Prednisolone Trial: Study protocol for a randomised controlled trial of prednisolone for women with idiopathic recurrent miscarriage and raised levels of uterine natural killer (uNK) cells in the endometrium

Contradictory Effect of Lymphocyte Therapy and Prednisolone Therapy on CD3+CD8+CD56+ Natural Killer T Population in Women with Recurrent Spontaneous Abortion

Background

Natural killer T (NKT) cells are influential immune cells in pregnancy failures, including recurrent spontaneous abortion (RSA). Different approaches are used for these disorders due to their effects on maternal immunomodulation.

Aims

In the present study, we compared the effects of two typical immunotherapies (lymphocyte immunotherapy [LIT] and low-dose prednisolone) on CD3+CD56+CD16+ and CD3+CD56+CD8+ cells as two distinct subsets of NKT cells in Women with RSA.

Settings and Design

This study was a comparative cohort study conducted from 2021 to 2022. One hundred and five women with RSA were distributed into three treatment groups randomly.

Materials and Methods

Fifty women in the group of low-dose prednisolone therapy, fifty women in the LIT group and five women without any treatment as the control group were included in the study. NK and NKT cell subsets were assessed using flow cytometry. Furthermore, the concentration of interferon-gamma (IFN-γ), transforming growth factor-beta (TGF-β) and interleukin-10 (IL-10) was measured quantitatively using the enzyme-linked immunosorbent assay technique.

Statistical Analysis Used

Normality and comparisons between study groups were performed by non-parametric unpaired Mann-Whitney, Kruskal-Wallis rank sum test, and one-way ANOVA.

Results

The percentage of CD56dim NK cells was increased after prednisolone therapy, while this population significantly decreased in the LIT group. In contrast to the LIT group, the administration of prednisolone increased CD3+CD8+CD56+ NKT cells (P < 0.0001), which is helpful for pregnancy. The effect of the investigated treatment approaches on the population of peripheral CD3+CD56+CD16+ NKT cells of women with RSA was not adequately significant. The same situation was also observed regarding the serum level of IFN-γ. However, a significant decrease in serum levels of IL-10 and TGF-β was observed after prednisolone therapy.

Conclusion

The lower capability of LIT in changing the population of NKT cells compared to prednisolone therapy may be due to its mechanism of action, which is related to the production of blocking antibodies. These treatment approaches had different effects on NKT cells, indicating that NKT cell population and function can be affected using LIT and prednisolone therapy distinctly. In addition, prednisolone therapy and LIT in women with normal serum levels of IFN-γ have no harmful effects in changing the production of this critical cytokine.

Glucocorticoids Improve the Pregnancy Rate and Outcome in Women With Unexplained Positive Autoantibodies: A Systematic Review and Meta-Analysis

The effect of glucocorticoid therapy on women with unexplained positive autoantibodies is under debate. This systemic review and meta-analysis were performed to evaluate whether glucocorticoid administration can improve the pregnancy outcome of this population. Relevant publications were searched from databases, and a total of seven prospective and retrospective cohort studies that investigated the effects of glucocorticoid administration on women with unexplained positive autoantibodies, were included. The outcomes of our systematic review and meta-analysis were measured in terms of risk ratios (RR) with 95% confidence intervals (CI) using fixed or random effect models. We found that glucocorticoid treatment improved the clinical pregnancy rate (RR 2.19, 95% CI 1.64–2.92) and live birth rate (RR 1.92, 95% CI 1.17–3.16), especially when glucocorticoid administration was started before pregnancy (clinical pregnancy rate: RR 2.30, 95% CI 1.58–3.34; live birth rate: RR 2.30, 95% CI 1.58–3.34). However, no effect of glucocorticoids on the miscarriage rate was found (RR 0.75, 95% CI 0.55–1.02) regardless of the time of drug administration. Our systematic review and meta-analysis support the rational use of glucocorticoids in women with unexplained positive autoantibodies.

