Immunomodulatory treatment with intravenous immunoglobulin and prednisone in patients with recurrent miscarriage and implantation failure after in vitro fertilization/intracytoplasmic sperm injection

Intravenous immunoglobulin for patients with unexplained recurrent implantation failure: a 6-year single center retrospective review of clinical outcomes

The effectiveness of intravenous immunoglobulin (IVIg) for patients with unexplained recurrent implantation failure (uRIF) remains debated. We retrospectively analysed outcomes of uRIF patients treated with IVIg compared to a separate control uRIF cohort within our center (01/2014-12/2021). Primary outcomes included live birth, miscarriage, or transfer failure. We documented IVIg side effects and maternal/fetal outcomes. Logistic regression analysis was used to assess for association of IVIg exposure with outcomes and adjust for confounders. The study included 143 patients, with a 2:1 ratio of controls to patients receiving IVIg treatment. Patient characteristics were similar between groups. There was higher live birth rate (LBR) in patients receiving IVIg (32/49; 65.3%) compared to controls (32/94; 34%); p < 0.001). When stratifying patients into moderate and severe uRIF (respectively 3-4 and [Formula: see text] 5 previous good quality blastocyst transfer failures), only patients with severe uRIF benefited from IVIg (LBR (20/29 (69%) versus 5/25 (20%) for controls, p = 0.0004). In the logistic regression analysis, IVIg was associated with higher odds of live birth (OR 3.64; 95% CI 1.78-7.67; p = 0.0004). There were no serious adverse events with IVIg. IVIg can be considered in well selected patients with [Formula: see text] 5 previous unexplained, high quality blastocyst transfer failures. A randomized controlled trial is needed to confirm these findings.

Pregnancy by Oocyte Donation: Reviewing Fetal-Maternal Risks and Complications

Oocyte donation (OD) has greatly improved over the last three decades, becoming a preferred practice of assisted reproductive technology (ART) for infertile women wishing for motherhood. Through OD, indeed, it has become possible to overcome the physiological limitation due to the ovarian reserve (OR) exhaustion as well as the poor gamete reliability which parallels the increasing age of women. However, despite the great scientific contribution related to the success of OD in the field of infertility, this practice seems to be associated with a higher rate of major risky events during pregnancy as recurrent miscarriage, infections and placental diseases including gestational hypertension, pre-eclampsia and post-partum hemorrhage, as well as several maternal-fetal complications due to gametes manipulation and immune system interaction. Here, we will revisit this questioned topic since a number of studies in the medical literature focus on the successful aspects of the OD procedure in terms of pregnancy rate without, however, neglecting the risks and complications potentially linked to external manipulation or heterologous implantation.

Pro- and anti-inflammatory cytokines and growth factors in patients undergoing in vitro fertilization procedure treated with prednisone

Embryo implantation is a key moment in pregnancy. Abnormal production of pro- and anti-inflammatory cytokines, their receptors and other immune factors may result in embryo implantation failure and pregnancy loss. The aim of this study was to determine the profile of selected pro- and anti-inflammatory factors in the blood plasma of patients undergoing in vitro fertilization (IVF) and control women who achieved pregnancy after natural conception. The examined patients were administered steroid prednisone. We present results concern the plasma levels of IFN-ɣ, BDNF, LIF, VEGF-A, sTNFR1 and IL-10. We found that IVF patients receiving steroids differed significantly from patients who were not administered such treatment in terms of IFN-γ and IL-10 levels. Moreover, IVF patients differed in secretion of all tested factors with the fertile controls. Our results indicated that women who secrete at least 1409 pg/ml of sTNFR1 have a chance to become pregnant naturally and give birth to a child, while patients after IVF must achieve a concentration of 962.3 pg/ml sTNFR1 in blood plasma for successful pregnancy. In addition, IVF patients secreting VEGF-A above 43.28 pg/ml have a greater risk of miscarriage or a failed transfer in comparison to women secreting below this value. In conclusion, fertile women present a different profile of pro- and anti-inflammatory cytokines, and growth factors compared to patients with recurrent implantation failure (RIF).

Prednisone vs Placebo and Live Birth in Patients With Recurrent Implantation Failure Undergoing In Vitro Fertilization: A Randomized Clinical Trial

Importance

Implantation failure remains a critical barrier to in vitro fertilization. Prednisone, as an immune-regulatory agent, is widely used to improve the probability of implantation and pregnancy, although the evidence for efficacy is inadequate.

Objective

To determine the efficacy of 10 mg of prednisone compared with placebo on live birth among women with recurrent implantation failure.

Design, Setting, and Participants

A double-blind, placebo-controlled, randomized clinical trial conducted at 8 fertility centers in China. Eligible women who had a history of 2 or more unsuccessful embryo transfer cycles, were younger than 38 years when oocytes were retrieved, and were planning to undergo frozen-thawed embryo transfer with the availability of good-quality embryos were enrolled from November 2018 to August 2020 (final follow-up August 2021).

Interventions

Participants were randomized (1:1) to receive oral pills containing either 10 mg of prednisone (n = 357) or matching placebo (n = 358) once daily, from the day at which they started endometrial preparation for frozen-thawed embryo transfer through early pregnancy.

Main Outcomes and Measures

The primary outcome was live birth, defined as the delivery of any number of neonates born at 28 or more weeks' gestation with signs of life.

Results

Among 715 women randomized (mean age, 32 years), 714 (99.9%) had data available on live birth outcomes and were included in the primary analysis. Live birth occurred among 37.8% of women (135 of 357) in the prednisone group vs 38.8% of women (139 of 358) in the placebo group (absolute difference, -1.0% [95% CI, -8.1% to 6.1%]; relative ratio [RR], 0.97 [95% CI, 0.81 to 1.17]; P = .78). The rates of biochemical pregnancy loss were 17.3% in the prednisone group and 9.9% in the placebo group (absolute difference, 7.5% [95% CI, 0.6% to 14.3%]; RR, 1.75 [95% CI, 1.03 to 2.99]; P = .04). Of those in the prednisone group, preterm delivery occurred among 11.8% and of those in the placebo group, 5.5% of pregnancies (absolute difference, 6.3% [95% CI, 0.2% to 12.4%]; RR, 2.14 [95% CI, 1.00 to 4.58]; P = .04). There were no statistically significant between-group differences in the rates of biochemical pregnancy, clinical pregnancy, implantation, neonatal complications, congenital anomalies, other adverse events, or mean birthweights.

