Toll-like Receptors and Celiac Disease

Changes upon the gluten-free diet of HLA-DQ2 and TRAFD1 gene expression in peripheral blood of celiac disease patients

Background

Celiac disease (CD) is a chronic immuno-mediated enteropathy caused by dietary gluten in genetically susceptible individuals carrying HLA (Human Leukocytes Antigen) genes that encode for DQ2.5 and DQ8 molecules. TRAFD1 (TRAF-type zinc finger domain 1) is a gene recently found associated with CD and defined as a master regulator of IFNγ signalling and of MHC class I antigen processing/presentation. There is no specific drug therapy and the only effective treatment is the gluten-free diet (GFD). The great majority of celiac patients when compliant with GFD have a complete remission of symptoms and recovery of gut mucosa architecture and function. Until now, very few studies have investigated molecular differences occurring in CD patients upon the GFD therapy.

Methods

We looked at the expression of both HLA DQ2.5 and TRAFD1 risk genes in adult patients with acute CD at the time of and in treated patients on GFD. Specifically, we measured by qPCR the HLA-DQ2.5 and TRAFD1 mRNAs on peripheral blood mononuclear cells (PBMC) from the two groups of patients.

Results

When we compared the HLA-DQ mRNA expression, we didn't find significant variation between the two groups of patients, thus indicating that GFD patients have the same capability to present gliadin antigens to cognate T cells as patients with active disease. Conversely, TRAFD1 was more expressed in PBMC from treated CD subjects. Notably, TRAFD1 transcripts significantly increased in the patients analyzed longitudinally during the GFD, indicating a role in the downregulation of gluten-induced inflammatory pathways.

Conclusion

Our study demonstrated that HLA-DQ2.5 and TRAFD1 molecules are two important mediators of anti-gluten immune response and inflammatory process.

Non-Host Factors Influencing Onset and Severity of Celiac Disease

Celiac disease (CeD) is a chronic autoimmune condition driven by gluten ingestion in genetically predisposed individuals, resulting in inflammatory lesions in the proximal small intestine. Although the presence of specific HLA-linked haplotypes and gluten consumption are necessary for disease development, they alone do not account for the variable onset of CeD in susceptible individuals. This review explores the multifaceted role of non-host factors in CeD development, including dietary and microbial influences. We discuss clinical associations and observations highlighting the impact of these factors on disease onset and severity. Furthermore, we discuss studies in CeD-relevant animal models that offer mechanistic insights into how diet, the microbiome, and enteric infections modulate CeD pathogenesis. Finally, we address the clinical implications and therapeutic potential of understanding these cofactors offering a promising avenue for preventive and therapeutic interventions in CeD management.

When inflammatory stressors dramatically change, disease phenotypes may transform between autoimmune hematopoietic failure and myeloid neoplasms

Aplastic anemia (AA) and hypoplastic myelodysplastic syndrome are paradigms of autoimmune hematopoietic failure (AHF). Myelodysplastic syndrome and acute myeloid leukemia are unequivocal myeloid neoplasms (MNs). Currently, AA is also known to be a clonal hematological disease. Genetic aberrations typically observed in MNs are detected in approximately one-third of AA patients. In AA patients harboring MN-related genetic aberrations, a poor response to immunosuppressive therapy (IST) and an increased risk of transformation to MNs occurring either naturally or after IST are predicted. Approximately 10%-15% of patients with severe AA transform the disease phenotype to MNs following IST, and in some patients, leukemic transformation emerges during or shortly after IST. Phenotypic transformations between AHF and MNs can occur reciprocally. A fraction of advanced MN patients experience an aplastic crisis during which leukemic blasts are repressed. The switch that shapes the disease phenotype is a change in the strength of extramedullary inflammation. Both AHF and MNs have an immune-active bone marrow (BM) environment (BME). In AHF patients, an inflamed BME can be evoked by infiltrated immune cells targeting neoplastic molecules, which contributes to the BM-specific autoimmune impairment. Autoimmune responses in AHF may represent an antileukemic mechanism, and inflammatory stressors strengthen antileukemic immunity, at least in a significant proportion of patients who have MN-related genetic aberrations. During active inflammatory episodes, normal and leukemic hematopoieses are suppressed, which leads to the occurrence of aplastic cytopenia and leukemic cell regression. The successful treatment of underlying infections mitigates inflammatory stress-related antileukemic activities and promotes the penetration of leukemic hematopoiesis. The effect of IST is similar to that of treating underlying infections. Investigating inflammatory stress-powered antileukemic immunity is highly important in theoretical studies and clinical practice, especially given the wide application of immune-activating agents and immune checkpoint inhibitors in the treatment of hematological neoplasms.

Prevalence of coeliac disease in patients with systemic lupus erythematosus: a systematic review and meta-analysis

BACKGROUND

There is some evidence of a higher prevalence of coeliac disease (CD) among patients with SLE than in the general population. However, the prevalence estimates vary substantially.

OBJECTIVE

To investigate the prevalence of CD among patients with SLE through systematic review and meta-analysis.

