Celiac disease, pregnancy, small for gestational age: role of extravillous trophoblast

Dose-, stage- and sex- difference of prenatal prednisone exposure on placental morphological and functional development

Prednisone, a synthetic glucocorticoid, is commonly used to treat autoimmune diseases in pregnant women. However, some studies suggest that the use of prednisone during pregnancy may lead to adverse pregnancy outcomes. In this study, we established PPE mouse models at different doses (0.25, 0.5, 1.0 mg/kg·d) and different stages (whole pregnancy, early pregnancy and middle-late pregnancy) and determined outcomes on the placenta and fetus. The results of our study indicated that at the highest dose of 1 mg/kg PPE using a GD 0-18 dosing regime, PPE caused placental morphological changes measured as a decrease in placental weight relative to controls and a decrease in the placenta junctional zone (JZ)/labyrinth zone (LZ) ratio. No changes were observed on the fetuses for number of live, stillborn, and absorbed fetuses between the experimental groups and the control group. In the placentas at some doses, there were decreases in cell proliferation markers measured at the RNA and protein level by Western blot and increased apoptosis. Measures of gene expression at the mRNA level showed altered nutrients (including glucose, amino acid, and cholesterol) transport gene expressions with the most significant change associated with the male placentas at high-dose and whole pregnancy PPE group. It was further found that PPE led to the inhibition of the insulin-like growth factor 2 (IGF2)/insulin-like growth factor 1 receptor (IGF1R) signaling pathway, which was well correlated with the indicators of cell proliferation, syncytialization and nutrient (glucose and amino acid) transport indices. In conclusion, PPE can alter placental morphology and nutrient transport function, with differences in effect related to dose, stage and gender. Differential gene expressions measured for genes of the IGF2/IGF1R signaling pathway suggested this pathway may be involved in the effects seen with PPE. This study provides a theoretical and experimental basis for enhancing the understanding of the effects of prednisone use on placenta during human pregnancy but does not currently raise concerns for human use as effects were not seen on the fetuses and while the effects on cell proliferation are informative they were inconsistent and the differential effects on female and male placentas unexplained suggesting that further work is required to elucidate if these findings have relevance for human use of PPE during pregnancy.

Navigating the Challenges of Gluten Enteropathy and Infertility: The Role of Celiac-Related Antibodies and Dietary Changes

Celiac disease (CD) is an autoimmune condition that is initiated in genetically susceptible individuals by the exposure of the intestines to gluten, and the early start of symptoms is related to malabsorption. Atypical variants of the illness are often identified in adulthood and are frequently associated with manifestations outside of the intestines, including metabolic osteopathy, anemia, and dermatitis herpetiformis. But also, empirical data suggest a correlation between CD and reproductive abnormalities, including repeated abortions. Infertility and repeated miscarriages frequently manifest in women diagnosed with CD and may serve as the initial clinical indication of a subclinical form. Furthermore, the condition may manifest as amenorrhea, infertility, and the delivery of infants with a low birth weight. Regarding the mechanisms of CD in infertility, along with the anti-tTG action to hinder the invasiveness of trophoblast, these antibodies could damage endometrial angiogenesis, which has been shown in in vitro models with human endometrial cells and in vivo in murine models. Another important aspect is the role of nutrient deficiencies, such as zinc deficiency (connected to impaired hormone production, secondary amenorrhea, and pre-eclampsia) and folic acid, etc. Therefore, our objective was to conduct a comprehensive review of the existing literature pertaining to this specific topic and to elucidate the role of the autoantibodies in its pathogenesis.

Hypoxia and inflammation conditions differentially affect the expression of tissue transglutaminase spliced variants and functional properties of extravillous trophoblast cells

PROBLEM

Persistent hypoxia and inflammation beyond early pregnancy are involved in a bad outcome because of defective trophoblast invasiveness. Tissue transglutaminase (TG2) coregulates several cell functions. An aberrant expression and/or transamidation activity could contribute to placental dysfunction.

