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

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.

Anti-tissue transglutaminase antibodies (TG2A) positivity and the risk of vitamin D deficiency among children - a cross-sectional study in the generation R cohort

BACKGROUND

Suboptimal vitamin D status is common in people with celiac disease (CeD), a disease that can be characterized by the presence of serum anti-tissue transglutaminase antibodies (TG2A) (i.e., TG2A positivity). To date, it remains unclear whether childhood TG2A positivity is associated with vitamin D status and how this potential association can be explained by other factors than malabsorption only, since vitamin D is mainly derived from exposure to sunlight. The aim of our study was therefore to assess whether childhood TG2A positivity is associated with vitamin D concentrations, and if so, to what extent this association can be explained by sociodemographic and lifestyle factors.

METHODS

This cross-sectional study was embedded in the Generation R Study, a population-based prospective cohort. We measured serum anti-tissue transglutaminase antibodies (TG2A) concentrations and serum 25-hydroxyvitamin D (25(OH)D) concentrations of 3994 children (median age of 5.9 years). Children with serum TG2A concentrations ≥ 7 U/mL were considered TG2A positive. To examine associations between TG2A positivity and 25(OH)D concentrations, we performed multivariable linear regression, adjusted for sociodemographic and lifestyle factors.

RESULTS

Vitamin D deficiency (serum 25(OH)D < 50 nmol/L) was found in 17 out of 54 TG2A positive children (31.5%), as compared to 1182 out of 3940 TG2A negative children (30.0%). Furthermore, TG2A positivity was not associated with 25(OH)D concentrations (β -2.20; 95% CI -9.72;5.33 for TG2A positive vs. TG2A negative children), and this did not change after adjustment for confounders (β -1.73, 95% CI -8.31;4.85).

CONCLUSIONS

Our findings suggest there is no association between TG2A positivity and suboptimal vitamin D status in the general pediatric population. However, the overall prevalence of vitamin D deficiency in both populations was high, suggesting that screening for vitamin D deficiency among children, regardless of TG2A positivity, would be beneficial to ensure early dietary intervention if needed.

Review article: Systemic consequences of coeliac disease

BACKGROUND

The best-known symptoms of coeliac disease are related to the gastrointestinal tract, but the disease may also present with various systemic manifestations outside the intestine. Some of these consequences may remain permanent in undiagnosed individuals or if the diagnostic delay is prolonged. However, for many of the systemic manifestations, the scientific evidence remains scant and contradictory.

AIMS AND METHODS

We conducted a narrative review of the most thoroughly studied and clinically relevant systemic consequences of coeliac disease, especially those that could be prevented or alleviated by early diagnosis. The review is intended particularly for physicians encountering these patients in daily clinical practice.

RESULTS

The possible systemic consequences of coeliac disease extend to multiple organ systems, the best studied of which are related to skeletal, reproductive, cardiovascular and neurological systems. Furthermore, the disease is associated with an elevated risk of psychiatric comorbidities, non-Hodgkin lymphomas and intestinal adenocarcinoma.

CONCLUSIONS

The various systemic consequences of coeliac disease play a significant role in the overall health of patients. Early diagnosis and treatment with a gluten-free diet appear to be beneficial for most, but not all of these conditions. The possible negative metabolic and psychosocial effects of the diet should be acknowledged during follow-up.

Early diagnosis of coeliac disease in the Preventive Youth Health Care Centres in the Netherlands: study protocol of a case finding study (GLUTENSCREEN)

Introduction

Coeliac disease (CD) occurs in 1% of the population, develops early in life and is severely underdiagnosed. Undiagnosed and untreated disease is associated with short-term and long-term complications. The current healthcare approach is unable to solve the underdiagnosis of CD and timely diagnosis and treatment is only achieved by active case finding. Aim: to perform a case finding project to detect CD children who visit the Youth Health Care Centres (YHCCs) in a well-described region in the Netherlands to evaluate whether it is feasible, cost-effective and well accepted by the population.

Methods/analysis

Prospective intervention cohort study. Parents of all children aged 12 months and 4 years attending the YHCCs for a regular visit are asked whether their child has one or more CD-related symptoms from a standardised list. If so, they will be invited to participate in the case finding study. After informed consent, a point of care test (POCT) to assess CD-specific antibodies against tissue transglutaminase (TG2A) is performed onsite the YHCCs. If the POCT is positive, CD is highly suspected and the child will be referred to hospital for definitive diagnosis according to the Guideline Coeliac Disease of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition guideline.