The Role of Uterine Natural Killer Cells on Recurrent Miscarriage and Recurrent Implantation Failure: From Pathophysiology to Treatment

Uterine natural killer (uNK) cells constitute a unique uterine leucocyte subpopulation facilitating implantation and maintaining pregnancy. Herein, we critically analyze current evidence regarding the role of uNK cells in the events entailed in recurrent implantation failure (RIF) and recurrent miscarriages (RM). Data suggest an association between RIF and RM with abnormally elevated uNK cells’ numbers, as well as with a defective biological activity leading to cytotoxicity. However, other studies do not concur on these associations. Robust data suggesting a definitive causative relationship between uNK cells and RIF and RM is missing. Considering the possibility of uNK cells involvement on RIF and RM pathophysiology, possible treatments including glucocorticoids, intralipids, and intravenous immunoglobulin administration have been proposed towards addressing uNK related RIF and RM. When considering clinical routine practice, this study indicated that solid evidence is required to report on efficiency and safety of these treatments as there are recommendations that clearly advise against their employment. In conclusion, defining a causative relationship between uNK and RIF–RM pathologies certainly merits investigation. Future studies should serve as a prerequisite prior to proposing the use of uNK as a biomarker or prior to targeting uNK cells for therapeutic purposes addressing RIF and RM.

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.

The Role of Natural Killer Cells and Mast Cells in Female Infertility and Associated Treatment Outcomes

Introduction:

One of the identified causes of infertility has been related to the inability to regulate immunological tolerance of the maternal immune system against the developing fetus, thereby inhibiting the process of implantation. Various immune cells have been identified to contribute to the concept of un-regulated immunological tolerance, such as mast cells (MCs) and natural killer cells (NK). There are available evidences that MC play a role in the pathogenesis of infertility diseases like endometriosis and NK in specific infertility disease.

Objective:

Presently, there are studies to formulate and develop immunosuppressive drugs in order to suppress or inhibit the process of immune rejection caused by maternal immune cells. In addition, there have been reports regarding the use of steroids for the treatment of miscarriage that can inhibit the activity of most immune cells.

Conclusion:

This review is to give a comprehensive mini-review on the role of immune cells, especially mast cells and NK cells in developing novel infertility treatment.

Outcomes in prevention and management of miscarriage trials: a systematic review

BACKGROUND

There is a substantial body of research evaluating ways to prevent and manage miscarriage, but all studies do not report on the same outcomes.

OBJECTIVE

To review systematically, outcomes reported in existing miscarriage trials.

SEARCH STRATEGY

MEDLINE, Embase, CINAHL, and Cochrane were searched from inception until January 2017.

SELECTION CRITERIA

Randomised controlled trials (RCTs) reporting prevention or management of miscarriage. Miscarriage was defined as a pregnancy loss in the first trimester.

DATA COLLECTION AND ANALYSIS

Data about the study characteristics, primary, and secondary outcomes were extracted.

MAIN RESULTS

We retrieved 1553 titles and abstracts, from which 208 RCTs were included. For prevention of miscarriage, the most commonly reported primary outcome was live birth and the top four reported outcomes were pregnancy loss/stillbirth (n = 112), gestation of birth (n = 68), birth dimensions (n = 65), and live birth (n = 49). For these four outcomes, 58 specific measures were used for evaluation. For management of miscarriage, the most commonly reported primary outcome was efficacy of treatment. The top four reported outcomes were bleeding (n = 186), efficacy of miscarriage treatment (n = 105), infection (n = 97), and quality of life (n = 90). For these outcomes, 130 specific measures were used for evaluation.

CONCLUSIONS

Our review found considerable variation in the reporting of primary and secondary outcomes along with the measures used to assess them. There is a need for standardised patient-centred clinical outcomes through the development of a core outcome set; the work from this systematic review will form the foundation of the core outcome set for miscarriage.

TWEETABLE ABSTRACT

There is disparity in the reporting of outcomes and the measures used to assess them in miscarriage trials.