METHOD OF STUDY

The first-trimester trophoblast cell line (Swan-71) was used to study TG2 expression and cell functions in the absence or presence of inflammatory cytokines (TNF-α, IL-1β) or chemical hypoxia (CoCl₂ ). We analyzed The concentration of cytokines in the supernatant by ELISA; Cell migration by scratch assay; NF-κB activation by detection of nuclear p65 by immunofluorescence or flow cytometry using a Swan-71 NF-κB-hrGFP reporter cell line. Tissue transglutaminase expression was analyzed by immunoblot and confocal microscopy. Expression of spliced mRNA variants of tissue transglutaminase was analyzed by RT-PCR. Transamidation activity was assessed by flow cytometry using 5-(biotinamido)-pentylamine substrate.

RESULTS

Chemical hypoxia and TGase inhibition, but not inflammatory stimuli, decreased Swan-71 migration. IL-6 production was also decreased by chemical hypoxia, but increased by inflammation. Intracellular TGase activity was increased by all stimuli, but NF-κB activation was observed only in the presence of proinflammatory cytokines. TG2 expression was decreased by CoCl₂ and TNF-α. Translocation of TG2 and p65 to nuclei was observed only with TNF-α, without colocalization. Differential relative expression of spliced variants of mRNA was observed between CoCl₂ and inflammatory stimuli.

CONCLUSION

The observed decrease in total TG2 expression and relative increase in short variants under hypoxia conditions could contribute to impaired trophoblast invasion and impact on pregnancy outcome.

Recurrent Spontaneous Miscarriage: a Comparison of International Guidelines

While roughly 30% of all women experience a spontaneous miscarriage in their lifetime, the incidence of recurrent (habitual) spontaneous miscarriage is 1 – 3% depending on the employed definition. The established risk factors include endocrine, anatomical, infection-related, genetic, haemostasis-related and immunological factors. Diagnosis is made more difficult by the sometimes diverging recommendations of the respective international specialist societies. The present study is therefore intended to provide a comparison of existing international guidelines and recommendations. The guidelines of the ESHRE, ASRM, the DGGG/OEGGG/SGGG and the recommendations of the RCOG were analysed. It was shown that investigation is indicated after 2 clinical pregnancies and the diagnosis should be made using a standardised timetable that includes the most frequent causes of spontaneous miscarriage. The guidelines concur that anatomical malformations, antiphospholipid syndrome and thyroid dysfunction should be excluded. Moreover, the guidelines recommend carrying out pre-conception chromosomal analysis of both partners (or of the aborted material). Other risk factors have not been included in the recommendations by all specialist societies, on the one hand because of a lack of diagnostic criteria (luteal phase insufficiency) and on the other hand because of the different age of the guidelines (chronic endometritis). In addition, various economic and consensus aspects in producing the guidelines influence the individual recommendations. An understanding of the underlying decision-making process should lead in practice to the best individual diagnosis and resulting treatment being offered to each couple.

Celiac Disease and Pregnancy Outcomes in Patients with Gestational Diabetes Mellitus

AIM

Gestational diabetes mellitus (GDM) and celiac disease, if not diagnosed and properly treated, are associated with adverse outcomes of pregnancy. The aim of our study was to examine pregnancies complicated by GDM in celiac and nonceliac women in terms of their metabolic parameters and maternal and fetal outcomes.

METHODS

The study involved 60 women with GDM, 20 with and 40 without celiac disease. Maternal clinical and metabolic parameters (glucose and insulin levels in the oral glucose tolerance test (OGTT), fasting plasma glucose, HbA1c, lipid profile, prepregnancy BMI, gestational weight gain, and chronic diseases), pregnancy outcomes (gestational hypertension, pre-eclampsia, eclampsia, time, and mode of delivery), and fetal parameters (weight and length at birth, and neonatal complications) were recorded.

