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

Placental Histopathological Lesions and Adverse Neonatal Outcomes in Patients with Inflammatory Bowel Diseases- A retrospective Cohort Study

Inflammatory bowel diseases (IBD) are significantly associated with adverse pregnancy and neonatal outcomes, though the pathomechanism is yet unknown. To investigate the relationship between IBD and adverse pregnancy outcomes by comparing neonatal outcomes and placental histopathology in two matched groups of patients with and without IBD. In this retrospective study, data of all patients who gave birth between 2008-2021 and were diagnosed with IBD were reviewed and compared to a control group matching two control cases for every IBD case. Neonatal outcomes and placental pathology were compared between the groups. Compared to the control group (n=76), the placentas of patients with IBD (n=36) were characterized by significantly lower placental weight (p < 0.001), and higher rates of maternal vascular malperfusion lesions (MVM, p < 0.001) and maternal and fetal inflammatory response lesions (p < 0.001). Neonates of patients with IBD were more frequently small for gestational age (SGA) (p=0.01), with increased rates of need for phototherapy (p = 0.03), respiratory morbidity and NICU admission (p < 0.001 for both outcomes). Multivariate logistic regression analyses adjusting for possible confounders (including maternal age, gestational age, chronic hypertension, smoking, and thrombophilia) confirmed the independent association between IBD and composite MVM lesions (aOR 4.31, p < 0.001), maternal inflammatory responses (aOR 40.22, p < 0.001) and SGA infants (aOR 4.31, p = 0.013). IBD is associated with increased rates of placental histopathological lesions and adverse pregnancy outcomes, including SGA infants. These novel findings imply the role of placental malperfusion and inflammatory processes in pregnancy complications of IBD patients, which should be followed accordingly. Approval of local ethics committee # WOMC-0219-20.

Reproductive functions and pregnancy outcome in female patients with celiac disease

BACKGROUND AND AIM

Abnormalities in the reproductive functions are often ignored while evaluating a patient with celiac disease (CeD). We evaluated the entire reproductive functions in female patients with CeD.

METHODS

In a case control study between 2020 and 2021 using detailed questionnaire, we evaluated reproductive functions (age at menarche, menstrual pattern, fertility, pregnancy outcome and menopause) in biopsy-proven female patients with CeD of age >10 years. The questionnaire was administered either in person or telephonically. Age-matched healthy female controls (twice the number) were also recruited.

RESULTS

Of 1086 CeD patients, 470 were females and 288 were included. As compared with controls (n = 586), females with CeD had higher age at menarche (14.6 ± 2.0 vs 13.6 ± 1.5 years; P = 0.001), delayed menarche (30.8% vs 11.4%; P = 0.001), abnormal menstrual pattern (39.7% vs 25.8%; P < 0.001), involuntary delay in conception at > 1 year (33.8% vs 11.8%; P = 0.01), current infertility rate (10.5% vs 5.2%;P = 0.028), and poorer overall pregnancy outcomes (abortion [23.5% vs 12.8%; P = 0.001], pre-term birth [16.3% vs 3.7%; P = 0.001]).

CONCLUSIONS

Either one or more aspect of reproductive functions and pregnancy outcome is affected adversely in three-fourth female patients with CeD.

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.

Human Leukocyte Antigen (HLA) Typing Study Identifies Maternal DQ2 Susceptibility Alleles among Infertile Women: Potential Associations with Autoimmunity and Micronutrients

BACKGROUND

The interplay between female fertility and autoimmune diseases (AIDs) can involve HLA haplotypes and micronutrients. We analyzed the distribution of HLA-DQ2/-DQ8 in women with infertility or recurrent spontaneous abortion (RSA) and possible associations with AIDs and micronutrient status.

METHODS

Consecutive women (n = 187) with infertility and RSA, and controls (n = 350) were included. All women were genotyped for HLA-DQ2 (DQA1*0201, A1*05, and B1*02) and -DQ8 (DQA1*03 and DQB1*0302) alleles. Serum 25(OH)D, VB12, folate, and ferritin were evaluated.

RESULTS

DQA1*05/B1*02 and the occurrence of at least one DQ2 allele were more prevalent among RSA and infertile women than controls. Infertile women showed lower 25(OH)D and higher prevalence of AIDs than RSA women. In the multivariate analysis, DQA1*05/B1*02 was associated with a significantly higher risk of AIDs in infertile women, and DQA1*05 was independently associated with both 25(OH)D deficiency and AIDs. In RSA women, the presence of AIDs was associated with a significantly higher risk of 25(OH)D deficiency.

CONCLUSION

Our findings showed, for the first time, a higher proportion of DQ2 alleles in infertile and RSA women as compared to controls. Predisposing DQ2 alleles are independent risk factors for AIDs and 25(OH)D deficiency in infertile women and could represent biomarkers for performing early detection of women requiring individually tailored management.