Conclusions and Relevance

Among patients with recurrent implantation failure, treatment with prednisone did not improve live birth rate compared with placebo. Data suggested that the use of prednisone may increase the risk of preterm delivery and biochemical pregnancy loss. Our results challenge the value of prednisone use in clinical practice for the treatment of recurrent implantation failure.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR1800018783.

Intravenous Immunoglobulins as Immunomodulators in Autoimmune Diseases and Reproductive Medicine

Intravenous administration of immunoglobulins has been routinely used for more than 60 years in clinical practice, developed initially as replacement therapy in immunodeficiency disorders. Today, the use of intravenous immunoglobulins (IVIGs) is embedded in the modern algorithms for the management of a few diseases, while in most cases, their application is off-label and thus different from their registered therapeutic indications according to the summary of product characteristics. In this review, we present the state-of-the-art use of IVIGs in various autoimmune conditions and immune-mediated disorders associated with reproductive failure, as approved therapy, based on indications or off-label. IVIGs are often an alternative to other treatments, and the administration of IVIGs continues to expand as data accumulate. Additionally, new insights into the pathophysiology of immune-mediated disorders have been gained. Therefore, the need for immunomodulation has increased, where IVIG therapy represents an option for stimulating, inhibiting and regulating various immune processes.

Analysis of pregnancy outcomes in patients with recurrent implantation failure complicated with chronic endometritis

Chronic endometritis (CE) has been considered to reduce uterine receptivity and negatively affect reproductive outcomes for in vitro fertilization-embryo transfer (IVF-ET) patients, especially for people undergoing recurrent implantation failure (RIF). To investigate the effects of antibiotic and platelet-rich plasma (PRP) therapy on pregnancy outcomes following frozen-thawed embryo transfer (FET) in RIF patients with CE, endometrial specimens of 327 patients with RIF obtained by endometrial scratching during mid-luteal phase were immunostained by multiple myeloma oncogene-1 (Mum-1)/syndecan-1 (CD138). RIF patients with CE were given antibiotics and PRP treatment. According to the Mum-1⁺/CD138⁺ plasmacytes after treatment, patients were divided into persistent weak positive CE (+) group, CE (-) group and non-CE group. FET was performed and the basic characteristics and pregnancy outcomes of patients in three groups were compared. Among 327 RIF patients, 117 patients were complicated with CE, the prevalence was 35.78%. The prevalence of strong positive was 27.22% and that of weak positive was 8.56%. 70.94% patients with CE converted to negative after treatment. There was no significant difference in the basic characteristics, including age, BMI, AMH, AFC, infertility years, infertility types, number of previous transplant cycles, endometrial thickness on transplantation day and number of transplanted embryos (p > 0.05); The positive rate of hCG, clinical pregnancy rate and implantation rate in CE (-) group were significantly increased compared with the weak CE (+) group and non-CE group (p < .01), and the live birth rate also improved (p < .05). Whereas, the rate of early abortion in CE (-) group was 12.70%, which was higher than that in weak CE (+) group and non-CE group (p < .05). After multivariate analysis, number of previous failed cycles and CE remained independent factors associated with live birth rate, while only CE remained to be the independent factor of clinical pregnancy rate. It is recommended to perform CE-related examination for patients with RIF. Antibiotic and PRP treatment can significantly improve pregnancy outcomes of patients with CE negative conversion in FET cycle.

Recurrent implantation failure: A comprehensive summary from etiology to treatment

Implantation is the first step in human reproduction. Successful implantation depends on the crosstalk between embryo and endometrium. Recurrent implantation failure (RIF) is a clinical phenomenon characterized by a lack of implantation after the transfer of several embryos and disturbs approximately 10% couples undergoing in vitro fertilization and embryo transfer. Despite increasing literature on RIF, there is still no widely accepted definition or standard protocol for the diagnosis and treatment of RIF. Progress in predicting and preventing RIF has been hampered by a lack of widely accepted definitions. Most couples with RIF can become pregnant after clinical intervention. The prognosis for couples with RIF is related to maternal age. RIF can be caused by immunology, thrombophilias, endometrial receptivity, microbiome, anatomical abnormalities, male factors, and embryo aneuploidy. It is important to determine the most possible etiologies, and individualized treatment aimed at the primary cause seems to be an effective method for increasing the implantation rate. Couples with RIF require psychological support and appropriate clinical intervention. Further studies are required to evaluate diagnostic method and he effectiveness of each therapy, and guide clinical treatment.

Intravenous immunoglobulin and prednisolone to women with unexplained recurrent pregnancy loss after assisted reproductive technology treatment: a protocol for a randomised, double-blind, placebo-controlled trial

INTRODUCTION

Recurrent pregnancy loss (RPL), defined as two or more consecutive pregnancy losses in the first trimester, affects around 5% of fertile women. The underlying causes remain unknown in up to 60% of patients; however, most studies point at an immunological pathology in unexplained RPL, and therefore, an effective treatment may be immunomodulatory. This study aims to evaluate the effect of intravenous immunoglobulin (IVIg) and prednisolone on reproductive outcome and the immune system in women with unexplained RPL undergoing assisted reproductive technology treatment.

