Cytokine profile in coeliac disease

Microscopic Colitis and Celiac Disease: Sharing More than a Diagnostic Overlap

Microscopic colitis (MC) is an emergent group of chronic inflammatory diseases of the colon, and celiac disease (CD) is a chronic gluten-induced immune-mediated enteropathy affecting the small bowel. We performed a narrative review to provide an overview regarding the relationship between both disorders, analyzing the most recent studies published at the epidemiological, clinical and pathophysiological levels. In fact, MC and CD are concomitantly prevalent in approximately 6% of the cases, mainly in the subset of refractory patients. Thus, physicians should screen refractory patients with CD against MC and vice versa. Both disorders share more than a simple epidemiological association, being multifactorial diseases involving innate and adaptive immune responses to known or unknown luminal factors based on a rather common genetic ground. Moreover, autoimmunity is a shared characteristic between the patients with MC and those with CD, with autoimmunity in the latter being quite well-established. Furthermore, CD and MC share some common clinical symptoms and risk factors and overlap with other gastrointestinal diseases, but some differences exist between both disorders. More studies are therefore needed to better understand the complex mechanisms involving the common pathogenetic ground contributing to the CD and MC epidemiological association.

Limited Clinical Impact of Genetic Associations between Celiac Disease and Type 2 Inflammatory Diseases: Insights from Mendelian Randomization

Background: Celiac disease, a gluten-triggered autoimmune disorder, is known for its systemic inflammatory effects. Its genetic associations with type 2 inflammatory diseases like asthma, allergic rhinitis, and atopic dermatitis remain unclear, prompting this study to explore their potential genetic interplay. Methods: Utilizing two-sample Mendelian randomization (TSMR), we examined the genetic associations using 15 genetic instruments from GWAS datasets. Our analysis focused on celiac disease and its relation to asthma, allergic rhinitis, atopic dermatitis, and IgE-mediated food allergies. A power analysis was conducted to determine the study's detection capabilities, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using various MR methods. Results: Our Mendelian randomization analysis identified statistically significant genetic associations between celiac disease and several type 2 inflammatory diseases, although these were practically insignificant. Specifically, celiac disease was associated with a slight increase in the risk of atopic dermatitis (OR = 1.037) and a minor protective effect against asthma (OR = 0.97). The link with allergic rhinitis was statistically detectable (OR = 1.002) but practically negligible. Despite robust statistical confirmation through various sensitivity analyses, all observed effects remained within the range of practical equivalence (ROPE). Conclusions: Our study identifies potential genetic associations between celiac disease and certain type 2 inflammatory diseases. However, these associations, predominantly within the ROPE range, suggest only limited clinical implications. These findings highlight the need for cautious interpretation and indicate that further exploration for clinical applications may not be warranted at this stage.

Role of Regulatory T Cells and Their Potential Therapeutic Applications in Celiac Disease

Celiac disease (CeD) is a T-cell-mediated immune disease, in which gluten-derived peptides activate lamina propria effector CD4+ T cells. While this effector T cell subset produces proinflammatory cytokines, which cause substantial tissue injury in vivo, additional subsets of T cells exist with regulatory functions (Treg). These subsets include CD4+ type 1 regulatory T cells (Tr1) and CD4+ CD25+ T cells expressing the master transcription factor forkhead box P3 (Foxp3) that may have important implications in disease pathogenesis. In this review, we provide an overview of the current knowledge about the effects of immunomodulating cytokines on CeD inflammatory status. Moreover, we outline the main Treg cell populations found in CeD and how their regulatory activity could be influenced by the intestinal microenvironment. Finally, we discuss the Treg therapeutic potential for the development of alternative strategies to the gluten-free diet (GFD).

Expression analysis of IL-2, TBX21 and SOCS1 in peripheral blood cells of celiac disease patients reveals the diagnostic potential of IL-2

BACKGROUND

Celiac disease (CD) is a chronic immune-mediated enteropathy and a cytokine network is involved in its pathogenesis. Interleukin-2 (IL-2) has a key role in the adaptive immune pathogenesis of CD and has been reported to be one of the earliest cytokines to be elicited after gluten exposure by CD patients. This study aimed at investigating the expression level of IL-2 and functionally related genes SOCS1 and TBX21 in active and treated CD patients compared to controls.

METHODS AND RESULTS

Peripheral blood (PB) samples were collected from 40 active CD (ACD), 100 treated CD, and 100 healthy subjects. RNA was extracted, cDNA was synthesized and mRNA expression levels of the desired genes were investigated by Real-time PCR. The gene-gene interaction network was also constructed by GeneMANIA. Our results showed a higher PB mRNA expression of IL-2 in ACD patients compared to controls (p = 0.001) and treated CD patients (p˂0.0001). The mRNA expression level of TBX21 was also significantly up-regulated in ACD patients compared to controls (P = 0.03). SOCS1 mRNA level did not differ between active and treated CD patients and controls (p˃0.05) but showed a significant correlation with the patient's aphthous stomatitis symptom (r = 0.37, p = 0.01). ROC curve analysis suggested that the use of IL-2 levels can reach a high specificity and sensitivity in discriminating active CD patients.

CONCLUSIONS

The PB level of IL-2 has the potential to be introduced as a diagnostic biomarker for CD. Larger cohort studies, including pediatric patients, are needed to achieve more insights in this regard.

Why are western diet and western lifestyle pro-inflammatory risk factors of celiac disease?

The prevalence of celiac disease increased in recent years. In addition to the genetic and immunological factors, it appears that environmental determinants are also involved in the pathophysiology of celiac disease. Gastrointestinal infections impact the development of celiac disease. Current research does not directly confirm the protective effect of natural childbirth and breastfeeding on celiac disease. However, it seems that in genetically predisposed children, the amount of gluten introduced into the diet may have an impact on celiac disease development. Also western lifestyle, including western dietary patterns high in fat, sugar, and gliadin, potentially may increase the risk of celiac disease due to changes in intestinal microbiota, intestinal permeability, or mucosal inflammation. Further research is needed to expand the knowledge of the relationship between environmental factors and the development of celiac disease to define evidence-based preventive interventions against the development of celiac disease. The manuscript summarizes current knowledge on factors predisposing to the development of celiac disease including factors associated with the western lifestyle.

Gene expression analysis of intestinal IL-8, IL-17 A and IL-10 in patients with celiac and inflammatory bowel diseases

BACKGROUND

Celiac disease (CeD) and inflammatory bowel disease (IBD) are accompanied by impaired immune responses. To study the immune regulation of these diseases, we evaluated the expression levels of pro-inflammatory (IL-8 and IL-17 A) and anti-inflammatory (IL-10) cytokines in intestinal biopsy specimens of CeD and IBD patients in comparison to healthy subjects.

METHODS AND RESULTS

Intestinal biopsies were collected from 33 patients with IBD, 47 patients with CeD, and 20 healthy individuals. Total RNA was extracted and mRNA expression levels of IL-8, IL-17 A and IL-10 were assessed by qPCR. P-value < 0.05 was considered statistically significant. The expression levels of IL-8 and IL-17 A were higher in biopsies of IBD (UC and CD) and CeD patients compared to the control group (P < 0.05). IBD patients (UC and CD) had higher IL-8 intestinal level than CeD patients (P < 0.0001 and P = 0.0007, respectively). The expression of IL-10 was significantly down-regulated in intestinal biopsies of CeD and IBD patients compared with controls (P < 0.001). In addition, the expression level of this cytokine was significantly lower in IBD patients (P < 0.001 for UC patients and P < 0.0001 for CD patients) than CeD group.

CONCLUSIONS

The three selected pro- and anti-inflammatory cytokines showed a similar expression pattern in both IBD and CeD patients. As IBD and CeD are immune-mediated disorders and are accompanied by inflammatory events, the understanding of the similarities and differences among them can help researchers to find out useful candidate therapeutic protocols. We suggest that larger cohort studies be organized to achieve more insights into this regulation.

Assessing Hydrolyzed Gluten Content in Dietary Enzyme Supplements Following Fermentation

Partially digested gluten fragments from grains including wheat, rye, spelt and barley are responsible for triggering an inflammatory response in the intestinal tract of Celiac Disease (CD) and Non-Celiac Gluten Sensitive (NCGS) individuals. Fermentation is an effective method to metabolize gluten, with enzymes from bacterial or fungal species being released to help in this process. However, the levels of gluten in commercially available enzymes, including those involved in gluten fermentation, are unknown. In this study we investigated gluten levels in commercially available dietary enzymes combined with assessing their effect on inflammatory response in human cell culture assays. Using antibodies that recognize different gluten epitopes (G12, R5, 2D4, MloBS and Skerritt), we employed ELISA and immunoblotting methodologies to determine gluten content in crude gluten, crude gliadin, pepsin-trypsin digested gluten and a selection of commercially available enzymes. We further investigated the effect of these compounds on inflammatory response in immortalized immune and intestinal human cell lines, as well as in peripheral blood mononuclear cells (PBMCs) from coeliac individuals. All tested supplemental enzyme products reported a gluten concentration that was equivalent to or below 20 parts per million (ppm) as compared with an intact wheat reference standard and a pepsin-trypsin digested standard. Similarly, the inflammatory response to IL-8 and TNF-α inflammatory cytokines in mammalian cell lines and PBMCs from coeliac individuals to the commercial enzymes was not significantly different to 20 ppm of crude gluten, crude gliadin or pepsin-trypsin digested gluten. This combined approach provides insight into the extent of gluten breakdown in the fermentation process and the safety of these products to gluten-sensitive individuals.