Reproductive Characteristics and Pregnancy Outcomes in Hidden Celiac Disease Autoimmunity

INTRODUCTION

Untreated symptomatic celiac disease (CD) adversely affects female reproduction; however, the effect of hidden CD autoimmunity is uncertain.

METHODS

We identified women who were not previously diagnosed with CD and tested positive for tissue transglutaminase and endomysial antibodies between 2006 and 2011 in a community-based retrospective cohort study. We evaluated (i) the rate of adverse pregnancy outcomes and medical complications of pregnancy in successful singleton deliveries and (ii) reproductive characteristics in seropositive women without a clinical diagnosis of CD and age-matched seronegative women.

RESULTS

Among 17,888 women whose serum samples were tested for CD autoimmunity, 215 seropositive and 415 seronegative women were included. We reviewed 231 and 509 live singleton deliveries of 117 seropositive and 250 seronegative mothers, respectively. Menarche and menopausal age, gravidity, parity, and age at first child were similar in seropositive and seronegative women. CD seropositivity was not associated with an increased risk of maternal pregnancy complications. Maternal seropositivity was associated with small for gestational age in boys (OR 3.77, 95% CI: 1.47-9.71; P = 0.006), but not in girls (OR 0.57, 95% CI: 0.15-2.17; P = 0.41). CD serum positivity was not associated with prematurity, small for gestational age (birth weight <10th percentile), or 5-minute Apgar score of less than 7.

DISCUSSION

Although underpowered, the present study did not show any difference in reproductive characteristics or rates of adverse pregnancy outcomes in women with and without CD autoimmunity, except for birth weight in male offspring. Larger studies are needed to determine the effects of CD autoimmunity on female reproduction.

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.

Celiac disease and reproductive failures: An update on pathogenic mechanisms

Celiac disease (CD) is an autoimmune disorder that occurs in genetically predisposed people in which the ingestion of gluten leads to damage in the small intestine that clinically presents with malabsorption-related symptoms. CD can also be the underlying cause of several non-gastrointestinal symptoms. This review summarizes evidence on the relationship between CD and gynecological/obstetric disorders like reproductive failures. Although much has been reported on such a linkage, the pathogenic mechanisms remain unclear, especially those underlying extra-gastrointestinal clinical manifestations. Studies conducted on celiac subjects presenting gynecological/obstetric disorders have pointed to intestinal malabsorption, coagulation alterations, immune-mediated tissue damage, and endometrial inflammation as the main responsible pathogenic mechanisms. Currently, however, the knowledge of such mechanisms is insufficient, and further studies are needed to gain a more thorough understanding of the matter.

Biochemistry of infertility

Infertility affects approximately 186 million people worldwide and 8-12% of couples of reproductive age. Therefore, a comprehensive diagnostic evaluation of infertility is crucial to achieving improvements in targeted prevention and treatment outcomes. The aim of this review is to explore the biochemistry of infertility in order to properly diagnose and treat infertile couples. Recent studies indicate that routine measurement of biochemical parameters reflecting thyroid dysfunction, immunological disorders, autoimmune mechanisms, insulin resistance and malabsorption of selected micro- and macronutrients are required to assess infertility. Due to the complexity of this approach, algorithmic protocols that integrate these biochemical parameters in a dynamic test environment are necessary to provide a more comprehensive diagnostic assessment and more effective treatment strategy for infertile couples.

Reproductive life in women with celiac disease; a nationwide, population-based matched cohort study

STUDY QUESTION

How does celiac disease (CD) influence women's reproductive life, both prior to and after the diagnosis?

SUMMARY ANSWER

Prior to the diagnosis of CD, an increased risk of adverse pregnancy outcomes was seen, whereas after the diagnosis, no influence on reproductive outcomes was found.

WHAT IS KNOWN ALREADY

CD has been associated with several conditions influencing female reproduction and pregnancy outcomes including spontaneous abortion and stillbirth.

STUDY DESIGN, SIZE, DURATION

A nationwide matched cohort study following 6319 women diagnosed with CD and 63166 comparison women and identifying reproductive events between the ages of 15 and 50 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Through linkage of several Danish national health registers, we identified all women diagnosed with CD between 1977 and 2016. We identified an age- and sex-matched comparison cohort and obtained data on reproductive outcomes for both cohorts. Adjusted stratified Cox and logistic regression models were used to estimate differences in reproductive outcomes between women with and without CD.