METHODS AND ANALYSIS

This randomised, placebo-controlled trial with double-blinded randomisation to two parallel arms evaluate if immunomodulatory (active) treatment is superior to placebo in increasing the chance of ongoing pregnancy assessed at nuchal translucency scan in gestational weeks (GW) 11-13 after embryo transfer (ET) in 74 RPL patients with ≥2 pregnancy losses as its primary objective. The active treatment consists of IVIg (one infusion preferably 1-5 days before ET and in GW 5, 6 and 7) and prednisolone (5 mg/day from first day of menstrual bleeding until ET and 10 mg/day from ET to GW 8+0) while the comparator consists of intravenous human albumin (5%) and placebo tablets. Allocation is concealed for participants, caregivers, and investigators until trial termination and is performed in a 1:1 ratio. The secondary objective is to evaluate treatment safety, and the tertiary objective is exploration of the association between treatment, reproductive outcome after ET, and the lymphocyte subset distribution in peripheral blood collected before and after intravenous infusion(s). Excess biological material is stored in a biobank for future research.

ETHICS AND DISSEMINATION

The North Denmark Region Committee on Health Research Ethics (N-20200066) approved this trial. The results will be published in peer-reviewed scientific journals and presented to relevant patient associations, at relevant academic conferences and to key stakeholders.

TRIAL REGISTRATION NUMBER

NCT04701034.

[HLA-C KIR interactions and placental defects: Implications in ART pregnancy issues]

OBJECTIVE

The aim of this review is to update data concerning the impact of HLA-C KIR system on placental disorders and assess the involvement on ART clinical outcomes.

METHOD

Ensuring the maintenance of human pregnancy requires the set up of immunological tolerance to prevent foetus rejection. This phenomenon involves different actors of the immune system: among them, uterine NK cells (uNK) hold specific KIR (killer-cell immunoglobulin-like) receptors linking to HLA molecules on the surface of trophoblastic cells at implantation. Many studies provided evidence that the specific interaction between maternal KIR and foetal HLA-C could influence the process of placentation; according to the KIR haplotype and the type of HLA-C, the interaction could be detrimental for placental function. We reviewed the latest data available regarding HLA-C KIR interactions and ART outcomes.

RESULTS

The available results highlight a significant increase of preeclampsia risk and recurrent miscarriages when the maternal inhibitory haplotype KIR AA is present, this risk is all the more enhanced when the interaction occurs with foetal HLA-C2. Recent data suggest the consequences of this detrimental interaction in case of DET (double embryo transfer) or use of donor's oocytes in ART practice. On the other hand, maternal KIR AB or BB haplotypes haven't been related to an additional obstetrical risk, as well as the foetal HLA-C1 homozygous allotype.

CONCLUSION

Despite the existence of many confoundings in current literature on the subject, interaction between maternal KIR and foetal HLA-C represent a promising target lead to broaden the spectrum of placental defects etiologies, especially in the reproductive health area.

Outcomes of Empirical Treatment With Intravenous Immunoglobulin G Combined With Low-Dose Aspirin in Women With Unexplained Recurrent Pregnancy Loss

BACKGROUND

To assess the clinical efficacy of intravenous immunoglobulin G (IVIG) administration combined with low-dose aspirin in women with unexplained recurrent pregnancy loss (RPL).

METHODS

We retrospectively analyzed the medical records of patients who had been diagnosed with unexplained RPL and treated with IVIG and low-dose aspirin between January 2000 and March 2020 at Asan Medical Center. We analyzed pregnancy outcomes and their association with the percentage of natural killer (NK) cells.

RESULTS

The study analyzed a total of 93 patients and 113 natural and assisted reproductive technology pregnancy cycles. The live birth rate per cycle was 73.5% (83/113), and the term delivery rate was 86.7% (72/83). The live birth rate was high regardless of the type of RPL, method of pregnancy, timing of IVIG treatment, and presence or absence of autoantibodies. In addition, the live birth rate was significantly higher in patients who received IVIG more than once, compared with patients who received IVIG only once (77.8% vs. 42.9%, P = 0.006). There was no significant association between the NK cell counts and live birth rate (65.5% in the group with NK cell < 12%, and 69.7% in that with NK cell ≥ 12%, P = 0.725). Among all patients, 87.6% had no complications, and there were no congenital malformation among newborn babies.

CONCLUSION

IVIG combined with low-dose aspirin treatment showed favorable pregnancy outcomes regardless of the patient's NK cell counts (%).

Live Birth Rate in Women with Recurrent Pregnancy Loss after In Vitro Fertilization with Concomitant Intravenous Immunoglobulin and Prednisone

Pregnancy loss after in vitro fertilization (IVF) is at least as common as after spontaneous conception. Recurrent pregnancy loss (RPL) may often have an immunological background, and it is therefore relevant to test immune-based interventions in these patients. The objective was to investigate the effect of immunotherapy with intravenous immunoglobulin (IvIg) and prednisone (PRS) as concomitant therapy to IVF in women with RPL after earlier IVF treatments. In a cohort study conducted at The Danish RPL Clinic, 41 women with three or more consecutive pregnancy losses after IVF underwent at least one further IVF cycle with concomitant immunotherapy from 2012 to 2017. The immunotherapy with IvIg and PRS was given before embryo transfer and repeatedly in the first trimester when pregnancy was achieved. Fourteen women (34.2%) achieved a live birth after the first embryo transfer with immunotherapy, and a total of 32/41 (78%) achieved a live birth after up to 4 embryo transfers. Baseline characteristics and the presence of autoantibodies were not significantly different among women achieving live birth or not. The observed 34% birth rate in women with RPL after IVF receiving immunotherapy appears higher than the expected 16-19% birth rate without immunotherapy and is similar to findings in a previous cohort from our clinic. Concomitant immunotherapy as described may be a promising intervention for women with RPL after IVF; however, the effect must be tested in a randomized controlled trial.

Is there any difference between the obstetric and perinatal complications of pregnancy in patients with and without repeated implantation failure in fresh and frozen-thawed embryo transfer cycles?

