Behçet disease: From pathogenesis to novel therapeutic options

Implications of innate lymphoid cells in oral diseases

Innate lymphoid cells (ILCs), as newly discovered antigen-independent innate immune cells, respond promptly to stimuli by secreting effector cytokines to exert effector functions similar to those of T cells. ILCs predominantly reside at mucosal sites and play critical roles in defending against infections, maintaining mucosal homeostasis, regulating inflammatory and immune responses, and participating in tumorigenesis. Recently, there has been a growing interest in the role of ILCs in oral diseases. This review outlines the classifications and the major characteristics of ILCs, and then comprehensively expatiates the research on ILCs in oral cancer, primary Sjogren's syndrome, periodontal diseases, oral lichen planus, oral candidiasis, Behcet's disease, and pemphigus vulgaris, aiming at summarising the implications of ILCs in oral diseases and providing new ideas for further research.

Pseudotumoral neuro-behcet's disease: case series and review of literature

BACKGROUND

Behcet's disease (BD) is a multisystem autoimmune relapsing vasculitis with an almost unknown etiology involving both large and small vessels. The neurological involvement called neuro-Behcet's disease (NBD) is rare. NBD can be responsible for tumor-like masses mimicking low-grade gliomas in only a few cases.

METHODS

We report here the main characteristics, treatment, and outcome of 43 patients (4 personal cases and 39 patients from the literature) with a pseudotumoral presentation of NBD (PT NBD). We compared our findings with those of the classical form of NBD.

RESULTS

The median age was 35.86 (12-59 years) years, with a male predominance (67.4%). PT NBD was the inaugural of the disease in 51.2% of cases. The neurological manifestations included headache (n = 31), pyramidal syndrome (n = 28), cerebellar syndrome (n = 5), behavioral changes (n = 5), and pseudobulbar signs (n = 2). Ophthalmologic examination revealed papilledema in 3 cases. On cerebral imaging, the most affected regions of the brain were the capsulothalamic region (n = 15, 37.5%) and the brainstem (n = 14, 35). Histological analysis revealed necrotic lesions with perivascular inflammatory infiltrate without signs of tumoral or infectious lesions. Treatment consisted of corticosteroids (n = 40, 93%) and immunosuppressive agents (n = 28, 65.11%), leading to complete clinical and imaging remission in 41.5% of patients.

CONCLUSION

PT NBD is a rare but life-threatening condition.

Kurarinone regulates Th17/Treg balance and ameliorates autoimmune uveitis via Rac1 inhibition

INTRODUCTION

Autoimmune uveitis (AU) is a severe intraocular autoimmune disorder with a chronic disease course and a high rate of blindness. Kurarinone (KU), a major component of the traditional Chinese medicine Sophorae Flavescentis Radix, possesses a wide spectrum of activities and has been used to treat several inflammation-related diseases.

OBJECTIVE

We aimed to investigate the effects of KU on AU and its modulatory mechanisms.

METHODS

We used an experimental autoimmune uveitis (EAU) animal model and characterized the comprehensive immune landscape of KU-treated EAU mice using single-cell RNA sequencing (scRNA-seq). The retina and lymph nodes were analyzed. The siRNAs and selective inhibitors were used to study the signaling pathway. The effect of KU on peripheral blood mononuclear cells (PBMCs) from uveitis patients was also examined.

RESULTS

We found that KU relieved chorioretinal lesions and immune cell infiltration in EAU model mice. Subsequent single-cell analysis revealed that KU downregulated the EAU-upregulated expression of inflammatory and autoimmune-related genes and suppressed pathways associated with immune cell differentiation, activation, and migration in a cell-specific manner. KU was implicated in restoring T helper 17 (Th17)/regulatory T (Treg) cell balance by alleviating inflammatory injury and elevating the expression of modulatory mediators in Tregs, while simultaneously ameliorating excessive inflammation by Th17 cells. Furthermore, Rac1 and the Id2/Pim1 axis potentiated the pathogenicity of Th17 cells during EAU, which was inhibited by KU treatment, contributing to the amelioration of EAU-induced inflammation and treatment of AU. In addition, KU suppressed inflammatory cytokine production in activated human PBMCs by inhibiting Rac1. Integration of the glucocorticoid-treated transcriptome suggests that KU has immunomodulatory effects on lymphocytes.