MAIN RESULTS AND THE ROLE OF CHANCE

Comparing women with diagnosed CD with the non-CD women, the chance of pregnancy, live birth and risk of stillbirth, molar and ectopic pregnancy, spontaneous abortion and abortion due to foetal disease was the same. However, prior to being diagnosed, CD women had an excess risk of spontaneous abortion equal to 11 extra spontaneous abortions per 1000 pregnancies (adjusted odds ratio (OR) = 1.12, 95% CI: 1.03, 1.22) and 1.62 extra stillbirths per 1000 pregnancies (adjusted OR = 1.57, 95% CI: 1.05, 2.33) compared with the non-CD women. In the period 0-2 years prior to diagnosis fewer pregnancies occurred in the undiagnosed CD group, equal to 25 (95% CI: 20-31) fewer pregnancies per 1000 pregnancies compared to the non-CD group and in addition, fewer undiagnosed CD women initiated ART-treatment in this period, corresponding to 4.8 (95% CI: 0.9, 8.7) fewer per 1000 women compared to non-CD women.

LIMITATIONS, REASONS FOR CAUTION

Validity of the diagnoses in the registers was not confirmed, but reporting to the registers is mandatory for all hospitals in Denmark. Not all spontaneous abortions will come to attention and be registered, whereas live- and stillbirths, ectopic and molar pregnancies and abortion due to foetal disease are unlikely not to be registered. We adjusted for several confounding factors but residual confounding cannot be ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

These findings suggest that undiagnosed CD can affect female reproduction and the focus should be on early detection of CD in risk groups.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Health Research Fund of Central Denmark Region and The Hede Nielsens Foundation, Denmark. The authors report no conflicts of interest in this work.

The effect of celiac disease and gluten-free diet on pubertal development: a two-center study

Objectives We aimed to assess whether age at menarche and pubertal development (Tanner stage) are related to gluten-free diet (GFD) adherence, hormonal status, micro-nutrient levels and body mass index (BMI) in children with celiac disease (CD). Methods In this two-center, cross-sectional study, CD patients and healthy individuals were studied. CD patients were re-evaluated after 1 year of follow-up. Height, weight, Tanner stage, age at menarche and diet compliance were recorded. Blood samples for anti-tissue transglutaminase IgA (TTG), pituitary gonadotropins, gonadal hormones, prolactin and micronutrients (folate, vitamin B12, vitamin D, ferritin, iron and, iron-binding capacity [IBC]) were assayed. Results Consecutive age- and sex-matched 228 celiac patients (12.92 ± 2.35 years; 67.9% female) and 135 non-celiac healthy individuals (12.77 ± 2.25 years; 65.2% female) were studied. Tanner stage was significantly higher in the control group for both girls and boys (p < 0.05). The mean age at menarche was significantly lower in healthy individuals (13.13 ± 1.01 vs. 12.15 ± 0.97, p < 0.001). By multivariate analysis, GFD adherence, transferrin saturation (sTrf), total IBC (TIBC) and vitamin D status were found to be positively correlated with Tanner stage (p < 0.05). After 1 year, 192 of the CD patients were re-evaluated. GFD compliance was better (TTG levels: 135.59 ± 73.88 vs. 71.53 ± 69.40, p < 0.001) and it was correlated with Tanner stage (r = 0.49, p < 0.01), sTrf (r = 0.66, p < 0.01) and IBC (r = 0.23, p < 0.05). Conclusions Our data show that adequate weight gain, adherence to GFD, sufficient iron and vitamin D status are essential factors for salubrious puberty in CD patients.

The pathogenic role of autoantibodies in recurrent pregnancy loss

In the present manuscript, we review the recent research investigating the pathogenic association between most studied autoantibodies and recurrent pregnancy loss. Pregnancy loss represents a common obstetric complication occurring in about 15%-25% of all clinically recognized pregnancies. The recurrence of pregnancy loss identifies a distinct clinical entity, that is recurrent pregnancy loss (RPL), affecting about 2%-4% of couples. Several factors, including age, chromosomal abnormalities, uterine anomalies, thrombophilic disorders, endocrinopathies, hormonal and metabolic disorders, infections, sperm quality, and lifestyle issues, are involved in RPL. The role of autoantibodies in RPL is only partially determined. In some cases (antiphospholipid antibodies [aPL]), their involvement is well established. In other cases (anti-thyroid autoantibodies, antinuclear, anti-transglutaminase, and anti-endomysial antibodies), it is still debated, despite multiple, although not fully conclusive, evidences strongly suggest a possible involvement in RPL. Further extensive research is needed to definitively confirm or exclude their actual role.