Background

Repeated implantation failure (RIF) is the main challenge in assisted reproduction; the present study aimed to compare the obstetric and perinatal outcomes between RIF and control patients who experienced a successful pregnancy after fresh embryo transfer (ET) or frozen-thawed embryo transfer (FET) cycles. Data were obtained from 1150 women experiencing embryo transfer(s), consisting of 720 fresh ET and 430 FET cycles, at the Research and Clinical Center for Infertility, Yazd, Iran. The 370 women, in total, reached chemical pregnancies and finally 321 cases in fresh ET (n=216) and FET (n=105) cycles with singleton deliveries divided into two groups of control and RIF according to the number of last implantation failures. Then, the rate of obstetric and prenatal complications was compared between two groups in fresh ET and FET cycles.

Results

The results showed a higher abortion rate in the RIF group compared to the control group in fresh and FET cycles. In the assessment of the data from the cases with singleton pregnancies in fresh and FET cycles, the results showed almost similar obstetric and perinatal complications in the patients of RIF and control groups. Although the rates of some complications like vaginal bleeding, PROM, preterm delivery, and NICU administration were higher in the RIF patients, these were not significant (P > 0.05).

Conclusion

There was some variation in the normal rates of obstetric and perinatal outcomes between RIF patients compared to control. But, it seems necessary to run studies on more patients to endorse this conclusion.

Combined treatment of prednisone and hydroxychloroquine may improve outcomes of frozen embryo transfer in antinuclear antibody-positive patients undergoing IVF/ICSI treatment

BACKGROUND

The influence of anti-nuclear antibody (ANA) on induced ovulation was controversial, and the effect of prednisone plus hydroxychloroquine (HCQ) treatment on frozen embryo transfer outcomes of in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) for ANA-positive women was unclear.

METHODS

Fifty ANA-positive women and one-hundred ANA-negative women matched for age and anti-Mullerian hormone (AMH) were included from a Reproductive Medical Central of a University Hospital. Sixty-one oocytes pick-up (OPU) cycles in ANA+ group and one-hundred OPU cycles in ANA- group were compared; 30 frozen embryo transfer cycles without treatment and 66 with prednisone plus HCQ treatment among ANA-positive women were compared.

RESULTS

There was no statistical difference in number of retrieved oocytes (13.66 ± 7.71 vs 13.72 ± 7.23, p = .445), available embryos (5.23 ± 3.37 vs 5.47 ± 3.26, p = .347), high-quality embryos (3.64 ± 3.25 vs 3.70 ± 3.52, p = .832), and proportion of high-quality embryos (26.5% vs. 26.7%, p = .940). Biochemical pregnancy rate (33.3% vs. 68.2%, p < .05), clinical pregnancy rate (20.0% vs. 50.1%, p < .05), and implantation rate (5.6% vs. 31.8%, p < .05) were lower, and pregnancy loss rate (83.3% vs. 23.1%, p < .05) was higher in patients with treatment than no treatment.

CONCLUSION

The influence of ANA on number of retrieved oocytes, available embryos, high-quality embryos, and proration of high-quality embryos was not found. The treatment of prednisone plus HCQ may improve implantation rate, biochemical pregnancy rate, and clinical pregnancy rate, and reduce pregnancy loss rate in frozen embryo transfer outcomes for ANA-positive women.

A comparative evaluation of subendometrial and intrauterine platelet-rich plasma treatment for women with recurrent implantation failure

OBJECTIVE

To compare the effectiveness of treatment with autologous activated platelet-rich plasma (PRP), administered to either the subendometrium (SE-PRP) or endometrial surface (intrauterine; IU-PRP), against controls.

DESIGN

Prospective observational cohort study.

SETTING

Tertiary fertility unit.

PATIENTS

Women aged <40 years with a history of recurrent implantation failure undergoing frozen embryo transfer (FET) (n = 318).

INTERVENTIONS

In SE-PRP, PRP was injected into the subendometrial space transvaginally in the luteal phase of the previous cycle of embryo transfer under ultrasound guidance (n = 55). In IU-PRP, PRP was administered during the index FET cycle when the endometrium was approximately 7 mm (n = 109). Both SE-PRP and IU-PRP groups were administered 300 μg of granulocyte colony-stimulating factor (G-CSF) subcutaneously once a day for 3 days to boost white blood cells (WBC) and growth factor production in the PRP sample. The control group consisted of women who did not choose PRP treatment and underwent standard FET with no intervention (n = 154).

MAIN OUTCOME MEASURES

Ongoing pregnancy rate or live birth rate (OPR/LBR) per transfer cycle, clinical pregnancy rate (CPR) per transfer cycle, and miscarriage rate.

RESULTS

As a result, OPR/LBR was higher in the SE-PRP (22/55, 40%) and IU-PRP (45/109, 41.3%) groups than that in the control group (34/154, 22.1%). It was similar between the SE-PRP and IU-PRP groups. Moreover, CPR showed a similar trend with a higher rate in the SE-PRP (28/55, 51%) and IU-PRP (57/109, 52.3%) groups than that in the controls (52/154, 33.8%). No statistical difference in the CPR was noted between the SE-PRP and IU-PRP groups. The miscarriage rate was similar in all three groups (14/55, 25.45%; 25/109, 22.23%; and 34/154, 22.07%, respectively).

CONCLUSION

In women with a history of recurrent implantation failure, PRP treatment appears to improve FET outcome with an increase in OPR/LBR. However, SE-PRP treatment does not offer any advantage over lesser invasive IU-PRP treatment.

Immunological Testing in Assisted Reproductive Technology

Fetal implantation requires carefully orchestrated involvement of the maternal immune system. Aberrant function within implantation has been suggested as a cause of implantation failure. The emergence of immunological theories of miscarriage has led to immunological testing as an adjuvant treatment in assisted reproductive technology; however, it remains controversial, with mixed evidence both for immunological cause and the benefits of immunological testing. Literature on common methods of immunological testing within assisted reproductive technology is reviewed including those of peripheral and uterine natural killer cells, chronic endometritis, and T-helper cells cytokine ratio. There is little consensus in the evidence on immunological testing in the context of recurrent implantation failure. The field is limited by a lack of uniformity in approach to testing and heterogeneity of the pathophysiological cause. Nevertheless, the maternal immune system is heavily involved in implantation and the new era of personalized medicine ensures that a more defined approach to immunological testing will be achieved.