Single-Cell RNA Sequencing of Peripheral Blood Mononuclear Cells From Pediatric Coeliac Disease Patients Suggests Potential Pre-Seroconversion Markers

Celiac Disease (CeD) is a complex immune disorder involving villous atrophy in the small intestine that is triggered by gluten intake. Current CeD diagnosis is based on late-stage pathophysiological parameters such as detection of specific antibodies in blood and histochemical detection of villus atrophy and lymphocyte infiltration in intestinal biopsies. To date, no early onset biomarkers are available that would help prevent widespread villous atrophy and severe symptoms and co-morbidities. To search for novel CeD biomarkers, we used single-cell RNA sequencing (scRNAseq) to investigate PBMC samples from 11 children before and after seroconversion for CeD and 10 control individuals matched for age, sex and HLA-genotype. We generated scRNAseq profiles of 9559 cells and identified the expected major cellular lineages. Cell proportions remained stable across the different timepoints and health conditions, but we observed differences in gene expression profiles in specific cell types when comparing patient samples before and after disease development and comparing patients with controls. Based on the time when transcripts were differentially expressed, we could classify the deregulated genes as biomarkers for active CeD or as potential pre-diagnostic markers. Pathway analysis showed that active CeD biomarkers display a transcriptional profile associated with antigen activation in CD4+ T cells, whereas NK cells express a subset of biomarker genes even before CeD diagnosis. Intersection of biomarker genes with CeD-associated genetic risk loci pinpointed genetic factors that might play a role in CeD onset. Investigation of potential cellular interaction pathways of PBMC cell subpopulations highlighted the importance of TNF pathways in CeD. Altogether, our results pinpoint genes and pathways that are altered prior to and during CeD onset, thereby identifying novel potential biomarkers for CeD diagnosis in blood.

Pathophysiology and immunogenetics of celiac disease

Celiac disease (CD) is a chronic inflammatory enteropathy caused by gluten (protein from wheat, rye and, barley) in genetically predisposed individuals carrying the HLA-DQ2/HLA-DQ8 genotype. This pathology has a multifactorial etiology in which HLA genes, the microbiome, gluten and, other environmental factors are involved in the development of the disease. Its pathogenesis involves both innate and adaptive immunity as well as upregulation of IL-15. The objective of this review is to examine the results of current studies on genetic and environmental variables to better understand the pathogenesis of this enteropathy. The complex etiology of celiac disease makes our understanding of the pathogenesis of the disease incomplete, and a better knowledge of the many genetic and environmental components would help us better understand the pathophysiology of celiac disease.

Potential impact of celiac disease genetic risk factors on T cell receptor signaling in gluten-specific CD4+ T cells

Celiac disease is an auto-immune disease in which an immune response to dietary gluten leads to inflammation and subsequent atrophy of small intestinal villi, causing severe bowel discomfort and malabsorption of nutrients. The major instigating factor for the immune response in celiac disease is the activation of gluten-specific CD4+ T cells expressing T cell receptors that recognize gluten peptides presented in the context of HLA-DQ2 and DQ8. Here we provide an in-depth characterization of 28 gluten-specific T cell clones. We assess their transcriptional and epigenetic response to T cell receptor stimulation and link this to genetic factors associated with celiac disease. Gluten-specific T cells have a distinct transcriptional profile that mostly resembles that of Th1 cells but also express cytokines characteristic of other types of T-helper cells. This transcriptional response appears not to be regulated by changes in chromatin state, but rather by early upregulation of transcription factors and non-coding RNAs that likely orchestrate the subsequent activation of genes that play a role in immune pathways. Finally, integration of chromatin and transcription factor binding profiles suggest that genes activated by T cell receptor stimulation of gluten‑specific T cells may be impacted by genetic variation at several genetic loci associated with celiac disease.

Intestinal Regulatory T Cells

Mucosal surfaces are distinctive sites exposed to environmental, dietary, and microbial antigens. Particularly in the gut, the host continuously actively adapts via complex interactions between the microbiota and dietary compounds and immune and other tissue cells. Regulatory T cells (Tregs) are critical for tuning the intestinal immune response to self- and non-self-antigens in the intestine. Its importance in intestinal homeostasis is illustrated by the onset of overt inflammation caused by deficiency in Treg generation, function, or stability in the gut. A substantial imbalance in Tregs has been observed in intestinal tissue during pathogenic conditions, when a tightly regulated and equilibrated system becomes dysregulated and leads to unimpeded and chronic immune responses. In this chapter, we compile and critically discuss the current knowledge on the key factors that promote Treg-mediated tolerance in the gut, such as those involved in intestinal Treg differentiation, specificity and suppressive function, and their immunophenotype during health and disease. We also discuss the current state of knowledge on Treg dysregulation in human intestine during pathological states such as inflammatory bowel disease (IBD), necrotizing enterocolitis (NEC), graft-versus-host disease (GVHD), and colorectal cancer (CRC), and how that knowledge is guiding development of Treg-targeted therapies to treat or prevent intestinal disorders.

IL-33 Alarmin and Its Active Proinflammatory Fragments Are Released in Small Intestine in Celiac Disease

Initially described as Th2 promoter cytokine, more recently, IL-33 has been recognized as an alarmin, mainly in epithelial and endothelial cells. While localized in the nucleus acting as a gene regulator, it can be also released after injury, stress or inflammatory cell death. As proinflammatory signal, IL-33 binds to the surface receptor ST2, which enhances mast cell, Th2, regulatory T cell, and innate lymphoid cell type 2 functions. Besides these Th2 roles, free IL-33 can activate CD8⁺ T cells during ongoing Th1 immune responses to potentiate its cytotoxic function. Celiac Disease (CD) is a chronic inflammatory disorder characterized by a predominant Th1 response leading to multiple pathways of mucosal damage in the proximal small intestine. By immunofluorescence and western blot analysis of duodenal tissues, we found an increased expression of IL-33 in duodenal mucosa of active CD (ACD) patients. Particularly, locally digested IL-33 releases active 18/21kDa fragments which can contribute to expand the proinflammatory signal. Endothelial (CD31⁺) and mesenchymal, myofibroblast and pericyte cells from microvascular structures in villi and crypts, showed IL-33 nuclear location; while B cells (CD20⁺) showed a strong cytoplasmic staining. Both ST2 forms, ST2L and sST2, were also upregulated in duodenal mucosa of CD patients. This was accompanied by increased number of CD8⁺ST2⁺ T cells and the expression of T-bet in some ST2⁺ intraepithelial lymphocytes and lamina propria cells. IL-33 and sST2 mRNA levels correlated with IRF1, an IFN induced factor relevant in responses to viral infections and interferon mediated proinflammatory responses highly represented in duodenal tissues in ACD. These findings highlight the potential contribution of IL-33 and its fragments to exacerbate the proinflammatory circuit and potentiate the cytotoxic activity of CD8⁺ T cells in CD pathology.

Suppressed immune profile in children with combined type 1 diabetes and celiac disease

Children diagnosed with a combination of type 1 diabetes (T1D) and celiac disease (CD) show a dysregulated T helper type 1 (Th1)/Th17 response. Besides the cellular involvement, several soluble immune markers are involved in the autoimmune process of both T1D and CD. Only few studies have examined the peripheral pattern of different cytokines, chemokines and acute-phase proteins (APP) in children with combined T1D and CD. To our knowledge, no studies have evaluated the serum levels of adipocytokines and matrix metalloproteinases (MMPs) in this context. The purpose of the present study was to acquire more knowledge and to gain deeper understanding regarding the peripheral immunoregulatory milieu in children with both T1D and CD. The study included children diagnosed with both T1D and CD (n = 18), children with T1D (n = 27) or CD (n = 16) and reference children (n = 42). Sera were collected and analysis of 28 immune markers (cytokines, chemokines, APPs, adipocytokines and MMPs) was performed using the Luminex technique. The major findings showed that children with a double diagnosis had lower serum levels of interleukin (IL)-22, monocyte chemoattractant protein (MIP)-1α, monocyte chemoattractant protein (MCP)-1, procalcitonin, fibrinogen, visfatin and matrix metalloproteinase (MMP)-2. These results indicate a suppressed immune profile in children with combined T1D and CD, including Th17 cytokines, chemokines, APPs, adipocytokines and MMPs. We conclude that, besides cytokines and chemokines, other immune markers, e.g. APPs, adipocytokines and MMPs, are of importance for further investigations to elucidate the heterogeneous immune processes present in patients diagnosed with T1D in combination with CD.

