Coeliac disease and risk of schizophrenia and other psychosis: a general population cohort study

Psychological, Psychiatric, and Organic Brain Manifestations of Celiac Disease

INTRODUCTION

Celiac disease is an autoimmune condition that affects approximately 1% of the population worldwide. Although its main impact often concerns the small intestine, resulting in villous atrophy and nutrient malabsorption, it can also cause systemic manifestations, particularly when undiagnosed or left untreated.

METHOD

Attention is directed to the possible psychological, psychiatric, and organic brain manifestations of celiac disease. Specific topics related to the influence and risk of such manifestations with respect to celiac disease are defined and discussed. Overall, eighteen main topics are considered, sifted from over 500 references.

RESULTS

The most often studied topics were found to be the effect on quality of life, organic brain dysfunction and ataxia, epilepsy, Down syndrome, generalized psychological disorders, eating dysfunction, depression, and schizophrenia. For most every topic, although many studies report a connection to celiac disease, there are often one or more contrary studies and opinions. A bibliographic analysis of the cited articles was also done. There has been a sharp increase in interest in this research since 1990. Recently published articles tend to receive more referencing, up to as many as 15 citations per year, suggesting an increasing impact of the topics. The number of manuscript pages per article has also tended to increase, up to as many as 12 pages. The impact factor of the publishing journal has remained level over the years.

CONCLUSION

This compendium may be useful in developing a consensus regarding psychological, psychiatric, and organic brain manifestations that can occur in celiac disease and for determining the best direction for ongoing research focus.

Gastrointestinal and liver disease in patients with schizophrenia: A narrative review

Schizophrenia is a severe mental illness which can have a devastating impact on an individual's quality of life. Comorbidities are high amongst patients and life expectancy is approximately 15 years less than the general population. Despite the well-known increased mortality, little is known about the impact of gastrointestinal and liver disease on patients with schizophrenia. We aimed to review the literature and to make recommendations regarding future care. Literature searches were performed on PubMed to identify studies related to gastrointestinal and liver disease in patients with schizophrenia. High rates of chronic liver disease were reported, with Non-Alcoholic Fatty Liver Disease being of particular concern; antipsychotics and metabolic syndrome were contributing factors. Rates of acute liver failure were low but have been associated with antipsychotic use and paracetamol overdose. Coeliac disease has historically been linked to schizophrenia; however, recent research suggests that a causal link is yet to be proven. Evidence is emerging regarding the relationships between schizophrenia and peptic ulcer disease, inflammatory bowel disease and irritable bowel syndrome; clinical vigilance regarding these conditions should be high. Patients with schizophrenia poorly engage with bowel cancer screening programmes, leading to late diagnosis and increased mortality. Clozapine induced constipation is a significant issue for many patients and requires close monitoring. There is a significant burden of gastrointestinal and liver disease amongst patients with schizophrenia. Better levels of support from all members of the medical team are essential to ensure that appropriate, timely care is provided.

Exploiting horizontal pleiotropy to search for causal pathways within a Mendelian randomization framework

In Mendelian randomization (MR) analysis, variants that exert horizontal pleiotropy are typically treated as a nuisance. However, they could be valuable in identifying alternative pathways to the traits under investigation. Here, we develop MR-TRYX, a framework that exploits horizontal pleiotropy to discover putative risk factors for disease. We begin by detecting outliers in a single exposure-outcome MR analysis, hypothesising they are due to horizontal pleiotropy. We search across hundreds of complete GWAS summary datasets to systematically identify other (candidate) traits that associate with the outliers. We develop a multi-trait pleiotropy model of the heterogeneity in the exposure-outcome analysis due to pathways through candidate traits. Through detailed investigation of several causal relationships, many pleiotropic pathways are uncovered with already established causal effects, validating the approach, but also alternative putative causal pathways. Adjustment for pleiotropic pathways reduces the heterogeneity across the analyses.

The immunobiology of autoimmune encephalitides

Autoimmune encephalitides, with an estimated incidence of 1.5 per million population per year, although described only 15 years ago, have already had a remarkable impact in neurology and paved the field to autoimmune neuropsychiatry. Many patients traditionally presented with aberrant behavior, especially of acute or subacute onset, and treated with anti-psychotic therapies, turn out to have a CNS autoimmune disease with pathogenic autoantibodies against synaptic antigens responding to immunotherapies. The review describes the clinical spectrum of these disorders, and the pathogenetic role of key autoantibodies directed against: a) cell surface synaptic antigens and receptors, including NMDAR, GABAa, GABAb, AMPA and glycine receptors; b) channels such as AQP4 water-permeable channel or voltage-gated potassium channels; c) proteins that stabilize voltage-gated potassium channel complex into the membrane, like the LGI1 and CASPR2; and d) enzymes that catalyze the formation of neurotransmitters such as Glutamic Acid Decarboxylase (GAD). These antibodies, effectively target excitatory or inhibitory synapses in the limbic system, basal ganglia or brainstem altering synaptic function and resulting in uncontrolled neurological excitability disorder clinically manifested with psychosis, agitation, behavioral alterations, depression, sleep disturbances, seizure-like phenomena, movement disorders such as ataxia, chorea and dystonia, memory changes or coma. Some of the identified triggering factors include: viruses, especially herpes simplex, accounting for the majority of relapses occurring after viral encephalitis, which respond to immunotherapy rather than antiviral agents; tumors especially teratoma, SCLC and thymomas; and biological cancer therapies (immune-check-point inhibitors). As anti-synaptic antibodies persist after viral infections or tumor removal, augmentation of autoreactive B cells which release autoantigens to draining lymph nodes, molecular mimicry and infection-induced bystander immune activation products play a role in autoimmunization process or perpetuating autoimmune neuroinflammation. The review stresses the importance of early detection, clinical recognition, proper antibody testing and early therapy initiation as these disorders, regardless of a known or not trigger, are potentially treatable responding to systemic immunotherapy with intravenous steroids, IVIg, rituximab or even bortezomid.

