Oral dydrogesterone versus micronized vaginal progesterone for luteal phase support: a double-blind crossover study investigating pharmacokinetics and impact on the endometrium

STUDY QUESTION

How do plasma progesterone (P) and dydrogesterone (D) concentrations together with endometrial histology, transcriptomic signatures, and immune cell composition differ when oral dydrogesterone (O-DYD) or micronized vaginal progesterone (MVP) is used for luteal phase support (LPS)?

SUMMARY ANSWER

Although after O-DYD intake, even at steady-state, plasma D and 20αdihydrodydrogesterone (DHD) concentrations spiked in comparison to P concentrations, a similar endometrial signature was observed by histological and transcriptomic analysis of the endometrium.

WHAT IS KNOWN ALREADY

O-DYD for LPS has been proven to be noninferior compared to MVP in two phase III randomized controlled trials. Additionally, a combined individual participant data and aggregate data meta-analysis indicated that a higher pregnancy rate and live birth rate may be obtained in women receiving O-DYD versus MVP for LPS in fresh IVF/ICSI cycles. Little data are available on the pharmacokinetic (PK) profiles of O-DYD versus MVP and their potential molecular differences at the level of the reproductive organs, particularly at the endometrial level.

STUDY DESIGN, SIZE, DURATION

Thirty oocyte donors were planned to undergo two ovarian stimulation (OS) cycles with dual triggering (1.000 IU hCG + 0.2 mg triptorelin), each followed by 1 week of LPS: O-DYD or MVP, in a randomized, cross-over, double-blind, double-dummy fashion. On both the first and eighth days of LPS, serial blood samples upon first dosing were harvested for plasma D, DHD, and P concentration analyses. On Day 8 of LPS, an endometrial biopsy was collected for histologic examination, transcriptomics, and immune cell analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All oocyte donors were <35 years old, had regular menstrual cycles, no intrauterine contraceptive device, anti-Müllerian hormone within normal range and a BMI ≤29 kg/m2. OS was performed on a GnRH antagonist protocol followed by dual triggering (1.000 IU hCG + 0.2 mg triptorelin) as soon as ≥3 follicles of 20 mm were present. Following oocyte retrieval, subjects initiated LPS consisting of MVP 200 mg or O-DYD 10 mg, both three times daily. D, DHD, and P plasma levels were measured using liquid chromatography-tandem mass spectrometry. Histological assessment was carried out using the Noyes criteria. Endometrial RNA-sequencing was performed for individual biopsies and differential gene expression was analyzed. Endometrial single-cell suspensions were created followed by flow cytometry for immune cell typing.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 21 women completed the entire study protocol. Subjects and stimulation characteristics were found to be similar between groups. Following the first dose of O-DYD, the average observed maximal plasma concentrations (Cmax) for D and DHD were 2.9 and 77 ng/ml, respectively. The Cmax for D and DHD was reached after 1.5 and 1.6 h (=Tmax), respectively. On the eighth day of LPS, the first administration of that day gave rise to a Cmax of 3.6 and 88 ng/ml for D and DHD, respectively. For both, the observed Tmax was 1.5 h. Following the first dose of MVP, the Cmax for P was 16 ng/ml with a Tmax of 4.2 h. On the eighth day of LPS, the first administration of that day showed a Cmax for P of 21 ng/ml with a Tmax of 7.3 h. All 42 biopsies showed endometrium in the secretory phase. The mean cycle day was 23.9 (±1.2) in the O-DYD group versus 24.0 (±1.3) in the MVP group. RNA-sequencing did not reveal significantly differentially expressed genes between samples of both study groups. The average Euclidean distance between samples following O-DYD was significantly lower than following MVP (respectively 12.1 versus 18.8, Mann-Whitney P = 6.98e-14). Immune cell profiling showed a decrease of CD3 T-cell, γδ T-cell, and B-cell frequencies after MVP treatment compared to O-DYD, while the frequency of natural killer (NK) cells was significantly increased.