Serum biomarker analysis in patients with recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) occurs in 1–5% of parturients. The sustained therapy and research for RSA is expensive, which is a serious issue faced by both patients and doctors. The aim of the present study was to detect protein expression profiles in the serum of RSA patients and healthy controls, and to identify potential biomarkers for this disease. A 1,000-protein microarray consisting of a combination of Human L-507 and L-493 was used. The microarray data revealed that eight serum protein expression levels were significantly upregulated and 143 proteins were downregulated in RSA patients compared with the healthy controls. ELISA individually validated 5 of these 151 proteins in a larger cohort of patients and control samples, demonstrating a significant decrease in insulin-like growth factor-binding protein-related protein 1 (IFGBP-rp1)/IGFBP-7, Dickkopf-related protein 3 (Dkk3), receptor for advanced glycation end products (RAGE) and angiopoietin-2 levels in patients with RSA. Sensitivity and specificity analyses were calculated by a receiver operating characteristics curve, and were revealed to be 0.881, 0.823, 0.79 and 0.814, with diagnostic cut-off points of 95.44 ng/ml for IFGBP-rp1, 32.84 ng/ml for Dkk3, 147.27 ng/ml for RAGE and 441.40 ng/ml for angiopoietin-2. The present study indicated that these four proteins were downregulated in RSA samples and may be useful as biomarkers for the prediction and diagnosis of RSA. Subsequent studies in larger-scale cohorts are required to further validate the diagnostic value of these markers.

Efficacy of Intrauterine Injection of Granulocyte Colony Stimulating Factor (G-CSF) on Treatment of Unexplained Recurrent Miscarriage: A Pilot RCT Study

BACKGROUND

Endometrium undergoes several changes in structure and cellular composition during pregnancy. Granulocyte Colony-stimulating Factor (GCS-F) is an important cytokine with critical role in embryo implantation and pregnancy. The aim of the present study was to evaluate the impact of intrauterine injection of G-CSF in patients who suffer from unexplained recurrent miscarriage (RM).

METHODS

In the present randomized clinical trial, a total of 68 patients were randomly allocated into two study groups including intrauterine G-CSF (n=23, 300 μg) injection and control group (n=27, no G-CSF injection). Eighteen out of 68 patients were excluded from the final analysis due to different reasons. All patients were in Ovulation Induction (I/O) cycle. In G-CSF group, intrauterine injection of G-CSF was done twice in the cycle. All enrolled patients were under 40 years old and had at least two unexplained pregnancy losses. Pregnancy was evaluated by titer of βhCG, presence of gestational sac (implantation) and fetal heart rate (clinical pregnancy) was assessed by vaginal ultrasonography. Student's T test and Mann-Whitney U were used for analysis. The p≤0.05 was determined as statistically significant.

RESULTS

No significant differences were observed between the two study groups when the rates of chemical pregnancy (26.1% vs. 29.6%, p=0.781), implantation (26.1% vs. 22.2%, p=0.750), clinical pregnancy (17.4% vs. 11.1%, p=0.689) and abortion (33% vs. 37.5%, p=0.296) were compared.

CONCLUSION

In our study, no significant difference was observed between the two study groups when the rates of chemical pregnancy, implantation, clinical pregnancy and abortion were compared.

Decidual CD56+ Natural Killer Cells in Spontaneous Early Pregnancy Loss- An Immunohistochemical Study

INTRODUCTION

Natural killer cells are believed to promote placental and trophoblastic growth and provide immune- modulation at maternal-fetal interface in pregnancy and their role in reproductive failure has been a matter of discussion.

AIM

To study CD56+ Natural killer cells in spontaneous pregnancy loss.

MATERIALS AND METHODS

In this prospective observational study, formalin-fixed paraffin embedded sections from products of conception from twenty women each with spontaneous early pregnancy loss (test group) and elective pregnancy termination (control group). Immunohistochemical staining with CD 56 monoclonal antibody was done by avidin-biotin peroxidase technique. CD56+ cells in decidua were counted under light microscopy by two independent observers in ten high power fields (40X) and mean cell count taken. Student's paired 't'-test was used to statistically compare CD56+ NK cell population between the test and control groups.