RESULTS

The two groups did not differ significantly in maternal parameters other than blood glucose levels at 120' in the diagnostic OGTT (141.2 ± 35.2 vs 161.2 ± 35.4, mg/dl, p=0.047), prepartum cLDL (127.2 ± 43.5 vs 179.6 ± 31.7 mg/dl, p ≤ 0.001), and total cholesterol (229.0 ± 45.9 vs 292.5 ± 42.1 mg/dl, p ≤ 0.001), which were significantly lower in celiac women than in nonceliac controls. Children born from celiac women had a significantly higher birth weight (3458.1 ± 409.8 vs 3209.0 ± 432.7 g, p=0.044) and ponderal index (2.89 ± 0.32 vs 2.66 ± 0.25 g/cm3, p=0.006) and were more likely to be large for gestational age (27.8% vs 2.5%, p=0.012). Analyzing the composition of the celiac and nonceliac women's diet showed that, for the same amount of kilocalories, the gluten-free diet was associated with a slight increase in the amount of carbohydrates (49.75% vs 48.54%) and a reduction in the amount of protein (21.10% vs 23.31%) and especially of fiber (9.84% vs 12.71%).

CONCLUSIONS

Celiac women with GDM have much the same pregnancy outcomes as nonceliac women with GDM, except for fetal overgrowth. Gluten-free food, being richer in carbohydrates and less rich in fiber and protein, could have a role in fetal growth in celiac women.

Effect of celiac disease on maternal and neonatal outcomes of pregnancy

PURPOSE

Celiac disease (CD) is a permanent immune reaction to gluten that is likely related to genetic factors. Some studies have linked CD to adverse maternal and/or neonatal outcomes but the data has been contradictory. The purpose of this study was to evaluate the effect of CD on pregnancy outcomes.

MATERIALS AND METHODS

We used data from the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample (NIS) of the USA to conduct a population-based retrospective cohort study of women who delivered between 1999 and 2014. Pregnancies were categorized as having CD if corresponding ICD-9 code was present. Unconditional logistic regression models were used to estimate the adjusted effect on maternal and fetal outcomes.

RESULTS

There were 14,513,587 births during the study period of which 2755 were to women with CD, for an overall prevalence of 1.9 cases/10,000 births and with rates increasing over the study period. Women with CD tended to be older, Caucasian and to have pre-existing comorbidities, especially other autoimmune diseases. Women with CD were at greater risk of hyperemesis gravidarum, 4.52 (3.68-5.57), Clostridium difficile colitis, 7.56 (3.14-18.20), and venous thromboembolic events, 2.93 (2.07-4.15), as well as, hospital stays >3 d, 2.06 (1.75-2.43). Infants of women with CD were more likely to be growth restricted, 1.80 (1.46-2.21) and have congenital malformations, 3.51 (2.68-4.58).

CONCLUSIONS

CD in pregnancy is associated with increased adverse maternal and newborn complications. These pregnancies should be considered high risk and may benefit from increased surveillance.

Reproductive complications in celiac disease patients in Slovenia

OBJECTIVE

Celiac disease is associated with higher risk of infertility, recurrent abortions, and adverse outcomes in pregnancy and in puerperium. The aim of the study was to analyse the association between celiac disease and reproductive disorders in the group of celiac patients and compare these to healthy controls.

METHODS

A retrospective case-control matched study. The association between celiac disease and menstrual cycle, gyneco-obstetrical complications was assessed with a questionnaire specifically developed for the study. 144 celiac women and 61 celiac men, members of Slovenian Celiac Society, together with 71 healthy women and 31 healthy men participated in the study.

RESULTS

A higher percentage of celiac women (27.1%) had difficulties in conception of the first child when compared to healthy controls (12.7%) (p = 0.042). In addition, celiac women experienced more complications than healthy controls during the pregnancy, such as abortions or intrauterine growth retardation (p < 0.005). In our study, the prevalence of reproductive problems was not the same in celiac males and females. Altogether 2 celiac men (3.3%) reported having fertility problems, however, the difference between male cases and controls was not statistically significant (p = 0.548).