Uterine natural killer cells: from foe to friend in reproduction

BACKGROUND

Recurrent miscarriage and pre-eclampsia are common reproductive disorders, but their causes are often unknown. Recent evidence has provided new insight into immune system influences in reproductive disorders. A subset of lymphocytes of the innate immune system known as uterine natural killer (uNK) cells are now recognized as fundamental to achieving embryo implantation and successful pregnancy, but were initially attributed a bad reputation. Indeed, immune therapies have been developed to treat the 'exaggerated' immune response from uNK cells. These treatments have been based on studies of peripheral blood natural killer (pbNK) cells. However, uNK cells and pbNK cells have different phenotypic and functional characteristics. The functions of uNK cells are closely related to their interactions with the extravillous trophoblast cells (EVTs) and spiral arteries, which underlie an essential role in regulating vascular function, controlling trophoblast invasion and promoting placental development. EVTs express MHC molecules of class I HLA-C/E/G/F, while uNK cells express, among other receptors, killer cell immunoglobulin-like receptors (KIRs) that bind to HLA-C or CD94/NKG2A inhibitory receptors, and then bind HLA-E. Associations of certain KIR/HLA-C combinations with recurrent miscarriage, pre-eclampsia, and foetal growth restriction and the interactions between uNK cells, trophoblasts and vascular cells have led to the hypothesis that uNK cells may play a role in embryo implantation.

OBJECTIVE AND RATIONALE

Our objective was to review the evolution of our understanding of uNK cells, their functions, and their increasingly relevant role in reproduction.

SEARCH METHODS

Relevant literature through June 2020 was retrieved using Google Scholar and PubMed. Search terms comprised uNK cells, human pregnancy, reproductive failure, maternal KIR and HLA-C, HLA-E/G/F in EVT cells, angiogenic cytokines, CD56+ NK cells, spiral artery, oestrogen and progesterone receptors, KIR haplotype and paternal HLA-C2.

OUTCOMES

This review provides key insights into the evolving conceptualization of uNK cells, from their not-so-promising beginnings to now, when they are considered allies in reproduction. We synthesized current knowledge about uNK cells, their involvement in reproduction and their main functions in placental vascular remodeling and trophoblast invasion. One of the issues that this review presents is the enormous complexity involved in studying the immune system in reproduction. The complexity in the immunology of the maternal-foetal interface lies in the great variety of participating molecules, the processes and interactions that occur at different levels (molecular, cellular, tissue, etc.) and the great diversity of genetic combinations that are translated into different types of responses.

WIDER IMPLICATIONS

Insights into uNK cells could offer an important breakthrough for ART outcomes, since each patient could be assessed based on the combination of HLA and its receptors in their uNK cells, evaluating the critical interactions at the materno-foetal interface. However, owing to the technical challenges in studying uNK cells in vivo, there is still much knowledge to gain, particularly regarding their exact origin and functions. New studies using novel molecular and genetic approaches can facilitate the identification of mechanisms by which uNK cells interact with other cells at the materno-foetal interface, perhaps translating this knowledge into clinical applicability.

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.

A systemic review of intravenous immunoglobulin G treatment in women with recurrent implantation failures and recurrent pregnancy losses

Over the last few decades, the advancement in reproductive technologies and protocols to improve embryo quality through culture techniques and genetic testing to eliminate chromosomally abnormal embryos resulted in better pregnancy rates and outcomes after fertility treatments. Unfortunately, some patients still struggle with recurrent implantation failures (RIFs) and recurrent pregnancy losses (RPLs). Immune etiologies have been attributed to play an important role in some of those patients. Maintaining a pre-conceptional anti-inflammatory environment for implantation and pregnancy continuation yields superior results. Intravenous immunoglobulin G (IVIG) treatment has been reported to enhance reproductive outcome in patients with RIF and RPL with immune dysregulations. In this systemic review, we analyzed outcomes of IVIG trials for RIF and RPL, its mechanism of action, dosing, administration, side-effects, and evidence for its use in women with RIF and RPL.

The use of multiplex staining to measure the density and clustering of four endometrial immune cells around the implantation period in women with recurrent miscarriage: comparison with fertile controls

Serval studies showed an increased uterine natural killer cell density in women with recurrent miscarriage. However, no study has previously investigated the density and clustering of major immune cells simultaneously in precisely timed endometrial specimen section of this group of women. This study aimed to investigate the profile of endometrial immune cells populations and clustering level simultaneously in women with recurrent miscarriage and compare the results to fertile controls. A total of 30 women with unexplained recurrent miscarriage and 30 fertile controls were included in this study. Endometrial biopsy was performed precisely 7 days after LH surge. The cells density was expressed as percentage of positive immune cell/total stromal cells and the clustering of different endometrial cells was measured by R language toolbox 'spatstat'. Multiplex immunohistochemical method was employed to stain a panel of human endometrium samples simultaneously with antibodies against CD3 for T cells, CD20 for B cells, CD68 for macrophages and CD56 for uterine natural killer cells. The median CD3⁺, CD68⁺ and CD56⁺ cell density in the miscarriage group were significantly higher than those of the fertile controls. In addition, the clustering between CD56⁺ uterine natural killer cells and CD68⁺ macrophages in the miscarriage group was significantly increased compared with fertile controls. In conclusion, the significant change in numbers of three out of four endometrial immune cell density and a significant increase in clustering between CD68⁺ and CD56⁺ cells suggest that several immune cells and their interactions may be important in the function of the endometrium; abnormal interactions may predispose to recurrent miscarriage.