CONCLUSION

Our study constructed a high-resolution atlas of the immunoregulatory effects of KU treatment on EAU and identified its potential therapeutic mechanisms, which hold great promise in treating autoimmune disorders.

Toll-like receptor 9 (TLR9) genetic variants rs187084 and rs352140 confer protection from Behcet's disease among Iranians

BACKGROUND

Behcet's disease (BD) is a multisystem and multifactorial autoimmune disease characterized by relapsing episodes of oral aphthae, genital ulcers, and ocular and skin lesions. Toll-like receptor 9 (TLR9) has pro-inflammatory roles and its genetic variants might be involved in the pathogenesis of inflammatory diseases.  METHODS: Two hundred five BD patients and 207 age and sex-matched healthy controls were evaluated for TLR9 single nucleotide polymorphisms - 1486 T/C (rs187084) and + 2848:G/A (rs352140) using polymerase chain reaction-restriction fragment length polymorphism (RFLP-PCR).

RESULTS

Healthy individuals had a significantly higher frequency of rs187084 AG and AG + GG genotypes than BD patients (p = 0.02 and p = 0.018; respectively). Of interest, healthy males had a significantly higher frequency of rs187084 AG + GG genotype and G allele than male BD patients (p = 0.035 and p = 0.045; respectively). However, rs187084 AG genotype and G allele frequencies were significantly higher in male patients with genital aphthous (p = 0.01 and p = 0.046; respectively). Furthermore, a significantly higher frequency of rs352140 CT and TT + CT genotypes was detected in healthy individuals than in BD patients (p = 0.01, and p = 0.032; respectively). Such results were also seen in healthy females than female patients (p = 0.001, and p = 0.004; respectively). Haplotype analysis revealed a significantly higher frequency of A-C and G-C haplotypes among patients and healthy subjects, respectively (p = 0.002 and p = 0.000; respectively).

CONCLUSION

Our data suggested that rs187084 AG and AG + GG genotypes and rs352140 CT and TT + CT genotypes protect Iranian individuals from BD but rs187084 AG genotype and G allele predispose male BD individuals to genital aphthous. However, additional studies are required to verify these results.

Unraveling the microbiome-metabolome nexus: a comprehensive study protocol for personalized management of Behçet's disease using explainable artificial intelligence

The presented study protocol outlines a comprehensive investigation into the interplay among the human microbiota, volatilome, and disease biomarkers, with a specific focus on Behçet's disease (BD) using methods based on explainable artificial intelligence. The protocol is structured in three phases. During the initial three-month clinical study, participants will be divided into control and experimental groups. The experimental groups will receive a soluble fiber-based dietary supplement alongside standard therapy. Data collection will encompass oral and fecal microbiota, breath samples, clinical characteristics, laboratory parameters, and dietary habits. The subsequent biological data analysis will involve gas chromatography, mass spectrometry, and metagenetic analysis to examine the volatilome and microbiota composition of salivary and fecal samples. Additionally, chemical characterization of breath samples will be performed. The third phase introduces Explainable Artificial Intelligence (XAI) for the analysis of the collected data. This novel approach aims to evaluate eubiosis and dysbiosis conditions, identify markers associated with BD, dietary habits, and the supplement. Primary objectives include establishing correlations between microbiota, volatilome, phenotypic BD characteristics, and identifying patient groups with shared features. The study aims to identify taxonomic units and metabolic markers predicting clinical outcomes, assess the supplement's impact, and investigate the relationship between dietary habits and patient outcomes. This protocol contributes to understanding the microbiome's role in health and disease and pioneers an XAI-driven approach for personalized BD management. With 70 recruited BD patients, XAI algorithms will analyze multi-modal clinical data, potentially revolutionizing BD management and paving the way for improved patient outcomes.

The roles of immune cells in Behçet's disease

Behçet's disease (BD) is a systemic vasculitis that can affect multiple systems, including the skin, mucous membranes, joints, eyes, gastrointestinal and nervous. However, the pathogenesis of BD remains unclear, and it is believed that immune-inflammatory reactions play a crucial role in its development. Immune cells are a critical component of this process and contribute to the onset and progression of BD. By regulating the function of these immune cells, effective control over the occurrence and development of BD can be achieved, particularly with regards to monocyte activation and aggregation, macrophage differentiation and polarization, as well as T cell subset differentiation. This review provides a brief overview of immune cells and their role in regulating BD progression, which may serve as a theoretical foundation for preventing and treating this disease.