Magnetic Resonance Imaging Reveals Distinct Roles for Tissue Transglutaminase and Factor XIII in Maternal Angiogenesis During Early Mouse Pregnancy

OBJECTIVE

The early embryo implantation is characterized by enhanced uterine vascular permeability at the site of blastocyst attachment, followed by extracellular-matrix remodeling and angiogenesis. Two TG (transglutaminase) isoenzymes, TG2 (tissue TG) and FXIII (factor XIII), catalyze covalent cross-linking of the extracellular-matrix. However, their specific role during embryo implantation is not fully understood. Approach and Results: For mapping the distribution as well as the enzymatic activities of TG2 and FXIII towards blood-borne and resident extracellular-matrix substrates, we synthetized selective and specific low molecular weight substrate analogs for each of the isoenzymes. The implantation sites were challenged by genetically modifying the trophoblast cells in the outer layer of blastocysts, to either overexpress or deplete TG2 or FXIII, and the angiogenic response was studied by dynamic contrast-enhanced-magnetic resonance imaging. Dynamic contrast-enhanced-magnetic resonance imaging revealed a decrease in the permeability of decidual vasculature surrounding embryos in which FXIII were overexpressed in trophoblast cell. Reduction in decidual blood volume fraction was demonstrated when either FXIII or TG2 were overexpressed in embryonic trophoblast cell and was elevated when trophoblast cell was depleted of FXIII. These results were corroborated by histological analysis.

CONCLUSIONS

In this study, we report on the isoenzyme-specific roles of TG2 and FXIII during the early days of mouse pregnancy and further reveal their involvement in decidual angiogenesis. Our results reveal an important magnetic resonance imaging-detectable function of embryo-derived TG2 and FXIII on regulating maternal angiogenesis during embryo implantation in mice.Visual Overview: An online visual overview is available for this article.

Coeliac disease and obstetric and gynaecological disorders: where are we now?

Coeliac disease (CD) is a chronic gluten-dependent enteropathy very common in the general population and characterized by an extremely heterogeneous clinical picture. Although its prevalence is growing worldwide, case-finding strategy remains the mainstay to diagnosis. Thus, correct identification of high-risk categories of patients who need to be tested for CD is an essential part of medical knowledge to a large number of specialists and primary care providers. In this regard, although CD might have a serious effect on women's reproductive health, a widespread consensus is lacking on which categories of obstetric and gynaecological disorders should be tested for CD. The aim of this review is to critically summarize the current literature relevant to CD and obstetric and gynaecological disorders and to provide practical proposals that may be helpful to clinicians involved in the management of these patients.

Endocrine complications of celiac disease: a case report and review of the literature

PURPOSE

The purpose of this article is to review recent literature regarding endocrine disorders related to celiac disease (CD).

METHODS

We describe a case report and review existing literature on the endocrine manifestations of CD.

RESULTS

CD is an autoimmune disorder characterized by intestinal inflammation in response to gluten. CD can cause a wide range of extra-intestinal complications, including endocrine manifestations. Metabolic bone disease including osteoporosis and osteopenia, vitamin D deficiency, secondary hyperparathyroidism and less frequently osteomalacia can be seen. In CD, fracture risk is increased by 30-40%, while risk for hip fracture is approximately doubled. The risk for other endocrine disorders, particularly autoimmune endocrinopathies, is also increased in those with CD compared to the general population. Epidemiologic data indicate the risk for hypothyroidism is 3-4 times higher among those with CD, while risk of type 1 diabetes is greater than double. Risk for primary adrenal insufficiency is a striking 11-fold higher in those with versus without CD, though the absolute risk is low. Fertility is reduced in women with CD before diagnosis by 37% while male fertility in the absence of hypogonadism does not appear to be affected. Other endocrine conditions including hyperthyroidism, ovarian failure, androgen insensitivity, impaired growth and growth hormone deficiency and autoimmune polyendocrine syndromes have also been associated with CD.

CONCLUSIONS

CD is associated with a wide range of endocrine manifestations.

Unrecognised coeliac disease among men and women undergoing fertility treatment: A screening study

BACKGROUND

Coeliac disease is an autoimmune disease triggered by dietary gluten and has been associated with several conditions influencing female and male reproduction. Due to unspecific symptoms, coeliac disease can be unrecognised for years.

OBJECTIVE

To estimate the prevalence of unrecognised coeliac disease among couples referred to fertility treatment.

METHODS

Cross-sectional screening for coeliac disease in men and women referred to fertility treatment using IgA tissue transglutaminase antibodies as a marker of coeliac disease and small-bowel biopsies to confirm the diagnosis. Participants answered a questionnaire on gluten intake, gastrointestinal symptoms and reproductive history.

RESULTS

A total of 893 participants (51% women) were screened and eight were coeliac disease antibody positive. Small-bowel biopsies were obtained from seven antibody positive participants and unrecognised coeliac disease was confirmed in one woman and three men, corresponding to a prevalence of 0.45% (95% confidence interval 0.12-1.14). The total prevalence, combining already diagnosed and unrecognised CD cases, was 0.63% (95% confidence interval 0.29-1.12).

CONCLUSION

The prevalence of unrecognised coeliac disease in a group of infertile patients was equivalent to that of the Danish general population and low compared with that observed in the majority of other screening studies of infertile patients. Surprisingly, it should be noted that more men than women had coeliac disease. This result does not support a need for routine screening among infertile patients.