Associations Between Non-neurological Autoimmune Disorders and Psychosis: A Meta-analysis

BACKGROUND

A relationship between non-neurological autoimmune (NNAI) disorders and psychosis has been widely reported but not yet subjected to meta-analysis. We conducted the first meta-analysis examining the association between NNAI disorders and psychosis and investigated the effect of 1) temporality (as determined by study design), 2) psychiatric diagnosis, and 3) specific autoimmune disorders.

METHODS

Major databases were searched for articles published until April 2018; 31 studies, comprising data for >25 million individuals, were eligible. Using random-effects models, we examined the overall association between all NNAI disorders and psychosis; rheumatoid arthritis was examined separately given the well-established negative association with psychosis. Stratified analyses investigated the effect of temporality, psychiatric diagnosis, and specific NNAI disorders.

RESULTS

We observed a positive overall association between NNAI disorders and psychosis (odds ratio [OR] = 1.26; 95% confidence interval [CI], 1.12-1.41) that was consistent across study designs and psychiatric diagnoses; however, considerable heterogeneity was detected (I² = 88.08). Patterns varied across individual NNAI disorders; associations were positive for pernicious anemia (OR = 1.91; 95% CI, 1.29-2.84), pemphigoid (OR = 1.90; 95% CI, 1.62-2.24), psoriasis (OR = 1.70; 95% CI, 1.51-1.91), celiac disease (OR = 1.53; 95% CI, 1.12-2.10), and Graves' disease (OR = 1.33; 95% CI, 1.03-1.72) and negative for ankylosing spondylitis (OR = 0.72; 95% CI, 0.54-0.98) and rheumatoid arthritis (OR = 0.65; 95% CI, 0.50-0.84).

CONCLUSIONS

While we observed a positive overall association between NNAI disorders and psychosis, this was not consistent across all NNAI disorders. Specific factors, including distinct inflammatory pathways, genetic influences, autoantibodies targeting brain proteins, and exposure to corticosteroid treatment, may therefore underlie this association.

Use of a Gluten-Free Diet in Schizophrenia: A Systematic Review

We performed a systematic review of the literature to determine whether adherence to a gluten-free diet (GFD) leads to improved outcomes for patients with schizophrenia. We searched the AMED (Allied and Complementary Medicine; 1985-June 2016), MEDLINE (1946-June 2016), and Embase (1980-2016 week 24) databases using the terms "wheat" or "glutenin" or "gliadin" or "gluten" AND "schizophrenia." A total of 9 studies met the inclusion criteria for this review: 1 randomized controlled trial, 7 crossover studies, and 1 open-label pilot study. Six of the included studies demonstrated beneficial effects including improved functioning and decreased symptom severity after the course of a GFD, whereas 3 studies found no benefits. All of the included studies found that a GFD is well tolerated and can be adhered to by patients with schizophrenia. The findings of this systematic review should be interpreted with caution due to limitations inherent to nonrandomized trials, as well as the heterogeneity in the study design and the length of the GFD applied in each study. Publication bias is another potential limitation. Further research is required to examine the biomarkers of gluten sensitivity and inflammation to effectively target those patients with schizophrenia who will benefit most from this dietary intervention.

Psychiatric Comorbidity in Children and Adults with Gluten-Related Disorders: A Narrative Review

Gluten-related disorders are characterized by both intestinal and extraintestinal manifestations. Previous studies have suggested an association between gluten-related disorder and psychiatric comorbidities. The objective of our current review is to provide a comprehensive review of this association in children and adults. A systematic literature search using MEDLINE, Embase and PsycINFO from inception to 2018 using terms of ‘celiac disease’ or ‘gluten-sensitivity-related disorders’ combined with terms of ‘mental disorders’ was conducted. A total of 47 articles were included in our review, of which 28 studies were conducted in adults, 11 studies in children and eight studies included both children and adults. The majority of studies were conducted in celiac disease, two studies in non-celiac gluten sensitivity and none in wheat allergy. Enough evidence is currently available supporting the association of celiac disease with depression and, to a lesser extent, with eating disorders. Further investigation is warranted to evaluate the association suggested with other psychiatric disorders. In conclusion, routine surveillance of potential psychiatric manifestations in children and adults with gluten-related disorders should be carried out by the attending physician.

Association between celiac disease and schizophrenia: a meta-analysis

BACKGROUND/OBJECTIVE

Recent epidemiologic studies have suggested that patients with celiac disease might be at an increased risk of schizophrenia. However, the data on this risk remain inconclusive. This meta-analysis was conducted with the aim to summarize all available evidence.

METHODS

A literature search was carried out using MEDLINE and Embase database from inception to June 2017. Studies that compared the risk of schizophrenia among patients with celiac disease versus individuals without celiac disease were included. Pooled odds ratio and 95% confidence interval were calculated using a random-effect, generic inverse-variance method.

RESULTS

Of the 284 retrieved studies, four met our eligibility criteria and were included in the analysis. We found a higher risk of schizophrenia among patients with celiac disease compared with individuals without celiac disease with the pooled odds ratio of 2.03 (95% confidence interval: 1.45-2.86). The statistical heterogeneity of this study was insignificant (I=0%).

CONCLUSION

This systematic review and meta-analysis found a significantly higher risk of schizophrenia among patients with celiac disease.