LIMITATIONS, REASONS FOR CAUTION

The main reason for caution is the small sample size, given the basic research nature of the project. The plasma concentrations are best estimates as this was not a formal PK study. Whole tissue bulk RNA-sequencing has been performed not correcting for bias caused by different tissue compositions across biopsies.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study comparing O-DYD/MVP, head-to-head, in a randomized design on a molecular level in IVF/ICSI. Plasma serum concentrations suggest that administration frequency is important, in addition to dose, specifically for O-DYD showing a rapid clearance. The molecular endometrial data are overall comparable and thus support the previously reported noninferior reproductive outcomes for O-DYD as compared to MVP. Further research is needed to explore the smaller intersample distance following O-DYD and the subtle changes detected in endometrial immune cells.

STUDY FUNDING/COMPETING INTEREST(S)

Not related to this work, C.Bl. has received honoraria for lectures, presentations, manuscript writing, educational events, or scientific advice from Abbott, Ferring, Organon, Cooper Surgical, Gedeon-Richter, IBSA, and Merck. H.T. has received honoraria for lectures, presentations, manuscript writing, educational events, or scientific advice from Abbott, Ferring, Cooper Surgical, Gedeon-Richter, Cook, and Goodlife. S.M. has received honoraria for lectures, presentations, educational events, or scientific advice from Abbott, Cooper Surgical, Gedeon-Richter, IBSA, and Merck and Oxolife. G.G. has received honoraria for lectures, presentations, educational events, or scientific advice from Merck, MSD, Organon, Ferring, Theramex, Gedeon-Richter, Abbott, Biosilu, ReprodWissen, Obseva, PregLem, Guerbet, Cooper, Igyxos, and OxoLife. S.V.-S. is listed as inventor on two patents (WO2019115755A1 and WO2022073973A1), which are not related to this work.

TRIAL REGISTRATION NUMBER

EUDRACT 2018-000105-23.

O-054 COVID-19 during pregnancy, maternal immune response and neonatal cell-specific immunity

Pathogens are a major threat to maternal health and the progression of pregnancy. The immune response during normally progressing pregnancies, primarily the suppression of inflammation, likely accounts for this high susceptibility of pregnant women to infections. An increased morbidity and mortality related to influenza, COVID-19 and malaria has been reported for pregnant women, compared to non-pregnant women. Especially influenza infections during pregnancy have been well studied, as humans are severely and recurrently affected by seasonal epidemics and random pandemics. Besides severe maternal symptoms such as acute cardiopulmonary events, pneumonia, and acute respiratory distress syndrome, maternal influenza infection also causes foetal complications, such as intrauterine growth restriction, preterm birth or even foetal death. However, vertical transmission of the influenza virus across the placenta and infection of the foetus has not been observed, suggesting that the pregnancy pathologies are maternally derived.

In addition to influenza-mediated adverse conditions, the recent COVID-19 pandemic has underscored that infection with the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) can also lead to severe illnesses in pregnant women, accompanied by a higher risk for foetal loss or preterm birth. Fortunately, with the ongoing pandemic, large cohort studies and meta-analyses revealed that vertical transmission and related fetal infection is a rare complication affecting only 1-3% of SARS-CoV-2 infections in pregnancy. These low risk for placental infection is likely due to the inefficient SARS-CoV-2 virus replication in placental tissues. Since understanding SARS-CoV-2-related pathogenicity during pregnancy is highly relevant, we initiated a study early in 2020, to which we have recruited more than 160 pregnant women with COVID-19. Our comprehensive placental analyses unearthed a paucity of SARS-CoV-2 viral expression ex vivo in term placentae under acute infection and in convalescent pregnant women. Furthermore, we could show inefficient SARS-CoV-2 replication in placental tissues in vitro, which provides a rationale for the low ex vivo viral expression. We detected specific SARS-CoV-2 T cell responses in mothers within a few days upon infection, which is undetectable in cord blood. Reports by others have shown that maternal SARS-CoV-2 during pregnancy may cause placental insufficiency, defined by increased perivillous fibrin deposition, histiocytic intervillositis and trophoblast necrosis. These changes can cause extensive placental damage leading to placental malperfusion and insufficiency that is incompatible with intrauterine survival. Considering that multiple SARS-CoV-2 variants of concern which emerged until today may affect pregnant women differently and bear a differential risk for pregnancy complication. This, continuous vigilance is needed in order to provide best protection of the highly vulnerable group of pregnant women and their unborn children.