Deciphering crucial genes in coeliac disease by bioinformatics analysis

Coeliac disease (CD) is a chronic autoimmune disease that is characterized by malabsorption in sensitive individuals. CD is triggered by the ingestion of grains containing gluten. CD is concomitant with several other disorders, including dermatitis herpetiformis, selective IgA deficiency, thyroid disorders, diabetes mellitus, various connective tissue disorders, inflammatory bowel disease, and rheumatoid arthritis. The advent of high throughput technologies has provided a massive wealth of data which are processed in various omics scale fields. These approaches have revolutionized the medical research and monitoring of the biological systems. In this regard, omics scaled analyses of CD by Comparative Toxicogenomics Database (CTD), DISEASES, and GeneCards databases have retrieved 2656 CD associated genes. Amongst, 54 genes were assigned by Venn Diagram of the intersection to be shared by these 3 databases for CD. These common genes were subjected to further analysis and screening. The Enrich database, GeneMANIA, Cytoscape, and WebGestalt (WEB-based GEne SeT AnaLysis Toolkit) were employed for functional analysis. These analyses indicated that the obtained genes are mainly involved in the immune system and signalling pathways related to autoimmune diseases. The STAT1, ALB, IL10, IL2, IL4, IL17A, TGFB1, IL1B, IL6, TNF, IFNG hub genes were particularly indicated to have significant roles in CD. Functional analyses of these hub genes by GeneMANIA indicated that they are involved in immune systems regulation. Moreover, 25 out of 54 genes were identified to be seed genes by the WebGestalt database. Gene set analysis with GEO2R tool from Gene Expression Omnibus (GEO) showed that there were 15 significant genes in GSE76168, 29 significant genes in GSE87460, 12 significant genes in GSE87458, 9 significant genes in GSE87457, 3753 significant genes in GSE112102 and 1043 significant genes in GSE102991 with differential expression in coeliac patients compared to controls. The IRF1and STAT1 genes were common between the significant genes from GEO and the 54 CD related genes from three public databases. In the light these results, nine key genes, including IRF1, STAT1, IL17A, TGFB1, ALB, IL10, IL2, IL4, and IL1B, were identified to be associated with CD. These findings could be used to find novel diagnostic biomarkers, understand the pathology of disease, and devise more efficient treatments.

Immunoregulatory properties of cell-free DNA in plasma of celiac disease patients - A pilot study

The elevated plasma cell-free DNA (cfDNA) concentrations were repeatedly reported in association with the process of inflammation. The qualitative and quantitative characteristics of plasma cfDNA in active (newly diagnosed) celiac disease patients (CD) have not yet been studied despite the fact that cfDNA of healthy individuals is able to regulate immune response. We determined the total cfDNA concentration and relative content of telomeric sequences in plasma cfDNA in CD (n = 10) and healthy age- and sex-matched controls (HC, n = 10) by quantitative PCR. To obtain the evidence that the observed biological effects are caused solely by cfDNA molecules, we applied the treatment of paired plasma samples with DNase. Using paired samples of plasma (non-treated/native and treated by DNase), we analyzed the contribution of cfDNA to the activation of TLR9 and TNF-α mRNA expression in THP1 monocytic cell line. There were no significant differences in the quantities of plasma cfDNA and relative contents of telomeric sequences in their pools. When we compared the levels of TNF-α mRNA expression in THP1 cells achieved after stimulation with native CD and HC plasma samples, we found significantly (p = .031) higher expression after stimulation with CD samples. We documented also the ability of cfDNA contained in CD plasma samples to stimulate the production of TLR9 mRNA. The TLR9 mRNA expression levels were significantly (p = .014) lowered after cfDNA removal from CD plasma samples. The design of our experiments allowed us to study the effects of cfDNA without its isolation from plasma. cfDNA contained in CD plasma samples differs significantly in its immunoregulatory capacity from cfDNA in HC plasma. The differences are caused neither by different concentrations of cfDNA in plasma samples nor by different relative abundance of telomeric sequences. Further studies are needed to elucidate the role of plasma cfDNA in celiac disease pathogenesis.

Pachychoroid Pigment Epitheliopathy and Choroidal Thickness Changes in Coeliac Disease

Purpose

To evaluate choroidal thickness in patients with coeliac disease (CD) using spectral domain optical coherence tomography (SD-OCT) and to compare the results to normal eyes.

Methods

Seventy patients with CD and 70 healthy controls were included in this prospective, comparative study. All participants underwent a complete ophthalmologic evaluation and SD-OCT. Subfoveal, nasal (nasal distance to fovea 500 μm, 1000 μm, and 1500 μm), and temporal (temporal distance to fovea 500 μm, 1000 μm, and 1500 μm) choroidal thickness measurements were performed using SD-OCT.

Results

There were no significant differences in sex, ages, and axial lengths between the groups (p=1.0, p=0.601, p=0.314, respectively). The mean choroidal thickness measurements at all predefined measurement point areas were higher in the coeliac group than in the healthy controls (p < 0.001). Of all patients with coeliac disease (70 eyes of 70 patients), 64 eyes (84.2%) had uncomplicated pachychoroid (UCP), one eye had pachychoroid pigment epitheliopathy (PPE), and five eyes in the UCP group had PPE in fellow eyes.

Conclusion

It is probable that systemic inflammation in coeliac patients causes the enlargement of choroidal vessels and increasing choroidal thickness. PPE, which is believed to be the precursor of central serous chorioretinopathy, can be observed in coeliac patients.

Ex vivo immunomodulatory effect of ethanolic extract of propolis during Celiac Disease: involvement of nitric oxide pathway

Celiac Disease (CeD) is a chronic immune-mediated enteropathy, in which dietary gluten induces an inflammatory reaction, predominantly in the duodenum. Propolis is a resinous hive product, collected by honeybees from various plant sources. Propolis is well-known for its anti-inflammatory, anti-oxidant and immunomodulatory effects, due to its major compounds, polyphenols and flavonoids. The aim of our study was to assess the ex vivo effect of ethanolic extract of propolis (EEP) upon the activity and expression of iNOS, along with IFN-γ and IL-10 production in Algerian Celiac patients. In this context, PBMCs isolated from peripheral blood of Celiac patients and healthy controls were cultured with different concentrations of EEP. NO production was measured using the Griess method, whereas quantitation of IFN-γ and IL-10 levels was performed by ELISA. Inducible nitric oxide synthase (iNOS) expression, NFκB and pSTAT-3 activity were analyzed by immunofluorescence assay. Our results showed that PBMCs from Celiac patients produced high levels of NO and IFN-γ compared with healthy controls (HC). Interestingly, EEP reduced significantly, NO and IFN-γ levels and significantly increased IL-10 levels at a concentration of 50 µg/mL. Importantly, EEP downmodulated the iNOS expression as well as the activity of NFκB and pSTAT-3 transcription factors. Altogether, our results highlight the immunomodulatory effect of propolis on NO pathway and on pro-inflammatory cytokines. Therefore, we suggest that propolis may constitute a potential candidate to modulate inflammation during Celiac Disease and has a potential therapeutic value.

Laser Capture Microdissection as a Tool to Study the Mucosal Immune Response in Celiac Disease

Laser capture microdissection (LCM) is a powerful tool for selection and isolation of single cells or compartments from complex primary tissues to perform molecular analyses. Celiac disease is a genetic autoimmune disorder where the ingestion of gluten leads to damage in the small intestine. Increased intraepithelial lymphocytes and the presence of the lamina propria inflammatory infiltrate of the duodenal mucosa is a common part of the disease. These cells promote inflammatory processes through the release of cytokines. Here, we describe the use of LCM and real-time quantitative PCR (RT-qPCR) to analyze cytokine profile information in distinct duodenal mucosa tissue compartments of celiac patients.

Local ocular surface parameters in patients with systemic celiac disease

PurposeThis was a collaborative study from the Ophthalmology and Gastroenterology departments of a tertiary care hospital, designed to investigate the local ocular surface parameters in patients with celiac disease (CD).MethodsFifty-six eyes of 28 patients with CD and 58 eyes of 29 healthy adult subjects serving as controls were evaluated. The Schirmer test, tear-film break-up time, and conjunctival impression cytology were performed in addition to a complete ophthalmological examination. Impression cytology specimens of each group were graded and scored in the range 0-3.ResultsThe 28 patients with CD consisted of 24 females (86%) and 4 males (14%). The mean age was 34.4±11.3 years (22-55 years). Tear-film break-up time and Schirmer test results were significantly lower in the study group than in the controls (P<0.05). Also, there was a significant difference between the groups for impression cytology grading scores (P=0.001).ConclusionsThe CD group showed a marked preponderance of females with an F/M ratio of six females per male, as reported in the literature. Tear-film functions and conjunctival surface epithelial morphology were significantly altered in patients with CD.

TNF-α -308 G > A (rs1800629) Polymorphism is Associated with Celiac Disease: A Meta-analysis of 11 Case-Control Studies

Celiac disease (CD) remains one of the most significant autoimmune diseases worldwide. The pathogenesis of CD is not clearly understood and is probably attributed to genomic variations and host genetic make-up. Case-control and cohort studies of the association between the TNF-α -308 G > A (rs1800629) polymorphism and CD susceptibility have yielded inconsistent results. In this study, PubMed, EMBASE, and Google Scholar web-databases were searched for pertinent reports showing association of TNF-α -308 G > A gene with CD risk. A total of eleven reports involving 1774 controls and 1147 CD cases were included. Significant associations in four genetic models, viz. variant allele (A vs. G: p = 0.001; OR = 2.051, 95% CI = 1.452-2.895), variant homozygous (AA vs. GG: p = 0.001; OR = 6.626, 95% CI = 3.569-12.300), recessive (AA vs. GG + AG: p = 0.001; OR = 4.766, 95% CI = 3.177-7.152) and dominant (AA + AG vs. GG: p = 0.008; OR = 1.910, 95% CI = 1.181-3.088) were found in comparison with wild type homozygous GG genotype. However, heterozygous genetic model did not show any association. Sensitivity analysis revealed stable and statistically robust results. Our results suggest that TNF-α -308 G > A gene polymorphism significantly contributes to CD susceptibility.