A study on the association of mood disorders and gluten-related diseases

Our study aimed to evaluate the presence of antibodies related to gluten intolerance in patients with mood disorders. A total of 60 patients with a diagnosis of bipolar disorder or depressive disorder were recruited. Fourty-eight subjects randomly selected among unrelated family members were included as controls. Celiac disease-associated antibodies were assayed both in the patients and controls. Mean values of IgA/IgG anti-gliadin antibodies, IgA/IgG anti-deamidated gliadin peptide antibodies and IgA anti-transglutaminase (tTG) antibodies were not different between patients and controls. However, a significant difference was found for anti-tTG IgG antibodies. Even if both in controls and in patients the mean anti-tTG IgG value was below the cutoff, the estimates produced by the statistical model showed that each unit increase in the anti-tTG IgG antibody value corresponded to an approximately 5% increased chance of having a mood disorder. The patient group showed a more frequent presence of symptoms associated to non-celiac gluten sensitivity. However, as there was neither any correlation between antibody levels and gastrointestinal symptoms, nor with the intensity of the psychiatric symptoms, it may be conceivable that the increase in anti-tTG IgG antibodies is not disorder-related but possibly an outcome of the psychiatric disorder itself.

Gluten related illnesses and severe mental disorders: a comprehensive review

The putative role of gluten in the pathophysiology of severe mental illnesses remains uncertain and there is doubt about the possible benefit of gluten-free diets for individuals affected by psychosis and mood disorders. The objective of this review was to summarize the findings linking gluten related conditions to pathophysiological substrates implicated in schizophrenia and mood disorders and review the evidences of potential benefits of glute-free diets in these populations. A literature search was conducted within PubMed and Scielo databases including references from inception until March 1st 2017. The strategy search was to use the key words "gluten", "celiac disease", "wheat", "bipolar disorder", "mood disorders", "psychosis", "schizophrenia", "depression". In the review about the potential efficacy of gluten-free diets in severe mental illnesses, we included only studies with original data, including cross sectional and longitudinal studies and clinical trials. Book chapters, review articles and meta-analysis and republished data were excluded. Although the current available evidences suggest that people with celiac disease or gluten allergy could have a slightly higher risk of schizophrenia and mood disorders compared to the general population, the literature review reveals significant inaccuracies in the data. There is insufficient evidence to recommend gluten-free diets for populations with psychosis and mood disorders.

Celiac Disease Is Associated with Childhood Psychiatric Disorders: A Population-Based Study

OBJECTIVES

To determine the risk of future childhood psychiatric disorders in celiac disease, assess the association between previous psychiatric disorders and celiac disease in children, and investigate the risk of childhood psychiatric disorders in siblings of celiac disease probands.

STUDY DESIGN

This was a nationwide registry-based matched cohort study in Sweden with 10 903 children (aged <18 years) with celiac disease and 12 710 of their siblings. We assessed the risk of childhood psychiatric disorders (any psychiatric disorder, psychotic disorder, mood disorder, anxiety disorder, eating disorder, psychoactive substance misuse, behavioral disorder, attention-deficit hyperactivity disorder [ADHD], autism spectrum disorder [ASD], and intellectual disability). HRs of future psychiatric disorders in children with celiac disease and their siblings was estimated by Cox regression. The association between previous diagnosis of a psychiatric disorder and current celiac disease was assessed using logistic regression.

RESULTS

Compared with the general population, children with celiac disease had a 1.4-fold greater risk of future psychiatric disorders. Childhood celiac disease was identified as a risk factor for mood disorders, anxiety disorders, eating disorders, behavioral disorders, ADHD, ASD, and intellectual disability. In addition, a previous diagnosis of a mood, eating, or behavioral disorder was more common before the diagnosis of celiac disease. In contrast, siblings of celiac disease probands were at no increased risk of any of the investigated psychiatric disorders.

CONCLUSIONS

Children with celiac disease are at increased risk for most psychiatric disorders, apparently owing to the biological and/or psychological effects of celiac disease.

A review on the relationship between gluten and schizophrenia: Is gluten the cause?

INTRODUCTION

Schizophrenia is a chronic disease that possesses various clinical manifestations. It presents rather heterogeneous characteristics with respect to onset type, symptoms, and the course of the disease. Although the lifetime prevalence is as low as 1%, it can cause serious disability. Thus, it is very important to develop efficient treatment methods. In some studies, it is hypothesized that removing gluten from the diet leads to a significant improvement in disease symptoms. Epidemiological studies revealed that the prevalence of celiac disease among schizophrenic patients is almost two times higher than that of the general population.

OBJECTIVE

In this review, we evaluate the effects of gluten and celiac disease on the onset of schizophrenia. Efficacy of gluten-free diet applications, antibody response against gluten, and the interaction of the brain-gut axis and the presence of common genetic points are also investigated.

METHODS

Without any publication date restriction, Pubmed database searches were made for 'schizophrenia, gluten, gliadin, celiac disease, exorphin, brain-gut axis, psychiatric disorders.' The keywords and the articles about the schizophrenia-celiac disease relationship are included in our review.

RESULTS

Several studies presented evidence to suggest that symptoms associated with schizophrenia were minimized when gluten was excluded from patients' diets. Immunological searches revealed that most schizophrenic patients with increased anti-gliadin antibodies did not possess celiac disease; yet, the presence of increased antibodies against gliadin can be the share point of the immunological abnormalities found in both of the diseases.

DISCUSSION

There were no consistent results in the clinical, immunological, microbiological, and epidemiological studies that investigated the relationship between schizophrenia and celiac disease. This presents a need for a larger scale study to confirm the presence of this suggested correlation between schizophrenia and celiac disease. The underlying mechanisms between the two diseases should be explored.

[Acute psychosis secondary to dysthyroidism: about 2 cases]

Des anomalies fonctionnelles de la thyroïde sont fréquentes et touchent près de 5 % de la population générale, avec une prédominance pour les femmes. La survenue de troubles mentaux, en particulier de l'humeur, au cours des affections thyroïdiennes est connue depuis plus d'un siècle, alors que les troubles psychotiques associés aux dysthyroïdies sont rarement décrits. Nous rapportons les observations de 2 patientes présentant des troubles psychotiques dans deux situations différentes, la première suite à une hyperthyroïdie avec mauvaise observance thérapeutique et la deuxième secondaire à une hypothyroïdie après une thyroïdectomie. Ces observations suggèrent la responsabilité de l'équilibre hormonal thyroïdien dans l'installation des manifestations psychotiques et elles soulignent la nécessité d'éliminer une dysthyroïdie avant tout traitement psychotrope.