Tregitopes regulate the tolerogenic immune response and decrease the foetal death rate in abortion-prone mouse matings

The imbalance in immune tolerance may cause the variety of reproductive failures. An intravenous immunoglobulin infusion (IVIg) therapy is used to improve the live birth rate in women suffering from recurrent pregnancy loss, recurrent spontaneous abortions and recurrent implantation failures. However, the results of IVIg studies are still inconclusive as IVIg infusion in women suffering from pregnancy loss is sometimes ineffective. One of the mechanisms of action of this treatment is inhibition of B cells differentiation and expansion of Tregs and secretion of interleukin 10. It was proposed that immunomodulatory effects of IVIg may be attributed to tregitopes - self-IgG-derived epitopes present in the structure of immunoglobulins. Similarly to IVIg, tregitopes cause the expansion of Tregs and secretion of antigen-specific effector cytokine response. Here, we studied whether the administration of mouse tregitope 167 and/or 289 can prevent abortions in mouse abortion-prone mouse matings. We revealed that tregitopes reduce the foetal death rate. This may be driven by observed higher pool of peripheral Tregs, increased production of IL-10 by Tregs and Bregs and/or maintaining the tolerogenic phenotype of antigen-presenting cells. We believe that our findings may indicate a potential alternative to IVIg for therapeutic intervention in case of pregnancy failures.

Corticosteroids Prior to Embryo Transfer in Assisted Reproduction in Women with Crohn's Disease and Ulcerative Colitis - A Nationwide Cohort Study

Purpose

Former studies have suggested that women with Crohn’s disease (CD) and ulcerative colitis (UC) have a decreased chance of a live born child after assisted reproductive technology (ART) treatment. It is debated whether corticosteroids before ART may improve outcomes, either by decreasing inflammatory bowel disease-related inflammation or increasing endometrial receptivity. We examined the efficacy of corticosteroids before embryo transfer in women with CD and UC.

Patients and Methods

Our cohort study is based on nationwide Danish health registries, comprising women with CD and UC receiving an embryo transfer (1 January 2006 through 2017). Exposed cohorts constituted women with CD and UC who had received corticosteroids within three months before embryo transfer, and the unexposed cohorts women with CD and UC who did not receive corticosteroids. Our primary outcome was live birth. We controlled for multiple covariates in the analyses.

Results

We examined 2408 embryo transfers. In patients with CD, 114 embryo transfers were preceded by a corticosteroid prescription, and 964 were not. The corresponding numbers in UC were 122 and 1208, respectively. The adjusted odds ratio (aOR) for live birth in women with CD receiving corticosteroids before embryo transfer, relative to women with CD not receiving corticosteroids, was 0.89 (95% CI 0.49–1.63). The corresponding aOR in UC was 0.98 (95% CI 0.55–1.74).

Conclusion

Corticosteroids prior to ART in women with CD and UC did not increase the chance of a live born child. The exact impact of corticosteroids prior to embryo transfer in patients with CD and UC still remains to be determined.

Intralipid Immunotherapy for Repeated IVF Failure

The intravenous fat emulsion, intralipid, has been hypothesised to be an effective and safe treatment for repeated in vitro fertilisation (IVF), implantation failure and pregnancy loss. This exploratory, retrospective cohort study determined pregnancy outcomes and documented adverse events associated with intralipid use. Ninety-three women were identified as having received intralipid for a history of repeated unsuccessful IVF cycles and pre-viable pregnancy loss in two Australian IVF units that independently recruited between October 2014 and July 2016. Pregnancy outcomes and adverse events were recorded in fresh and frozen embryo transfer cycles in which the infusion was administered. The 93 women who received intralipid had a clinical pregnancy rate of 40.0%, compared with 35.0% in 651 age-matched controls undergoing IVF, which was not significantly different. The intralipid group had a livebirth rate of 35.7%. Apart from flushing, which was experienced by one individual, there were no adverse events associated with intralipid use. As a prelude to definitive evidence of benefit, we did not identify a safety concern or reduced pregnancy rates in intralipid users compared to controls. Indeed, these outcomes were better than expected in a poor prognosis group. This data supports an argument for large, randomised controlled trials to determine the benefit of intralipid in the treatment of recurrent implantation failure or miscarriage.

Frozen blastocyst embryo transfer vs. frozen cleavage-stage embryo transfer in couples with recurrent implantation failure: a cohort study

The objective of this prospective cohort study was to investigate whether cryopreservation of cleavage or blastocyst stage embryos improves in vitro fertilization outcomes in recurrent implantation failure (RIF) patients. The study comprised 575 patients who were allocated to receive either single frozen/thawed blastocyst-stage transfer (SBT) or frozen/thawed double-cleavage-stage embryo transfer (DET). The clinical pregnancy rate, implantation rate, and ongoing pregnancy rate were higher in the SBT group compared with the DET group (41.15% vs. 27.11%, p < 0.001; 41.15% vs. 19.28%, p < 0.001; 40.03% vs. 25.9%, p < 0.001), but the miscarriage rate did not differ between the two groups. It was concluded that frozen/thawed SBT could be a preferred strategy for RIF patients.

Prednisone may rebuild the immunologic homeostasis: Alteration of Th17 and Treg cells in the lymphocytes from rats' spleens after treated with prednisone-containing serum

Background

This study aimed to investigate alterations of T helper 17 (Th17), regulatory T (Treg) cells and relative cytokines after treating with prednisone‐contained serum. Lymphocytes were isolated from female rats' spleens.

Methods

The splenic lymphocytes were divided into four groups: which were treated with normal rats' serum (control); prednisone‐containing rats' serum (PDN); normal rats' serum and cytokines (CTK); cytokines and prednisone‐containing rats' serum (PDN + CTK). The mRNA expression level of RORC, Foxp3 and interleukin‐17 (IL‐17) was examined by reverse transcription‐polymerase chain reaction. The quantities of Th17 and Treg cells were tested by flow cytometry, and the concentrations of IL‐17 and IL‐10 were detected by enzyme‐linked immunosorbent assay.

Results

Higher mRNA expression level of Foxp3, percentages of Treg/CD4⁺, and concentrations of IL‐10, lower mRNA expressions of RORC and IL‐17, concentrations of IL‐17 and percentages of Th17/CD4⁺ in PDN group were detected, compared with control group (all p < 0.01). Similar trend was detected in PDN + CTK group, compared with CTK group (all p < 0.01).