The role of miRNAs in Behçet's disease

The symptoms of Behçet's disease (BD), a multisystemic condition with autoimmune and inflammation as hallmarks, include arthritis, recurring oral and vaginal ulcers, skin rashes and lesions, and involvement of the nervous, gastrointestinal, and vascular systems. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), may be important regulators of inflammation and autoimmune disease. These ncRNAs are essential to the physiological and pathophysiological disease course, and miRNA in particular has received significant attention for its role and function in BD and its potential use as a diagnostic biomarker in recent years. Although promising as therapeutic targets, miRNAs must be studied further to fully comprehend how miRNAs in BD act biologically.

cAMP: A master regulator of cadherin-mediated binding in endothelium, epithelium and myocardium

Regulation of cadherin-mediated cell adhesion is crucial not only for maintaining tissue integrity and barrier function in the endothelium and epithelium but also for electromechanical coupling within the myocardium. Therefore, loss of cadherin-mediated adhesion causes various disorders, including vascular inflammation and desmosome-related diseases such as the autoimmune blistering skin dermatosis pemphigus and arrhythmogenic cardiomyopathy. Mechanisms regulating cadherin-mediated binding contribute to the pathogenesis of diseases and may also be used as therapeutic targets. Over the last 30 years, cyclic adenosine 3',5'-monophosphate (cAMP) has emerged as one of the master regulators of cell adhesion in endothelium and, more recently, also in epithelial cells as well as in cardiomyocytes. A broad spectrum of experimental models from vascular physiology and cell biology applied by different generations of researchers provided evidence that not only cadherins of endothelial adherens junctions (AJ) but also desmosomal contacts in keratinocytes and the cardiomyocyte intercalated discs are central targets in this scenario. The molecular mechanisms involve protein kinase A- and exchange protein directly activated by cAMP-mediated regulation of Rho family GTPases and S665 phosphorylation of the AJ and desmosome adaptor protein plakoglobin. In line with this, phosphodiesterase 4 inhibitors such as apremilast have been proposed as a therapeutic strategy to stabilize cadherin-mediated adhesion in pemphigus and may also be effective to treat other disorders where cadherin-mediated binding is compromised.

Oral Lesions as the Primary Manifestations of Behçet's Disease: The Importance of Interdisciplinary Diagnostics-A Case Report

BACKGROUND

Behçet's disease (BD) is a rare chronic auto-inflammatory systemic disease with non-specific oral manifestations, categorised as generalised variable vessel vasculitis that requires an interdisciplinary approach to diagnose due to its phenotypic heterogeneity. Whilst the oral lesions that reoccur in BD underpin the complex diagnostic process, the crucial role of dental professionals is highlighted in a case report summarised herein. We present a case of a 47-year-old male referred to the Oral Medicine Department by a rheumatologist after previous hospitalization for thrombosis of the iliac vein and inferior vena cava. He had elevated inflammatory C-reactive protein biomarker and an increased erythrocyte sedimentation rate. Recurrent episodes of folliculitis, oral and genital ulcers were reported. Clinical examination revealed multiple ulcerations in the oral mucosa. The complementary, histopathological analysis performed to rule out other disorders, based on excisional biopsy, showed non-keratinised stratified squamous epithelium with areas of exocytosis and ulceration. The connective tissue presented an intense mixed inflammatory infiltrate, congested blood vessels, haemorrhage, vasculitis, and HLA-B genotyping identified the expression of HLA-B15, further supporting the BD diagnosis. Treatment was initiated with colchicine, prednisolone, and weekly subcutaneous administration of methotrexate and resulted in the complete remission of oral lesions and no recurrence of other manifestations.

CONCLUSIONS

This BD case report emphasizes the importance of a multidisciplinary approach in diagnosing BD, including the use of histopathological assessment and genetic profiling. It highlights the significance of thorough intraoral assessment and referral to a multidisciplinary team for diagnosis. The oral manifestations of BD as the primary symptoms often indicate underlying major systemic pathologies. The authors stress the need for a structured diagnostic algorithm to facilitate timely and effective management of BD.