Main outcomes

Incidence rate of new CD diagnoses in the study region in comparison to the one in the same age diagnosed by standard of care in the rest of the Netherlands.Feasibility and cost-effectiveness of active CD case finding at the YHCCs. All costs of active case finding, diagnostics and treatment of CD and the potential short-term and long-term consequences of the disease will be calculated for the setting with and without case finding.Ethical acceptability: by questionnaires on parental and healthcare professionals' satisfaction.A statistical analysis plan was prepared and is published on the GLUTENSCREEN website (Statistical-Analysis-Plan-11-5-2021_def.pdf (glutenscreen.nl) and added as annex 1).

Ethics and dissemination

The Medical Ethics Committee Leiden approved this study. If we prove that case finding at the YHCC is feasible, cost-effective and well accepted by the population, implementation is recommended.

Trial registration number

NL63291.058.17.

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.

Pregnancy and coeliac disease

Coeliac disease (CD) is a small bowel disorder known for its intestinal manifestations like diarrhoea and weight loss. Less known are the extraintestinal manifestations of CD like haematological abnormalities but also altered female reproduction and pregnancy outcomes. Especially, undiagnosed CD may lead to adverse reproductive outcomes such as intrauterine growth restriction, stillbirth and preterm birth. In diagnosed and treated CD, adverse pregnancy outcomes might be prevented.

Perinatal Outcome and Long-Term Gastrointestinal Morbidity of Offspring of Women with Celiac Disease

The aim of this study was to evaluate perinatal outcome and long-term offspring gastrointestinal morbidity of women with celiac disease. Perinatal outcomes, as well as long-term gastrointestinal morbidity of offspring of mothers with and without celiac disease were assessed. The study groups were followed until 18 years of age for gastrointestinal-related morbidity. For perinatal outcomes, generalized estimation equation (GEE) models were used. A Kaplan–Meier survival curve was used to compare cumulative incidence of long-term gastrointestinal morbidity, and Cox proportional hazards models were constructed to control for confounders. During the study period, 243,682 deliveries met the inclusion criteria, of which 212 (0.08%) were to mothers with celiac disease. Using GEE models, maternal celiac disease was noted as an independent risk factor for low birth weight and cesarean delivery. Offspring born to mothers with celiac disease had higher rates of gastrointestinal related morbidity (Kaplan–Meier log rank test p < 0.001). Using a Cox proportional hazards model, being born to a mother with celiac disease was found to be an independent risk factor for long-term gastrointestinal morbidity of the offspring. Pregnancy of women with celiac disease is independently associated with adverse perinatal outcome as well as higher risk for long-term gastrointestinal morbidity of offspring.

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.

Coeliac disease

Coeliac disease is an immune-mediated enteropathy against dietary gluten present in wheat, rye and barley and is one of the most common lifelong food-related disorders worldwide. Coeliac disease is also considered to be a systemic disorder characterized by a variable combination of gluten-related signs and symptoms and disease-specific antibodies in addition to enteropathy. The ingestion of gluten leads to the generation of harmful gluten peptides, which, in predisposed individuals, can induce adaptive and innate immune responses. The clinical presentation is extremely variable; patients may have severe gastrointestinal symptoms and malabsorption, extraintestinal symptoms or have no symptoms at all. Owing to the multifaceted clinical presentation, diagnosis remains a challenge and coeliac disease is heavily underdiagnosed. The diagnosis of coeliac disease is achieved by combining coeliac disease serology and small intestinal mucosal histology during a gluten-containing diet. Currently, the only effective treatment for coeliac disease is a lifelong strict gluten-free diet; however, the diet is restrictive and gluten is difficult to avoid. Optimizing diagnosis and care in coeliac disease requires continuous research and education of both patients and health-care professionals.