CONCLUSION

Physicians should examine women with unexplained infertility, recurrent abortions or intrauterine growth retardation for undiagnosed celiac disease. Compared with healthy women, women with celiac disease have increased risk of spontaneous abortions, preterm delivery and fewer successful pregnancies.

Human leukocyte antigen DQ2/DQ8 positivity in women with history of stillbirth

PROBLEM

The aim of this study was to investigate the prevalence of human leukocyte antigens (HLA) DQ2 and DQ8 haplotypes, two common polymorphisms associate with celiac disease (CD), in women with previous stillbirth, but not affected by CD.

METHOD OF STUDY

Women with history of unexplained term stillbirth referred to our Center for High-Risk Pregnancies for a preconception counseling, and women with previous uncomplicated pregnancies, were enrolled as cases and controls. Celiac women were excluded from the study. Genetic tests for HLA DQ2/DQ8 were performed, and patients' data were compared.

RESULTS

The population included 56 women with a previous term stillbirth and 379 women with history of uncomplicated pregnancies. The prevalence of HLA-DQ2 or DQ8 positivity was significantly higher in cases than in controls (50% vs 29.5%) (P = 0.0031). Women with HLA DQ8 genotype have a significantly higher risk of stillbirth (OR: 2.84 CI: 1.1840-6.817) and in case of DQ2 genotype the OR for stillbirth was even higher (OR: 4.46 CI: 2.408-8.270). In the stillbirth group, SGA neonates were significantly more frequent in those with HLA-DQ2/DQ8 haplotypes than in those resulted negative to genetic testing (85.7% vs 42 .8%, P = 0.004).

CONCLUSION

In women with history of term stillbirth, a significantly higher prevalence of HLA DQ2/DQ8 haplotypes has been found compared to women with previous uneventful pregnancies. In addition, HLA DQ2/DQ8 positivity was significantly associated with suboptimal fetal growth in intrauterine fetal death cases, as shown by an increased prevalence of SGA babies.

The Association Between Serological Markers of Celiac Disease and Idiopathic Recurrent Pregnancy Loss

INTRODUCTION

Antiphospholipid syndrome, uterine anomalies, and chromosomal aberrations are identifiable causes of recurrent pregnancy loss (RPL). Herein, our aim is to investigate the relationship between celiac disease (CD) specific antitransglutaminase antibodies (ATA) and unexplained RPL.

MATERIALS AND METHODS

This was a cross sectional case-control study conducted on 86 women (45 RPL and 41 controls) in a tertiary level maternity hospital. Elisa kit was used to determine ATA IgA and IgG levels.

RESULTS

One (2.2%) patient with ATA IgG positivity was present in the RPL group. There were three (7.3%) cases with positive for ATA IgA in the control group, and one (2.2%) case in the study group. No statistically significant differences were observed between the groups in terms of ATA IgG and IgA.

CONCLUSION

There is no association between CD markers and unexplained RPL. For the present, we do not recommend screening for ATA IgA and ATA IgG in patients with a history of RPL.

Extraintestinal manifestations of celiac disease: 33-mer gliadin binding to glutamate receptor GRINA as a new explanation

We propose a biochemical mechanism for celiac disease and non-celiac gluten sensitivity that may rationalize many of the extradigestive disorders not explained by the current immunogenetic model. Our hypothesis is based on the homology between the 33-mer gliadin peptide and a component of the NMDA glutamate receptor ion channel - the human GRINA protein - using BLASTP software. Based on this homology the 33-mer may act as a natural antagonist interfering with the normal interactions of GRINA and its partners. The theory is supported by numerous independent data from the literature, and provides a mechanistic link with otherwise unrelated disorders, such as cleft lip and palate, thyroid dysfunction, restless legs syndrome, depression, ataxia, hearing loss, fibromyalgia, dermatitis herpetiformis, schizophrenia, toxoplasmosis, anemia, osteopenia, Fabry disease, Barret's adenocarcinoma, neuroblastoma, urinary incontinence, recurrent miscarriage, cardiac anomalies, reduced risk of breast cancer, stiff person syndrome, etc. The hypothesis also anticipates better animal models, and has the potential to open new avenues of research.