Kynurenine and Tryptophan Levels in Patients With Schizophrenia and Elevated Antigliadin Immunoglobulin G Antibodies

OBJECTIVE

Several studies have reported an association between nonceliac gluten sensitivity and schizophrenia. Immune and kynurenine (KYN) pathways have also been implicated in the pathophysiology of schizophrenia, and certain proinflammatory immune mediators may increase KYN and reduce tryptophan (TRP) levels.

METHODS

We measured serum antigliadin immunoglobulin G (IgG), KYN, and TRP in 950 patients with schizophrenia. Patients with antibody level at the 90th percentile or higher of control participants (21.9% of all patients) were classified as having elevated antigliadin IgG. Independent t tests and linear regression models were used to compare TRP, KYN, and KYN-TRP ratio (indicator of TRP metabolism) between patients with and those without elevated antigliadin IgG. The correlation between antigliadin IgG and TRP, KYN, and the ratio was also evaluated in the patients.

RESULTS

KYN and KYN-TRP ratio were higher in patients with elevated antigliadin IgG (geometric mean [standard deviation {SD}] = 2.65 [0.25] µmol/L versus 2.25 [0.23] µmol/L [p < .001] and 0.05 [0.26] versus 0.04 [0.25; p = .001] respectively), findings robust to adjustment for potential demographic and clinical confounders. Antigliadin IgG positively correlated with KYN and KYN-TRP ratio (r = 0.12, p < .001; r = 0.11, p = .002). TRP did not differ between the two groups and did not correlate with antigliadin IgG.

CONCLUSIONS

Our results connect nonceliac gluten sensitivity with the KYN pathway of TRP metabolism in psychotic illness and hint toward potential individualized treatment targets.

Bread and Other Edible Agents of Mental Disease

Perhaps because gastroenterology, immunology, toxicology, and the nutrition and agricultural sciences are outside of their competence and responsibility, psychologists and psychiatrists typically fail to appreciate the impact that food can have on their patients' condition. Here we attempt to help correct this situation by reviewing, in non-technical, plain English, how cereal grains-the world's most abundant food source-can affect human behavior and mental health. We present the implications for the psychological sciences of the findings that, in all of us, bread (1) makes the gut more permeable and can thus encourage the migration of food particles to sites where they are not expected, prompting the immune system to attack both these particles and brain-relevant substances that resemble them, and (2) releases opioid-like compounds, capable of causing mental derangement if they make it to the brain. A grain-free diet, although difficult to maintain (especially for those that need it the most), could improve the mental health of many and be a complete cure for others.

The aetiology of schizophrenia: what have the Swedish Medical Registers taught us?

OBJECTIVE

To review the last thirty years of studies that, using Swedish population registers, have added to our understanding of the aetiology of schizophrenia SAMPLE INCLUDED/METHODS: A literature search was performed to systematically review all studies that using Swedish Population based registers have investigated the aetiology of schizophrenia. Key authors in the field, predominately from Swedish institutions, were additionally contacted and key journals hand searched, for missing references. A quality assessment methodological review was then conducted on each study. Data was extracted and tabulated on identified aetiological themes

RESULTS

61 articles were included corresponding to 10 identified aetiological themes. Although the majority of included studies were retrospective cohort studies, case control studies were also included where they used population based registers. Confirming previous research, schizophrenia was found to have a multi-factorial aetiological basis with pregnancy and birth factors, parental age, social adversity, genetics, substance misuse, migration and ethnicity, personality, non-psychiatric co-morbidity, psychiatric history and poor cognitive performance all found to be significantly associated with an increased risk of later schizophrenia.

CONCLUSIONS

Although some difficulties exist in analysing the interplay between each of these factors, the Swedish population registers have added considerably to our understanding of each of the presented individual aetiological themes. The ability to study the whole population over several decades has been particularly useful in determining the timing of exposures.

Coeliac disease and autoimmune disease-genetic overlap and screening

Coeliac disease is a treatable, gluten-induced disease that often occurs concurrently with other autoimmune diseases. In genetic studies since 2007, a partial genetic overlap between these diseases has been revealed and further insights into the pathophysiology of coeliac disease and autoimmunity have been gained. However, genetic screening is not sensitive and specific enough to accurately predict disease development. The current method to diagnose individuals with coeliac disease is serological testing for the presence of autoantibodies whilst the patient is on a regular, gluten-containing diet, followed by gastroduodenoscopy with duodenal biopsy. Serological test results can also predict the probability of coeliac disease development, even if asymptomatic. In patients with autoimmune diseases known to occur alongside coeliac disease (particularly type 1 diabetes mellitus or thyroid disorders), disease screening-and subsequent treatment if coeliac disease is detected-could have beneficial effects on progression or potential complications of both diseases, owing to the effectiveness of gluten-free dietary interventions in coeliac disease. However, whether diagnosis of coeliac disease and subsequent dietary treatment can prevent autoimmune diseases is debated. In this Review, the genetic and immunological features of coeliac disease, overlap with other autoimmune diseases and implications for current screening strategies will be discussed.

Celiac and non-celiac gluten sensitivity: a review on the association with schizophrenia and mood disorders

An association between many psychiatric and gluten-related disorders has been known for some time. In the case of schizophrenia and mood disorders, the major psychiatric disorders, there is much evidence, not without contradictions, of a possible association between schizophrenia and celiac disease. The association between mood disorders and gluten-related disorders, especially celiac disease, has only been studied for depression, often coupled with anxiety, and very recently for bipolar disorder. Since non-celiac gluten sensitivity is now known to be different from celiac disease, many studies have shown that gluten sensitivity is also associated with major psychiatric disorders. Here we review the literature on the association between schizophrenia/mood disorders and celiac disease/gluten sensitivity, pointing out the differences between these associations.

