Potential blood-based markers of celiac disease

HMGB1 is related to disease activity in children with celiac disease

INTRODUCTION

We aim to evaluate of the relationship between high mobility gene box-1 (HMGB1) levels and clinical, laboratory and histopathological findings at diagnosis and in remission in children with Celiac Disease (CD).

MATERIAL AND METHODS

The study included 36 celiac patients at diagnosis, 36 celiac patients in remission, and 36 healthy controls. Patients with intestinal pathologies other than CD, and accompanying inflammatory and/or autoimmune diseases were excluded. Relationship between HMGB1 levels and clinical, laboratory and histopathological findings were evaluated.

RESULTS

A total of 72 celiac patients [36 (18 girls, 18 boys, mean age 9.41±3.9 years) in group 1 and 36 (18 girls, 18 boys, mean age 9.91±3.36 years) in group 2] and 36 healthy controls in group 3 (19 girls, 17 boys, mean age 9.56±4 years) were included. The HMGB1 level was significantly higher in group 1 compared to group 2 and group 3 [36.63 (17.98-54.72) ng/ml vs 20.31 (16.89-29.79) ng/ml, p = 0.028 and 36.63 (17.98-54.72) ng/ml vs 20.38 (17.54-24.53) ng/ml p = 0.012, respectively]. A serum HMGB-1 level of 26.553 ng/ml was found to be a cut-off value for the CD with 61% sensitivity, 83% specificity, 78% positive predictive value, and 68% negative predictive value. Higher HMGB1 values were seen in patients with intestinal findings, anemia, anti-tissue transglutaminase IgA levels that were greater than 10 times upper limit of normal, and patients with a higher degree of atrophy as classified by Marsh-Oberhuber.

CONCLUSIONS

In conclusion, it was thought that HMGB-1 might be a marker that reflects the severity of atrophy at the time of diagnosis and could be used to control dietary compliance in the follow-up. However, there is need for larger population studies in order to evaluate its value as a serological marker for the diagnosis and follow-up of CD and to find a more reliable cut-off value.

Characterisation of gene and pathway expression in stabilised blood from children with coeliac disease

Introduction

A coeliac disease (CD) diagnosis is likely in children with levels of tissue transglutaminase autoantibodies (anti-TG2) >10 times the upper reference value, whereas children with lower anti-TG2 levels need an intestinal biopsy to confirm or rule out CD. A blood sample is easier to obtain than an intestinal biopsy sample, and stabilised blood is suitable for routine diagnostics because transcript levels are preserved at sampling. Therefore, we investigated gene expression in stabilised whole blood to explore the possibility of gene expression-based diagnostics for the diagnosis and follow-up of CD.

Design

We performed RNA sequencing of stabilised whole blood from active CD cases (n=10), non-CD cases (n=10), and treated CD cases on a gluten-free diet (n=10) to identify diagnostic CD biomarkers and pathways involved in CD pathogenesis.

Results

No single gene was differentially expressed between the sample groups. However, by using gene set enrichment analysis (GSEA), significantly differentially expressed pathways were identified in active CD, and these pathways involved the inflammatory response, negative regulation of viral replication, translation, as well as cell proliferation, differentiation, migration, and survival. The results indicate that there are differences in pathway regulation in CD, which could be used for diagnostic purposes. Comparison between GSEA results based on stabilised blood with GSEA results based on small intestinal biopsies revealed that type I interferon response, defence response to virus, and negative regulation of viral replication were identified as pathways common to both tissues.

Conclusions

Stabilised whole blood is not a suitable sample for clinical diagnostics of CD based on single genes. However, diagnostics based on a pathway-focused gene expression panel may be feasible, but requires further investigation.

Molecular Biomarkers for Celiac Disease: Past, Present and Future

Celiac disease (CeD) is a complex immune-mediated disorder that is triggered by dietary gluten in genetically predisposed individuals. CeD is characterized by inflammation and villous atrophy of the small intestine, which can lead to gastrointestinal complaints, malnutrition, and malignancies. Currently, diagnosis of CeD relies on serology (antibodies against transglutaminase and endomysium) and small-intestinal biopsies. Since small-intestinal biopsies require invasive upper-endoscopy, and serology cannot predict CeD in an early stage or be used for monitoring disease after initiation of a gluten-free diet, the search for non-invasive biomarkers is ongoing. Here, we summarize current and up-and-coming non-invasive biomarkers that may be able to predict, diagnose, and monitor the progression of CeD. We further discuss how current and emerging techniques, such as (single-cell) transcriptomics and genomics, can be used to uncover the pathophysiology of CeD and identify non-invasive biomarkers.

Evaluation of expression of common genes in the intestine and peripheral blood mononuclear cells (PBMC) associated with celiac disease

AIM

this study was conducted to investigate expression of the genes associated with CD in the target tissue in order to estimate contribution of each single gene to development of immune response. Then, the same set of genes was evaluated in peripheral blood mononuclear cells (PBMCs).

BACKGROUND

Celiac disease (CD) is a chronic systemic autoimmune disease of the small intestine occurring in genetically-susceptible individuals. There are several genes related to immune response.