Transglutaminase 2-specific coeliac disease autoantibodies induce morphological changes and signs of inflammation in the small-bowel mucosa of mice

Coeliac disease is hallmarked by an abnormal immune reaction against ingested wheat-, rye- and barley-derived gluten and the presence of transglutaminase 2 (TG2)-targeted autoantibodies. The small-bowel mucosal damage characteristic of the disorder develops gradually from normal villus morphology to inflammation and finally to villus atrophy with crypt hyperplasia. Patients with early-stage coeliac disease have TG2-autoantibodies present in serum and small-intestinal mucosa and they may already suffer from abdominal symptoms before the development of villus atrophy. Previously, we have shown that intraperitoneal injections of coeliac patient-derived sera or purified immunoglobulin fraction into mice induce a condition mimicking early-stage coeliac disease. In the current study, we sought to establish whether recombinantly produced patient-derived TG2-targeted autoantibodies are by themselves sufficient for the development of such an experimentally induced condition in immune-compromised mice. Interestingly, mice injected with coeliac patient TG2-antibodies had altered small-intestinal mucosal morphology, increased lamina propria cellular infiltration and disease-specific autoantibodies deposited in the small bowel, but did not evince clinical features of the disease. Thus, coeliac patient-derived TG2-specific autoantibodies seem to be sufficient for the induction of subtle small-bowel mucosal alterations in mice, but the development of clinical features probably requires additional factors such as other antibody populations relevant in coeliac disease.

The Role of T-Cell Subsets in Chronic Inflammation in Celiac Disease and Inflammatory Bowel Disease Patients: More Common Mechanisms or More Differences?

Background

Chronic intestinal inflammation due to noninfectious causes represents a growing health issue all over the world. Celiac disease as well as inflammatory bowel diseases (IBD) like Crohn's disease and ulcerative and microscopic colitis involve uncontrolled T-cell activation and T-cell-mediated damage as common denominators. Therefore, diagnosis and treatment decisions clearly benefit from the knowledge of the intricacies of the systemic and the local T-cell activity.

Summary

Depending on the cytokine milieu, CD4⁺ T cells can differentiate into proinflammatory T helper 1 (Th1), anti-inflammatory Th2, antimicrobial Th17, pleiotropic Th9, tissue-instructing Th22 cells, and in the regulatory compartment forkhead box protein 3⁺ Treg, suppressive Tr1 or Th3 cells. Additionally, follicular Th cells provide B-cell help in antibody class switching; cytotoxic CD8⁺ T cells target virus-infected or tumor cells. This review discusses our current knowledge on the contribution of defined T-cell subpopulations to establishing and maintaining chronic intestinal inflammation in either of the above entities. It also puts emphasis on the differences in the prevalence of these diseases between Eastern and Western countries.

Key Messages

In celiac disease, the driving role of T cells in the lamina propria and in the epithelium mainly specific for two defined antigens is well established. Differences in genetics and lifestyle between Western and Eastern countries were instrumental in understanding underlying mechanisms. In IBD, the vast amount of potential antigens and the corresponding antigen-specific T cells makes it unlikely to find universal triggers. Increased mucosal CD4⁺ regulatory T cells in all four entities fail to control or abrogate local inflammatory processes. Thus, prevailing differences in the functional T-cell subtypes driving chronic intestinal inflammation in celiac disease and IBD at best allow some overlap in the treatment options for either disease.

Celiac disease: role of intestinal compartments in the mucosal immune response

Different approaches have been used to study the pattern of cytokines in celiac disease (CD). Laser capture microdissection (LCM) is a powerful tool for the isolation of specific tissue compartments. We aimed to investigate the mucosal immune response that takes place in different intestinal compartments of CD patients, dissected by LCM, analyzing cytokine expression profile. Frozen section of jejunum was obtained from 15 untreated CD and 15 control. Surface epithelium and lamina propria compartment were isolated by LCM. RNA from each LCM sample was extracted and, after a retrotranscription step, messenger RNA levels for MxA, IL-15, TNF-α, IFN-γ, IL-17α, IL-21, IL-10, and TGF-β were determined by quantitative reverse transcriptase-PCR. Increased gene expression levels of MxA, IL-15, TNF-α, IL-10, and TGF-β was observed in the surface epithelium of untreated CD with respect to control. Furthermore, all the cytokines investigated were upregulated in the lamina propria of untreated CD as compared to control. Within the untreated CD group the expression of IL-15 was higher, in the surface epithelium than in the lamina propria, whereas the expression levels of IL-17 and IL-21 were higher in the lamina propria than in the surface epithelium. Finally, high levels of IL-10 and TGF-β were detected in both compartments of untreated CD biopsies. In CD, surface epithelium and lamina propria compartments, play a prominent role in determining innate and adaptive immunity, respectively. Conversely, surface epithelium and lamina propria produce high levels of anti-inflammatory cytokines, suggesting that both compartments are involved in the immunoregulatory response.

Low expression of CD39(+) /CD45RA(+) on regulatory T cells (Treg ) cells in type 1 diabetic children in contrast to high expression of CD101(+) /CD129(+) on Treg cells in children with coeliac disease

Type 1 diabetes (T1D) and coeliac disease are both characterized by an autoimmune feature. As T1D and coeliac disease share the same risk genes, patients risk subsequently developing the other disease. This study aimed to investigate the expression of T helper (Th), T cytotoxic (Tc) and regulatory T cells (Treg ) in T1D and/or coeliac disease children in comparison to healthy children. Subgroups of T cells (Th : CD4(+) or Tc : CD8(+) ); naive (CD27(+) CD28(+) CD45RA(+) CCR7(+) ), central memory (CD27(+) CD28(+) CD45RA(-) CCR7(+) ), effector memory (early differentiated; CD27(+) CD28(+) CD45RA(-) CCR7(-) and late differentiated; CD27(-) CD28(-) CD45RA(-) CCR7(-) ), terminally differentiated effector cells (TEMRA; CD27(-) CD28(-) CD45RA(+) CCR7(-) ) and Treg (CD4(+) CD25(+) FOXP3(+) CD127(-) ) cells, and their expression of CD39, CD45RA, CD101 and CD129, were studied by flow cytometry in T1D and/or coeliac disease children or without any of these diseases (reference group). Children diagnosed with both T1D and coeliac disease showed a higher percentage of TEMRA CD4(+) cells (P < 0·05), but lower percentages of both early and late effector memory CD8(+) cells (P < 0·05) compared to references. Children with exclusively T1D had lower median fluorescence intensity (MFI) of forkhead box protein 3 (FoxP3) (P < 0·05) and also a lower percentage of CD39(+) and CD45RA(+) within the Treg population (CD4(+) CD25(+) FOXP3(+) CD127(-) ) (P < 0·05). Children with exclusively coeliac disease had a higher MFI of CD101 (P < 0·01), as well as a higher percentage of CD129(+) (P < 0·05), in the CD4(+) CD25(hi) lymphocyte population, compared to references. In conclusion, children with combined T1D and coeliac disease have a higher percentage of differentiated CD4(+) cells compared to CD8(+) cells. T1D children show signs of low CD39(+) /CD45RA(+) Treg cells that may indicate loss of suppressive function. Conversely, children with coeliac disease show signs of CD101(+) /CD129(+) Treg cells that may indicate suppressor activity.

Vaccination and other antigen-specific immunomodulatory strategies in celiac disease

BACKGROUND

Celiac disease (CD) results from an alteration in the oral tolerance to dietary gluten. The response to gluten is normally tightly regulated and involves the secretion of TGF-β and IL-10 from different subtypes of regulatory T cells (Tregs). Interestingly, in addition to proinflammatory cytokines, the inflamed CD mucosa also contains high levels of T cell-derived IL-10 compared with treated CD patients or normal donors. Furthermore, most studies describe an increase in the number of Foxp3+ Tregs in the small intestinal mucosa in CD patients compared to controls. This paradoxical condition suggests that regulatory mechanisms might operate to counterbalance the abnormal gliadin-triggered immune activation in untreated mucosa. Indeed, addition of exogenous IL-10 to mucosal cultures from treated CD patients can suppress gliadin-induced T cell activation. Considering the central role of adaptive immunity in CD, the development of strategies to stimulate these mechanisms is a primary goal of efforts to restore gluten tolerance. Key Messages: Different immunomodulatory strategies have been explored. NexVax2, a desensitizing vaccine that uses three dominant gluten peptides administered subcutaneously to induce a tolerogenic response in CD patients, is under development. Alternatively, the potential of substituted, cyclic or dimeric peptide analogues as blockers to prevent HLA from binding to the immunodominant gliadin epitopes has been demonstrated in vitro. In line with these results, we recently found that modified (transamidated) gliadins influenced the immune response in intestinal biopsy samples from CD patients with overt disease by drastically reducing the production of IFN-γ. Notably, in a mouse model, transamidated gliadins reverted the phenotype of the gliadin-inducible immune response from an inflammatory phenotype to an anti-inflammatory phenotype.

CONCLUSIONS

Various approaches are currently under investigation to recover gluten tolerance based on the use of both modified and native antigen molecules. More specific studies are now required to test the efficacy of such strategies for preventing CD.