Conclusion

Our results suggest that prednisone may rebuild the immunologic homeostasis and may be used in human diseases with changes in the imbalance immune system such as unexplained recurrent spontaneous abortion (URSA), hepatitis B infection, or other autoimmune diseases.

Recombinant human granulocyte- colony stimulating factor in women with unexplained recurrent pregnancy losses: a randomized clinical trial

STUDY QUESTION

Does administration of recombinant human granulocyte colony stimulating factor (rhG-CSF) in the first trimester improve pregnancy outcomes, among women with a history of unexplained recurrent pregnancy loss?

SUMMARY ANSWER

rhG-CSF administered in the first trimester of pregnancy did not improve outcomes among women with a history of unexplained recurrent pregnancy loss.

WHAT IS KNOWN ALREADY

The only previous randomized controlled study of granulocyte colony stimulating factor in recurrent miscarriage in 68 women with unexplained primary recurrent miscarriage found a statistically significant reduction in miscarriage and improvement in live birth rates. A further four observational studies where G-CSF was used in a recurrent miscarriage population were identified in the literature, two of which confirmed statistically significant increase in clinical pregnancy and live birth rates.

STUDY DESIGN, SIZE, DURATION

A randomized, double-blind, placebo controlled clinical trial involving 150 women with a history of unexplained recurrent pregnancy loss was conducted at 21 sites with established recurrent miscarriage clinics in the United Kingdom between 23 June 2014 and 05 June 2016. The study was coordinated by University of Birmingham, UK.

PARTICIPANTS/MATERIALS, SETTING, METHODS

One hundred and fifty women with a history of unexplained recurrent pregnancy loss: 76 were randomized to rhG-CSF and 74 to placebo. Daily subcutaneous injections of recombinant human granulocyte - colony stimulating factor 130 μg or identical appearing placebo from as early as three to five weeks of gestation for a maximum of 9 weeks. The trial used central randomization with allocation concealment. The primary outcome was clinical pregnancy at 20 weeks of gestation, as demonstrated by an ultrasound scan. Secondary outcomes included miscarriages, livebirth, adverse events, stillbirth, neonatal birth weight, changes in clinical laboratory variables following study drug exposure, major congenital anomalies, preterm births and incidence of anti-drug antibody formation. Analysis was by intention to treat.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 340 participants were screened for eligibility of which 150 women were randomized. 76 women (median age, 32[IQR, 29-34] years; mean BMI, 26.3[SD, 4.2]) and 74 women (median age, 31[IQR, 26-33] years; mean BMI, 25.8[SD, 4.2]) were randomized to placebo. All women were followed-up to primary outcome, and beyond to live birth. The clinical pregnancy rate at 20 weeks, as well as the live birth rate, was 59.2% (45/76) in the rhG-CSF group, and 64.9% (48/74) in the placebo group, giving a relative risk of 0.9 (95% CI: 0.7-1.2; P = 0.48). There was no evidence of a significant difference between the groups for any of the secondary outcomes. Adverse events (AEs) occurred in 52 (68.4%) participants in rhG-CSF group and 43 (58.1%) participants in the placebo group. Neonatal congenital anomalies were observed in 1/46 (2.1%) of babies in the rhG-CSF group versus 1/49 (2.0%) in the placebo group (RR of 0.9; 95% CI: 0.1-13.4; P = 0.93).

LIMITATIONS, REASONS FOR CAUTION

This trial was conducted in women diagnosed with unexplained recurrent pregnancy loss and therefore no screening tests (commercially available) were performed for immune dysfunction related pregnancy failure/s.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the first multicentre study and largest randomized clinical trial to investigate the efficacy and safety of granulocyte human colony stimulating factor in women with recurrent miscarriages. Unlike the only available single center RCT, our trial showed no significant increase in clinical pregnancy or live births with the use of rhG-CSF in the first trimester of pregnancy.

STUDY FUNDING/COMPETING INTEREST(S)

This study was sponsored and supported by Nora Therapeutics, Inc., 530 Lytton Avenue, 2nd Floor, Palo Alto, CA 94301, USA. Darryl Carter was the co-founder and VP of research, Nora Therapeutics, Inc. and held shares in the company. He holds a patent for the use of recombinant human granulocyte colony stimulating factor to reduce unexplained recurrent pregnancy loss. Mark Joing, Paul Kwon and Jeff Tong were or are employees of Nora Therapeutics, Inc. No other potential conflict of interest relevant to this article was reported.

TRIAL REGISTRATION NUMBER

EUDRACT No: 2014-000084-40; ClinicalTrials.gov Identifier: NCT02156063.

TRIAL REGISTRATION DATE

31 Mar 2014.

DATE OF FIRST PATIENT’S ENROLMENT

23 Jun 2014.

A retrospective comparative study of prednisolone use in antagonist co-treated assisted reproductive technology cycles for patients with good prognosis

OBJECTIVE

To investigate the impact of peri-implantation prednisolone use and its duration in antagonist co-treated assisted reproductive technology (ART) cycles of patients with good prognosis.

MATERIALS AND METHODS

Infertile patients treated with gonadotropin-releasing hormone antagonist protocol between January 2010 and June 2013 were included. The patients in group A (n=196) received no prednisolone. The patients in groups B (n=397) and C (n=371) received 5 mg oral prednisolone daily, for 4 and 12 days following embryo transfer, respectively. The main outcome parameter was live birth rate.

RESULTS

The ages of the groups were 30.1±4.6, 31.5±4.5, and 30.9±4.7 years, respectively (p=0.163). There was no statistically significant difference between the groups regarding cycle characteristics. Implantation rates were 20.7%, 24.6%, and 23.8%, respectively (p=0.163). Miscarriage rates were 1.5%, 3.5%, and 3.2%, respectively (p=0.859). Live birth rates were 28.7%, 29.3%, and 32.8%, respectively (p=0.482).

