Immune etiology of recurrent pregnancy loss and its diagnosis

Biopsy-free profiling of the uterine immune system in patients with recurrent pregnancy loss and unexplained infertility

RESEARCH QUESTION

What are the differences in menstrual blood lymphocytes between controls, patients with recurrent pregnancy loss (RPL) and patients with unexplained infertility (uINF)?

DESIGN

Prospective study including 46 healthy controls, 28 RPL and 11 uINF patients. A feasibility study compared lymphocyte compositions of endometrial biopsies and menstrual blood collected during the first 48 h of menstruation in seven controls. In all patients, peripheral and menstrual blood from the first and subsequent 24 h were analysed separately by flow cytometry, focusing on the main lymphocyte populations and natural killer (NK) cell subsets.

RESULTS

The first 24 h of menstrual blood resembles the uterine immune milieu as tested by endometrial biopsy. RPL patients showed significantly higher menstrual blood CD56+ NK cell numbers than controls (mean ± SD: 31.13 ± 7.52% versus 36.73 ± 5.4%, P = 0.002). Menstrual blood CD56dimCD16bright NK cells within the CD56+ NK cell population were decreased in RPL (16.34 ± 14.65%, P = 0.011) and uINF (15.7 ± 5.91%, P = 0.02) patients versus control (20.42 ± 11.53%). uINF patients had the lowest menstrual blood CD3+ T cell counts (38.81 ± 5.04%, control versus uINF: P = 0.01) and cytotoxicity receptors NKp46 and NKG2D on CD56brightCD16dim cells were higher in uINF (68.12 ± 11.84%, P = 0.006; 45.99 ± 13.83%, P = 0.01, respectively) and RPL (NKp46: 66.21 ± 15.36%, P = 0.009) patients versus controls. RPL and uINF patients had higher peripheral CD56+ NK cell counts versus controls (11.42 ± 4.05%, P = 0.021; 12.86 ± 4.29%, P = 0.009 versus 8.4 ± 3.5%).

CONCLUSIONS

Compared with controls, RPL and uINF patients had a different menstrual blood-NK-subtype profile, indicating an altered cytotoxicity. In future studies, this non-invasive analysis might enable identification and monitoring of patients receiving immunomodulatory medications.

Network pharmacology-based study on immunomodulatory mechanism of danggui-yimucao herb pair for the treatment of RU486-induced abortion

ETHNOPHARMACOLOGICAL RELEVANCE

The Danggui-Yimucao herb pair (DY) is a classic combination in Chinese herbal formulas, consisting of the root of Angelica sinensis (Oliv.) Diels and the aerial parts of Leonurus japonicus Houtt. DY first appeared in "Zhulinsi fuke mifang" in the Jin Dynasty, and it has a long history as a drug for the treatment of abortion. However, its underlying immunomodulatory mechanisms involved are still unclear.

AIM OF THE STUDY

In this study, network pharmacology and pharmacological experiments were used to explore the role and mechanism of DY in the treatment of medical abortion.

MATERIALS AND METHODS

Network pharmacology was used to establish the relationship between the components of DY and abortion-related targets, and to enrich important pathways and biological process for verification. ELISA was used to assess progesterone levels. Flow cytometry was used to detect the degree of differentiation of Th1/Th2 cells. Immunohistochemical methods and qPCR were used to measure the expression levels of T-bet, GATA-3 and IL-4.

RESULTS

Through the prediction analysis of network pharmacology, we found that key pathway for DY treatment of abortion, such as anemia, pelvic infection, immune disorders, and coagulation disorders, was Th1/Th2 cell differentiation pathway. The pharmacological results revealed that DY greatly corrected the imbalance of Th cell subsets in abortion mice, significantly inhibited the differentiation of Th2 cells, and resulted in an increase in the Th1/Th2 ratio. In addition, the concentration of progesterone in the serum of mice after abortion was significantly reduced. We also found that DY upregulated spleen T-bet and downregulated IL-4 gene expression in mice. Besides, immunohistochemical results showed that DYE could up-regulate T-bet but inhibit GATA-3 expression.

CONCLUSIONS

Our results showed that after RU486-induced abortion, progesterone and Th1/Th2 paradigm were disordered in mice, but DY could make mice recover more quickly, which indicated that DY had great development value in immunoregulation.