Surgical management of aortic regurgitation secondary to Behcet's disease

Background

Aortic regurgitation (AR) related to Behcet's disease (BD) is rare, but usually fatal. Perivalvular leakage (PVL) is high if AR related to BD treated with regular AVR. In this study, we report the surgical management of AR secondary to BD.

Methods

Between September 2017 and April 2022, 38 patients with AR secondary to Behcet's disease had surgery in our center. 17 patients did not have a BD diagnosis before surgery, 2 of them were diagnosed during surgery and received Bentall procedure. The remaining 15 patients received conventional AVR. 21 patients were diagnosed as BD before surgery, all of them received modified Bentall procedures. All patients were followed up by regular outpatient visits, transthoracic echocardiogram and CT angiography were performed to evaluate the aorta and aortic valve.

Results

Seventeen patients did not have a BD diagnosis at the time of surgery. Out of them, 15 patients received conventional AVR, and a total of 13 patients suffered PVL after surgery. Twenty-one patients had a BD diagnosis before surgery. They received modified Bentall procedures and IST and steroids were given both pre- and post-surgery. In this group treated with Bentall procedure no patient suffered PVL during follow up.

Conclusions

PVL is a complex scenario after conventional AVR for AR in BD. Modified Bentall procedure seems superior to isolated AVR in these cases. The use of IST and steroids before and after surgery in combination with modified Bentall procedure could have a role in effectively reducing PVL.

Comprehensive analysis of T-cell receptor repertoires reveals antigen-driven T-cell clusters in patients with Behçet's syndrome

T lymphocytes are the major components of adaptive immunity in Behçet's syndrome (BS) pathology. However, the precise mechanism of T-cell-induced inflammatory condition remains to be determined. We applied bulk sequencing of the T-cell receptor (TCR) β chain in peripheral blood samples from 45 patients with BS and 10 healthy donors as controls. TCR repertoires in BS patients displayed more clonality and less diversity than in healthy donors. Male patients exhibited lower diversity metrics of TCR and had a larger proportion in the top 10 clones than females (p = 0.016). There were no TCR clonality differences in other clinical features, such as age, disease duration, organ involvement, disease severity, and activity. By "Grouping of Lymphocyte Interactions by Paratope Hotspots" (GLIPH2) for antigen prediction, we found distinct 2477 clusters of TCR-β sequences that potentially recognize similar antigens shared between BS patients. We observed clonal T-cell expansion in BS patients. Sexual differences in TCR clonal expansion and public TCR groups deserve further study to reveal the underline T-cell-mediated immunity in BS.

T cells in ocular autoimmune uveitis: Pathways and therapeutic approaches

Autoimmune uveitis is a non-infectious intraocular condition that affects the uveal tract of the eye and threatens vision if not treated properly. Increasing evidence suggests that activated CD4⁺ T cells are associated with progressive and permanent destruction of photoreceptors in ocular autoimmune diseases. As such, the purpose of this review is to offer an overview of the role of CD4⁺ T cells in autoimmune uveitis as well as a justification for the current development and assessment of innovative autoimmune uveitis medications targeting CD4⁺ T cells. With an emphasis on T helper (Th)17, Th1, and Th2 cells, follicular helper CD4⁺ T cells, and regulatory T cells, this review presents a summary of recent research related to the pathways and signaling that encourage CD4⁺ T cells to develop into specialized effector cells. We also describe immunotherapeutic approaches based on CD4⁺ T cell subsets and their potential as therapeutic agents for autoimmune disorders.

Serum Endocan Levels and Subclinical Atherosclerosis in Behçet's Syndrome

Background and Aim

Behçet disease (BD) is a rare chronic relapsing-remitting inflammatory systemic vasculitis. BD patients were reported to have marked acceleration of subclinical atherosclerosis (SCA). Endocan is a soluble proteoglycan mainly secreted by the activated endothelium. The present study aimed to assess the relation between serum endocan levels and SCA in BD patients.

Subjects and Methods

The study included 40 adult BD patients in addition to twenty age- and sex-matched healthy controls. BD was diagnosed according to International Study Group criteria. Upon recruitment, all participants were subjected to careful history taking and thorough clinical examination. BD activity was assessed using Behçet Syndrome Activity Score. Measurement of serum endocan was performed using quantitative double-antibody sandwich ELISA kit. CIMT measurement was done using B-mode ultrasound.