METHODS

For this purpose, the genes related to CD were extracted from public databases (documents of proteomics and microarray-based techniques) and were organized in a protein-protein interaction network using the search tool for retrieval of interacting genes/proteins (STRING) database as a plugin of Cytoscape software version 3.6.0. The main genes were introduced and enriched via ClueGO to find the related biochemical pathways. The network was analyzed, and the most important genes were introduced based on central indices.

RESULTS

Among 20 CD genes as hub and bottleneck nodes, there were 7 genes with common expression in blood and intestinal tissue (C-X-C motif chemokine 11(CXCL11), granzyme B (GZMB), interleukin 15(IL-15), interleukin 17(IL-17A), interleukin 23(IL-23A), t-box transcription factor 21(TBX21), and tumor necrosis factor alpha-induced protein 3(TNFAIP3)).

CONCLUSION

The enriched biological process related to the central nodes of celiac network indicated that most of hub-bottleneck genes are the well-known ones involved in different types of autoimmune and inflammatory diseases.

Comparison of cytokine and gene activities in tissue and blood samples of patients with celiac disease

AIM

The aim of this study is to explore the expression of genes associated to celiac disease (CD) in the target tissue and peripheral blood monocytes (PBMC) or serum to introduce possible potential biomarkers.

BACKGROUND

Celiac disease (CD) is an autoimmune disease induced by gluten ingestion in genetically predisposed individuals. Despite technological progress, small intestine biopsy is still the gold standard for diagnosis of CD.

METHODS

CD data were collected from public databases (proteomics and microarray-based techniques documents). Differentially expressed genes (DEGs) in PBMC or serum as well as small intestinal biopsies from celiac patients compared to normal were collected and analyzed to introduce common individuals. Gene ontology was done to identify the involved biological terms.

RESULTS

Among 598 CD genes in biopsies and 260 genes in PBMC or serum, 32 common genes with a similar expression pattern in both sources were identified. A total of 48 biological terms were introduced which were involved in the CD via the determined DEGs. "Cytokine activity" was the most expanded one of the biological terms.

CONCLUSION

In this analysis, it was concluded that 32 potential biomarkers of CD can be assessed by complementary research to introduce effective and available biomarkers in biopsy and blood.

Celiac disease biomarkers identified by transcriptome analysis of small intestinal biopsies

Establishing a celiac disease (CD) diagnosis can be difficult, such as when CD-specific antibody levels are just above cutoff or when small intestinal biopsies show low-grade injuries. To investigate the biological pathways involved in CD and select potential biomarkers to aid in CD diagnosis, RNA sequencing of duodenal biopsies from subjects with either confirmed Active CD (n = 20) or without any signs of CD (n = 20) was performed. Gene enrichment and pathway analysis highlighted contexts, such as immune response, microbial infection, phagocytosis, intestinal barrier function, metabolism, and transportation. Twenty-nine potential CD biomarkers were selected based on differential expression and biological context. The biomarkers were validated by real-time polymerase chain reaction of eight RNA sequencing study subjects, and further investigated using an independent study group (n = 43) consisting of subjects not affected by CD, with a clear diagnosis of CD on either a gluten-containing or a gluten-free diet, or with low-grade intestinal injury. Selected biomarkers were able to classify subjects with clear CD/non-CD status, and a subset of the biomarkers (CXCL10, GBP5, IFI27, IFNG, and UBD) showed differential expression in biopsies from subjects with no or low-grade intestinal injury that received a CD diagnosis based on biopsies taken at a later time point. A large number of pathways are involved in CD pathogenesis, and gene expression is affected in CD mucosa already in low-grade intestinal injuries. RNA sequencing of low-grade intestinal injuries might discover pathways and biomarkers involved in early stages of CD pathogenesis.

Elevated Total Iron-Binding Capacity Is Associated with an Increased Risk of Celiac Disease

BACKGROUND

Several lines of evidence suggest that abnormal iron homeostasis may itself play an important role in the development of celiac disease.

AIM

We sought to determine whether abnormalities in iron status could be detected prior to the diagnosis of celiac disease, and to understand the relationship between altered iron indices and the natural history of celiac disease.

METHODS

We conducted a case-control study at two major tertiary referral hospitals. Cases were comprised of patients with celiac disease in whom iron status was assessed prior to the diagnosis. Each case was matched to five controls without known gastrointestinal disease according to age and sex. Information on potential covariates and laboratory values within 1, 1-3, and 3-5 years prior to diagnosis was collected. We used conditional logistic regression to evaluate the effect of iron indices on risk of celiac disease.

RESULTS

We identified 157 celiac cases and 695 matched controls. Compared to participants with normal TIBC, the age-adjusted risk of celiac disease was significantly elevated among patients with elevated TIBC. For each 10 μg/dL increase in TIBC, the risk of celiac disease increased by 4.6, 3.8, and 7.9% within 1, 1-3, and 3-5 years prior to diagnosis, respectively. Patients with elevated pre-diagnosis TIBC were more likely to have abnormal liver enzymes and osteoporosis.

CONCLUSIONS

Elevated TIBC is associated with an increased risk of celiac disease. Further investigation into the potential role of altered iron homeostasis may uncover important environmental factors that contribute to the development of celiac disease.