Celiac Disease Prevention

Celiac disease (CD) is a common autoimmune disorder induced by ingestion of gluten in genetically susceptible individuals. Despite the prerequisite for a genetic predisposition, only a minority of the 40% of the Caucasian population that has this genetic predisposition develops the disease. Thus, environmental and/or lifestyle factors play a causal role in the development of CD. The incidence of CD has increased over the last half-century, resulting in rising interest in identifying risk factors for CD to enable primary prevention. Early infant feeding practices have been suggested as one of the factors influencing the risk of CD in genetically susceptible individuals. However, recent large prospective studies have shown that neither the timing of gluten introduction nor the duration or maintenance of breastfeeding influence the risk of CD. Also, other environmental influences have been investigated as potential risk factors, but have not led to primary prevention strategies. Secondary prevention is possible through early diagnosis and treatment. Since CD is significantly underdiagnosed and a large proportion of CD patients are asymptomatic at the time of diagnosis, secondary prevention will not identify all CD patients, as long as mass screening has not been introduced. As following a gluten-free diet is a major challenge, tertiary prevention strategies are discussed as well.

Celiac disease or positive tissue transglutaminase antibodies in patients undergoing renal biopsies

BACKGROUND

An association between celiac disease and renal diseases has been suggested, but the results are controversial.

AIMS

To investigate the prevalence of celiac disease autoimmunity among individuals undergoing renal biopsies and to evaluate whether co-existent celiac autoimmunity influences the clinical outcome of the renal disease.

METHODS

The prevalence of celiac autoimmunity (previous diagnosis of celiac disease or positive tissue transglutaminase antibodies) was determined in 827 consecutive patients undergoing kidney biopsies due to clinical indications. Up to 15 years' follow-up data on kidney function and co-morbidities were obtained.

RESULTS

Celiac autoimmunity was found in 45 (5.4%) patients. Among the IgA nephropathy patients, 8.2% of had celiac autoimmunity. At the time of kidney biopsy and after a median follow-up of 5 to 6 years, renal function measured by estimated glomerular filtration rate (eGFR) was inferior in IgA nephropathy patients with celiac autoimmunity compared to those without it (P=0.048 and P=0.022, respectively).

CONCLUSION

The prevalence of celiac autoimmunity seems to be high in patients undergoing renal biopsies, especially in patients with IgA nephropathy. Such autoimmunity may be associated with worse renal function in IgA nephropathy. Hence the co-existence of celiac disease should be taken into consideration when treating patients with renal diseases.

Abnormalities in CD57+ cytotoxic T cells and Vδ1+ γδT cells in subclinical celiac disease in childhood are affected by cytomegalovirus. The Generation R Study

Celiac disease (CD) is a digestive and autoimmune disorder driven by an immune response to modified gluten peptides. Affected intestines show infiltrates of various T-cell and NK-cell subsets. It is currently unclear if individuals with subclinical CD have systemic abnormalities in immune cells. We here studied whether subclinical CD is associated with changes in blood CD57-expressing and Vδ1-expressing lymphocytes in children, and whether cytomegalovirus (CMV) infection modifies this association. Included were 1068 children from the Generation R Study. Serum Immunoglobulin G (IgG) levels against CMV were measured by ELISA; Tissue transglutaminase type 2 antibody (TG2A) levels with fluorescence enzyme immunoassay (FEIA). Duodenal biopsies, additional Human Leukocyte Antigen (HLA) DQ 2.2, 2.5 and 8 and endomysial antibody (EMA) typing were performed in TG2A positive children. Subclinical CD cases (n=12) had 1.8 fold (95% CI 1.06; 3.1) fewer Vδ1+ T cells which was predominantly observed in CMV seronegative children (p-interaction 0.02), and 2.7 fold (95% CI 1.25; 5.99) more CD57+ T cells than HLA DQ2/-DQ8 positive controls (n=339). Hence, children with subclinical CD have alterations in specific blood T cell subsets that are linked to viral pathology. The observed interaction effect between subclinical CD and CMV may contribute to the understanding of disease pathogenesis.