Serum cytokine pattern in young children with screening detected coeliac disease

Coeliac disease is an autoimmune disease characterized by inflammation localized to the small bowel, but less is known about systemic signs of inflammation. The aim was to measure cytokines of the T helper 1 (Th1) and T helper 2 (Th2) cell patterns in children with screening-detected coeliac disease before and after treatment with a gluten-free diet. Serum samples selected before and after the start of a gluten-free diet from 26 3-year-old children diagnosed with biopsy-proven coeliac disease and from 52 matched controls were assayed in an multiplex enzyme-linked immunosorbent assay (ELISA) for the 10 cytokines: interferon (IFN)-γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-8, IL-10, IL-12p70, IL-13 and tumour necrosis factor (TNF)-α. Among Th1 cytokines, IFN-γ and IL-12p70 were elevated significantly in children with coeliac disease compared to controls (P < 0·001 and P = 0·001, respectively). Similar findings were demonstrated for the Th2 cytokines IL-5 (P < 0·001), IL-10 (P = 0·001) and IL-13 (P = 0·002). No difference in cytokine levels between the two groups was found for TNF-α, IL-1β, IL-2, IL-4 and IL-8. After gluten-free diet, levels of IL-5, IL-12 and IL-10 decreased significantly (P < 0·001, P = 0·002 and P = 0·007) and IFN-γ levels were reduced (P = 0·059). Young children with coeliac disease detected by screening demonstrate elevated levels of serum cytokines at time of diagnosis. A prolonged systemic inflammation may, in turn, contribute to long-term complications known to be associated with untreated coeliac disease.

Peroxisome proliferator-activated receptor-γ and thymic stromal lymphopoietin are involved in the pathophysiology of childhood coeliac disease

Celiac disease (CD) is a chronic autoimmune enteropathy caused by exposure to dietary gluten in genetically predisposed individuals. The transcription factor peroxisome proliferator-activated receptor gamma (PPARγ) was shown to exert protective effects in several immune-mediated disorders. Activation of PPARγ suppressed the expression of thymic stromal lymphopoietin (TSLP), an inducer of proinflammatory cytokines. Since the role of TSLP in gluten-sensitive enteropathy is completely unknown, we investigated the involvement of TSLP and its regulator PPARγ in childhood CD. We collected duodenal biopsy specimens from 19 children with newly diagnosed CD, 6 children with treated CD (gluten-free diet, GFD), and 10 controls. Expression of mRNA and protein levels of PPARγ, TSLP, and TSLP receptor were determined by real-time RT-PCR and Western blot, respectively. Duodenal localization of PPARγ and TSLP was studied by immunohistochemistry. In duodenal mucosa of children with CD, the amount of PPARγ was significantly lower and simultaneously that of TSLP significantly higher compared to controls (p < 0.05). In GFD-treated patients, the levels of PPARγ mRNA and protein were significantly higher while that of TSLP markedly lower compared to newly diagnosed CD (p < 0.05). Immunohistochemistry revealed PPARγ and TSLP expression in lamina propria immune cells and in enterocytes. Low expression of PPARγ and high expression of TSLP in the duodenal mucosa of children with newly diagnosed CD suggest that they are involved in the pathophysiology of CD. We hypothesize that PPARγ may be an inhibitory regulator of TSLP-stimulated inflammatory processes in CD.

DHA serum levels were significantly higher in celiac disease patients compared to healthy controls and were unrelated to depression

Objectives

Celiac disease (CD), a genetically predisposed intolerance for gluten, is associated with an increased risk of major depressive disorder (MDD). We investigated whether dietary intake and serum levels of the essential n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) found in fatty fish play a role in this association.

Methods

Cross-sectional study in 71 adult CD patients and 31 healthy volunteers, matched on age, gender and level of education, who were not using n-3 PUFA supplements. Dietary intake, as assessed using a 203-item food frequency questionnaire, and serum levels of EPA and DHA were compared in analyses of covariance, adjusting for potential confounders. Serum PUFA were determined using gas chromatography.

Results

Mean serum DHA was significantly higher in CD patients (1.72 mass%) than controls (1.28 mass%) after multivariable adjustment (mean diff. 0.45 mass%; 95% CI: 0.22–0.68; p = 0.001). The mean intake of EPA plus DHA did not differ between CD patients and controls after multivariable adjustment (0.15 and 0.22 g/d, respectively; p = 0.10). There were no significant differences in intake or serum levels of EPA and DHA between any of the CD patient groups (never depressed, current MDD, minor/partially remitted MDD, remitted MDD) and controls.

Conclusions

Patients on a long term gluten-free diet had similar intakes of EPA plus DHA compared to controls. Contrary to expectations, DHA serum levels were significantly higher in CD patients compared to healthy controls and were unrelated to MDD status.

Molecular mechanisms of the adaptive, innate and regulatory immune responses in the intestinal mucosa of celiac disease patients

Celiac disease is a complex genetic disorder that affects the small intestine of genetically predisposed individuals when they ingest gluten, a dietary protein. Although several genome screens have been successful in identifying susceptibility loci in celiac disease, the only genetic contributors identified so far are the human leukocyte antigen (HLA)-DQ2/DQ8 molecules. One of the most important aspects in the pathogenesis of celiac disease is the activation of a T-helper 1 immune response, when the antigen-presenting cells that express HLA-DQ2/DQ8 molecules present the toxic gluten peptides to reactive CD4(+) T-cells. Recently, new insights into the activation of an innate immune response have also been described. It is generally accepted that the immune response triggers destruction of the mucosa in the small intestine of celiac disease patients. Hence, the activation of a detrimental immune response in the intestine of celiac disease patients appears to be key in the initiation and progression of the disease. This review summarizes the immunologic pathways that have been studied in celiac disease thus far, and will point to new potential candidate genes and pathways involved in the etiopathogenesis of celiac disease, which should lead to novel alternatives for diagnosis and treatment.

The role of transforming growth factor (TGF)-β in modulating the immune response and fibrogenesis in the gut

Transforming growth factor (TGF)-β, a pleiotropic cytokine released by both immune and non-immune cells in the gut, exerts an important tolerogenic action by promoting regulatory T cell differentiation. TGF-β also enhances enterocyte migration and regulates extracellular matrix turnover, thereby playing a crucial role in tissue remodeling in the gut. In this review we describe the mechanisms by which abnormal TGF-β signaling impairs intestinal immune tolerance and tissue repair, thus predisposing to the onset of immune-mediated bowel disorders, such as inflammatory bowel disease and celiac disease. Additionally, we will discuss potential therapeutic strategies aiming at restoring physiologic TGF-β signaling in chronic intestinal diseases.

Serum soluble interleukin-2 receptor, interleukin-6 and tumor necrosis factor alpha as markers of celiac disease activity

OBJECTIVES

To evaluate the markers of lymphocyte activation (sIL-2R, IL-6 and TNF α) in the peripheral blood of newly diagnosed patients with celiac disease (CD) and patients with CD on Gluten free diet (GFD) for at least 2 y. The markers were correlated with conventional serological tests Anti-tissue transglutaminase (Anti-TTG) used for diagnosis and follow up of the disease; wherever possible.

METHODS

Thirty newly diagnosed cases of CD (on the basis of histopathology and serology) not on GFD were enrolled as Group 1 of the study. Thirty age and sex matched controls from the Pediatric Surgery OPD formed Group 2. Thirty cases of CD on GFD for at least 2 y (Group 3) were also enrolled in the study. Upper G.I. endoscopy was performed in all Group 1 patients and cytokine levels assayed by ELISA on serum obtained from all patients in Groups 1, 2, 3.

RESULTS

Mean sIL-2R level in Group 1(1498.1+/-1234.31 pg/ml) and Group 3 (488.78+/-396.18 pg/ml) were significantly higher than the controls (336.27+/-218.67 pg/ml p < 0.05). Among the patients with CD, mean serum levels in Group 1 were higher than in Group 3 (p < 0.05). sIL-2R levels showed good correlation with tTg levels in Group 1 patients (p < 0.000, r = 0.69). Mean IL-6 levels in Group 1 were significantly higher (28.43+/-28.32 pg/ml) than Group 2(15.03+/-7.72 pg/ml p < 0.05) and Group 3(11.26+/-5.13 pg/ml p < 0.05). IL-6 levels were comparable between Groups 2 and 3 (p > 0.05).IL-6 levels showed good correlation with tTg levels in Group 1(p < 0.008, r = 0.471). Mean TNFα levels in Group 1(179.66+/-102.93 pg/ml), Group 2 (153.16+/-27.02 pg/ml) and Group 3 (166.67+/-28.95 pg/ml) were comparable (p > 0.05). TNFα levels showed poor correlation with tTg levels in Group 1 patients (p > 0.604, r = -0.099).

CONCLUSIONS

sIL-2R and IL-6 levels have a good correlation with CD activity and can be used as reliable markers for detecting minimal transgression from GFD.

Smad7 inhibits autocrine expression of TGF-β2 in intestinal epithelial cells in baboon necrotizing enterocolitis

Preterm infants may be at risk of necrotizing enterocolitis (NEC) due to deficiency of transforming growth factor-β 2 (TGF-β(2)) in the developing intestine. We hypothesized that low epithelial TGF-β(2) expression in preterm intestine and during NEC results from diminished autocrine induction of TGF-β(2) in these cells. Premature baboons delivered at 67% gestation were treated per current norms for human preterm infants. NEC was diagnosed by clinical and radiological findings. Inflammatory cytokines, TGF-β(2), Smad7, Ski, and strawberry notch N (SnoN)/Ski-like oncoprotein (SKIL) was measured using quantitative reverse transcriptase-polymerase chain reaction, immunoblots, and immunohistochemistry. Smad7 effects were examined in transfected IEC6 intestinal epithelial cells in vitro. Findings were validated in archived human tissue samples of NEC. NEC was recorded in seven premature baboons. Consistent with existing human data, premature baboon intestine expressed less TGF-β(2) than term intestine. TGF-β(2) expression was regulated in epithelial cells in an autocrine fashion, which was interrupted in the premature intestine and during NEC due to increased expression of Smad7. LPS increased Smad7 binding to the TGF-β(2) promoter and was associated with dimethylation of the lysine H3K9, a marker of transcriptional silencing, on the nucleosome of TGF-β(2). Increased Smad7 expression in preterm intestine was correlated with the deficiency of SnoN/SKIL, a repressor of the Smad7 promoter. Smad7 inhibits autocrine expression of TGF-β(2) in intestinal epithelial cells in the normal premature intestine and during NEC. Increased Smad7 expression in the developing intestine may be due to a developmental deficiency of the SnoN/SKIL oncoprotein.