The Investigation of Metabonomic Pathways of Serum of Iranian Women with Recurrent Miscarriage Using 1H NMR

Purpose

Recurrent miscarriage applies to pregnancy loss expulsion of the fetus within the first 24 weeks of pregnancy. This study is aimed at comparatively investigating the sera of women with RM with those who have no record of miscarriages to identify if there were any metabolite and metabolic pathway differences using ¹H NMR spectroscopy.

Methods

Serum samples were collected from women with RM (n = 30) and those who had no records of RM (n = 30) to obtain metabolomics information. ¹H NMR spectroscopy was carried out on the samples using Carr Purcell Meiboom Gill spin echo; also, Partial Least Squares Discriminant Analysis was performed in MATLAB software using the ProMetab program to obtain the classifying chemical shifts; the metabolites were identified by using the Human Metabolome Database (HMDB) in both the experimental and control groups. The pathway analysis option of the Metaboanalyst.ca website was used to identify the changed metabolic pathways.

Results

The results of the study revealed that 14 metabolites were different in the patients with RM. Moreover, the pathway analysis showed that taurine and hypotaurine metabolism along with phenylalanine, tyrosine, and tryptophan biosynthesis was significantly different in patients with RM.

Conclusion

The present study proposes that any alteration in the above metabolic pathways might lead to metabolic dysfunctions which may result in a higher probability of RM.

Effects of aspirin, vitamin D3, and progesterone on pregnancy outcomes in an autoimmune recurrent spontaneous abortion model

High proportions of placental lymphocytes expressing DX5+/CD25+/FOXP3+/CD45+/CD4+ are beneficial to maintain immune tolerance and improve pregnancy outcomes. This study aimed to compare and evaluate the therapeutic effects of aspirin, vitamin D3 (VitD3), and progesterone on the autoimmune recurrent spontaneous abortion (RSA) model. The autoimmune RSA mouse model was constructed, and the embryo loss rate was calculated for each group. Then, primary mouse placental lymphocytes were isolated, and the expression of DX5+/CD25+/FOXP3+/CD45+/CD4+ was detected through flow cytometry. The serum levels of anti-cardiolipin antibody (ACA), β2-GP1, CXCL6, IFN-γ, and IL-6 were measured by ELISA to evaluate the proportion of Th1 and Th2 cells. Autoimmune RSA significantly increased the embryo loss rate, which was improved by aspirin, VitD3, and progesterone treatment, and progesterone treatment had the best effect among the three treatments. The positive expression of DX5+/CD25+/FOXP3+/CD45+/CD4+ in the VitD3 and progesterone groups was significantly higher than that in the autoimmune RSA group, and the expression was highest in the progesterone treatment group. In the plasma of autoimmune RSA mice, the ACA, β2-GP1, CXCL6, and IFN-γ levels were significantly higher and the IL-6 level was lower than the levels in control mice. All these changes could be reversed by aspirin and progesterone treatment. In conclusion, aspirin, VitD3 and progesterone treatment improved pregnancy outcomes in autoimmune RSA mice by regulating the Th1/Th2 balance and cytokines, and progesterone had the best effect of the three treatments.

NKG2D Natural Killer Cell Receptor-A Short Description and Potential Clinical Applications

Natural Killer (NK) cells are natural cytotoxic, effector cells of the innate immune system. They can recognize transformed or infected cells. NK cells are armed with a set of activating and inhibitory receptors which are able to bind to their ligands on target cells. The right balance between expression and activation of those receptors is fundamental for the proper functionality of NK cells. One of the best known activating receptors is NKG2D, a member of the CD94/NKG2 family. Due to a specific NKG2D binding with its eight different ligands, which are overexpressed in transformed, infected and stressed cells, NK cells are able to recognize and attack their targets. The NKG2D receptor has an enormous significance in various, autoimmune diseases, viral and bacterial infections as well as for transplantation outcomes and complications. This review focuses on the NKG2D receptor, the mechanism of its action, clinical relevance of its gene polymorphisms and a potential application in various clinical settings.

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.

Regulatory B Cells: Dark Horse in Pregnancy Immunotherapy?