Results

Comparison between patients and controls regarding serum endocan levels revealed significantly higher endocan levels in BD patients [median (IQR): 155.0 (69.3–610.0) versus 73.8 (51.9–94.6)]. Using ultrasound assessment, SCA was found in 14 BD patients (35.0%). Comparison between patients with SCA and patients without regarding the clinical and laboratory data revealed that the former group had significantly higher CRP [median (IQR): 36.5 (26.8–43.5) versus 21.0 (11.8–26.8) mg/dL, p < 0.001] and endocan [median (IQR): 622.0 (107.4–974.8) versus 104.5 (64.0–342.0) mg/dL, p = 0.004] levels. Logistic regression analysis recognized endocan [OR (95% CI): 1.0 (1.0–1.012), p0.035] levels as significant predictor of SCA in multivariate analysis.

Conclusion

The present study identified the clinical value of serum endocan levels as a possible early marker of vascular involvement in BD patients.

"Listen to Your Immune System When It's Calling for You": Monitoring Autoimmune Diseases Using the iShU App

The immune system plays a key role in protecting living beings against bacteria, viruses, and fungi, among other pathogens, which may be harmful and represent a threat to our own health. However, for reasons that are not fully understood, in some people this protective mechanism accidentally attacks the organs and tissues, thus causing inflammation and leads to the development of autoimmune diseases. Remote monitoring of human health involves the use of sensor network technology as a means of capturing patient data, and wearable devices, such as smartwatches, have lately been considered good collectors of biofeedback data, owing to their easy connectivity with a mHealth system. Moreover, the use of gamification may encourage the frequent usage of such devices and behavior changes to improve self-care for autoimmune diseases. This study reports on the use of wearable sensors for inflammation surveillance and autoimmune disease management based on a literature search and evaluation of an app prototype with fifteen stakeholders, in which eight participants were diagnosed with autoimmune or inflammatory diseases and four were healthcare professionals. Of these, six were experts in human–computer interaction to assess critical aspects of user experience. The developed prototype allows the monitoring of autoimmune diseases in pre-, during-, and post-inflammatory crises, meeting the personal needs of people with this health condition. The findings suggest that the proposed prototype—iShU—achieves its purpose and the overall experience may serve as a foundation for designing inflammation surveillance and autoimmune disease management monitoring solutions.

An Abdominal Aortic Pseudoaneurysm Revealing Behçet’s Disease

Behçet's disease (BD) is a vasculitis with multisystemic manifestations. Articular involvement is frequent and benign whereas vascular complications are rare but serious and can form the onset of the disease. The assessment of the thickness of the common femoral vein wall is a new tool for the diagnosis of BD with good sensitivity and specificity. We report the case of a 52-year-old man diagnosed with BD revealed by an abdominal aortic pseudoaneurysm and a chronic monoarthritis. The first flare-up of BD can occur in men over 50 years of age. In a context of a multisystemic disease, lumbar pain should lead to the search of abdominal aortic aneurysm. The assessment of the thickness of the common femoral vein wall is accessible and should be used especially in challenging cases.

Contribution of Arab countries to Behçet disease research: a PubMed-based bibliometric and altmetric analysis

Behçet's disease (BD), a rare multisystemic disorder, has an unknown etiology. Interactions between genetic and environmental factors play a major role in this disorder. Human leukocyte antigen B51 allele is the strongest risk factor for the development of Behçet disease. The high prevalence of BD in the Arab world makes it necessary to undergo local research and publications, to target particular genetic, geographical, or even cultural risk factors. This study aims to assess the numerical contribution of the Arab world to research on Behçet disease. Using the PubMed platform, the number of BD-related publications from 2005 to 2019 was assessed for all 22 Arab countries, and countries having the highest prevalence of the disease. Number of publications on BD was normalized to the average population size and GDP for each Arab country. From 2005 to 2019, Arab countries published 198 articles related to BD. This accounts for 0.1% of the total number of BD-related articles published in this period (4170). A significant, positive correlation of moderate strength exists between the number of publications and the average population, while a non-significant, positive correlation of week strength exists between the number of publications and GDP. Concerning the top 15 countries according to Behçet disease prevalence, Turkey had the greatest number of articles, while the USA had the highest ratio of publications per prevalence. The high prevalence of BD in Arabic countries was faced by paradoxically low research activity in this field. Arab countries are lagging behind in the field of Behçet disease-related research, which highlights the need for improving research productivity.