METHODS

We performed searches in the databases of Medline, Embase, Cochrane and Web of Science Core Collection between 1 January 1990 and 9 July 2023. A total of 2053 publications were rendered in the searches, of which 68 were reviewed in full text and 14 included in the analyses. Primary analysis estimated the pooled prevalence of biopsy-verified CD in patients with SLE. In the secondary analysis, the prevalence of serological markers indicative of CD was investigated. The quality of studies was appraised using the Joanna Briggs Institute Critical Appraisal Tool. We conducted meta-regression analyses to investigate associations between the prevalence of CD in individuals with SLE and publication year, study population size, CD prevalence in the general population, proportion of females and quality assessment score.

RESULTS

A total of 14 studies met the inclusion criteria, of which 11 were included in the primary analysis of biopsy-verified CD. Among 1238 patients with SLE, 14 had CD. The weighted pooled prevalence of CD was 0.7% (95% CI 0.0 to 1.8). The weighted pooled prevalence of CD serological markers in 1063 patients with SLE was 3.7% (95% CI 1.4 to 6.7). In meta-regression analyses, no associations between CD prevalence and study characteristics, demographics and quality assessment scores were found.

CONCLUSIONS

In this meta-analysis, we found a weighted pooled prevalence of biopsy-verified CD in patients with SLE comparable with the prevalence in the general population. Our findings do not support routine screening for CD in patients with SLE. However, individual screening could be considered in cases of clinical suspicion and additional risk factors for CD.

PROSPERO REGISTRATION NUMBER

CRD42022339594.

Viral Triggered Celiac Disease: A Case Report

Celiac disease (CD) is an autoimmune condition presenting with a wide variety of nonspecific gastrointestinal symptoms. It can be difficult to diagnose due to the vagueness of complaints such as diarrhea, anemia due to malabsorption, vitamin or electrolyte deficiencies, and/or failure to thrive. This condition is characterized by a sensitivity to ingested gluten-containing compounds. Blood tests can be used for screening, though confirmatory testing by a small intestine biopsy is needed for diagnosis. Viral infections can trigger autoimmune conditions in individuals. It is possible that viral infections, such as Ebsetein-Barr virus(EBV) or Cytomegalovirus (CMV), can trigger the clinical presentation of celiac disease in certain individuals with genetic predispositions. Early recognition of celiac disease is important to prevent both short and long-term complications and improve the quality of life for the individual. Here, we discuss a case where the patient developed celiac disease only months after a diagnosis of mononucleosis.

T helper 17 (Th17) cell responses to the gut microbiota in human diseases

The gut microbiota colonizing the gastrointestinal tract, is an indispensable "invisible organ" that affects multiple aspects of human health. The gut microbial community has been assumed to be an important stimulus to the immune homeostasis and development, and increasing data support the role of the gut microbiota-immunity axis in autoimmune diseases. Host's immune system requires recognition tools to communicate with the gut microbial evolutionary partners. Among these microbial perceptions, T cells enable the widest spectrum of gut microbial recognition resolution. Specific gut microbiota direct the induction and differentiation of Th17 cells in intestine. However, the detailed links between the gut microbiota and Th17 cells have not been well established. In this review, we describe the generation and characterization of Th17 cells. Notably, we discuss the induction and differentiation of Th17 cells by the gut microbiota and their metabolites, as well as recent advances in our understanding of interactions between Th17 cells and the gut microbiota in human diseases. In addition, we provide the emerging evidences in support of interventions targeting the gut microbes/Th17 cells in human diseases.

Psychiatric and Neurological Manifestations of Celiac Disease in Adults

Celiac disease (CD), a chronic inflammatory disorder of the intestines, affects 0.7% to 1.4% of the world's population. CD causes diarrhea, abdominal discomfort, bloating, flatulence, and, in rare cases, constipation in the digestive tract. Since the identification of gluten as the disease-causing antigen, CD patients have been treated with a gluten-free diet, which is advantageous but has limitations for certain patient groups. CD is associated with mood disorders, such as manic-depressive disease, schizophrenia, and bipolar disorder, as well as other disorders such as depression and anxiety. The relationship between CD and psychological issues is not entirely understood. Here, we look at the most recent psychiatric data as they pertain to CD, as well as the relevant psychiatric manifestations that have been associated with this condition. Clinicians should examine mental health factors when a CD diagnosis is established. More research is needed to understand the pathophysiology of CD's psychiatric manifestations.

The Roles of TRAF3 in Immune Responses

Seven tumor necrosis factor receptor- (TNFR-) associated factors (TRAFs) have been found in mammals, which are primarily involved in the signal translation of the TNFR superfamily, the Toll-like receptor (TLR) family, and the retinoic acid-inducible gene I- (RIG-I-) like receptor (RLR) family. TRAF3 is one of the most diverse members of the TRAF family. It can positively regulate type I interferon production while negatively regulating signaling pathways of classical nuclear factor-κB, nonclassical nuclear factor-κB, and mitogen-activated protein kinase (MAPK). This review summarizes the roles of TRAF3 signaling and the related immune receptors (e.g., TLRs) in several preclinical and clinical diseases and focuses on the roles of TRAF3 in immune responses, the regulatory mechanisms, and its role in disease.