RESULTS

The mean number of CD56+ NK cells was higher in the decidual tissue of women who had spontaneous early pregnancy loss (mean±SD, 57.55±1.79) as compared to the mean number of CD56+ NK cells in the decidual tissue from women who underwent elective termination (mean±SD, 50.9±3.46). The difference was statistically significant (difference of 6.65 with 95% confidence interval of 4.76 to 8.54, p-value <0.0001).

CONCLUSION

This could imply that CD56+ NK cells have a role in the pathogenesis of spontaneous early pregnancy loss and further large scale studies can throw more light on the mechanism and designing of appropriate therapy.

The clinical use of corticosteroids in pregnancy

BACKGROUND

The use of antenatal steroid therapy is common in pregnancy. In early pregnancy, steroids may be used in women for the treatment of recurrent miscarriage or fetal abnormalities such as congenital adrenal hyperplasia. In mid-late pregnancy, the antenatal administration of corticosteroids to expectant mothers in anticipation of preterm birth is one of the most important advances in perinatal medicine; antenatal corticosteroids are now standard care for pregnancies at risk of premature delivery in high- and middle-income countries. The widespread uptake of this therapy is due to a compelling body of evidence demonstrating improved neonatal outcomes following antenatal corticosteroid exposure, stemming most notably from corticosteroid-driven maturation of fetal pulmonary function. As we approach the 50th anniversary of landmark work in this area by Liggins and Howie, it is apparent that much remains to be understood with regards to how we might best apply antenatal corticosteroid therapy to improve pregnancy outcomes at both early and mid to late gestation.

METHODS

Drawing on advances in laboratory science, pre-clinical and clinical studies, we performed a narrative review of the scientific literature to provide a timely update on the benefits, risks and uncertainties regarding antenatal corticosteroid use in pregnancy. Three, well-established therapeutic uses of antenatal steroids, namely recurrent miscarriage, congenital adrenal hyperplasia and preterm birth, were selected to frame the review.

RESULTS

Even the most well-established antenatal steroid therapies lack the comprehensive pharmacokinetic and dose-response data necessary to optimize dosing regimens. New insights into complex, tissue-specific corticosteroid signalling by genomic-dependent and independent mechanisms have not been used to inform corticosteroid treatment strategies. There is growing evidence that some fetal corticosteroid treatments are either ineffective, or may result in adverse outcomes, in addition to lasting epigenetic changes in a variety of homeostatic mechanisms. Nowhere is the need to better understand the intricacies of corticosteroid therapy better conveyed than in the findings of Althabe and colleagues who recently reported an increase in overall neonatal mortality and maternal morbidity in association with antenatal corticosteroid administration in low-resource settings.

CONCLUSIONS

New research to clarify the benefits and potential risks of antenatal corticosteroid therapy is urgently needed, especially with regard to corticosteroid use in low-resource environments. We conclude that there is both significant scope and an urgent need for further research-informed refinement to the use of antenatal corticosteroids in pregnancy.

Evidence-based management of recurrent miscarriages

Recurrent miscarriages are postimplantation failures in natural conception; they are also termed as habitual abortions or recurrent pregnancy losses. Recurrent pregnancy loss is disheartening to the couple and to the treating clinician. There has been a wide range of research from aetiology to management of recurrent pregnancy loss. It is one of the most debated topic among clinicians and academics. The ideal management is unanswered. This review is aimed to produce an evidence-based guidance on clinical management of recurrent miscarriage. The review is structured to be clinically relevant. We have searched electronic databases (PubMed and Embase) using different key words. We have combined the searches and arranged them with the hierarchy of evidences. We have critically appraised the evidence to produce a concise answer for clinical practice. We have graded the evidence from level I to V on which these recommendations are based.

Immunotherapy for recurrent miscarriage

BACKGROUND

Because immunological aberrations might be the cause of miscarriage in some women, several immunotherapies have been used to treat women with otherwise unexplained recurrent pregnancy loss.