The Evaluation of The Effects of Paternal And Maternal Silent Coeliac Disease on Birthweight and Gestational Age in Newborns

OBJECTIVE

Coeliac disease is a chronic disease and is common all over the world. It has many other associated systemic side effects. This study investigated the effect of paternal and maternal silent coeliac disease on birthweight and gestational age in newborns.

METHODS

The study group consisted of 81 newborns who were hospitalized for prematurity or term-intrauterine growth retardation. The parents of premature and/or small for gestational age babies born with coeliac disease-specific antigens were investigated.

RESULTS

The differences were not statistically significant in fathers' tissue transglutaminase levels between premature appropriate gestational age, premature small gestational age and term small gestational age infants (p > 0.05), but statistically significant in mothers (p < 0.05).

CONCLUSIONS

Silent coeliac disease may occur in parents, especially in mothers of preterm and small for gestational age infants, even in the absence of apparent clinical indications.

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.

Celiac disease and reproductive disorders: meta-analysis of epidemiologic associations and potential pathogenic mechanisms

BACKGROUND

An increased risk of reproductive failures in women with celiac disease (CD) has been shown by several studies but a comprehensive evaluation of this risk is lacking. Furthermore, the pathogenic mechanisms responsible for obstetric complications occurring in CD have not been unraveled.

METHODS

To better define the risk of CD in patients with reproductive disorders as well as the risk in known CD patients of developing obstetric complications, we performed an extensive literature search of Medline and Embase databases. Odds ratio (OR) and relative risk (RR) with 95% confidence intervals (95% CI) were used in order to combine data from case-control and cohort studies, respectively. All data were analyzed using Review Manager software. In addition, we summarized and discussed the current hypotheses of pathogenic mechanisms potentially responsible for obstetric complications occurring in CD.

RESULTS

Patients with unexplained infertility, recurrent miscarriage or intrauterine growth restriction (IUGR) were found to have a significantly higher risk of CD than the general population. The OR for CD was 5.06 (95% CI 2.13-11.35) in patients with unexplained infertility, 5.82 (95% CI 2.30-14.74) in women experiencing recurrent miscarriage and 8.73 (95% CI 3.23-23.58) in patients with IUGR. We did not observe an increased risk of CD in women delivering small-for-gestational age or preterm babies. Furthermore, we found that in celiac patients, the risk of miscarriage, IUGR, low birthweight (LBW) and preterm delivery is significantly higher with an RR of 1.39 (95% CI 1.15-1.67), 1.54 (95% CI 1.22-1.95), 1.75 (95% CI 1.23-2.49) and 1.37 (95% CI 1.19-1.57), respectively. In addition, we observed that the risk for IUGR, LBW and preterm delivery was significantly higher in untreated patients than in treated patients. No increased risk of recurrent miscarriage, unexplained stillbirth or pre-eclampsia was found in celiac patients. In vitro studies have provided two main pathogenic models of placental damage at the feto-maternal interface. On the embryonic side of the placenta, a direct binding of anti-transglutaminase (-TG) antibodies to trophoblast cells and, thus, invasiveness reduction via an apoptotic damage, has been proposed. Anti-TG antibodies may also be detrimental to endometrial angiogenesis as shown in vitro in human endometrial endothelial cells (cultures and in vivo in a murine model). The angiogenesis inhibition seems to be the final effect of anti-TG antibody-mediated cytoskeletal damage in endometrial endothelial cells.

CONCLUSIONS

Physicians should investigate women with unexplained infertility, recurrent miscarriage or IUGR for undiagnosed CD. Women with CD show an increased risk of miscarriage, IUGR, LBW and preterm delivery. However, the risk is significantly reduced by a gluten-free diet. These patients should therefore be made aware of the potential negative effects of active CD also in terms of reproductive performances, and of the importance of a strict diet to ameliorate their health condition and reproductive health. Different mechanisms seem to be involved in determining placental tissue damage in CD patients.