There are many unanswered questions surrounding the function of immune cells and how they interact with the reproductive system to support successful pregnancy or contribute to pregnancy pathologies. While the role of immune cells such as uterine natural killer and dendritic cells, and more recently regulatory T cells has been established, the role of another major immune cell population, the B cell, and particularly the regulatory B cells, is relatively poorly understood. This review outlines what is known about B-cell subsets in the context of pregnancy, what constitutes a regulatory B cell and what role they may play, particularly during early pregnancy. Lastly, we discuss why immunotherapies for the treatment of pregnancy disorders is not widely progressed clinically and speculate on the potential of functional regulatory B cells as the basis of novel immunotherapeutic approaches for the treatment of immune-based pregnancy pathologies.

Antinuclear antibodies positivity is a risk factor of recurrent pregnancy loss: A meta-analysis

OBJECTIVE

Immunologic mechanisms have been proposed as part of the pathogenesis mechanisms involved in recurrent pregnancy loss (RPL). Presence of positive antinuclear antibodies (ANA) is regarded as a typical feature of autoimmunity. Many studies had tried to clarify the association of ANA with RPL, but the conclusions were controversial. The aim of this meta-analysis was to assess whether ANA was positively associated with increased RPL risk.

METHODS

We searched PubMed and Embase databases for relevant literatures on the association between ANA positivity and RPL. The odds ratios (OR) with 95% confidence intervals (95%CI) were pooled using meta-analysis, and either fixed-effect or random-effect model was used based on heterogeneity across the included studies.

RESULTS

Twenty-one studies with 5038 participants (including 2683 RPL patients and 2355 controls) met the inclusion criteria were included. The total positive rate of ANA was 22.0% (591/2683) in RPL group, and 8.3% (196/2355) in the control group. RPL patients had a significantly higher ANA positive rate than controls (OR = 2.97, 95%CI 1.91-4.64, P<0.00001; I² = 75%), and a significant association between positive ANA and unexplained RPL was also observed (OR = 3.27, 95%CI 2.01-5.31, P<0.00001; I² = 70%). ANA positivity was also significantly associated with increased risk of RPL in women without defined autoimmune diseases (OR = 2.23, 95%CI 1.40-3.55, P=0.0007). Subgroup analysis demonstrated low titers of ANA (1:40≤ANA≤1: 80) were not associated with RPL (OR = 2.44, 95%CI 0.42-14.06, P=0.32), while higher ANA titer (≥1:160) had a significant association with RPL (OR = 45.89, 95%CI 8.44-249.45, P<0.00001). A higher rate of homogenous pattern in RPL patients was observed (OR = 4.89, 95%CI 2.20-10.87, P<0.001), and no significant difference in speckled pattern or nucleolar pattern was found.

CONCLUSIONS

This study demonstrated that ANA positivity was positively associated with increased RPL risk. ANA positivity is an important risk factor for RPL which needed to be screened among women with RPL.

Evaluation of T cell cytokines and their role in recurrent miscarriage

Recurrent miscarriage (RM) is defined as two or more consecutive pregnancy losses that affect approximately 5% of conceived women worldwide. RM is a multi-factorial reproductive problem and has been associated with parental chromosomal abnormalities, embryonic chromosomal rearrangements, uterine anomalies, autoimmune disorders, endocrine dysfunction, thrombophilia, life style factors, and maternal infections. However, the exact cause is still undecided in remaining 50% of cases. Immunological rejection of the embryo due to exacerbated maternal immune reaction against paternal embryonic antigens has been set forth as one of the significant reason for RM. The accurate means that shield the embryo during normal pregnancy from the attack of maternal immune network and dismissal are inadequately implicit. However, it is suggested that the genetically irreconcilable embryo escapes maternal immune rejection due to communication among many vital cytokines exuded at maternal-embryonic interface both by maternal and embryonic cells. Previous investigations suggested the Th1/Th2 dominance in altered immunity of RM patients, according to which the allogenic embryo flees maternal T cell reaction by inclining the Th0 differentiation toward Th2 pathway resulting into diminished pro-inflammatory Th1 immunity. However, recently pro-inflammatory Th17 cells and immunoregulatory Treg cells have been discovered as essential immune players in RM besides Th1/Th2 components. Cytokines are believed to develop a complicated regulatory network so as to establish a state of homeostasis between the semi-allogenic embryo and the maternal immune system. However, an adverse imbalance among cytokines at maternal-embryonic interface perhaps due to their gene polymorphisms may render immunoregulatory means not enough to re-establish homeostasis and thus may collapse pregnancy.