Evaluation of European coeliac disease risk variants in a north Indian population

Studies in European populations have contributed to a better understanding of the genetics of complex diseases, for example, in coeliac disease (CeD), studies of over 23 000 European samples have reported association to the HLA locus and another 39 loci. However, these associations have not been evaluated in detail in other ethnicities. We sought to better understand how disease-associated loci that have been mapped in Europeans translate to a disease risk for a population with a different ethnic background. We therefore performed a validation of European risk loci for CeD in 497 cases and 736 controls of north Indian origin. Using a dense-genotyping platform (Immunochip), we confirmed the strong association to the HLA region (rs2854275, P=8.2 × 10⁻⁴⁹). Three loci showed suggestive association (rs4948256, P=9.3 × 10⁻⁷, rs4758538, P=8.6 × 10⁻⁵ and rs17080877, P=2.7 × 10⁻⁵). We directly replicated five previously reported European variants (P<0.05; mapping to loci harbouring FASLG/TNFSF18, SCHIP1/IL12A, PFKFB3/PRKCQ, ZMIZ1 and ICOSLG). Using a transferability test, we further confirmed association at PFKFB3/PRKCQ (rs2387397, P=2.8 × 10⁻⁴) and PTPRK/THEMIS (rs55743914, P=3.4 × 10⁻⁴). The north Indian population has a higher degree of consanguinity than Europeans and we therefore explored the role of recessively acting variants, which replicated the HLA locus (rs9271850, P=3.7 × 10⁻²³) and suggested a role of additional four loci. To our knowledge, this is the first replication study of CeD variants in a non-European population.

[Psychological alterations in patients with adult celiac disease]

Patients with recently-diagnosed adult celiac disease were evaluated with the Gastrointestinal Symptom rating Scale (GSRS) and Psychological General Well-Being Index (PGWBI) to evaluate their psychological alterations, the association between any alterations and gastrointestinal symptoms, and their outcome after starting a gluten-free diet. The patients underwent nutritional assessment and then started a gluten-free diet; they were reassessed 6 months later. Quantitative variables are expressed as the median and 25th-75th percentiles.

RESULTS

We included 21 patients, 17 women and 4 mena, with a mean age of 43 years (31-47). The results of histological analysis were compatible with Marsh I lesions in 6 patients, Marsh IIIa in 6 and Marsh IIIb in 9. At baseline, 8 patients showed severe psychological distress, 4 showed moderate distress and 9 showed no distress. The GSRS score was 34 (17-43) and the PGWBI was 64 (48-87), with a significant correlation between the 2 indexes (rho=-.58, P=.006). At 6 months, 3 patients had severe psychological distress, 5 had moderate distress, 9 showed no distress and 4 showed psychological well-being. The GSRS score at 6 months was 13 (8-17) and the PGWBI was 83 (68-95) (P<.05 compared with baseline data for the 3 indicators). The 6 axes of the PGWBI showed significant improvement. At 6 months, no correlation was found between the GSRS and PGWBI.

CONCLUSIONS

Patients with celiac disease have psychological alterations whose intensity is related to gastrointestinal symptoms. These symptoms improve after the start of a gluten-free diet.

The epidemiologic evidence linking autoimmune diseases and psychosis

This review summarizes the epidemiologic evidence linking autoimmune diseases and psychosis. The associations between autoimmune diseases and psychosis have been studied for more than a half century, but research has intensified within the last decades, since psychosis has been associated with genetic markers of the immune system and with excess autoreactivity and other immune alterations. A range of psychiatric disorders, including psychosis, have been observed to occur more frequently in some autoimmune diseases, such as systemic lupus erythematosus and multiple sclerosis. Many autoimmune diseases involve multiple organs and general dysfunction of the immune system, which could affect the brain and induce psychiatric symptoms. Most studies have been cross-sectional, observing an increased prevalence of a broad number of autoimmune diseases in people with psychotic disorders. Furthermore, there is some evidence of associations of psychosis with a family history of autoimmune disorders and vice versa. Additionally, several autoimmune diseases, individually and in aggregate, have been identified as raising the risk for psychotic disorders in longitudinal studies. The associations have been suspected to be caused by inflammation or brain-reactive antibodies associated with the autoimmune diseases. However, the associations could also be caused by shared genetic factors or common etiologic components such as infections. Infections can induce the development of autoimmune diseases and autoantibodies, possibly affecting the brain. Autoimmune diseases and brain-reactive antibodies should be considered by clinicians in the treatment of individuals with psychotic symptoms, and even if the association is not causal, treatment would probably still improve quality of life and survival.

Autoimmunity, inflammation, and psychosis: a search for peripheral markers

Accumulating evidence supports the view that deregulation of the immune system represents an important vulnerability factor for psychosis. In a subgroup of psychotic patients, the high comorbidity with autoimmune and chronic inflammatory conditions suggests a common underlying immune abnormality leading to both conditions. The reviewed data of affective and nonaffective psychosis show that if immune biomarkers exist for such immune abnormality, they may be found in raised macrophage/monocyte inflammatory activation patterns (monocytosis, high-inflammatory gene expression, raised glucocorticoid receptor β/glucocorticoid receptor α ratio, and high levels of proinflammatory and anti-inflammatory monocyte/macrophage derived cytokines in serum/plasma), reduced T cell numbers/proliferation, and TH1 skewing. This activation of the inflammatory response system may be suggestive for microglia activation, as these cells are the macrophages of the brain. Indeed, there is some evidence of activation of the microglia as detected in positron emission tomography scans and in histopathology, and it is assumed that this activation disturbs the development and function of neuronal circuits in the brain. Further, animal models of psychotic conditions (maternal stress and inflammation paradigms) suggest that such monocyte/microglia activation could be seen as the result of a combination of genetic predisposition and an immune-mediated two-hit model. Infection but also environmental stressors during gestation/early life activate microglia, perturbing neuronal development, thereby setting the stage for vulnerability for later psychotic disorders. A second hit, such as endocrine changes, stress, or infection, could further activate microglia, leading to functional abnormalities of the neuronal circuitry in the brain and psychosis.