Gay Male Only-Children: Evidence for Low Birth Weight and High Maternal Miscarriage Rates

Recent findings suggest that there may be a maternal immune response underpinning the etiology of sexual orientation of gay male only-children. This maternal immune response appears to be distinct from that which is purported to explain the classic fraternal birth order effect found in studies of male sexual orientation. We tested two predictions related to the hypothesized maternal immune response in mothers of gay male only-children: (1) elevated fetal loss among mothers who have had gay male only-children and (2) lower birth weight in gay male only-children. Mothers of at least one gay son (n = 54) and mothers of heterosexual son(s) (n = 72) self-reported their pregnancy histories, including the birth weights of newborns and number of fetal losses (e.g., miscarriages). Mothers of gay male only-children (n = 8) reported significantly greater fetal loss compared with mothers of males with four other sibship compositions (gay with no older brothers, gay with older brothers, heterosexual only-children, heterosexual with siblings) (n = 118). Also, firstborn gay male only-children (n = 4) had a significantly lower birth weight than firstborn children in the four other sibship compositions (n = 59). Duration of pregnancy was not significantly different among the groups of firstborn children in the birth weight analyses. Thus, this study found further support for a distinct pattern of maternal immune response implicated in the etiology of male sexual orientation. Mechanisms that may underlie this potential second type of maternal immune response are discussed.

Effects of nongenetic factors on immune cell dynamics in early childhood: The Generation R Study

BACKGROUND

Numbers of blood leukocyte subsets are highly dynamic in childhood and differ greatly between subjects. Interindividual variation is only partly accounted for by genetic factors.

OBJECTIVE

We sought to determine which nongenetic factors affect the dynamics of innate leukocytes and naive and memory lymphocyte subsets.

METHODS

We performed 6-color flow cytometry and linear mixed-effects modeling to define the dynamics of 62 leukocyte subsets from birth to 6 years of age in 1182 children, with 1 to 5 measurements per subject. Subsequently, we defined the effect of prenatal maternal lifestyle-related or immune-mediated determinants, birth characteristics, and bacterial/viral exposure-related determinants on leukocyte subset dynamics.

RESULTS

Functionally similar leukocyte populations were grouped by using unbiased hierarchical clustering of patterns of age-related leukocyte dynamics. Innate leukocyte numbers were high at birth and predominantly affected by maternal low education level. Naive lymphocyte counts peaked around 1 year, whereas most memory lymphocyte subsets more gradually increased during the first 4 years of life. Dynamics of CD4⁺ T cells were predominantly associated with sex, birth characteristics, and persistent infections with cytomegalovirus (CMV) or EBV. CD8⁺ T cells were predominantly associated with CMV and EBV infections, and T-cell receptor γδ⁺ T cells were predominantly associated with premature rupture of membranes and CMV infection. B-cell subsets were predominantly associated with sex, breast-feeding, and Helicobacter pylori carriership.

CONCLUSIONS

Our study identifies specific dynamic patterns of leukocyte subset numbers, as well as nongenetic determinants that affect these patterns, thereby providing new insights into the shaping of the childhood immune system.

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.

Generation R birth cohort study shows that specific enamel defects were not associated with elevated serum transglutaminase type 2 antibodies

AIM

Coeliac disease can induce specific enamel defects (SED), but little is known about the consequences of antitissue transglutaminase (TG2A) autoimmunity. We investigated whether TG2A positivity in children and their mothers was associated with SED in the primary dentition.

METHODS

Maternal and child serum immunoglobulin A-TG2A levels were measured as part of the Generation R prospective cohort study. Clinical oral photographs of the primary dentition were taken, and SED and caries were recorded. We performed logistic regression analysis.

RESULTS

We analysed data on 4775 mothers and 4233 children (median age of 6.2 ± 0.5 years). SED and caries were not associated with maternal TG2A levels. The 59 TG2A-positive children tended to have more SED, particularly the 31 in the strongly positive subgroup, with odds ratio of 1.72 and 2.29, respectively. A positive linear trend was observed between higher TG2A levels and paediatric SED (p = 0.04), but this became nonsignificant after adjusting for ethnic and socio-economic background. No difference in caries was found between the groups.

CONCLUSION

TG2A did not play an independent role on SED in the primary dentition during pregnancy and childhood, and the relationship may be explained by ethnic and socio-economic background.

Herpesvirus Infections and Transglutaminase Type 2 Antibody Positivity in Childhood: The Generation R Study

OBJECTIVES

Persistent viral infections have been implicated in the etiology of autoimmune diseases in adulthood, but it is not known whether herpesviruses are associated with the development of celiac disease autoimmunity in childhood. We assessed whether herpesvirus infections are associated with transglutaminase type 2 antibody (TG2A) concentrations in children at 6 years of age.