Recurrent Pregnancy Loss in Women with Hashimoto's Thyroiditis with Concurrent Non-Endocrine Autoimmune Disorders

Background: An increased rate of recurrent miscarriage has been described in patients with autoimmune thyroid disease. However, there is a lack of studies that assess the rate of recurrent pregnancy loss (RPL) in patients with Hashimoto's thyroiditis (HT) isolated or with concurrent non-endocrine autoimmune disorders (NEAD). The objective of the study was to assess the rate of RPL in patients with HT isolated or accompanied with non-endocrine autoimmune diseases. Methods: This is a retrospective observational cohort study with a systematic review of the NEAD with concurrent HT in an outpatient Endocrinology Unit at a University Hospital. Among the 3480 consecutively examined women with HT, 87 patients met the criteria of RPL and represented the study group. Sixty-five of them had isolated HT and 22 women had HT+NEAD. Results: The rate of RPL in women with HT was 2.1% versus 5.64% observed in women with HT+NEAD (odds ratio = 2.78 [95% confidence interval 1.70-4.57]; p < 0.0001). On subdivision, this difference was still evident in euthyroid patients (p < 0.0001), while it disappeared in hypothyroid women (p = 0.21). The RPL did not correlate with the autoantibody concentrations nor in women with isolated HT nor in those with HT+NEAD. The presence of antiphospholipid syndrome (APS) explained RPL in 3 out of 22 (14%) patients with HT+NEAD, the remaining being related to different autoimmune disorders. Interestingly, even subtracting the patients with APS, RPL was more frequent in patients with poly-autoimmunity than in patients with isolated HT (p = 0.0013). Conclusions: The co-presence of NEAD is correlated with a higher risk of RPL in women with HT. The association with APS may explain only a fraction of RPL rate in patients with poly-autoimmunity.

Uterine Dendritic Cells Modulation by Mesenchymal Stem Cells Provides A Protective Microenvironment at The Feto-Maternal Interface: Improved Pregnancy Outcome in Abortion-Prone Mice

Objective

Dendritic cells (DCs) as major regulators of the immune response in the decidua play a pivotal role in establishment and maintenance of pregnancy. Immunological disorders are considered to be the main causes of unexplained recurrent spontaneous abortions (RSAs). Recently, we reported that mesenchymal stem cells (MSCs) therapy could improve fetal survival and reduce the abortion rate in abortion-prone mice, although the precise mechanisms of this action are poorly understood. Since MSCs have been shown to exert immunomodulatory effects on the immune cells, especially DCs, this study was performed to investigate the capability of MSCs to modulate the frequency, maturation state, and phenotype of uterine DCs (uDCs) as a potential mechanism for the improvement of pregnancy outcome.

Materials and Methods

In this experimental study, adipose-derived MSCs were intraperitoneally administered to abortion-prone pregnant mice on the fourth day of gestation. On the day 13.5 of pregnancy, after the determination of abortion rates, the frequency, phenotype, and maturation state of uDCs were analyzed using flow cytometry.

Results

Our results indicated that the administration of MSCs, at the implantation window, could significantly decrease the abortion rate and besides, increase the frequency of uDCs. MSCs administration also remarkably decreased the expression of DCs maturation markers (MHC-II, CD86, and CD40) on uDCs. However, we did not find any difference in the expression of CD11b on uDCs in MSCs-treated compared to control mice.

Conclusion

Regarding the mutual role of uDCs in establishment of a particular immunological state required for appropriate implantation, proper maternal immune responses and development of successful pregnancy, it seems that the modulation of uDCs by MSCs could be considered as one of the main mechanisms responsible for the positive effect of MSCs on treatment of RSA.