Serum parameters in the spectrum of coeliac disease: beyond standard antibody testing--a cohort study

BACKGROUND

Invasive techniques are still required to distinguish between uncomplicated and complicated forms of CD.

METHODS

We set out to investigate the potential use of novel serum parameters, including IL-6, IL-8, IL-17, IL-22, sCD25, sCD27, granzyme-B, sMICA and sCTLA-4 in patients diagnosed with active CD, CD on a GFD, Refractory coeliac disease (RCD) type I and II, and enteropathy associated T-cell lymphoma (EATL).

RESULTS

In both active CD and RCDI-II elevated levels of the proinflammatory IL-8, IL-17 and sCD25 were observed. In addition, RCDII patients displayed higher serum levels of soluble granzyme-B and IL-6 in comparison to active CD patients. In contrast, no differences between RCDI and active CD or RCDII were observed. Furthermore, EATL patients displayed higher levels of IL-6 as compared to all other groups.

CONCLUSIONS

A series of novel serum parameters reveal distinctive immunological characteristics of RCDII and EATL in comparison to uncomplicated CD and RCDI.

Intestinal cell targeting of a stable recombinant Cu-Zn SOD from Cucumis melo fused to a gliadin peptide

The mRNA encoding full length chloroplastic Cu-Zn SOD (superoxide dismutase) of Cucumis melo (Cantaloupe melon) was cloned. This sequence was then used to generate a mature recombinant SOD by deleting the first 64 codons expected to encode a chloroplastic peptide signal. A second hybrid SOD was created by inserting ten codons to encode a gliadin peptide at the N-terminal end of the mature SOD. Taking account of codon bias, both recombinant proteins were successfully expressed and produced in Escherichia coli. Both recombinant SODs display an enzymatic activity of ~5000U mg(-1) and were shown to be stable for at least 4h at 37°C in biological fluids mimicking the conditions of intestinal transit. These recombinant proteins were capable in vitro, albeit at different levels, of reducing ROS-induced-apoptosis of human epithelial cells. They also stimulated production and release in a time-dependent manner of an autologous SOD activity from cells located into jejunum biopsies. Nevertheless, the fused gliadin peptide enable the recombinant Cu-Zn SOD to maintain a sufficiently sustained interaction with the intestinal cells membrane in vivo rather than being eliminated with the flow. According to these observations, the new hybrid Cu-Zn SOD should show promise in applications for managing inflammatory bowel diseases.

Enzyme linked immuno-spot; a useful tool in the search for elusive immune markers in common pediatric immunological diseases

In order to provide better therapy we strive to increase our knowledge of how the immune system behaves and communicates in common pediatric immunological diseases, such as type 1 diabetes, allergic and celiac diseases. However, when dealing with pediatric diseases, where study subjects are almost exclusively children, blood volumes available for immunological studies are limited and as such must be carefully handled and used to their full extent. Single immune markers can easily be detected by a traditional Enzyme Linked Immunosorbent Assay (ELISA), whereas multiple markers can be detected by a fluorochrome (Luminex) or electrochemiluminescence (MSD) technique. These techniques however are sometimes not sensitive enough to detect low levels of secreted immune markers in limited sample sizes. To detect immune markers at the single-cell level, an Enzyme Linked Immuno-spot (ELISPOT) can be used to pin-point elusive immune markers in common pediatric immunological diseases.

The sourdough fermentation may enhance the recovery from intestinal inflammation of coeliac patients at the early stage of the gluten-free diet

PURPOSE

This study aimed at investigating the effect of corn, rice and amaranth gluten-free (GF) sourdoughs on the release of nitric oxide (NO) and synthesis of pro-inflammatory cytokines by duodenal mucosa biopsies of eight coeliac disease (CD) patients.

METHODS

Selected lactic acid bacteria were used as starters for the manufacture of corn, rice or amaranth sourdoughs. Chemically acidified doughs, without bacterial starters, and doughs started with baker's yeast alone were also manufactured from the same GF matrices. Pepsin-trypsin (PT) digests were produced from all sourdoughs and doughs, and used to assay the rate of recovery of biopsy specimens from eight CD patients at diagnosis. The release of NO and the synthesis of pro-inflammatory cytokines interferon-γ (IFN-γ) were assayed.

RESULTS

During fermentation, lactic acid bacteria acidified and grew well (ca. log 9.0 CFU/g) on all GF matrices, showing intense proteolysis. Duodenal biopsy specimens still released NO and IFN-γ when subjected to treatments with basal medium (control), PT-digest from chemically acidified doughs and PT-digest from doughs fermented with baker's yeast alone. On the contrary, the treatment of all the biopsy specimens with PT-digests from all GF matrices subjected to sourdough fermentation significantly decreased the release of NO and the synthesis of IFN-γ.

CONCLUSIONS

During manufacture of GF baked goods, the use of sourdough fermentation could be considered as an adjuvant to enhance the recovery from intestinal inflammation of coeliac patients at the early stage of the gluten-free diet.

IL-15 interferes with suppressive activity of intestinal regulatory T cells expanded in Celiac disease

OBJECTIVES

Celiac disease (CD) is a condition in which the regulation of the mucosal immune response to dietary gliadin might be altered. The transcription factor forkhead box P3 (Foxp3) has been identified as a marker of a subset of regulatory T cells (Treg). In this study, we have investigated the presence and the suppressive function of Treg cells in the celiac small intestinal mucosa, their correlation with the disease state, and the inducibility by gliadin in an organ culture system; moreover, we tried to define whether interleukin 15 (IL-15), overexpressed in CD, could influence the regulatory activity of such cells.

METHODS

The expression of Foxp3, CD3, CD4, and CD8 were analyzed by immunohistochemistry and flow cytometry in duodenal biopsies taken from patients with untreated CD, treated CD, and from non-CD controls, as well as in vitro cultured biopsy samples from treated CD patients, upon challenge with gliadin. Furthermore, we analyzed the suppressive function of CD4+CD25+ T cells, isolated from untreated CD biopsy samples, on autologous responder CD4+CD25- T cells, in the presence of a polyclonal stimulus, with or without IL-15.

RESULTS

Higher density of CD4+CD25+Foxp3+ T cells was seen in duodenal biopsy samples from active CD patients in comparison with treated CD and non-CD controls. In coculture, CD4+CD25+ T cells were functionally suppressive, but their activity was impaired by IL-15. Cells from CD subjects showed increased sensitivity to the IL-15 action, likely due to enhanced expression of IL-15 receptor. Finally, we demonstrated an expansion of Foxp3 in treated CD mucosa following in vitro challenge with gliadin.

CONCLUSIONS

These data suggest that CD4+CD25+Foxp3+ T cells are induced in situ by gliadin. However, their suppressor capacity might be impaired in vivo by IL-15; this phenomenon contributes to maintain and expand the local inflammatory response in CD.

The effect of gluten-free diet on Th1-Th2-Th3-associated intestinal immune responses in celiac disease

OBJECTIVE

To study T-helper (Th)1-Th2-Th3 gene activation profile in the small intestine and peripheral blood of children with celiac disease (CD) with special interest in the response to the gluten-free diet (GFD) treatment in order to elucidate an immune dysregulation not triggered by gluten.

MATERIAL AND METHODS

Small intestinal biopsies and venous blood were taken from seven children with CD (mean age: 8 years, four girls) at presentation and after 1 year of strict GFD. The Th1-Th2-Th3 gene expression profile was examined by real-time PCR arrays. The findings were compared with the corresponding expressions in peripheral blood and small intestinal biopsies from six reference children without CD (mean age: 6 years, four girls).

RESULTS

The Th1 gene expression profile including interferon (IFN)-γ, signal transducer and activator of transcription (STAT) 1 and interferon regulatory factor (IRF) 1 together with reduced interleukin (IL)-2 expression was pronounced in small intestinal biopsies from children with untreated CD. A downregulation of IFN-γ transcripts was seen after 1 year of GFD, but there was still increased expression of STAT1 and IRF1 in association with low IL-2 expression in spite of eliminated exposure to wheat gluten. By contrast, the decreased intestinal expression of Th2 gene markers observed at presentation was normalized with GFD. The alterations in the mucosal gene expression profile were not reflected in peripheral blood.

CONCLUSION

The GFD did not correct the increased activation of the IFN-γ signaling pathway related markers and reduced IL-2 expression, suggesting that they represent an immune dysregulation not dependent on gluten exposure.

Immune phenotype of children with newly diagnosed and gluten-free diet-treated celiac disease

BACKGROUND

Recent data suggest the involvement of both the adaptive and the innate immune system in celiac disease (CD). However, little is known about the immune phenotype of children with CD and its alteration upon dietary intervention.