Celiac Disease: A Review of Current Concepts in Pathogenesis, Prevention, and Novel Therapies

Our understanding of celiac disease and how it develops has evolved significantly over the last half century. Although traditionally viewed as a pediatric illness characterized by malabsorption, it is now better seen as an immune illness with systemic manifestations affecting all ages. Population studies reveal this global disease is common and, in many countries, increasing in prevalence. These studies underscore the importance of specific HLA susceptibility genes and gluten consumption in disease development and suggest that other genetic and environmental factors could also play a role. The emerging data on viral and bacterial microbe-host interactions and their alterations in celiac disease provides a plausible mechanism linking environmental risk and disease development. Although the inflammatory lesion of celiac disease is complex, the strong HLA association highlights a central role for pathogenic T cells responding to select gluten peptides that have now been defined for the most common genetic form of celiac disease. What remains less understood is how loss of tolerance to gluten occurs. New insights into celiac disease are now providing opportunities to intervene in its development, course, diagnosis, and treatment.

Retrospective evaluation of pregnant women with celiac disease

Objective:

To show celiac disease (CD) and its poor pregnancy outcome relationship, and to demonstrate the importance of a gluten-free diet together with low-dose low-molecular-weight heparin (LMWH) and low-dose corticosteroid (LDC) in the management of pregnancies with CD.

Material and Methods:

This study consisted of 2 groups of patients. Six patients with CD (control group) on a gluten-free diet were monitored during their first pregnancies within the framework of antenatal care program and their pregnancy outcomes were compared with eight poorly-treated pregnant patients with CD (study group) who were referred from other medical institutions. LMWH (enoxaparine 1x2000 Anti-XA IU/0.2 mL/day), and LDC (methylprednisolone 1x4 mg p.o/day) were used in the control group. Their obstetric histories and outcomes of their last pregnancies were compared. The patients’ obstetric risk levels were evaluated using the “Beksac Obstetrics Index” (BOI).

Results:

There were miscarriages in 50% of the study group. There were also 50% and 75% preterm deliveries in the control and study groups, respectively. The BOI of the study group was significantly worse than the control group (1.31 vs. 0.31±0.21, p<0.01). There were no statistically significant differences between age (24±4.7 vs 31.7±6 years, p=0.448), gestational day of birth (259.3±8.5 vs 246.6±24.3), birthweight (2691±698 vs 2262±359 g, p=0.394), and cesarean section rates (p=0.118).

Conclusion:

CD is a risk factor for adverse pregnancy outcome. Miscarriage and preterm labor are critical complications in pregnancies complicated by CD. A gluten-free diet is important in the treatment. LMWH and LDC seem to be helpful in the management of pregnant women with CD.

Recent Advances in Celiac Disease

Recent diagnostic advances have demonstrated that celiac disease is relatively common although most patients have less florid symptoms than previously recognised. The mucosal lesion of this autoimmune disorder depends on both adaptive and innate immune responses. The characteristic antibodies to tissue transglutaminase-2 (tTG-2) and deamidated gliadin peptides may be produced in persons possessing the relevant HLA-DQ genotypes if intact gliadin peptides can penetrate the epithelial barrier to reach antigen presenting cells. Progression from celiac autoimmunity to overt disease may depend on innate immune mechanisms, not HLA-restricted, where IL-15 is generated within the epithelial compartment. A specific innate immune response previously thought restricted to invertebrates, the encapsulation reaction, may contribute to mucosal volume expansion through recruitment of syndecan-expressing leukocytes and stimulated matrix production. It is notable that tissue transglutaminase is critical in this reaction in insects, and that the very few insects that can predate wheat, possess specific salivary or intestinal enzymes that degrade gluten. Animal models in HLA-DQ transgenic mice suggest that the microbial flora of the intestine may play a role in host responses and modulate the evolution of the disease. This suggests that therapeutic modulation of the microbiome may contribute to management of celiac disease. In developing world countries, there is a potential difficulty in histological diagnosis because of the widespread incidence of environmental enteropathy amongst apparently healthy children. Thus, recognition of local patterns of enteropathy will be important for histopathologists, and high titre tTG-2 autoantibody titres may hold considerable diagnostic significance.