Gestational and perinatal outcomes in recurrent miscarriages couples treated with lymphocyte immunotherapy

Objective

This study aims to elucidate which types of recurrent miscarriage (RM) patients experienced a livebirth after paternal lymphocyte immunotherapy (LIT) and to evaluate the perinatal outcome.

Study design

Retrospective analysis of a multicenter, observational study which enrolled 1096 couples with a history of two or more spontaneous miscarriages without any intercalated delivery. We conducted an intention-to-treat analysis of couples with RM treated with or without LIT regarding to gestational and perinatal outcomes. We compared groups by using the Student’s t-test or Kruskal–Wallis test, Fisher’s exact-test and χ² test when appropriate.

Results

The success of gestation was significantly higher in the LIT group (60.1% vs. 33.1%; p <  0.001). A sub-analysis of four different immune disorder groups revealed a significantly higher success in the LIT group in all immune categories, except in patients who had autoantibodies positive. We observed no significant differences in perinatal outcomes such as gestational age at birth, preterm and extreme preterm birth, and birth weight in successful pregnancy in both groups. The success rate was significantly higher when LIT was administrated before and during pregnancy and only during pregnancy compared to only before pregnancy (p <  0.01).

Conclusions

Careful laboratory test phenotyping of RM patients may identify subgroups most likely to benefit and exclude those with little likelihood of benefit, and LIT during a pregnancy may significantly improve success rates.

A Role for Iodide and Thyroglobulin in Modulating the Function of Human Immune Cells

Iodine is an essential element required for the function of all organ systems. Although the importance of iodine in thyroid hormone synthesis and reproduction is well known, its direct effects on the immune system are elusive. Human leukocytes expressed mRNA of iodide transporters (NIS and PENDRIN) and thyroid-related proteins [thyroglobulin (TG) and thyroid peroxidase (TPO)]. The mRNA levels of PENDRIN and TPO were increased whereas TG transcripts were decreased post leukocyte activation. Flow cytometric analysis revealed that both PENDRIN and NIS were expressed on the surface of leukocyte subsets with the highest expression occurring on monocytes and granulocytes. Treatment of leukocytes with sodium iodide (NaI) resulted in significant changes in immunity-related transcriptome with an emphasis on increased chemokine expression as probed with targeted RNASeq. Similarly, treatment of leukocytes with NaI or Lugol’s iodine induced increased protein production of both pro- and anti-inflammatory cytokines. These alterations were not attributed to iodide-induced de novo thyroid hormone synthesis. However, upon incubation with thyroid-derived TG, primary human leukocytes but not Jurkat T cells released thyroxine and triiodothyronine indicating that immune cells could potentially influence thyroid hormone balance. Overall, our studies reveal the novel network between human immune cells and thyroid-related molecules and highlight the importance of iodine in regulating the function of human immune cells.

Uterine CD56dim and CD16+ Cells in Refractory Antiphospholipid Antibody-Related Pregnancy Loss and Chromosomally Intact Abortuses: A Case-Control Study

AIM

To evaluate the role of uterine natural killer (uNK) CD56^dim and CD16⁺ cells in patients with refractory antiphospholipid, antibody-mediated, recurrent, pregnancy loss.

SETTINGS AND DESIGN

A case-control study was conducted between 2012 and 2015 at a university hospital.

PATIENTS AND METHODS

A group of 118 women with a history of antiphospholipid antibody syndrome experiencing fetal loss in spite of low dose aspirin (LDA) and low molecular weight heparin (LMWH) treatment in the current pregnancy were included in this study. A group of 32 patients undergoing an elective termination of viable pregnancies before 20 weeks were taken as controls. Suction evacuation was performed to collect abortus specimens, and uterine wall curettage was performed to collect decidua specimens, which were then stained using monoclonal antibodies specific to CD56 and CD16.

STATISTICS

Statistical analyses were performed using the Statistical Package for the Social Sciences version 18 software. Chi-square and Fisher exact tests were used for making comparison between the groups.

RESULTS

Abnormal fetal karyotype was found in nine (9/97) cases of the study group, which means that abnormal karyotype accounts for only 9.3% of the causes of failure of treatment. Abnormal karyotype was found in four cases of the control group. Only cases with normal karyotyping were subjected to decidual uNK cells analysis. We found that CD56^dim and CD16⁺ were found in the decidua of 79 cases (79/97), which means that aberrant natural killer cells expression might account for 81.4% of the cases of refractory antiphospholipid antibody (APA)-mediated recurrent pregnancy loss.