OBJECTIVES

The objective of this review was to assess the effects of any immunotherapy, including paternal leukocyte immunization and intravenous immunoglobulin on the live birth rate in women with previous unexplained recurrent miscarriages.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 February 2014) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomized trials of immunotherapies used to treat women with three or more prior miscarriages and no more than one live birth after, in whom all recognized non-immunologic causes of recurrent miscarriage had been ruled out and no simultaneous treatment was given.

DATA COLLECTION AND ANALYSIS

The review author and the two co-authors independently extracted data and assessed study quality for all studies considered for this review.

MAIN RESULTS

Twenty trials of high quality were included. The various forms of immunotherapy did not show significant differences between treatment and control groups in terms of subsequent live births: paternal cell immunization (12 trials, 641 women), Peto odds ratio (Peto OR) 1.23, 95% confidence interval (CI) 0.89 to 1.70; third-party donor cell immunization (three trials, 156 women), Peto OR 1.39, 95% CI 0.68 to 2.82; trophoblast membrane infusion (one trial, 37 women), Peto OR 0.40, 95% CI 0.11 to 1.45; or intravenous immunoglobulin, (eight trials, 303 women), Peto OR 0.98, 95% CI 0.61 to 1.58.

AUTHORS' CONCLUSIONS

Paternal cell immunization, third-party donor leukocytes, trophoblast membranes, and intravenous immunoglobulin provide no significant beneficial effect over placebo in improving the live birth rate.

A rapid, reliable method for uNK cell density estimation

Interest in uterine NK cell density as a diagnostic or screening tool in reproductive disorders is growing. However, current methods of analysis are time consuming. In this study, 997 images from 100 women were analysed both by the currently used method combining manual and computer aided counting, and by using colour splitting combined with area measurement as an estimate of positively stained cells. Good correlation was found between both methods (r(2)=0.92) centred around the line of equality, with no systematic differences observed in Bland Altman plots. The area measurement was significantly faster and thus is a useful screening method.

Extravillous trophoblast and decidual natural killer cells: a remodelling partnership

BACKGROUND

During pregnancy, maternal uterine spiral arteries (SAs) are remodelled from minimal-flow, high-resistance vessels into larger diameter vessels with low resistance and high flow. Fetal extravillous trophoblasts (EVT) have important roles in this process. Decidual natural killer cells (dNK cells) are the major maternal immune component of the decidua and accumulate around SAs before trophoblast invasion. A role for dNK cells in vessel remodelling is beginning to be elucidated. This review examines the overlapping and dissimilar mechanisms used by EVT and dNK cells in this process and how this may mirror another example of tissue remodelling, namely cancer development.

METHODS

The published literature was searched using Pubmed focusing on EVT, dNK cells and SA remodelling. Additional papers discussing cancer development are also included.

RESULTS

Similarities exist between actions carried out by dNK cells and EVT. Both interact with vascular cells lining the SA, as well as with each other, to promote transformation of the SA. EVT differentiation has previously been likened to the epithelial-mesenchymal transition in cancer cells, and we discuss how dNK-EVT interactions at the maternal-fetal interface can also be compared with the roles of immune cells in cancer.

CONCLUSIONS

The combined role that dNK cells and EVT play in SA remodelling suggests that these interactions could be described as a partnership. The investigation of pregnancy as a multicellular system involving both fetal and maternal components, as well as comparisons to similar examples of tissue remodelling, will further identify the key mechanisms in SA remodelling that are required for a successful pregnancy.