Trial registration number

Psychometric properties of the German version of the pregnancy-related anxiety questionnaire-revised 2 (PRAQ-R2) in the third trimester of pregnancy

Background

Pregnancy-related anxiety (PrA) has been identified as a construct distinct from general stress and anxiety with a negative impact on birth and child outcomes. Validated instruments with good psychometric properties to assess pregnancy-related anxiety in German-speaking expectant mothers are still lacking. The Pregnancy-Related Anxiety Questionnaire revised for its use independent of parity (PRAQ-R2) assesses fear of giving birth (FoGB), worries of bearing a physically or mentally handicapped child (WaHC) and concerns about own appearance (CoA). The aim of this study was to investigate the psychometric properties of the PRAQ-R2 in a German sample of pregnant women in their third pregnancy trimester.

Methods

The PRAQ-R2 and several questionnaires measuring different forms of anxiety as well as depressive symptoms and perceived general self-efficacy were administered cross-sectionally in a sample of nulliparous and parous women (N = 360) in the third trimester of pregnancy.

Results

Reliability was satisfactory to excellent for the PRAQ-R2 total scale (Cronbach’s α = .85) and the subscales (α = .77 to .90). Confirmatory and exploratory factor analysis confirmed the three-factorial structure of the instrument. The three factors together explained 68% of variance. Construct validity was confirmed by positive low- to moderate-sized correlations of the PRAQ-R2 total score and the subscales with measurements of anxiety and depression and by negative low correlations with general self-efficacy.

Conclusions

The German version of the PRAQ-R2 is a valid and feasible measurement for pregnancy-related anxiety for research and clinical practice.

Progesterone-induced blocking factor (PIBF) and trophoblast invasiveness

Controlled trophoblast invasion is a key process during human placentation and a prerequisite for successful pregnancy. Progesterone is one of the factors to regulate trophoblast invasiveness. Progesterone-induced blocking factor (PIBF) is a progesterone-induced molecule expressed by the trophoblast, and also by tumors. The distribution of PIBF within the first-trimester decidua coincides with sites of trophoblast invasion. Another molecule that has been implicated in the control of trophoblast invasiveness is placental leptin. Leptin inhibits the secretion of progesterone by cytotrophoblast. The aim of this work was to investigate the possible interaction of PIBF and leptins in regulating trophoblast invasion. Paraffin-embedded sections from normal first-trimester placentae, partial moles, complete moles, and choriocarcinomas were reacted with PIBF, leptin, and leptin receptor specific antibodies. PIBF-deficient trophoblast cells were generated using siRNA and leptin receptor was detected on Western blot analysis. The lysates of PIBF-treated cells were used for detecting leptin expression in a protein array. PIBF was expressed in both normal first-trimester villous trophoblast and in partial mole. Compared with this, PIBF expression was markedly decreased in complete mole and absent in choriocarcinoma. Neither leptinR nor leptin were detected in partial mole, whereas both of these molecules were present in complete mole and choriocarcinoma. Leptin receptor expression was upregulated in PIBF-deficient cells, while leptin expression was decreased in PIBF-treated cells. These data suggest that PIBF affects the expression of leptin and its receptor, and that PIBF expression is inversely related to trophoblast invasiveness.

Stress increases VCAM-1 expression at the fetomaternal interface in an abortion-prone mouse model

Sound stress exposure increases fetal loss via inflammatory pathways. Inflammation is known to up-regulate cell adhesion molecules, such as vascular cell adhesion molecule-1 (VCAM-1), which mediates the adhesion of leukocytes to the vascular endothelium. In this work, we studied the frequency of VCAM-1(+) vessels at the fetomaternal interface in stressed and non-stressed pregnant CBA/J female mice mated with DBA/2J (high fetal loss model) or BALB/c (low fetal loss model) males. The high fetal loss model had fewer large vessels on gestation day 6.5, and stress reduced the frequency of large vessels to a similar number in both high and low fetal loss models. In the high fetal loss model, however, the frequency of VCAM-1+ vessels was dramatically increased. This study shows that VCAM-1 expression is modulated by stress at the fetomaternal interface in abortion-prone cross-breeding.

Stress-related maternal factors during pregnancy in relation to childhood eczema: results from the LISA Study

BACKGROUND

Stress has been suggested to impact the onset and exacerbation of eczema and other atopic disorders. Whether early exposure to stress-related factors might exert long-term effects remains to be clarified.