Epitope-dependent Functional Effects of Celiac Disease Autoantibodies on Transglutaminase 2

Transglutaminase 2 (TG2) is a Ca²⁺-dependent cross-linking enzyme involved in the pathogenesis of CD. We have previously characterized a panel of anti-TG2 mAbs generated from gut plasma cells of celiac patients and identified four epitopes (epitopes 1-4) located in the N-terminal part of TG2. Binding of the mAbs induced allosteric changes in TG2. Thus, we aimed to determine whether these mAbs could influence enzymatic activity through modulation of TG2 susceptibility to oxidative inactivation and Ca²⁺ affinity. All tested epitope 1 mAbs, as well as 679-14-D04, which recognizes a previously uncharacterized epitope, prevented oxidative inactivation and increased Ca²⁺ sensitivity of TG2. We have identified crucial residues for binding of 679-14-D04 located within a Ca²⁺ binding site. Epitope 1 mAbs and 679-14-D04, although recognizing separate epitopes, behaved similarly when assessing their effect on TG2 conformation, suggesting that the shared effects on TG2 function can be explained by induction of the same conformational changes. None of the mAbs targeting other epitopes showed these effects, but epitope 2 mAbs reduced the rate of TG2-catalyzed reactions. Collectively, these effects could be relevant to the pathogenesis of CD. In A20 B cells transduced with TG2-specific B-cell receptor, epitope 2-expressing cells had poorer uptake of TG2-gluten complexes and were less efficient in gluten epitope presentation to T cells than cells expressing an epitope 1 receptor. Thus, the ability of epitope 1-targeting B cells to keep TG2 active and protected from oxidation might explain why generation of epitope 1-targeting plasma cells seems to be favored in celiac patients.

Celiac Disease in Women With Infertility: A Meta-Analysis

BACKGROUND

Celiac disease (CeD) is a systemic disease with manifestations not limited to small intestine. The data on association between CeD and infertility is contradictory. There are no recommendations for the screening of female patients with infertility for CeD.

AIM

We conducted a meta-analysis to find out whether women with infertility are at higher risk of CeD.

METHODS

Literature search was performed using the MeSH keywords "CeD," "gluten," and "infertility." Diagnosis of CeD was based on positive serology and biopsies showing villous atrophy. Data were extracted about CeD patients in 3 groups-women with infertility (including unexplained infertility), unexplained infertility, and controls. Pooled odds ratio (OR) and prevalence, with 95% confidence intervals (CI), were calculated.

RESULTS

Of 105 relevant studies, 5 studies were included for calculation of pooled OR. Four additional studies, where data on controls were not available, were also considered for calculation of pooled prevalence of CeD. Women with infertility had 3.5 times higher odds of having CeD in comparison with control population (OR=3.5; 95% CI, 1.3-9; P<0.01). Similarly, women with "unexplained infertility" had 6 times higher odds of having CeD than controls (OR=6; 95% CI, 2.4-14.6). Of 884 women with infertility, 20 had CeD indicating a pooled prevalence of 2.3% (95% CI, 1.4-3.5). Of 623 women with "unexplained infertility," 20 had CeD. The pooled prevalence of CeD in women with unexplained infertility was 3.2 (95% CI, 2-4.9).

CONCLUSIONS

CeD is more prevalent in women with "all-cause" infertility and "unexplained" infertility than that in general population.

Infertility and ovarian failure in celiac disease

Unexplained infertility in females may be a devastating event for the reproductive-aged female. However, infertility may be due to ovarian failure associated with celiac disease, an immune-mediated disorder that may have few or no symptoms and can be successfully treated. In some prospective serologically-based studies, over 4% of infertile females may prove to have celiac disease. Serological screening for celiac disease is relatively inexpensive and involves testing for antibodies to tissue transglutaminase. If positive, a small intestinal biopsy should be done to confirm the diagnosis. The initial treatment for this disorder is a gluten-free diet. To date, a number of reports have indicated that this treatment for celiac disease may result in successful pregnancy, in spite of prolonged periods of infertility. Celiac disease, when untreated, may also lead to several adverse events following pregnancy including increased risk of recurrent abortions, low birthweight and impaired fetal growth. Recent molecular and pathological studies from different laboratories suggest that altered placental function may be due to binding to cells in the trophoblast by tissue transglutaminase antibodies impairing embryo implantation and leading to failure of early pregnancy or retarded intrauterine growth.

Human IgG Antinuclear Antibodies Induce Pregnancy Loss in Mice by Increasing Immune Complex Deposition in Placental Tissue: In Vivo Study

PROBLEM

A threefold higher prevalence of antinuclear antibodies (ANA) has been reported in patients with recurrent pregnancy loss (RPL). Nevertheless, the role of ANA in reproductive failure is still unclear. The aim of this study was to investigate the role of ANA during early pregnancy in vivo.

METHOD OF STUDY

We used pregnant mice treated with immunoglobulin G (IgG) obtained from normal healthy subjects (NHS); ANA(+) sera of patients with RPL; and ANA(+) sera from women with uncomplicated pregnancies (HW). Placental immunohistochemical/immunofluorescence staining was performed to detect complement and immune complex deposition. ELISA was performed to evaluate complement levels.

RESULTS

ANA(+) IgG from RPL women significantly increased embryo resorption rate, reduced C3, and increased C3a serum levels compared to NHS IgG or ANA(+) -HW IgG. Increased C3 deposition and increased immune complex staining in placental tissues from mice treated with ANA(+) -RPL IgG fraction compared to NHS- and ANA(+) -HW-IgG-treated mice were found.