Fetal and neonatal outcome in celiac disease

Celiac disease (CD) is characterized by an abnormal immune response in susceptible individuals to dietary gluten derived from wheat, rye and barley. The disease affects not only the small bowel mucosa, but also many other extraintestinal organs resulting bone, liver, neurologic, skin and reproductive system disorders. The details of the pathogenic mechanism are not perfectly clear yet, but it is now proved that both humoral and cellular immune responses are triggered and autoimmune mechanisms are implicated. Studies have shown association of different pregnancy outcomes with maternal celiac disease. In this review, the most frequent fetal and neonatal outcome related to CD are presented, with a special focus on intrautherine growth restriction (IUGR) and prematurity. The need of active case finding of CD is discussed.

Revisiting the risk of celiac disease in children born small for gestational age: a sibling design perspective

OBJECTIVE

An association between small for gestational age (SGA) and risk for celiac disease (CD) in childhood has previously been reported. However, this association may reflect residual confounding by genetic or environmental factors. For example, presence of subclinical CD in the mother might be a common cause of both SGA and CD in the offspring. We investigate whether SGA is causally associated with CD before age six years by applying both conventional population-based regression models and sibling analysis that investigates the association in siblings discordant for SGA.

MATERIAL AND METHODS

Using the Swedish Medical Birth Registry, we identified all singleton children born in Sweden during 1987-1993 (792,401). Of these we included 681,954 children in the study and identified 2641 cases of CD using the Swedish National In-Hospital Registry. We applied both conventional Cox regression analysis and a quasi-experimental sibling design that to some extent simulates a counterfactual situation of exposure, reducing possible confounding effects of genetic and shared environmental factors.

RESULTS

We identified an increased risk of CD in both boys (hazard ratio (HR) 1.70, 95% confidence interval (CI) 1.25-2.32) and girls (HR 1.30, 95% CI 0.99-1.70) using conventional Cox regression models. Using sibling analysis, the association between SGA and CD was confirmed in boys (HR 4.23, 95% CI 1.19-15.04) but not in girls (HR 1.00, 95% CI 0.45-2.20).

CONCLUSIONS

Our results support a causal association between SGA and CD risk in boys but not in girls, although the mechanisms underlying this difference are still unclear.

Usefulness of tissue transglutaminase type 2 antibodies in early pregnancy

Celiac disease (CD), an autoimmune disease triggered by dietary gluten, is a multi-systemic disorder that primarily results in mucosal damage of the small intestine. Reproductive disorders and pregnancy complications have been associated with CD. Conflicting results have been published concerning CD and the risk of impaired fetal growth with reduced birthweight. The aim of our multicentric, perspective, case-control study was to determine the prevalence of undiagnosed CD in mothers of small for gestational age (SGA) newborns in two regions of Italy. The study included 480 mothers: group A consisted of 284 SGA newborns' mothers and group B consisted of 196 appropriate for gestational age (AGA) newborns' mothers. Tissue transglutaminase type 2 antibodies (TG2) IgA and IgG were measured in blood samples. We diagnosed two new cases of CD in asymptomatic mothers. It may be appropriate to include the TG2 to the panel of prenatal blood test.

Reproductive changes associated with celiac disease

Celiac disease is a mucosal disorder of the small intestine that may be triggered by dietary exposure to gluten in genetically-susceptible individuals. The disorder is often associated with diarrhea, malabsorption and weight loss along with other extra-intestinal complications. Reproductive changes have been described, including impaired fertility and adverse pregnancy outcomes possibly related to immune-mediated mechanisms or nutrient deficiency. Other possible pathogenetic factors that may alter placental function include maternal celiac disease autoantibodies binding to placental transglutaminase, and genetic mutations that may facilitate microthrombus formation. Reports noting activation during pregnancy or the puerperium may be important, and suggest that celiac disease may also be hypothetically precipitated by maternal exposure to one or more fetal antigens.