CONCLUSION

Empiric prednisolone administration during the peri-implantation period does not seem to have beneficial effects in ART cycles of patients with good prognosis.

Immune modulation of i.v. immunoglobulin in women with reproductive failure

Background

The mechanism of maternal immune tolerance of the semi‐allogenic fetus has been explored extensively. The immune reaction to defend from invasion by pathogenic microorganisms should be maintained during pregnancy. An imbalance between the immune tolerance to the fetus and immune activation to the pathogenic organisms is associated with poor pregnancy outcomes. This emphasizes that the immune mechanism of successful reproduction is not just immune suppression, but adequate immune modulation.

Methods

In this review, the action of i.v. immunoglobulin G (IVIg) on the immune system and its efficacy in reproductive failure (RF) was summarized. Also suggested is the indication of IVIg therapy for women with RF.

Main findings (Results)

Based on the mechanism of the immune regulation of IVIg and following confirmation of the immune modulation effects of it in various aberrant immune parameters in patients with RF, it is obvious that IVIg is effective in recurrent pregnancy losses and repeated implantation failures with immunologic disturbances.

Conclusion

The authors recommend IVIg therapy in patients with RF with aberrant cellular immunologic parameters, including a high natural killer cell proportion and its cytotoxicity or elevated T helper 1 to T helper 2 ratio, based on each clinic's cut‐off values. Further clinical studies about the safety of IVIg in the fetus and its efficacy in other immunologic abnormalities of RF are needed.

Prednisone may induce immunologic tolerance by activating the functions of decidual immune cells in early pregnancy

The objective of this study was to investigate alterations in human first-trimester decidual immune cells (DICs) and relevant cytokines after treatment with prednisone. Decidual lymphocytes were treated with prednisone alone, cytokines alone or the combination of prednisone and cytokines. Levels of STAT3, STAT5, RORC and FOXP3 mRNA were assayed using quantitative real-time PCR, proportions of CD4⁺ T helper 17 (Th17) and CD4⁺ T regulatory (Treg) cells were measured using flow cytometry, and concentrations of interleukin (IL)-17A and IL-10 were determined using enzyme-linked immunosorbent assay. After treatment with prednisone alone, levels of STAT5 and FOXP3 mRNA were significantly higher than in untreated control cells (both P < 0.01), while levels of RORC mRNA were significantly lower than in controls (P < 0.05). Levels of STAT3 mRNA did not vary significantly with treatment. After treatment with prednisone alone, proportions of Th17/CD4⁺ cells and levels of IL-17A were significantly lower than in control cells, and proportions of Treg/CD4⁺ cells and levels of IL-10 significantly higher than in controls (all P < 0.01). Our results suggest that prednisone may improve pregnancy outcomes by restoring immunological homeostasis through up-regulation of STAT5 and FOXP3, induction of DIC differentiation into Treg cells, inhibition of DIC differentiation into Th17 cells, reduction of IL-17A secretion and induction of IL-10 secretion.

Intralipid supplementation in women with recurrent spontaneous abortion and elevated levels of natural killer cells

OBJECTIVE

To investigate the efficacy of intralipid supplementation in women with recurrent spontaneous abortion (RSA) and elevated natural killer cell activity undergoing in vitro fertilization/intracytoplasmic sperm injection.

METHODS

Between February 10, 2013, and April 30, 2015, a double-blind randomized controlled study was conducted at a center in Egypt. Women with unexplained secondary infertility, RSA, and elevated levels of natural killer cells (>12%) were enrolled and randomly assigned to receive intralipid (2mL diluted at 20% in 250mL saline) or saline (250mL) infusion on the day of oocyte retrieval using random numbers and sealed envelopes. Patients and attending physicians were masked to group assignment. The infusions were repeated within 1week of a positive pregnancy test and then every 2weeks until the end of the first trimester. The primary outcome was chemical pregnancy 14days after embryo transfer. Analyses were by intention-to-treat.

RESULTS

Overall, 296 women were enrolled. Chemical pregnancy was recorded for 84 (58.3%) of 144 women in the intralipid group and 76 (50.0%) of 152 in the control group (P=0.129).

CONCLUSION

Intralipid supplementation did not increase frequency of chemical pregnancy. However, findings related to ongoing pregnancy and live birth should be investigated further. ClinicalTrials.gov:NCT01788540.

Successful Pregnancy Outcome in Women with Recurrent IVF Failure and Anti-hCG Autoimmunity: A Report of Three Cases

We report three cases of effective management of infertility in women with a history of repeated unsuccessful IVF attempts, who have developed antibodies to hCG. A novel approach to conservative treatment of immunologic reproductive failure, suggested for selected patients, included membrane plasmapheresis, combined prednisolone, and intravenous immunoglobulin therapy. No adverse side effects were observed; all cases resulted in pregnancy and subsequent life births. In order to be given an adequate efficient treatment, women with recurrent implantation failure should be suspected for autoimmune factor of infertility and its possible association with anti-hCG autoimmunity.

Successful Pregnancy Following Assisted Reproduction in Woman With Systemic Lupus Erythematosus and Hypertension: A Case Report

Patients with systemic lupus erythematosus have a poor prognosis of pregnancy, since it is associated with significant maternal and fetal morbidity, including spontaneous miscarriage, pre-eclampsia, intrauterine growth restriction, fetal death and pre-term delivery. We report a case with successful pregnancy in a patient with systemic lupus erythematosus and hypertension. A 39-year-old nulliparous woman presented with systemic lupus erythematosus with antinuclear and antiphospholipid antibodies, hypertension and recurrent pregnancy loss presented for assisted reproduction. The patient responded well to enoxaparin and prednisone during both assisted reproduction and prenatal treatment. This case report indicates that prescription of immunosuppressant and blood thinners can be safely recommended throughout the whole prenatal period in patients with systemic lupus erythematosus. Enoxaparin and prednisone may be prescribed concurrently during pregnancy.