METHODS

The present study was embedded within a population-based prospective cohort study. Serum immunoglobulin G levels against Epstein-Barr virus, cytomegalovirus (CMV), and herpes simplex virus type 1 were measured by enzyme-linked immunosorbent assay , and TG2A concentrations with fluorescence enzyme immunoassay in 4420 children at 6 years of age. Children were categorized based on TG2A concentrations into negative (<7 U/mL), positive (≥7-70 U/mL), and strongly positive (≥70 U/mL), that is, 10 times upper limit normal.

RESULTS

Fifty-nine children (1.3%) were TG2A positive, and of these 31 (53%) had concentrations 70 U/mL or more. Children with TG2A concentrations 70 U/mL or more were less often infected with CMV (adjusted odds ratio (aOR) 0.38, 95% CI 0.14-0.98, P = 0.04) and with any of the 3 viruses (aOR 0.38, 95% CI 0.18-0.78, P < 0.01) than children with TG2A negative concentrations. In addition, children with TG2A concentrations 70 U/mL or more were less often infected with 2 or more viruses than children with TG2A negative concentrations (aOR 0.15, 95% CI 0.03-0.65, P = 0.01).

CONCLUSIONS

Both CMV single infection and combined CMV, Epstein-Barr virus and/or herpes simplex virus type 1 infections are inversely associated with strongly TG2A positivity. This may indicate a protective effect of herpesvirus infections in the pathogenesis of celiac disease autoimmunity.

Celiac disease and non-celiac gluten sensitivity

Celiac disease is a multisystem immune based disorder that is triggered by the ingestion of gluten in genetically susceptible individuals. The prevalence of celiac disease has risen in recent decades and is currently about 1% in most Western populations. The reason for this rise is unknown, although environmental factors related to the hygiene hypothesis are suspected. The pathophysiology of celiac disease involves both the innate and adaptive immune response to dietary gluten. Clinical features are diverse and include gastrointestinal symptoms, metabolic bone disease, infertility, and many other manifestations. Although a gluten-free diet is effective in most patients, this diet can be burdensome and can limit quality of life; consequently, non-dietary therapies are at various stages of development. This review also covers non-celiac gluten sensitivity. The pathophysiology of this clinical phenotype is poorly understood, but it is a cause of increasing interest in gluten-free diets in the general population.

Coeliac disease and gluten-related disorders in childhood

Gluten-related disorders such as coeliac disease, wheat allergy and noncoeliac gluten sensitivity are increasingly being diagnosed in children. Coeliac disease occurs frequently, affecting 1-3% of the Western population. The condition manifests at a very young age, more so in girls, and is related to the HLA genotype. Coeliac disease might be considered a public health problem and, as primary prevention is not possible, the debate on mass screening should be reopened. Wheat proteins, including gluten, are responsible for one of the most common food allergies in children: wheat allergy. Unlike coeliac disease and wheat allergy, noncoeliac gluten sensitivity is an unclear and controversial entity. These three gluten-related disorders are treated with a gluten-free diet. In coeliac disease, the diet should be strictly followed, whereas wheat allergy only requires wheat elimination and in noncoeliac gluten sensitivity occasional trials of gluten reintroduction can be done. A good diagnostic work-up is important for gluten-related disorders in childhood to avoid unnecessary restrictive diets in children. In this Review, we provide an overview of the pathogenesis, diagnosis and management of the most common gluten-related disorders in children.

The prevention of coeliac disease

Primary prevention of coeliac disease is currently not possible. Previously, a 'window of opportunity' was suggested for primary prevention, by introducing gluten between four and six months of age. However, results from recent prospective studies establish that the timing of gluten introduction and the duration or maintenance of breastfeeding do not influence the development of the disease. Secondary prevention is possible through early diagnosis and treatment. Since coeliac disease is severely underdiagnosed, the only way to achieve large-scale secondary prevention is by mass screening. Prospective studies indicate that important health problems, such as reduced foetal growth and birth weight, delayed growth in height and weight in children, and reduced bone mineral density in both children and adults can be prevented by mass screening. Adherence to a strict gluten-free diet may be considered as tertiary prevention.

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.

Growth trajectories and bone mineral density in anti-tissue transglutaminase antibody-positive children: the Generation R Study

BACKGROUND & AIMS

Increased levels of anti-tissue transglutaminase (tTG) have been associated with reduced weight and bone mineral density (BMD) in symptomatic patients with celiac disease. Little is known about the effects of these antibodies in patients with subclinical or other forms of celiac disease. We examined associations between anti-tTG positivity and growth and BMD.