OBJECTIVE

The objective of this study was to investigate whether stress-related maternal factors during pregnancy are associated with childhood eczema during the first 6 years of life.

METHODS

Data from 3004 children from a prospective German birth cohort study (LISA) were analyzed. Information from maternity certificates and questionnaire information on unwanted pregnancy were used to evaluate stress-related maternal factors during pregnancy. Prevalence data for physician-diagnosed eczema were available up to the age of 6 years.

RESULTS

Maternal factors during pregnancy were positively associated with childhood eczema in terms of cumulative prevalence up to the age of 2 years (adjusted odds ratio, 1.48; 95% confidence interval, 0.95-2.30) after adjusting for potential confounders. Beyond the second year no increased risk was observed.

CONCLUSIONS

The results of this study suggest that stress-related maternal factors during pregnancy are associated with an increased risk of childhood eczema during the first 2 years of life. The impact of postnatal stress such as parental divorce or separation on this association could not be clarified. Future studies should therefore further elucidate how prenatal and postnatal stress interact and whether prenatal stress might have a programming effect. If future studies confirm the findings of this study, reducing maternal stress during pregnancy might be a possible target in the primary prevention of eczema during childhood.

Human Miscarriage is Associated with Increased Number of CD26+ Decidual Lymphocytes

Dipeptidyl peptidase-IV (DPP-IV, CD26), a serine protease with broad distribution in mammalian tissues and known activity in serum, participates in T-cell activation and promotes a Th1-like cytokine response. Previous data on murine abortion indicate that DPP-IV may play a critical role in pregnancy failure by inducing a Th1 local response. Here, we investigated the possible participation of DPP-IV in the onset of human spontaneous abortion (SA). The systemic (peripheral blood) and local (decidua) percentages of CD4(+), CD8(+), CD26(+) and CD56(+) cells as well as the number of Th1 lymphocytes (CCR5(+) cells) were assessed in samples from women after SAs (n = 20) and from women with normally progressing pregnancies (NPs) (n = 27) using flow cytometry and immunohistochemistry. We further measured the DPP-IV activity and concentrations of Th1 (interferon-gamma and tumour necrosis factor-alpha), Th2 [interleukin-4 (IL-4), IL-10] and Th3 (transforming growth factor-beta2) cytokines in serum samples. We could not find any difference in the number of CD4(+), CD8(+), CD26(+), CD26(+)/CD4(+) or CD8(+)/CD26(+) blood cells between NP and SA patients. No differences in the Th1, Th2 or Th3 cytokine levels could be observed between both groups. However, the percentages of decidual CD26(+) lymphocytes as well as the number of decidual Th1 cells were significantly higher in SA samples compared to samples from patients with NP. Our data support the hypothesis that CD26(+) decidual lymphocytes with DPP-IV activity may play a critical role in SAs, as previously suggested in an abortion mice model. This abortive effect may be mediated by enhancing the levels of Th1 abortogenic cytokines only locally.

Stress et implantation

Spontaneous abortion is the most common adverse pregnancy outcome, and stress has been suggested to be abortogenic in mice and humans. Stress-and/or pregnancy-related hormones (corticotropin releasing hormone, adrenocorticotropin, and progesterone) might interact with peripheral and local immunocompetent cells, such as certain T cell, mast cells or NK cells, and result in changes of cytokine production. In an established murine model, abortions can be triggered by exposing the mice to stress during early gestation. Recent data from this model indicated that increased levels of abortogenic Th1 cytokines, a decrease of progesterone and thus, PIBP were incongruous with successful pregnancy maintenance. Supplementation of progesterone exerts a pregnancy protective effect by induction of a pregnancy-protective Th2 biased immune response. Interestingly, data from a prospective study on human pregnancy revealed that women with a clinically normally progressing pregnancy but low levels of progesterone during the first trimester eventually suffered from a miscarriage. These data indicate that stress may lead to increase abortions by altering the endocrine system, which triggers an immune bias towards an abortogenic cytokine profile. Progesterone may be a good marker to identify a putative thread of a miscarriage in human and progesterone replacement therapy may abrogate this thread by inducing a Th2 biased immune response from the decidua.