CONCLUSION

ANA(+) IgG injection in mice is able to induce fetal resorption and complement activation. The presence on placental tissues of immune complexes and complement fragments suggests the complement activation as a possible mechanism of placental damage.

Mucosal healing in patients with celiac disease and outcomes of pregnancy: a nationwide population-based study

BACKGROUND & AIMS

Studies have associated undiagnosed celiac disease with adverse outcomes of pregnancy. We investigated the association between persistent villous atrophy and outcomes of pregnancy in women with celiac disease.

METHODS

We collected data on 337 women with celiac disease who gave birth (to 460 infants) within 5 years of a follow-up biopsy, from 28 pathology departments in Sweden. We compared birth outcomes from women whose follow-up biopsy showed persistent villous atrophy (Marsh score, 3; n = 142; 31% of study population) with those of women with mucosal recovery (n = 318; 69%). We used multivariable logistic regression (adjusted for maternal age, parity, country of birth, smoking, infant sex, and calendar year of birth) to evaluate the association between persistent villous atrophy and pregnancy outcomes.

RESULTS

Intrauterine growth restriction occurred during 3.5% of pregnancies in women with persistent villous atrophy vs 3.8% of those with mucosal healing (adjusted odds ratio [OR], 0.61; 95% confidence interval [CI], 0.19-1.99). There was no significant association between persistent villous atrophy and low birth weight (OR, 0.98; 95% CI, 0.41-2.39), preterm birth (OR, 1.66; 95% CI, 0.72-3.83), or cesarean section (OR, 0.86; 95% CI, 0.51-1.46).

CONCLUSIONS

Although undiagnosed celiac disease has been associated with adverse outcomes of pregnancy, we found no evidence from a nationwide population-based study that persistent villous atrophy, based on analysis of follow-up biopsies, increases risk compared with mucosal healing.

Activity-regulating structural changes and autoantibody epitopes in transglutaminase 2 assessed by hydrogen/deuterium exchange

The multifunctional enzyme transglutaminase 2 (TG2) is the target of autoantibodies in the gluten-sensitive enteropathy celiac disease. In addition, the enzyme is responsible for deamidation of gluten peptides, which are subsequently targeted by T cells. To understand the regulation of TG2 activity and the enzyme's role as an autoantigen in celiac disease, we have addressed structural properties of TG2 in solution by using hydrogen/deuterium exchange monitored by mass spectrometry. We demonstrate that Ca(2+) binding, which is necessary for TG2 activity, induces structural changes in the catalytic core domain of the enzyme. Cysteine oxidation was found to abolish these changes, suggesting a mechanism whereby disulfide bond formation inactivates the enzyme. Further, by using TG2-specific human monoclonal antibodies generated from intestinal plasma cells of celiac disease patients, we observed that binding of TG2 by autoantibodies can induce structural changes that could be relevant for the pathogenesis. Detailed mapping of two of the main epitopes targeted by celiac disease autoantibodies revealed that they are located adjacent to each other in the N-terminal part of the TG2 molecule.

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.

Transglutaminase 2-dependent deamidation of glyceraldehyde-3-phosphate dehydrogenase promotes trophoblastic cell fusion

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a multifunctional protein as well as a classic glycolytic enzyme, and its pleiotropic functions are achieved by various post-translational modifications and the resulting translocations to intracellular compartments. In the present study, GAPDH in the plasma membrane of BeWo choriocarcinoma cells displayed a striking acidic shift in two-dimensional electrophoresis after cell-cell fusion induction by forskolin. This post-translational modification was deamidation of multiple glutaminyl residues, as determined by molecular mass measurement and tandem mass spectrometry of acidic GAPDH isoforms. Transglutaminase (TG) inhibitors prevented this acidic shift and reduced cell fusion. Knockdown of the TG2 gene by short hairpin RNA reproduced these effects of TG inhibitors. Various GAPDH mutants with replacement of different numbers (one to seven) of Gln by Glu were expressed in BeWo cells. These deamidated mutants reversed the suppressive effect of wild-type GAPDH overexpression on cell fusion. Interestingly, the mutants accumulated in the plasma membrane, and this accumulation was increased according to the number of Gln/Glu substitutions. Considering that GAPDH binds F-actin via an electrostatic interaction and that the cytoskeleton is rearranged in trophoblastic cell fusion, TG2-dependent GAPDH deamidation was suggested to participate in actin cytoskeletal remodeling.

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.

Levels of antibodies against tissue transglutaminase during pregnancy are associated with reduced fetal weight and birth weight

BACKGROUND & AIMS

Celiac disease in pregnant women has been associated with poor growth of the fetus, but little is known about how the level of celiac disease affects fetal growth or birth outcomes. We assessed the associations between levels of antibodies against tissue transglutaminase (anti-tTG, a marker of celiac disease) and fetal growth and birth outcomes for pregnant women.