CONCLUSION

CD56^dim and CD16⁺ uNK cells might be correlated with refractory APA-mediated recurrent pregnancy loss.

Human Decidual Stromal Cells as a Component of the Implantation Niche and a Modulator of Maternal Immunity

The human decidua is a specialized tissue characterized by embryo-receptive properties. It is formed during the secretory phase of menstrual cycle from uterine mucosa termed endometrium. The decidua is composed of glands, immune cells, blood and lymph vessels, and decidual stromal cells (DSCs). In the process of decidualization, which is controlled by oestrogen and progesterone, DSCs acquire specific functions related to recognition, selection, and acceptance of the allogeneic embryo, as well as to development of maternal immune tolerance. In this review we discuss the relationship between the decidualization of DSCs and pathological obstetrical and gynaecological conditions. Moreover, the critical influence of DSCs on local immune cells populations as well as their relationship to the onset and maintenance of immune tolerance is described.

Patients with idiopathic recurrent miscarriage show higher levels of DR+ activated T-cells that are less responsive to mitogens

In 50% of recurrent miscarriages (RM) the cause remains unknown and standardized immunological diagnosis and treatment of idiopathic RM (iRM) is yet not established. In this prospective case-control study, out of 220 RM patients screened, 97 iRM patients were identified and compared to 26 healthy controls without a previous pregnancy or blood transfusion in order to identify deregulated immunological parameters. Blood levels of lymphocyte subpopulations, cytokines and neopterin were determined by FACS, ELISA, and Luminex technique. Lymphocyte function was studied by in-vitro lympocyte proliferation tests. As compared to controls, patients had significantly higher proportions of activated CD3+DR+, CD4+DR+ and CD8+DR+ lymphocytes, elevated levels of neopterin and a lower in-vitro proliferation of lymphocytes (all p<0.05). Within the iRM patients higher proportions of CD3+DR+ T-lymphocytes correlated with higher proportions and absolute numbers of CD4+DR+ and CD8+DR+ T-lymphocytes and lower CD16+CD56+ NK-cells. Further, it was associated with lower absolute numbers of CD19+ B-lymphocytes, CD3+CD25+ T-lymphocytes and CD45+ total lymphocytes (all p<0.05). In addition we found decreased in-vitro lymphocyte proliferation in iRM patients with high CD3+DR+ T-lymphocytes (p<0.05). In summary patients with iRM showed increased activated T-cells that are less responsive to mitogens in-vitro. The inverse relationship of increased DR but decreased CD25 expression on CD3+ T-cells and the decreased in-vitro proliferation characterize an immunological disorder with similarities to T-cell exhaustion in patients with HIV and cancer. These abnormalities potentially contribute to the pathogenesis of iRM and might be a target for future immunomodulatory therapies.

Expression and role of a2 vacuolar-ATPase (a2V) in trafficking of human neutrophil granules and exocytosis

Neutrophils kill microorganisms by inducing exocytosis of granules with antibacterial properties. Four isoforms of the "a" subunit of V-ATPase-a1V, a2V, a3V, and a4V-have been identified. a2V is expressed in white blood cells, that is, on the surface of monocytes or activated lymphocytes. Neutrophil associated-a2V was found on membranes of primary (azurophilic) granules and less often on secondary (specific) granules, tertiary (gelatinase granules), and secretory vesicles. However, it was not found on the surface of resting neutrophils. Following stimulation of neutrophils, primary granules containing a2V as well as CD63 translocated to the surface of the cell because of exocytosis. a2V was also found on the cell surface when the neutrophils were incubated in ammonium chloride buffer (pH 7.4) a weak base. The intracellular pH (cytosol) became alkaline within 5 min after stimulation, and the pH increased from 7.2 to 7.8; this pH change correlated with intragranular acidification of the neutrophil granules. Upon translocation and exocytosis, a2V on the membrane of primary granules remained on the cell surface, but myeloperoxidase was secreted. V-ATPase may have a role in the fusion of the granule membrane with the cell surface membrane before exocytosis. These findings suggest that the granule-associated a2V isoform has a role in maintaining a pH gradient within the cell between the cytosol and granules in neutrophils and also in fusion between the surface and the granules before exocytosis. Because a2V is not found on the surface of resting neutrophils, surface a2V may be useful as a biomarker for activated neutrophils.

