononuclear cells (hPBMCs) as a therapeutic agent for endometrial regeneration.

DESIGN

Experimental study Participants/Materials, Setting, Methods: To assess the in vitro effect of hPBMC, the human primary endometrial epithelial cell lines SNU-685 and SNU-1077 were co cultured with or without 1×10^5 hPBMCs for 24 hours. To evaluate the in vivo effect, either 1×10^5 hPBMCs in PBS or PBS alone were injected into the left uterine horn of NOD-SCID mice, and the right untreated uterine horn was used as control.

RESULTS

Co-culture with hPBMCs stimulated significant proliferation in both SNU-685 and SNU-1077 cell lines (p=0.002 and 0.044, respectively). Moreover, treatment with hPBMCs significantly increased the thickness in all parts of the endometrium compared with that in the untreated control uterine horn (proximal: 1.69±0.19 vs. 1.00±0.10, p=0.009; middle: 1.51±0.14 vs. 1.00±0.12, p=0.010; distal: 1.72±0.22 vs. 1.00±0.12, p=0.003, respectively). Compared with the PBS injection group, the hPBMC injection group had significantly thickened endometrium in the middle (P=0.036) and distal segments (P=0.002) of the uterine horn. Immunohistochemical analysis revealed the presence of exogenously injected hPBMCs in the uterus of recipient mice. hPBMC-recipient mice had cyclic uterus with normal histology in the endometrium.

LIMITATIONS

hPBMCs were not applied directly to a mouse model with thin endometrium, so further study is needed.

CONCLUSION

The beneficial effect of hPBMCs on endometrium may suggest their clinical feasibility for the safe treatment of infertile patients with persistently thin endometrium.

The Impact of New Immunological Therapeutic Strategies on Recurrent Miscarriage and Recurrent Implantation Failure

Maternal-fetal immune dysregulation is one of the risk factors that increases the probability of embryo rejection and reproductive failure. The stimulation of immunological tolerance and suppression of immunological rejection are prerequisites for protecting embryos and preventing immunological attacks. Hence, it appears that immunomodulatory and immunosuppressive therapies can manage reproductive failures by controlling immune cells. The current medical literature has shown that immunotherapy approaches and cell therapy have promising results in improving pregnancy outcomes and live birth rates. These outcomes are obtained by regulating maternal immune responses, and exerting positive effects on human reproductive processes.

Approaches to Improve Endometrial Receptivity in Case of Repeated Implantation Failures

Repeated implantation failures are a constant challenge in reproductive medicine with a significant impact both on health providers and on infertile couples. Several approaches have been proposed so far as effective; however, accumulative data have clarified that most of the treatment options do not have the evidence base for a generalized application to be suggested by the relevant societies. Implantation failures are attributed to either poor quality embryos or to defected endometrial receptivity. The current review aims to summarize in a systematic way all the new trends in managing RIF via interference with endometrial receptivity. The authors focus mainly, but not exclusively, on endometrial injury prior to embryo transfer and endometrial priming with autologous cells or biological agents. To this direction, a systematic search of the Pubmed database has been conducted taking into account the emerged evidence of the last two decades. All the suggested interventions are herein presented and analyzed in terms of reproductive outcomes. It is evident that properly powered and designed randomized trials are needed to support a new standard approach in RIF treatment that will safely be incorporated in national and international guidelines.

Migration of pre-induced human peripheral blood mononuclear cells from the transplanted to contralateral eye in mice

Background

Retina diseases may lead to blindness as they often afflict both eyes. Stem cell transplantation into the affected eye(s) is a promising therapeutic strategy for certain retinal diseases. Human peripheral blood mononuclear cells (hPBMCs) are a good source of stem cells, but it is unclear whether pre-induced hPBMCs can migrate from the injected eye to the contralateral eye for bilateral treatment. We examine the possibility of bilateral cell transplantation from unilateral cell injection.

Methods

One hundred and sixty-one 3-month-old retinal degeneration 1 (rd1) mice were divided randomly into 3 groups: an untreated group (n = 45), a control group receiving serum-free Dulbecco’s modified Eagle’s medium (DMEM) injection into the right subretina (n = 45), and a treatment group receiving injection of pre-induced hPBMCs into the right subretina (n = 71). Both eyes were examined by full-field electroretinogram (ERG), immunofluorescence, flow cytometry, and quantitative real-time polymerase chain reaction (qRT-PCR) at 1 and 3 months post-injection.

Results

At both 1 and 3 months post-injection, labeled pre-induced hPBMCs were observed in the retinal inner nuclear layer of the contralateral (left untreated) eye as well as the treated eye as evidenced by immunofluorescence staining for a human antigen. Flow cytometry of fluorescently label cells and qRT-PCR of hPBMCs genes confirmed that transplanted hPBMCs migrated from the treated to the contralateral untreated eye and remained viable for up to 3 months. Further, full-field ERG showed clear light-evoked a and b waves in both treated and untreated eyes at 3 months post-transplantation. Labeled pre-induced hPBMCs were also observed in the contralateral optic nerve but not in the blood circulation, suggesting migration via the optic chiasm.

Conclusion

It may be possible to treat binocular eye diseases by unilateral stem cell injection.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02180-5.