Role of stress in functional gastrointestinal disorders. Evidence for stress-induced alterations in gastrointestinal motility and sensitivity

Psychological stress is widely believed to play a major role in functional gastrointestinal (GI) disorders, especially irritable bowel syndrome (IBS), by precipitating exacerbation of symptoms. The available data clearly demonstrate that inhibition of gastric emptying and stimulation of colonic transit is the most consistent pattern in the motility response of the GI tract to acute or short-term stress. Thus, one might propose that these alterations might play a pathophysiological role in dyspeptic symptoms and alterations in stool frequency and consistency in patients with stress-related functional GI disorders. Taken together, the above-mentioned studies suggest that the colonic motor response to stress is exaggerated in IBS. There is evidence that an increased emotional response is associated with this difference in colonic, and perhaps also gastric motor responses to certain stressors. However, almost no valid data are available so far from human studies addressing the question if differences in motility responses to stress between patients with functional GI disorders and healthy subjects are due to an altered stress response associated with an imbalance of the autonomic nervous system or increased stress susceptibility. We can summarize that in experimental animals the most consistent pattern of GI motor alterations induced by various psychological and physical stressors is that of delaying gastric emptying and accelerating colonic transit. Endogenous corticotropin-releasing factor (CRF) in the brain plays a significant role in the central nervous system mediation of stress-induced inhibition of upper GI and stimulation of lower GI motor function through activation of brain CRF receptors. The inhibition of gastric emptying by CRF may be mediated by interaction with the CRF-2 receptor, while CRF-1 receptors are involved in the colonic and anxiogenic responses to stress. Endogenous serotonin, peripherally released in response to stress, seems to be involved in stress- and central CRF-induced stimulation of colonic motility by acting on 5HT-3 receptors. Taken together, the limited data available from investigations in healthy subjects and patients with functional GI disorders provide some evidence that stress affects visceral sensitivity in humans. Acute psychological stress seems to facilitate increased sensitivity to experimental visceral stimuli, if the stressor induces a significant emotional change. In summary, studies in experimental animals suggest that stress-induced visceral hypersensitivity is centrally mediated by endogenous CRF and involvement of structures of the emotional motor system, e.g. the amygdala. Stress-induced activation or sensitization of mucosal mast cells in the GI tract seem to be involved in stress-associated alterations of visceral sensitivity.

Dipeptidyl peptidase IV (DPP IV, CD26) in patients with mental eating disorders

The notion that patients with eating disorders maintain a functional immunosurveillance in spite of severe malnutrition has attracted researchers for years. Dipeptidyl Peptidase IV (DPP IV), a serine protease with broad tissue distribution and known activity in serum, operates in the cascade of immune responses. Membrane-bound DPP IV expressed on lymphocytes, also known as the leukocyte antigen CD26, is considered to participate in T cell activation. We hypothesized that the activity of DPP IV in serum and expression of CD26 in lymphocytes may be altered in patients with eating disorders. Serum DPP IV activity and the number of CD26 (DPP IV)-positive peripheral blood lymphocytes were measured in 44 patients (anorexia nervosa (AN): n = 21, bulimia (B): n = 23) in four consecutive weekly analyses. The analysis of CD26-positive cells included the characterization of CD26-bright and CD26-dim positive subsets. Additionally, the expression of CD25 (IL-2 Receptor alpha chain) was evaluated to estimate the degree of T cell activation. The same analyses were carried out in healthy female volunteers (HC, n = 20). CD26-positive cells were reduced in patients as compared to healthy controls (mean 40.2% (AN) and 41.1% (B) vs. 47.4% (HC), p < 0.01), while the DPP IV activity in serum was elevated (mean 108.4 U/l (AN) and 91.1 U/l (B) vs. 80.3 U/l (HC), p < 0.01). The potential implications of changes in DPP IV expression and serum activity on--and beyond--immune function are discussed.

A guardian angel: the involvement of dipeptidyl peptidase IV in psychoneuroendocrine function, nutrition and immune defence

Dipeptidyl peptidase IV (DPP IV, also known as CD26; EC 3.4.14.5) is a non-integrin receptor glycoprotein with multiple functions, including cell adhesion, cellular trafficking through the extracellular matrix and co-stimulatory potential during T cell activation. By virtue of its exopeptidase activity, DPP IV plays a key regulatory role in the metabolism of peptide hormones. Based on data emerging from different biomedical specialties, it appears worthwhile to highlight the different facets of DPP IV in nutrition, immune responses and peptide hormone metabolism. The presentation of the complex regulatory circuits in which DPP IV appears to be involved may also serve as a note of caution, in view of attempts to apply selective inhibitors of DPP IV enzymic activity for the treatment of disease, e.g. Type II diabetes.