Immune profiling in patients with recurrent miscarriage

The central role of the maternal immune system for successful and disturbed pregnancies such as recurrent miscarriage (RM) is apparent. Recent studies have increased understanding of the complex interaction of the different immunological players and the adaptation of the maternal immune system to the semi-allogeneic embryo. There is growing evidence for immunological abnormalities in RM patients, including autoimmune and allogeneic factors. However, the question remains unsolved whether these changes represent the cause or the consequence of RM. As in half of the RM patients the underlying mechanism remains unknown, further diagnostic methods are urgently needed. Within this review we summarize (recent) literature on the immunological diagnosis in RM patients to find out current trends and to identify potential targets of therapy. As the exact mechanisms of feto-maternal tolerance have not yet been determined we suggest that the immunological diagnosis should be implemented only in well-designed clinical trials in specialized centers to establish a standardized immunological work-up in RM patients.

Recurrent spontaneous miscarriage is still a challenging diagnostic and therapeutic quagmire

Recurrent spontaneous miscarriage (RSM), affecting 1-2% of women of reproductive age seeking pregnancy, has been a clinical quagmire and a formidable challenge for the treating physician. There are many areas of controversy in the definition, aetiology, investigations and treatment of RSM. This review will address the many factors involved in the aetiology of RSM which is multifactorial in many patients, with antiphospholipid syndrome (APS) being the most recognized aetiological factor. There is no identifiable cause in about 40-60% of these patients, in which case the condition is classified as idiopathic or unexplained RSM. The RSM investigations are extensive and should be undertaken in dedicated, specialized, well-equipped clinics/centres where services are provided by trained specialists. The challenges faced by the treating physician are even more overwhelming regarding the decision of what should be the most appropriate therapy offered to patients with RSM. Our review will cover the diverse modalities of therapy available including the role of preimplantation genetic testing using recent microarray technology, such as single nucleotide polymorphism and comparative genomic hybridization, as well as preimplantation genetic diagnosis; the greatest emphasis will be on the treatment of APS, and there will be important comments on the management of patients presenting with idiopathic RSM. The controversial areas of the role of natural killer cells in RSM, the varied modalities in the management of idiopathic RSM and the need for better-planned studies will be covered as well.

Polymorphisms in genes coding for the NK-cell receptor NKG2D and its ligand MICA in recurrent miscarriage

PROBLEM

To investigate the possible association of Natural Killer Group (NKG) receptors gene polymorphisms and MHC class I chain-related protein A (MICA) gene polymorphism with recurrent miscarriage (RM).

METHODS

Seven SNPs in NKG2D gene (rs1049174, rs2255336, rs2617160, rs2617161, rs2246809, rs2617169, and rs2617170), one SNP in NKG2A gene (rs1983526), and one SNP in MICA gene (MICA129) were assessed by allelic discrimination (real-time PCR) in both patients and control women.

RESULTS

The rs2617170 T/T genotype significantly protected against RM [OR (95%) = 0.63 (0.40-0.98)]. The NKG2D haplotypes analysis on the basis of pairwise LD revealed two haplotype blocks. In block1, we found an increased frequency of CAT (Pc = 0.007; OR = 2.13; 95% CI = 1.24-3.68) and GGA haplotypes (Pc = 0.041; OR = 2.02; 95%CI = 1.03-3.96) and reduced frequency of CAA haplotype (Pc = 0.027; OR = 0.72; 95% CI = 0.54-0.96) in patients. In block2, increased frequency of GATG haplotype (Pc = 10(-4) ; OR = 9.25; 95% CI = 3.04-28.12) and reduced frequency of ATTC haplotype (Pc = 0.035; OR = 0.69; 95%CI = 0.50-0.97) were seen in patients.

CONCLUSION

The NKG2D gene polymorphisms may influence the success of pregnancy in Tunisian women.