AIMS

We characterized the prevalence of major interacting members of the adaptive and innate immune system in peripheral blood of newly diagnosed children with CD and tested its alteration with the improvement of clinical signs after the introduction of gluten-free diet (GFD).

METHODS

Peripheral blood was taken from ten children with biopsy-proven CD at the time of diagnosis and after the resolution of clinical symptoms following GFD. As controls, 15 children with functional abdominal pain were enrolled. The prevalence of the cells of adaptive and innate immunity was measured with labeled antibodies against surface markers and intracellular FoxP3 using a flow cytometer.

RESULTS

Patients with CD were found to have lower T helper, Th1 and natural killer (NK), NKT and invariant NKT cell prevalence and with higher prevalence of activated CD4(+) cells, myeloid dendritic cells (DC) and Toll-like receptor (TLR) 2 and TLR-4 positive DCs and monocytes compared to controls. After resolution of symptoms on GFD, the majority of these changes normalized, although the prevalence of NK and NKT cell, DC and TLR-2 expressing DCs and monocytes remained abnormal.

CONCLUSIONS

The immune phenotype in childhood CD indicates the implication of both adaptive and innate immune system. The normalization of immune abnormalities occurs on GFD, but the kinetics of this process probably differs among different cell types.

The importance of toxoplasma gondii infection in diseases presenting with headaches. Headaches and aseptic meningitis may be manifestations of the Jarisch-Herxheimer reaction

Worldwide, approximately 2 billion people are chronically infected with T. gondii with largely unknown consequences. This review presents clinical symptoms, differential diagnosis, triggering factors, treatment, and pathomechanisms responsible for idiopathic intracranial hypertension, pseudotumor cerebri, and aseptic meningitis. Literature cited in this work illustrates that immune state and other biologic mediator imbalances due to various endogenous and exogenous triggering factors may markedly affect latent central nervous system T. gondii infection/inflammation intensity, and cause reactivation of cerebral toxoplasmosis (CT). Irregularities in pro- and anti-inflammatory processes may markedly disturb the host and/or T. gondii defense mechanisms important for immune control of the parasite thereby manifesting as a wide range of neurologic symptoms and signs observed in some patients with migraine, epilepsy, celiac disease, Henoch-Schönlein purpura, and other brain disorders. This is consistent with reactivation of CT in mice after treatment with dexamethasone associated with depression of type T(H)1 immune response, and development of CT after administration of etanercept or other bioproducts. It seems that various types of headaches, epilepsy, aseptic meningitis, systemic adverse reactions to drugs or other substances represent the Jarisch-Herxheimer reaction due to apoptosis of T. gondii tachyzoites. Also development of some brain tumors, such as ependymoma and glioma may be associated with a chronic course of CT. Thus, all these patients should be tested for T. gondii infection.

Serum cytokine elevations in celiac disease: association with disease presentation

Celiac disease (CD) is an autoimmune disorder that is triggered by an immune response to gluten in genetically predisposed individuals. Although considered a primary gastrointestinal disease, CD is now known to have widespread systemic manifestations. We attempted to define the nature and role of systemic cytokine levels in the pathophysiology of CD. Multiplex cytokine assays were performed on four different groups of adult patients; patients with active CD (ACD), patients on a gluten-free diet (GFD) with positive TTG IgA antibodies, patients on a GFD with negative antibodies, and those with refractory CD (RCD). The results were compared with values in healthy adult controls. Patients with active CD and those on GFD with positive antibodies had significantly higher levels of proinflammatory cytokines, such as interferon-gamma, interleukin (IL)-1beta, tumor necrosis factor-alpha, IL-6 and IL-8, and also T(h)-2 cytokines such as IL-4 and IL-10, compared with normal controls and patients on GFD without antibodies. Interestingly patients on GFD for less than 1 year had significantly higher levels of both proinflammatory cytokines and T(h)2 cytokines compared with the patients on GFD for more than 1 year. In addition, a statistically significant correlation between levels of TTG IgA titers and serum levels of T(h)-2 cytokines IL-4 (p < 0.001), IL-10 (p < 0.001) and inflammatory cytokines such as IL-1alpha (p < 0.001), IL-1beta (p < 0.005), and IL-8 (p < 0.05) was observed.

Involvement of interleukin-15 and interleukin-21, two γ-chain-related cytokines, in celiac disease

Celiac disease (CD), an enteropathy caused by dietary gluten in genetically susceptible individuals, is histologically characterized by villous atrophy, crypt cell hyperplasia, and increased number of intra-epithelial lymphocytes. The nature of CD pathogenesis remains unclear, but recent evidence indicates that both innate and adaptive immune responses are necessary for the phenotypic expression and pathologic changes characteristic of CD. Extensive studies of molecules produced by immune cells in the gut of CD patients have led to identification of two cytokines, namely interleukin (IL)-15 and IL-21, which are thought to play a major role in orchestrating the mucosal inflammatory response in CD. Here we review the current knowledge of the expression and function of IL-15 and IL-21 in CD.

T-cell response to different cultivars of farro wheat, Triticum turgidum ssp. dicoccum, in celiac disease patients

BACKGROUND & AIMS

Celiac disease is a gluten sensitive disorder that occurs in genetically susceptible individuals. The present study deals with variation in the immune response of mucosal T-cells from celiac children to prolamins extracted from nine landraces of farro wheat (Triticum turgidum ssp. dicoccum) with contrasting storage protein compositions.

METHODS

The prolamin fraction from nine 'dicoccum' wheat landraces was subjected to peptic-tryptic digestion and supplied to T-cells from mucosal explants of four celiac patients. Immune reactions in terms of cell proliferation and INF-gamma secretion by intestinal T lymphocytes were then determined.

RESULTS

T-cell lines exposed to digested prolamins from landraces L5563, L5558 and L5540 showed negligible proliferative responses and released INF-gamma amounts similar to that of untreated control cells. By contrast, landraces Ersa 6, Ersa 8, Leonessa 4 and Leonessa 5 proved to be very active in triggering the immune responses, whereas landraces Filosini and Prometeo exhibited an intermediate behavior. One-dimensional fractionations by A-PAGE or SDS-PAGE revealed distinctive prolamin patterns amongst the landraces analysed.

CONCLUSIONS

'Dicoccum' wheat represents a heterogeneous species showing a wide variation in both prolamin composition and T-cell immunological activation, some 'dicoccum' landraces being poor in or devoid of noxious gluten proteins.

Increased expression of mucosal addressin cell adhesion molecule 1 in the duodenum of patients with active celiac disease is associated with depletion of integrin alpha4beta7-positive T cells in blood

Mucosal addressin cell adhesion molecule 1, expressed on gut endothelial cells, in conjunction with integrin alpha(4)beta(7), expressed on lymphocytes, is critical in lymphocyte homing to the gut. The mucosal addressin cell adhesion molecule 1/integrin alpha(4)beta(7) pathway is involved in the pathogenesis of chronic intestinal inflammation by recruiting lymphocytes into inflamed gut. We explored the duodenal expression of mucosal addressin cell adhesion molecule 1 and the peripheral T-cell expression of integrin alpha(4)beta(7) in patients with celiac disease. Duodenal biopsies and a peripheral blood sample were collected from 15 celiac patients, before and after 12 months of gluten-free diet, and from 12 control subjects. Treated celiac biopsies were cultured with peptic-tryptic digest of gliadin and/or an anti-interferon alpha neutralizing antibody. Mucosal addressin cell adhesion molecule 1 was determined by confocal immunofluorescence microscopy and immunoblotting. Integrin beta(7)-positive T cells were analyzed by flow cytometry. Mucosal addressin cell adhesion molecule 1 expression was significantly higher in active celiac disease than in normal mucosa. After gluten-free diet, a dramatic reduction of mucosal addressin cell adhesion molecule 1 was also observed. No difference was seen between patients with celiac disease after treatment and controls. Ex vivo peptic-tryptic digest of gliadin challenge induced a marked increase of mucosal addressin cell adhesion molecule 1 expression. Blocking interferon alpha inhibited the peptic-tryptic digest of gliadin-induced mucosal addressin cell adhesion molecule 1 overexpression. The percentage of circulating beta(7)-positive T cells was significantly lower in untreated celiac disease in comparison to controls but normalized after gluten-free diet. Mucosal addressin cell adhesion molecule 1 is strongly up-regulated in active celiac disease dependent on interferon alpha and is associated with peripheral depletion of integrin alpha(4)beta(7)-expressing T cells. We conclude that mucosal addressin cell adhesion molecule 1 may represent an important determinant for the generation of mucosal damage in celiac disease.

In vitro differentiation of human monocytes into dendritic cells by peptic-tryptic digest of gliadin is independent of genetic predisposition and the presence of celiac disease

INTRODUCTION

This study was done to further reveal the role of the innate immune system in celiac disease.

METHODS

Dendritic cells were matured from venous blood of patients with active or treated celiac disease and DQ2-DQ8-positive or negative controls. Dendritic cells were treated with a peptic-tryptic digest of gliadin (500 microg/ml) and their activation was analyzed by fluorescent-activated cell sorting analysis, cytokine secretion, and their ability to elicit T cell proliferation.