Psychosis and silent celiac disease in a down syndrome adolescent: a case report

Celiac disease is an autoimmune systemic disorder. It presents gastrointestinal and nongastrointestinal manifestations as well as associated conditions. We report a 16-year-old Down syndrome girl who presented psychosis symptomatology, and she was diagnosed as having silent celiac disease. Olanzapine treatment and gluten-free diet were satisfactory. It is necessary to consider celiac disease in Down syndrome patients with psychiatric symptoms, mainly psychotic symptomatology.

No association observed between schizophrenia and non-HLA coeliac disease genes: integration with the initial MYO9B association with coeliac disease

Schizophrenia is a severe psychotic illness with a heterogeneous presentation and a devastating impact on social and occupational function. Worldwide variations in schizophrenia incidence rates suggest that local conditions may modify disease risk. The human leukocyte antigen (HLA) region has been confirmed to be associated with schizophrenia by genome-wide association studies in populations across the world. While the presence of autoimmune processes in a subgroup of schizophrenia cases is contentious, the immune system could allow environmental exposures to lead to schizophrenia by generating improper immune response. To investigate this topic, we reviewed the current evidence of the relationship between schizophrenia and coeliac disease. Based on this review, we performed genetic analysis of the MYO9B gene and the IL-2/IL-21 locus by genotyping SNPs that have been previously associated with coeliac disease or schizophrenia in 223 families, 108 unrelated individuals with schizophrenia and 120 controls. Finding no evidence for association with these two loci in our study samples, we applied meta-analytic techniques to combine our findings with previous reports. This synthesis, in light of our review of previous reports, suggests a differing developmental trajectory for schizophrenia and coeliac disease. It is possible that these two conditions do not share any functional overlap.

Increased suicide risk in coeliac disease--a Swedish nationwide cohort study

BACKGROUND AND AIM

Individuals with coeliac disease have increased risk of depression and death from external causes, but conclusive studies on death from suicide are missing. We examined the risk of suicide in coeliac disease and amongst individuals where the small intestinal biopsy showed no villous atrophy.

METHODS

We collected biopsy data from all 28 clinical pathology departments in Sweden for individuals diagnosed during 1969-2007 with coeliac disease (Marsh 3: villous atrophy; n=29,083 unique individuals), inflammation without villous atrophy (Marsh 1-2; n=13,263) or positive coeliac disease serology but normal mucosa (Marsh 0, n=3719). Through Cox regression we calculated Hazard ratios for suicide as recorded in the Swedish Cause of Death Register.

RESULTS

The risk for suicide was higher in patients with coeliac disease compared to general population controls (HR=1.55; 95%CI=1.15-2.10; based on 54 completed suicides). Whilst suicide was also more common amongst individuals with inflammation (HR=1.96; 95%CI=1.39-2.77), no such increase was seen amongst individuals with a normal mucosa but positive coeliac disease serology (HR=1.06; 95%CI=0.37-3.02).

CONCLUSIONS

We found a moderately increased risk of suicide amongst patients with coeliac disease. This merits increased attention amongst physicians treating these patients.

Markers of gluten sensitivity and celiac disease in bipolar disorder

OBJECTIVES

Increased immune sensitivity to dietary gluten proteins has been reported in schizophrenia but has not been studied in bipolar disorder. In this study, we examine the levels of antibody reactivity to gliadin, deamidated gliadin, and tissue transglutaminase (tTG) in individuals with bipolar disorder and compare these levels to those in individuals who do not have any history of psychiatric disorder.

METHODS

The sample of 275 individuals included 102 with bipolar disorder and 173 controls without a psychiatric disorder. Immunoglobulin G (IgG) and immunoglobulin A (IgA) antibodies to gliadin and tTG and IgG antibodies to deamidated gliadin were measured by enzyme immunoassay. Participants' levels of antibodies to deamidated gliadin and tTG were classified based on the cutoffs for positivity that are predictive of celiac disease. Quantitative levels of antibodies were compared between groups employing regression models which were controlled for demographic variables.

RESULTS

Individuals with bipolar disorder had increased levels of IgG antibodies to gliadin compared with controls in multivariate analyses. We also found evidence of increased levels of antibodies to deamidated gliadin in the bipolar disorder population. The levels of IgA class antigliadin antibodies and antibodies to tTG did not differ significantly between groups. There was also not a significant difference between groups in the number of persons who were classified as having levels of antibodies to deamidated gliadin or tTG that are predictive of celiac disease.

CONCLUSIONS

Individuals with bipolar disorder have increased levels of IgG antibodies to gliadin. However, such antibody increase is not accompanied by an elevation in IgA antibodies to gliadin or the celiac disease-associated antibodies against deamidated gliadin and tTG. These results warrant further detailed examination of the molecular specificity and pattern of reactivity of the antibody response to gluten antigens in bipolar disorder.