Future directions of clinical laboratory evaluation of pregnancy

In recent years, our understanding of how the immune system interacts with the developing fetus and placenta has greatly expanded. There are many laboratories that provide tests for diagnosis of pregnancy outcome in women who have recurrent pregnancy loss (RPL) or pre-eclampsia. These tests are based on the premise that immune response to the fetus is equivalent to the adaptive immune response to a transplant. New understanding leads to the concept that the activated innate response is vital for pregnancy and this can result in more effective testing and treatment to prevent an abnormal pregnancy in the future. We describe here only three such areas for future testing: one area involves sperm and semen and factors necessary for successful fertilization; another area would determine conditions for production of growth factors necessary for implantation in the uterus; finally, the last area would be to determine conditions necessary for the vascularization of the placenta and growing fetus by activated natural killer (NK) cells (combinations of killer cell immunoglobulin-like receptor (KIR) family genes with HLA-C haplotypes) that lead to capability of secreting angiogenic growth factors. These areas are novel but understanding their role in pregnancy can lead to insight into how to maintain and treat pregnancies with complicating factors.

New decision-tree model for defining the risk of reproductive failure

PROBLEM

Natural killer (NK) cells play a key role in embryo implantation and pregnancy success, whereas blood and uterine NK expansions have been involved in the pathophysiology of reproductive failure (RF). Our main goal was to design in a large observational study a tree-model decision for interpretation of risk factors for RF.

METHODS OF STUDY

A hierarchical multivariate decision model based on a classification and regression tree was developed. NK and NKT-like cell subsets were analyzed by flow cytometry.

RESULTS

By multivariate analysis, blood NK cells expansion was an independent risk factor for RF (both recurrent miscarriages and implantation failures). We propose a new decision-tree model for the risk interpretation of women with RF based on a combination of main risk factors.

CONCLUSIONS

Women with age above 35 years and >13% CD56⁺CD16⁺ NK cells showed the highest risk of further pregnancy loss (100%).

Killer cell immunoglobulin-like receptor gene associations with autoimmune and allergic diseases, recurrent spontaneous abortion, and neoplasms

Killer cell immunoglobulin-like receptors (KIRs) are a family of cell surface inhibitory or activating receptors expressed on natural killer cells and some subpopulations of T lymphocytes. KIR genes are clustered in the 19q13.4 region and are characterized by both allelic (high numbers of variants) and haplotypic (different numbers of genes for inhibitory and activating receptors on individual chromosomes) polymorphism. This contributes to diverse susceptibility to diseases and other clinical situations. Associations of KIR genes, as well as of genes for their ligands, with selected diseases such as psoriasis vulgaris and atopic dermatitis, rheumatoid arthritis, recurrent spontaneous abortion, and non-small cell lung cancer are discussed in the context of NK and T cell functions.

Presence of autoantibody against two placental proteins, peroxiredoxin 3 and peroxiredoxin 4, in sera of recurrent pregnancy loss patients

PROBLEM

Recurrent pregnancy loss (RPL) is defined as two or more consecutive abortion before the 20th week of gestation. Autoimmune diseases increase the risk and accounts for at least 20% of RPL. Placenta is a pregnancy unique tissue, and proper formation of placenta is key phenomenal for success of a pregnancy. The aim of this study was to investigate the placental proteins that may act as antibody targets in RPL patients.

METHOD OF STUDY

Total placental proteins were extracted and separated using 2D-PAGE technique. Separated protein spots were transferred on PVDF membrane and blotted with sera from 20 RPL patients and compared with the protein spots that membrane blotted with sera from 20 normal women. Differentially blotted spots were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry mass spectrometry technique. The results of the mass analysis also were confirmed by western blot using mAb and reverse transcriptase polymerase chain reaction technique.

RESULTS

The results indicated that RPL women may produce antibody against Peroxiredoxin 3 (Prx3) and Peroxiredoxin 4 (Prx4).

CONCLUSION

Our results indicate that two placental proteins, Prx3 and Prx4, may act as new placental immune targets. Considering the role of antioxidant defense in the protection of placenta from oxidative stress, production of antibodies against peroxiredoxins 3 and 4 may introduce a new autoimmune hypothesis in RPL, which is needed to be tested in the future works.