METHODS

In a population-based prospective cohort study, serum samples were collected from children (median age, 6 years; n = 4442) and analyzed for anti-tTG. All children were born between April 2002 and January 2006 and were not previously diagnosed with celiac disease. Children were categorized as anti-tTG negative (<7 U/mL, n = 4249) or anti-tTG positive (≥7 U/mL, n = 57). Children's levels of anti-tTG were further categorized on the basis of ≥10 times upper limit of normal (70 U/mL). Height, weight, and body mass index (BMI) age- and sex-adjusted standard deviation scores (SDS) ([observed value - mean]/SD) were obtained by using Dutch reference growth charts. BMD was measured by dual-energy x-ray absorptiometry. Multivariable linear regression and linear mixed models were performed.

RESULTS

Children who tested positive for anti-tTG had reduced growth in weight SDS/year (reduction of 0.05; 95% CI, reductions of 0.09-0.01) and BMI SDS/year (reduction of 0.10; 95% CI, reductions of 0.18-0.01) from 6 months until 6 years, compared with children without anti-tTG; they also tended to have reduced growth in height from 6 months until 6 years (reduction of 0.02 SDS/year; 95% CI, reductions of 0.06-0.02). Children who tested positive for anti-tTG were shorter (0.29 SDS shorter; 95% CI, reductions of 0.55-0.04 SDS), weighed less (0.38 SDS less; 95% CI, reductions of 0.64-0.12), and had lower BMIs (0.26 SDS less; 95% CI, reductions of 0.49-0.03) and BMDs (0.26 SDS less; 95% CI, reductions of 0.45-0.08) at 6 years of age than anti-tTG negative children.

CONCLUSIONS

Anti-tTG positive children without gastrointestinal symptoms have lower BMDs and reduced growth trajectories until they are 6 years old. This suggests that subclinical or potential celiac disease can affect BMD and growth.

The Generation R Study: Biobank update 2015

The Generation R Study is a population-based prospective cohort study from fetal life until adulthood. The study is designed to identify early environmental and genetic causes and causal pathways leading to normal and abnormal growth, development and health from fetal life, childhood and young adulthood. In total, 9,778 mothers were enrolled in the study. Data collection in children and their parents include questionnaires, interviews, detailed physical and ultrasound examinations, behavioural observations, Magnetic Resonance Imaging and biological samples. Efforts have been conducted for collecting biological samples including blood, hair, faeces, nasal swabs, saliva and urine samples and generating genomics data on DNA, RNA and microbiome. In this paper, we give an update of the collection, processing and storage of these biological samples and available measures. Together with detailed phenotype measurements, these biological samples provide a unique resource for epidemiological studies focused on environmental exposures, genetic and genomic determinants and their interactions in relation to growth, health and development from fetal life onwards.

Birth weight and two possible types of maternal effects on male sexual orientation: a clinical study of children and adolescents referred to a Gender Identity Service

This study tested predictions regarding two hypothesized maternal immune responses influencing sexual orientation: one affecting homosexual males with high fraternal birth order and another affecting firstborn homosexual individuals whose mothers experience repeated miscarriage after the birth of the first child. Low birth weight was treated as a marker of possible exposure to a maternal immune response during gestation. Birth weight was examined relative to sibship characteristics in a clinical sample of youth (N = 1,722) classified as heterosexual or homosexual based on self-reported or probable sexual orientation. No female sexual orientation differences in birth weight were found. Homosexual, compared to heterosexual, males showed lower birth weight if they had one or more older brothers--and especially two or more older brothers--or if they were an only-child. These findings support the existence of two maternal immune responses influencing male sexual orientation and possibly also cross-gender behavior and identity.

Infant feeding and anti-tissue transglutaminase antibody concentrations in the Generation R Study

BACKGROUND

Celiac disease (CD) has emerged as a common, but largely undiagnosed health problem. Numerous studies examined the influence of infant nutrition on the development of diagnosed CD. However, results are still inconsistent. In addition, the effect of infant feeding practices on the development of potential forms of CD might be different.

OBJECTIVE

The objective was to examine whether the timing of gluten introduction and breastfeeding duration are associated with CD autoimmunity (CDA) in children at the age of 6 y.