RESULTS AND DISCUSSION

Gliadin upregulated interleukin (IL)-6, IL-8, and IL-12 (p40) secretion in dendritic cells and induced strong expression of the maturation markers human leukocyte antigen (HLA)-DR, CD25, CD83, and CD86 of all subjects irrespective of their genotype or the presence of disease, whereas the digest of bovine serum albumin showed no effect. However, gliadin-stimulated dendritic cells from active celiac showed enhanced stimulation of autologous T cells compared to the other groups.

CONCLUSION

Further research should be aimed at identifying the mechanisms that control inflammation in healthy individuals.

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.

A 10-residue peptide from durum wheat promotes a shift from a Th1-type response toward a Th2-type response in celiac disease

BACKGROUND

Celiac disease (CD) is a Th1-driven autoimmune permanent enteropathy that is triggered by dietary gluten. Molecules able to shift the immune response from a Th1- to a Th2-type response have been suggested as therapeutic agents for Th1 autoimmune diseases.

OBJECTIVE

We sought to investigate the possibility that a decapeptide from durum wheat (p10mer, QQPQDAVQPF), which was previously shown to prevent the activation of celiac peripheral lymphocytes, may promote a shift from a Th1- to a Th2-type immune response in gluten-specific intestinal T cells of CD patients.

DESIGN

Intestinal T lymphocyte lines derived from 8 children with CD were incubated with gliadin peptides both alone and simultaneously with p10mer. Cell proliferation and the production of interferon-gamma and interleukin-10 by these T cells were measured.

RESULTS

The incubation of celiac intestinal T cells with deamidated gliadin peptides resulted in a significant (P < 0.008) increase in cell proliferation and interferon-gamma release, whereas the simultaneous exposure to p10mer totally abolished the cell proliferation and cytokine release. Moreover, incubation with p10mer maintained an elevated release of interleukin-10, whereas exposure of the cells to culture medium only did not. The replacement of the residues of aspartic acid in position 5 or those of alanine in position 6 in the sequence of p10mer resulted in peptides with no activity in the activation experiments.

CONCLUSION

In vitro, p10mer showed the ability to shift the pathogenic immune response of a CD patient from a Th1- to a Th2-type response.

Small intestinal CD8+TCRgammadelta+NKG2A+ intraepithelial lymphocytes have attributes of regulatory cells in patients with celiac disease

Intraepithelial lymphocytes (IELs) bearing the gammadelta TCR are more abundant in the small intestinal mucosa of patients with celiac disease (CD) compared with healthy individuals. However, their role in disease pathogenesis is not well understood. Here, we investigated the functional attributes of TCRgammadelta+ IELs isolated from intestinal biopsies of patients with either active celiac disease (ACD) or those on a gluten-free diet (GFD). We found that compared with individuals with ACD, individuals on GFD have a higher frequency of CD8+TCRgammadelta+ IELs that express the inhibitory NK receptor NKG2A and intracellular TGF-beta1. TCR triggering as well as cross-linking of NKG2A increased both TGF-beta1 intracellular expression and secretion in vitro. Coculture of sorted TCRgammadelta+NKG2A+ IELs, IL-15-stimulated TCRalphabeta+ IELs, and HLA-E+ enterocytes resulted in a decreased percentage of cytotoxic CD8+TCRalphabeta+ IELs expressing intracellular IFN-gamma and granzyme-B and surface NKG2D. This inhibition was partially abrogated by blocking either TGF-beta alone or both NKG2A and HLA-E. Thus, our data indicate that suppression was at least partially mediated by TGF-beta secretion as a result of engagement of NKG2A with its ligand, HLA-E, on enterocytes and/or TCRalphabeta+ IELs. These findings demonstrate that human small intestinal CD8+TCRgammadelta+ IELs may have regulatory potential in celiac disease.

Increased mucosal expression of Toll-like receptor (TLR)2 and TLR4 in coeliac disease

OBJECTIVES

The dysregulation of adaptive immunity is extensively investigated in celiac disease (CD). Recent data also suggest, however, the implication of innate immunity in CD. Toll-like receptors (TLRs) play a central role in the initiation or maintenance of innate immune responses. The aim of this study was to characterise the expression of TLR2, TLR3, and TLR4 in duodenal biopsy samples taken from children with CD and from controls.

PATIENTS AND METHODS

Duodenal biopsy specimens were collected from 16 children with untreated CD, 9 children with treated CD, and 10 controls. The mRNA expression of TLR2, TLR3, and TLR4 was determined by semiquantitative reverse transcription-polymerase chain reaction. Protein levels of TLRs were determined by Western blot.

RESULTS

We found higher TLR2 and TLR4 mRNA expression and protein levels in the duodenal mucosa of children with treated CD and untreated CD compared with controls. TLR2 and TLR4 mRNA expression and protein levels were even higher in the duodenal mucosa of children with treated CD than in untreated CD. TLR3 mRNA expression was increased in the duodenal mucosa of children with treated CD compared with untreated CD and controls. We were able to detect TLR3 protein only in the biopsy specimens of treated patients with CD.

CONCLUSIONS

The alteration of TLR2 and TLR4 expression in the duodenal mucosa of patients with CD supports the potential implication of innate immune system in the pathomechanism of this disease.

Recurrent headache as the main symptom of acquired cerebral toxoplasmosis in nonhuman immunodeficiency virus-infected subjects with no lymphadenopathy: the parasite may be responsible for the neurogenic inflammation postulated as a cause of different types of headaches

Headache and/or migraine, a common problem in pediatrics and internal medicine, affect about 5% to 10% children and adolescents, and nearly 30% of middle-aged women. Headache is also one of the most common clinical manifestations of acquired Toxoplasma gondii infection of the central nervous system (CNS) in immunosuppressed subjects. We present 11 apparently nonhuman immunodeficiency virus-infected children aged 7 to 17 years (8 girls, 3 boys) and 1 adult woman with recurrent severe headaches in whom latent chronic CNS T. gondii infection not manifested by enlarged peripheral lymph nodes typical for toxoplasmosis, was found. In 7 patients, the mean serum IgG Toxoplasma antibodies concentration was 189 +/- 85 (SD) IU/mL (range 89 to 300 IU/mL), and in 5 other subjects, the indirect fluorescent antibody test titer ranged from 1:40 to 1:5120 IU/mL (n= <1:10 IU/mL). Some of the patients suffered also from atopic dermatitis (AD) and were exposed to cat and/or other pet allergens, associated with an increased IL-4 and decreased IFN-gamma production. These cytokine irregularities caused limited control of cerebral toxoplasmosis probably because IL-4 down-regulated both the production of IFN-gamma and its activity, and stimulated production of a low NO-producing population of monocytes, which allowed cysts rupture, increased parasite multiplication and finally reactivation of T. gondii infection. The immune studies performed in 4 subjects showed a decreased percentage of T lymphocytes, increased total number of lymphocytes B and serum IgM concentration, and impaired phagocytosis. In addition, few of them had also urinary tract diseases known to produce IL-6 that can mediate immunosuppressive functions, involving induction of the anti-inflammatory cytokine IL-10. These disturbances probably resulted from the host protective immune reactions associated with the chronic latent CNS T. gondii infection/inflammation. This is consistent with significantly lower enzyme indoleamine 2,3-dioxygenase (IDO) activity reported in atopic than in nonatopic individuals, and an important role that IDO and tryptophan degradation pathways plays in both, the host resistance to T. gondii infection and its reactivation. Analysis of literature information on the subjects with different types of headaches caused by foods, medications, and other substances, may suggest that their clinical symptoms and changes in laboratory data result at least in part from interference of these factors with dietary tryptophan biotransformation pathways. Several of these agents caused headache attacks through enhancing NO production via the conversion of arginine to citrulline and NO by the inducible nitric oxide synthase enzyme, which results in the high-output pathway of NO synthesis. This increased production of NO is, however, quickly down-regulated by NO itself because this biomolecule can directly inactivate NOS, may inhibit Ia expression on IFN-gamma-activated macrophages, which would limit antigen-presenting capability, and block T-cell proliferation, thus decreasing the antitoxoplasmatic activity. Moreover, NO inhibits IDO activity, thereby suppressing kynurenine formation, and at least one member of the kynurenine pathway, 3-hydroxyanthranilic acid, has been shown to inhibit NOS enzyme activity, the expression of NOS mRNA, and activation of the inflammatory transcription factor, nuclear factor-kB. In addition, the anti-inflammatory cytokines IL-4 and IL-10, TGF-beta, and a cytokine known as macrophage deactivating factor, have been shown to directly modulate NO production, sometimes expressing synergistic activity. On the other hand, IL-4 and TGF-beta can suppress IDO activity in some cells, for example human monocytes and fibroblasts, which is consistent with metabolic pathways controlled by IDO being a significant contributor to the proinflammatory system. Also, it seems that idiopathic intracranial hypertension, pseudotumor cerebri, and aseptic meningitis, induced by various factors, may result from their interference with IDO and inducible nitric oxide synthase activities, endogenous NO level, and cytokine irregularities which finally affect former T. gondii status 2mo in the brain. All these biochemical disturbances caused by the CNS T. gondii infection/inflammation may also be responsible for the relationship found between neurologic symptoms, such as headache, vertigo, and syncope observed in apparently immunocompetent children and adolescents, and physical and psychiatric symptoms in adulthood. We therefore believe that tests for T. gondii should be performed obligatorily in apparently immunocompetent patients with different types of headaches, even if they have no enlarged peripheral lymph nodes. This may help to avoid overlooking this treatable cause of the CNS disease, markedly reduce costs of hospitalization, diagnosis and treatment, and eventually prevent developing serious neurologic and psychiatric disorders.