Human first-trimester decidua vascular density: an immunohistochemical study using VE-cadherin and endoglin as endothelial cell markers

PROBLEM

Angiogenesis and vasculogenesis appear to be of critical importance for the success of pregnancy. Recent data have emphasized that pregnancy complications, such as abortion or pre-eclampsia, are linked with vascular pathologies. The aim of this study was to quantify human first-trimester decidua microvascular density, using two novel, highly specific endothelial cell markers, VE-cadherin and endoglin.

METHOD OF STUDY

We collected decidua from women undergoing termination of normal pregnancies. VE-cadherin and endoglin were localized by immunohistochemistry. The blood vessel densities detected by VE-cadherin or endoglin-stainings were microscopically quantified per mm2.

RESULTS

Endothelial cells in first-trimester human decidua both express VE-cadherin and endoglin. The microvascular density detected by VE-cadherin-staining varied from 32.2 +/- 1.7 in decidua basalis, to 30 +/- 0.6 in decidua parietalis. For the endoglin-staining, the values varied from 37.5 +/- 3 in decidua basalis, and 26.7 +/- 1.2 in decidua parietalis.

CONCLUSIONS

Our data shows that both VE-cadherin and endoglin are good candidates to highlight the decidual endothelial cells, and to quantify the blood vessels density of endometrium.

[Validation of the new German translation version of the "Short Inflammatory Bowel Disease Questionnaire" (SIBDQ)]

In the face of a hardly predictable course of illness--potentially effecting a severe diminution of daily activities--the quality of life (QOL) represents a chief outcome measure in the treatment of inflammatory bowel diseases (IBD). For the German-speaking area an economical disease-specific instrument measuring QOL has been missing, so far. Therefore, we translated and adapted the recently validated "Short Inflammatory Bowel Disease Questionnaire" SIBDQ (11). Bowel symptoms, systemic symptoms, moods, and social activities are represented by a total of 10 items. Along with this questionnaire 7 accepted instruments assessing QOL-components were administered to 125 outpatients (54 ulcerative colitis, 71 Crohn's disease) and 51 healthy controls. The psychometric properties are good. Consistency is alpha = .84, thereby slightly surpassing the Anglo-American SIBDQ (alpha = .78). Retest-reliability after 26 weeks is r = .60. Systematic covariations with accepted QOL-instruments give evidence for its convergent and discriminatory validity. Differences between groups (high vs. low inflammatory activity vs. healthy controls) substantiate its sensitivity. Thus, the German adaptation of the accepted SIBDQ supplies an economic, reliable, and valid instrument that proved able to assess clinically relevant differences in QOL in patients with IBD. We suggest that it should be used by its overall score rather than its subscales. The instrument is appropriate to be used in therapy outcome and evaluation studies. It allows international comparison.

Increased blood vessel density in decidua parietalis is associated with spontaneous human first trimester abortion

Spontaneous pregnancy loss affects 15-18% of couples, and a number of potential causes are being discussed. The purpose of the present study was to assess if angiogenic disorders in the decidua of early human pregnancy could be related to spontaneous abortions. First trimester human decidua from elective terminations of normally progressing pregnancies and from missed abortions were investigated immunohistochemically. We quantified vessel density in decidua from normal pregnancies and from abortions by von Willebrand factor (vWF), platelet endothelial cell adhesion molecule (PECAM-1) and CD34 staining. Decidual blood vessel expression of alphavbeta3 integrin was also investigated. Significant increase (P < 0.02) in vessel density was observed in decidua parietalis of abortions, compared to decidua basalis. This increase was detected on slides stained for vWF and CD34, but not for PECAM-1. We observed a 15% increase analysing with vWF and a 77% increase with CD34 staining. alphavbeta3 integrin expression was not significantly different, neither in decidua parietalis from abortion, nor parietalis from normal pregnancies. Our data suggest that the increased vascularization in decidua parietalis from abortions could reflect complex disorders, such as specific cytokine expressions and hypoxia phenomena during the development of the decidua.