The distribution of immune cells and macrophages in the endometrium of women with recurrent reproductive failure I: Techniques

Recurrent miscarriage affects approximately 1% of the population and in half of these cases no cause is found. Abnormally functioning immunocompetent cells, including natural killer (NK) cells, in the endometrium, are thought to be responsible for many such cases and treatment trials including oral prednisolone and intravenous immunoglobulins are now underway. Despite these encouraging developments, there is neither adequate standardization of counting uterine NK cells nor consensus as to what constitutes an abnormal level. To address this issue, immunohistochemistry was used to examine the presence and distribution of selected immune cells and macrophages in the endometrium from 222 women who had a routine endometrial biopsy for investigation of recurrent miscarriage or IVF failure, at various stages of the menstrual cycle, and accessioned prospectively over a 7-month period. Biopsies were examined by H+E and immunostained for CD8(+) T-cells, CD163(+) macrophages, CD56(+) NK cells, and CD57(+) cells. Cell numbers (expressed as immunopositive cells per mm(2)) were determined in the stroma of the functional layer of endometrium and the relative concentrations of some cell types (CD163(+) macrophages, CD56(+) NK cells) were expressed as a percentage of all stromal cells. Routine H+E sections revealed 12 patients with focal "endometritis" without plasma cells. CD8(+) T-cells showed focal perivascular aggregates in most instances, and non-random but scattered cells in all cases, with a twofold increase in the luteal phase. CD163(+) cells were distributed evenly throughout the superficial endometrial stroma and also present as single or clustered macrophages within the lumens of superficial glands, mostly in the luteal phase. CD56(+) NK cells showed "diffuse" but variable distribution throughout the functional layer and perivascular aggregates of various sizes in two thirds of cases. Raw cell counts were low and relatively stable in the proliferative phase, but increased somewhat during the first half of the secretory phase, while in the second half of secretory phase they increased six to tenfold. Percentage counts rose from approximately 5% of stromal cells in the early part of the secretory phase of the cycle to over 35% in premenstrual endometrium. CD57(+) cells were present in very low numbers in most cases. The study illustrates the complexity and variability of immune cell infiltration of endometrium. We stress the need for strict counting protocols and attention to histological criteria if any immunological perturbations potentially responsible for recurrent reproductive failure are to be identified. Reference ranges for individual cell types are only valid for individual "days" of a normalized menstrual cycle.

Do uterine natural killer (uNK) cells contribute to female reproductive disorders?

The most abundant immune cells in the uterine decidua around the time of implantation and early placental development are the uterine natural killer (uNK) cells. Altered numbers of uNK cells have been associated with several human reproductive disorders, including recurrent miscarriage, recurrent implantation failure, uterine fibroids, sporadic miscarriage, fetal growth restriction and preeclampsia. Understanding of the function of uNK cells in non-pregnant and pregnant endometrium is now increasing; the potential contribution of altered numbers and function of uNK cells to reproductive disorders is the focus of this review.

Recent thoughts on management and prevention of recurrent early pregnancy loss

PURPOSE OF REVIEW

To provide an overview of the latest views and evidence available to clinicians managing couples with recurrent early pregnancy loss (RPL).

RECENT FINDINGS

RPL is a heterogeneous condition associated with many pathologies, none of which is found in more than 50% of couples after routine investigations. The recommended treatment of low-dose aspirin and heparin in women with antiphospholipid syndrome has a weak evidence base. Recent randomized controlled trials (RCTs) of low-dose aspirin and heparin have failed to find an improvement in live birth rates, even in the presence of thrombophilia. Although parental karyotypic abnormalities are associated with RPL, conservative management of such couples may be optimal. Observational studies of hysteroscopic metroplasty have promising results, but evidence from RCTs is awaited. Progestogen therapy may improve pregnancy outcomes, but further RCTs are needed. Immunological factors are thought to be important in idiopathic RPL. Research is focused on natural killer cells and cytokines in influencing implantation as potential therapeutic treatments. Currently, RCTs have not substantiated a benefit for immunotherapy.

SUMMARY

Management of RPL remains challenging, with many controversial issues regarding the underlying pathophysiology. Improvements in live birth rates in subsequent pregnancies have not been found in RCTs of treatment for most of the associated conditions. All women can be offered supportive care in subsequent pregnancies. Empirical treatment is widely used in idiopathic RPL. A better option may be to encourage women to participate in high-quality and methodologically sound studies to guide optimal management.