Prevalence of celiac disease and gluten sensitivity in the United States clinical antipsychotic trials of intervention effectiveness study population

Celiac disease (CD) and schizophrenia have approximately the same prevalence, but epidemiologic data show higher prevalence of CD among schizophrenia patients. The reason for this higher co-occurrence is not known, but the clinical knowledge about the presence of immunologic markers for CD or gluten intolerance in schizophrenia patients may have implications for treatment. Our goal was to evaluate antibody prevalence to gliadin (AGA), transglutaminase (tTG), and endomysium (EMA) in a group of individuals with schizophrenia and a comparison group. AGA, tTG, and EMA antibodies were assayed in 1401 schizophrenia patients who were part of the Clinical Antipsychotic Trials of Intervention Effectiveness study and 900 controls. Psychopathology in schizophrenia patients was assessed using the Positive and Negative Symptoms Scale (PANSS). Logistic regression was used to assess the difference in the frequency of AGA, immunoglobulin A (IgA), and tTG antibodies, adjusting for age, sex, and race. Linear regression was used to predict PANSS scores from AGA and tTG antibodies adjusting for age, gender, and race. Among schizophrenia patients, 23.1% had moderate to high levels of IgA-AGA compared with 3.1% of the comparison group (χ(2) = 1885, df = 2, P < .001.) Moderate to high levels of tTG antibodies were present in 5.4% of schizophrenia patients vs 0.80% of the comparison group (χ(2) = 392.0, df = 2, P < .001). Adjustments for sex, age, and race had trivial effects on the differences. Regression analyses failed to predict PANSS scores from AGA and tTG antibodies. Persons with schizophrenia have higher than expected titers of antibodies related to CD and gluten sensitivity.

Swedish women with coeliac disease in remission use more health care services than other women: a controlled study

OBJECTIVE

To examine whether the perceived poor outcome of dietary treatment makes Swedish women with coeliac disease (CD) prone to use more health care services than other women.

MATERIAL AND METHODS

The health care consumption over 36 consecutive months was examined for 137 Swedish women aged 20-80 years with CD in remission after living on a gluten-free diet for a median of 4 years (range 1-8 years). Comparisons were made with the health care consumption of 411 women in the general population matched for age and residence.

RESULTS

The results show that women with CD use health care services annually a median of 5.0 times (range 0-76) that is more than female controls 3.6 (0-311) (p < 0.05) mainly in primary care and for complaints related to mental and behavioral disorders (ICD F), diseases of the digestive system (ICD K) and diseases of the musculoskeletal system and connective tissue (ICD M).

CONCLUSIONS

Women with CD used health care services in keeping with studies indicating reduced health-related quality of life of people with this condition. The results provide evidence that women with CD in remission suffer from co-morbidities that may signal a need for a multidisciplinary follow-up of subjects with CD in Sweden.

Autoimmune diseases, bipolar disorder, and non-affective psychosis

OBJECTIVE

Clinic-based studies of immune function, as well as comorbidity of autoimmune diseases, bipolar disorder, and schizophrenia, suggest a possible autoimmune etiology. Studies of non-affective psychosis and schizophrenia suggest common etiologies. The objective was to determine the degree to which 30 different autoimmune diseases are antecedent risk factors for bipolar disorder, schizophrenia, and non-affective psychosis.

METHODS

A cohort of 3.57 million births in Denmark was linked to the Psychiatric Case Register and the National Hospital Register. There were 20,317 cases of schizophrenia, 39,076 cases of non-affective psychosis, and 9,920 cases of bipolar disorder.

RESULTS

As in prior studies, there was a range of autoimmune diseases which predicted raised risk of schizophrenia in individuals who had a history of autoimmune diseases, and also raised risk in persons whose first-degree relatives had an onset of autoimmune disease prior to onset of schizophrenia in the case. These relationships also existed for the broader category of non-affective psychosis. Only pernicious anemia in the family was associated with raised risk for bipolar disorder (relative risk: 1.7), suggesting a small role for genetic linkage. A history of Guillain-Barré syndrome, Crohn's disease, and autoimmune hepatitis in the individual was associated with raised risk of bipolar disorder.

CONCLUSIONS

The familial relationship of schizophrenia to a range of autoimmune diseases extends to non-affective psychosis, but not to bipolar disorder. The data suggest that autoimmune processes precede onset of schizophrenia, but also non-affective psychosis and bipolar disorder.

Markers of gluten sensitivity and celiac disease in recent-onset psychosis and multi-episode schizophrenia

BACKGROUND

Increased immune sensitivity to gluten has been reported in schizophrenia. However, studies are inconsistent about this association.

METHODS

The sample of 471 individuals included 129 with recent-onset psychosis, 191 with multi-episode schizophrenia, and 151 controls. Immunoglobulin (Ig)G and IgA antibodies to gliadin and to tissue transglutaminase, and IgG antibodies to deamidated gliadin were measured. Quantitative levels of antibodies in the psychiatric groups were compared with controls. All participants were categorized as to whether their levels of antibodies met standardized cutoffs for celiac disease. HLA DQ2 and HLA DQ8 alleles were detected by real-time polymerase chain reaction.

RESULTS

Individuals with recent-onset psychosis had increased levels of IgG (odds ratio [OR] 5.50; 95% confidence interval [CI] 2.65-11.42) and IgA (OR 2.75; 95% CI 1.31-5.75) antibodies to gliadin compared with control subjects. Individuals with multi-episode schizophrenia also had significantly increased levels of IgG antibodies to gliadin (OR 6.19; 95% CI 2.70-14.16). IgG antibodies to deamidated gliadin and IgA antibodies to tissue transglutaminase were not elevated in either psychiatric group, and fewer than 1% of individuals in each of the groups had levels of these antibodies predictive of celiac disease. There were no significant differences in the distribution of the HLA DQ2/8 alleles among the groups.

CONCLUSIONS

Individuals with recent-onset psychosis and with multi-episode schizophrenia who have increased antibodies to gliadin may share some immunologic features of celiac disease, but their immune response to gliadin differs from that of celiac disease.