DESIGN

This study was embedded in the Generation R Study, a population-based prospective cohort study. Participants included 1679 Dutch children who were positive for human leukocyte antigen (HLA) DQ2/DQ8. Data on the timing of gluten introduction (<6 mo compared with ≥6 mo) and duration of breastfeeding (<6 mo compared with ≥6 mo) were obtained by questionnaire. Serum samples were analyzed for anti-tissue transglutaminase (anti-tTG) concentrations at age 6 y. Anti-tTG concentrations were categorized into negative (<7 U/mL) and positive (≥7 U/mL) values. Positive anti-tTG concentrations were further categorized based on ≥10 times the upper limit of normal (ULN) values of the test kit (≥7-70 and ≥70 U/mL). Multivariable logistic regression analyses were performed.

RESULTS

Positive anti-tTG concentrations were found in 43 children, 26 of whom had concentrations ≥10 times the ULN (≥70 IU/mL). The introduction of gluten from the age of 6 mo onward and breastfeeding for ≥6 mo were not significantly associated with positive anti-tTG concentrations. In addition, the timing of gluten introduction and duration of breastfeeding were not significantly associated with positive anti-tTG concentrations below or above 10 times the ULN.

CONCLUSIONS

Delayed introduction of gluten beyond the age of 6 mo does not increase the risk of CDA. In addition, breastfeeding for ≥6 mo does not decrease the risk of CDA in children at 6 y of age.

Results from ad hoc and routinely collected data among celiac women with infertility or pregnancy related disorders: Italy, 2001-2011

Celiac disease (CD) is a chronic autoimmune illness triggered by gluten consumption in genetically predisposed individuals. Worldwide, CD prevalence is approximately 1%. Several studies suggest a higher prevalence of undiagnosed CD in patients with infertility. We described reproductive disorders and assessed the frequency of hospital admissions for infertility among celiac women aged 15–49. We conducted two surveys enrolling a convenient sample of celiac women, residing in Apulia or in Basilicata (Italy). Moreover, we selected hospital discharge records (HDRs) of celiac women and women with an exemption for CD, and matched the lists with HDRs for reproductive disorders. In the surveys we included 91 celiac women; 61.5% of them reported menstrual cycle disorders. 47/91 reported at least one pregnancy and 70.2% of them reported problems during pregnancy. From the HDRs and the registry of exemption, we selected 4,070 women with CD; the proportion of women hospitalized for infertility was higher among celiac women than among resident women in childbearing age (1.2% versus 0.2%). Our findings highlight a higher prevalence of reproductive disorders among celiac women than in the general population suggesting that clinicians might consider testing for CD women presenting with pregnancy disorders or infertility.

Advances in coeliac disease

PURPOSE OF REVIEW

To summarize the recent advances in coeliac disease.

RECENT FINDINGS

Details of the polygenic nature of coeliac disease with the human leukocyte antigen (HLA) locus as the dominating genetic element have been uncovered. The existence of a large number of non-HLA coeliac disease genes, only partly shared by each individual patient, suggests the genetic heterogeneity of the disease. The critical role for HLA-DQ-restricted CD4 T cells recognizing antigenic gluten peptides is further substantiated. Involvement of CD8 T cells has received new attention. Other components of wheat than gluten, in particular the amylase trypsin inhibitors, may also play a role. The disease is becoming more prevalent. New guidelines state that coeliac disease diagnosis in children can be made on the basis of clinical signs, serology and genetics without the need of biopsy. The clinical entity 'noncoeliac gluten sensitivity' has received much attention, but diagnostic and pathophysiological definitions are still elusive. The risk for mortality and morbidity in coeliac disease is less than previously thought.

SUMMARY

Our understanding of the basic and clinical aspects of coeliac disease increases. Coeliac disease stands out as a major health problem of almost global occurrence. Case finding, distinguishing coeliac disease from other gluten-sensitive conditions, better care and balanced use of resources are the current challenges.

Coeliac disease in 2013: new insights in dietary-gluten-induced autoimmunity

Coeliac disease comprises intolerance against dietary wheat, rye and barley gluten and is one of the most common food-related life-long disorders in Western countries. In 2013, new knowledge of the clinical diversity of coeliac disease and further details about the autoimmune aspects of this disorder have emerged.

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.