Anti-tissue transglutaminase antibodies from celiac patients are responsible for trophoblast damage via apoptosis in vitro

OBJECTIVES

The association between maternal celiac disease (CD) and both reduced fertility and increased risk of adverse pregnancy-related events has been long documented. However, no evidences are available regarding the pathogenic mechanisms of this link. The aim of this study was to determine whether anti-tissue transglutaminase (anti-tTG) antibodies are involved in the damage of trophoblastic cells in vitro.

METHODS

Human primary trophoblastic cells, isolated from term placenta, were exposed to anti-tTG immunoglobulin G (IgG) antibodies, both commercially available and separated from sera of three untreated celiac women. The ability of anti-tTG antibodies to bind to trophoblastic cells, invasiveness of placental cells through a layer of extracellular matrix, and the activity of cellular matrix metalloprotease (MMP) and cellular apoptosis were evaluated, as indicators of trophoblast damage, by TdT-mediated dUTP digoxigenin nick end labeling (TUNEL) and annexin V expression.

RESULTS

Anti-tTG IgG showed a specific dose- and time-dependent binding to human trophoblast. In addition, trophoblastic cells, after being exposed to anti-tTG IgG antibodies, both commercially available and separated from sera of celiac women, showed an impaired invasiveness, a decreased activity of cellular MMP, and a greater percentage of TUNEL positivity and annexin V positivity.

CONCLUSIONS

We showed that the binding of anti-tTG antibodies to trophoblast might represent a key mechanism by which the embryo implantation and pregnancy outcome are impaired in untreated celiac pregnant women. Because healthy trophoblast development is essential for placental and fetal development, these data provide a novel mechanism for CD-induced infertility, early pregnancy loss, and intrauterine growth retardation.

Coeliac disease and reproductive disorders

Reproductive problems, such as delayed menarche, amenorrhea, early menopause, infertility, impotence, hypogonadism, recurrent abortions, and low-birth-weight or preterm deliveries, are now known to be among the atypical symptoms of coeliac disease (CD). The pathogenesis of reproductive disorders in CD is unclear, but some hypotheses have been suggested, including autoimmunity and macro- and/or micronutrient deficiency. Recent investigations which have focused on tissue transglutaminase are promising with respect to the clarification of the mechanism of infertility and poor pregnancy outcomes in CD. In this review, the effects of CD on male and female reproductive disorders and pregnancy outcomes are discussed and the need for CD screening in the case of reproductive problems is emphasized.

Maternal celiac disease autoantibodies bind directly to syncytiotrophoblast and inhibit placental tissue transglutaminase activity

BACKGROUND

Celiac disease (CD) occurs in as many as 1 in 80 pregnant women and is associated with poor pregnancy outcome, but it is not known if this is an effect on maternal nutrient absorption or, alternatively, if the placenta is an autoimmune target. The major autoantigen, tissue transglutaminase (tTG), has previously been shown to be present in the maternal-facing syncytiotrophoblast plasma membrane of the placenta.

METHODS

ELISA was used to demonstrate the presence of antibodies to tissue transglutaminase in a panel of CD sera. Immunohistochemistry was used to evaluate the binding of IgA autoantibodies from CD serum to term placenta. In addition, novel direct binding and activity assays were developed to mimic the in vivo exposure of the villous placenta to maternal autoantibody.

RESULTS AND DISCUSSION

CD IgA autoantibodies located to the syncytial surface of the placenta significantly more than IgA antibodies in control sera (P < 0.0001). The distribution of antigen was similar to that observed using a monoclonal antibody to tissue transglutaminase. Staining was reduced by pre-absorption of CD serum with recombinant human tissue transglutaminase. In direct binding assays, autoimmune immunoglobulin A (IgA) from the maternal compartment became associated with antigen at the syncytial surface of the placenta, as a result of which transglutaminase activity at this site was inhibited.

CONCLUSION

These data indicate that direct immune effects in untreated CD women may compromise placental function.