Novel immune response to gluten in individuals with schizophrenia

A link between celiac disease and schizophrenia has been postulated for several years, based primarily on reports of elevated levels of antibody to gliadin in patients. We sought to examine the proposed connection between schizophrenia and celiac disease by characterizing the molecular specificity and mechanism of the anti-gliadin immune response in a subset of individuals with schizophrenia. Blood samples from individuals with schizophrenia and elevated anti-gliadin antibody titer were examined for celiac disease-associated biomarkers, including antibodies to transglutaminase 2 (TG2) enzyme and deamidated gliadin peptides, as well as the HLA-DQ2 and -DQ8 MHC genes. The anti-gliadin antibody response was further characterized through examination of reactivity towards chromatographically separated gluten proteins. Target proteins of interest were identified by peptide mass mapping. In contrast to celiac disease patients, an association between the anti-gliadin immune response and anti-TG2 antibody or HLA-DQ2 and -DQ8 markers was not found in individuals with schizophrenia. In addition, the majority of individuals with schizophrenia and anti-gliadin antibody did not exhibit antibody reactivity to deamidated gliadin peptides. Further characterization of the antibody specificity revealed preferential reactivity towards different gluten proteins in the schizophrenia and celiac disease groups. These findings indicate that the anti-gliadin immune response in schizophrenia has a different antigenic specificity from that in celiac disease and is independent of the action of transglutaminase enzyme and HLA-DQ2/DQ8. Meanwhile, the presence of elevated levels of antibodies to specific gluten proteins points to shared immunologic abnormalities in a subset of schizophrenia patients. Further characterization and understanding of the immune response to gluten in schizophrenia may provide novel insights into the etiopathogenesis of specific disease phenotypes.

The TGM2 gene is associated with schizophrenia in a British population

Several lines of evidence have suggested an interesting link between gluten ingestion and schizophrenia. Increased levels of gliadin antibodies have been observed in patients with schizophrenia. Tissue transglutaminase (transglutaminase 2, TGM2) is involved in the production of gliadin antibodies. To investigate genetic association of the TGM2 gene with schizophrenia, we detected eight single nucleotide polymorphisms (SNPs) present in the gene among 131 family trios composed of fathers, mothers and affected offspring with schizophrenia. Data analysis with the UNPHASED program showed allelic association for rs2076380 (chi(2) = 5.51, P = 0.019), rs7270785 (chi(2) = 8.13, P = 0.004), rs4811528 (chi(2) = 6.13, P = 0.013) and rs6023526 (chi(2) = 6.13, P = 0.013). The global P-value was 0.029 for 10,000 permutations with the TDT analysis. The strongest association was observed for the rs7270785-rs4811528 haplotypes (chi(2) = 16.18, df = 3, P = 0.001), and the global P-value was 0.008 for 10,000 permutations with the 2-SNP haplotype analysis. The 8-SNP haplotype analysis also revealed a strong haplotypic association (chi(2) = 44.82, df = 18, P = 0.0004) and the 1-df test showed that the A-T-A-A-T-G-A-G haplotype was excessively transmitted (chi(2) = 16.98, corrected P = 0.0007). The present results suggest that the TGM2 gene may be involved in the development of schizophrenia.

Systematic review: The evidence base for long-term management of coeliac disease

BACKGROUND

While gluten-free diet is an effective treatment for coeliac disease, the need for and goals of long-term management of patients are poorly defined.

AIM

To review systematically the complications and associations of coeliac disease, to identify potential risk factors, to define ways of assessing risk factors and to provide a strategy for management.

METHODS

Review of medical literature from 1975.

RESULTS

There is an increasing list of potential complications and/or conditions associated with coeliac disease, in particular, autoimmune disease, malignancy and bone disease. Risk factors that may predict or influence long-term outcomes include genetic susceptibility, environmental factors predominantly gluten ingestion, persistent small intestinal inflammation/injury and nutritional deficiencies. Genotyping of patients is yet to have an established clinical role in long-term management. Assessment of adherence to the gluten-free diet largely relies upon skilled dietary history, but the ultimate test is duodenal histopathology, which is the only currently established means of assessing healing. Symptoms, serology or other non-invasive means are poor predictors of healing and the likelihood of complications.

CONCLUSION

Evidence (albeit limited) that adherence to a gluten-free diet and mucosal healing prevent and/or ameliorate complications indicates that a planned long-term strategy for follow-up is essential.

Risk of pancreatitis in 14,000 individuals with celiac disease

BACKGROUND & AIMS

The aim of this study was to examine the risk of pancreatitis in patients with celiac disease (CD) from a general population cohort.

METHODS

By using Swedish national registers, we identified 14,239 individuals with a diagnosis of CD (1964-2003) and 69,381 reference individuals matched for age, sex, calendar year, and county of residence at the time of diagnosis. Cox regression estimated the hazard ratios (HRs) for a subsequent diagnosis of pancreatitis. We restricted analyses to individuals with more than 1 year of follow-up and no diagnosis of pancreatitis before or within 1 year after study entry. Conditional logistic regression estimated the association of pancreatitis with subsequent CD.

RESULTS

CD was associated with an increased risk of subsequent pancreatitis of any type (HR, 3.3; 95% confidence interval [CI], 2.6-4.4; P < .001; on the basis of 95 positive events in individuals with CD vs 163 positive events in reference individuals) and chronic pancreatitis (HR, 19.8; 95% CI, 9.2-42.8; P < .001; on the basis of 37 and 13 positive events, respectively). Adjustment for socioeconomic index, diabetes mellitus, alcohol-related disorders, or gallstone disease had no notable effect on the risk estimates. The risk increase for pancreatitis was only found among individuals with CD diagnosed in adulthood. Pancreatitis of any type (odds ratio, 3.2; 95% CI, 2.5-4.3; P < .001) and chronic pancreatitis (odds ratio, 7.3; 95% CI, 4.0-13.5; P < .001) were associated with subsequent CD.

CONCLUSIONS

This study suggests that individuals with CD are at increased risk of pancreatitis.