METHODS

We performed a population-based prospective birth cohort study of 7046 pregnant women. Serum samples were collected during the second trimester of pregnancy and analyzed for levels of anti-tTG. Based on these levels, the women were categorized into 3 groups: negative anti-tTG (≤0.79 U/mL; n = 6702), intermediate anti-tTG (0.8 to ≤6 U/mL; n = 308), or positive anti-tTG (>6 U/mL; n = 36). Data on fetal growth and birth outcomes were collected from ultrasound measurements and medical records.

RESULTS

Fetuses of women in the positive anti-tTG group weighed 16 g less than those of women in the negative anti-tTG group (95% confidence interval [CI], -32 to -1 g) during the second trimester and weighed 74 g less (95% CI, -140 to -8 g) during the third trimester. Newborns of women in the intermediate and positive anti-tTG groups weighed 53 g (95% CI, -106 to -1 g) and 159 g (95% CI, -316 to -1 g) less at birth, respectively, than those of women in the negative anti-tTG group. The reduction in birth weight in offspring of mothers in the intermediate anti-tTG group was 2-fold greater among mothers who carried HLA-DQ2 or -DQ8 than among those without HLA-DQ2 or -DQ8.

CONCLUSIONS

Levels of anti-tTG in pregnant women are inversely associated with fetal growth. Growth was reduced to the greatest extent in fetuses of women with the highest levels of anti-tTG (>6 U/mL). Birth weight was also reduced in women with intermediate levels of anti-tTG (0.8 to ≤6 U/mL) and further reduced in those carrying HLA-DQ2 and -DQ8.

The adaptive immune response in celiac disease

Compared to other human leukocyte antigen (HLA)-associated diseases such as type 1 diabetes, multiple sclerosis, and rheumatoid arthritis, fundamental aspects of the pathogenesis in celiac disease are relatively well understood. This is mostly because the causative antigen in celiac disease-cereal gluten proteins-is known and the culprit HLA molecules are well defined. This has facilitated the dissection of the disease-relevant CD4+ T cells interacting with the disease-associated HLA molecules. In addition, celiac disease has distinct antibody responses to gluten and the autoantigen transglutaminase 2, which give strong handles to understand all sides of the adaptive immune response leading to disease. Here we review recent developments in the understanding of the role of T cells, B cells, and antigen-presenting cells in the pathogenic immune response of this instructive disorder.

Coeliac disease and pregnancy outcomes

Coeliac disease is a gluten-sensitive enteropathy affecting up to 1% of the population. An accumulating body of evidence supports the association of coeliac disease with adverse pregnancy outcomes, including increased risk of miscarriage and intrauterine growth restriction. Reports differ regarding the extent and severity of these associations, in addition to the exact pathophysiology underlying these associations. Overall, coeliac disease is believed to be a significant condition in pregnancy and reproductive medicine with some advocating the screening of coeliac disease in all pregnant women or some specific high-risk groups.

Antibodies in celiac disease: implications beyond diagnostics

Celiac disease is a multisystemic dietary, gluten-induced autoimmune disorder characterized by the presence of transglutaminase (TG) 2 serum autoantibodies. Distinct autoantibodies targeting members of the TG family (TG2, TG3 and TG6) are found deposited in small-bowel mucosa and in extraintestinal tissues affected by the disease. Serum autoantibodies against other self-antigens also emerge in untreated celiac disease patients. Although villous atrophy and crypt hyperplasia in small-bowel biopsy samples are still the gold standards in diagnostics, celiac disease-specific antibodies are widely used as diagnostic aids. Gluten-induced small-bowel mucosal T-cell response is the cornerstone in the pathogenesis of the disorder, but humoral immunity may also play a central role. This review article is focused on the autoantibodies that occur in the context of celiac disease. The article summarizes the diagnostic utility of different celiac-related antibodies and discusses their roles in the pathogenesis of the disease.

Celiac disease: an underappreciated issue in women&#x2019;s health

Celiac disease (CD) is an immune-mediated enteropathy that is secondary to gluten ingestion and classically associated with gastrointestinal symptoms. Diagnosis is based on serology and confirmatory duodenal biopsy, and the only treatment is lifelong avoidance of gluten. CD has been increasingly recognized to encompass a wide variety of manifestations that are relevant to women&#x2019;s health, including infertility, adverse pregnancy outcomes and reduced BMD. Currently, CD is underdiagnosed, largely owing to lack of recognition of the diverse manifestations by general practitioners. Increased awareness of the clinical spectrum of this disease, as well as targeted testing in at-risk individuals (including women with unexplained infertility and previous adverse pregnancy outcomes, and in specific populations with reduced BMD) is greatly needed in order to improve rates of diagnosis.