Leukocyte populations, hormone receptors and apoptosis in eutopic and ectopic first trimester human pregnancies

The implantation of trophoblast cells at extrauterine sites still results in decidualization. The objective of the present study was to compare decidualization at eutopic and ectopic implantation sites. Tissues from women undergoing elective termination of uterine pregnancy and from women with ectopic pregnancy were used to detect the presence of cells important for the maintenance of pregnancy, such as BCL-2+, CD56+, CD3+, CD8+ and CD68+ cells, and the presence of oestrogen (ER) and progesterone receptors (PR) by immunohistochemistry. In-situ detection of fragmented DNA was performed to identify apoptotic cells. The percentage of CD3+ cells among all immunocompetent cells in the tubal epithelium was 46.6% (39.9% of CD3+ were also CD8+); the other 53.4% were CD68+ cells. CD56+ cells were undetectable in ectopic decidua at the feto-maternal interface in ectopic tissue. In uterine decidua, we found 29.9% CD3+ cells (2.2% of CD3+ were CD8+), 51.6% CD56+ cells and 18.5% CD68+ cells. The ratio of BCL2+ to CD3+ cells in ectopic pregnancy was 0.41. In uterine pregnancy, the ratio of BCL-2 to CD3 was 0.44 and 0.39 for CD56. Tissues from both ectopic and uterine pregnancies were positive for PR. Fewer apoptotic cell bodies were present in ectopic pregnancy. The use of tissue obtained from ectopic pregnancy may become an excellent model to identify the mechanism of trophoblast invasion in eutopic pregnancies.

From the decidual cell internet: trophoblast-recognizing T cells

The mammalian fetus has been perceived, paradoxically, as a successful allograft, a successful tumor, and a successful parasite. Success depends on fetal trophoblast cells, which form the interface with the mother. The maternal immune system is involved in the success of pregnancy and in its failure. The discovery that maternal gammadelta T cells may recognize and react to the fetal trophoblast and the definition of a vascular mechanism whereby their Th1 and Th2/3-type cytokines may abort embryos replaces confusion and debate with a new and simple clarity that enables further research.

Decidual mast cells might be involved in the onset of human first-trimester abortion

PROBLEM

The aim of the present study was to identify the role of mast cells and substance P (SP)-containing nerve fibers in human decidua in normal and pathological pregnancies.

METHOD OF STUDY

We collected decidua from women undergoing termination of normal pregnancies and from abortions. The presence of mast cells and SP was detected by immunohistochemistry.

RESULTS

We observed a sparse distribution of mast cells in the normal pregnancies (36.7 tryptase+ mast cells/mm2 decidua). In the decidua from abortion, we found a dramatic increase in the number of mast cells (448.7 and 469.2 tryptase+ mast cells/mm2 decidua in primary and secondary abortions, respectively). In addition, we observed an increase of SP-positive nerve fibers in the decidua of abortions.

CONCLUSIONS

Our data suggest that decidual mast cells may play an important role in the onset of abortion, due to the production of cytokines, such as tumor necrosis factor-alpha.

Immunosuppressive properties of monoclonal antibodies and human polyclonal alloantibodies to the R80K protein of trophoblast

PROBLEM

The R80K protein on human trophoblast is antigenically polymorphic, and in all placentae of successful pregnancies, the protein is covered by maternal alloantibody. Alloantibody eluted from human placenta has been shown to inhibit killing by human NK cells. Do those antibodies to R80K that inhibit NK killing also affect the murine abortion models?

METHODS

We made three murine monoclonal antibodies to conserved epitopes, on human R80K, all of which also reacted with the homologous murine molecule. One antibody only, BA11, suppressed NK cytotoxicity to K562 and of mouse spleen NK cells to murine trophoblast. All three were tested in mouse models of abortion: the CBA x DBA/2 model with a high resorption rate of F1 embryos compared with the parental strains, an endotoxin induced abortion/resorption model and a third model in which the pregnant mouse is subject to sonic stress.

CONCLUSION

Those IgG antibodies eluted from microvesicles which bound to K562, and one of the three monoclonals, BA11, inhibited NK killing. The antibodies react with the murine molecule, and BA11 inhibited abortion in all three mouse abortion models. This reinforces the thesis that interference with NK killing can influence abortion/resorption in mice, and the BA11 antibody may effect similar results in analogous human situations.