Synovial proinflammatory cytokines and their correlation with matrix metalloproteinase-3 expression in Behçet's disease. Does interleukin-1beta play a major role in Behçet's synovitis?

Innate immune responses in Behçet disease and relapsing polychondritis

Behçet disease (BD) and relapsing polychondritis (RP) are chronic multisystem disorders characterized by recurrent flare-ups of tissue inflammation. Major clinical manifestations of BD are oral aphthae, genital aphthous ulcers, skin lesions, arthritis, and uveitis. Patients with BD may develop rare but serious neural, intestinal, and vascular complications, with high relapse rates. Meanwhile, RP is characterized by the inflammation of the cartilaginous tissues of the ears, nose, peripheral joints, and tracheobronchial tree. Additionally, it affects the proteoglycan-rich structures in the eyes, inner ear, heart, blood vessels, and kidneys. The mouth and genital ulcers with inflamed cartilage (MAGIC) syndrome is a common characteristic of BD and RP. The immunopathology of these two diseases may be closely related. It is established that the genetic predisposition to BD is related to the human leukocyte antigen (HLA)-B51 gene. Skin histopathology demonstrates the overactivation of innate immunity, such as neutrophilic dermatitis/panniculitis, in patients with BD. Monocytes and neutrophils frequently infiltrate cartilaginous tissues of patients with RP. Somatic mutations in UBA1, which encodes a ubiquitylation-related enzyme, cause vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome (VEXAS) with severe systemic inflammation and activation of myeloid cells. VEXAS prompts auricular and/or nasal chondritis, with neutrophilic infiltration around the cartilage in 52-60% of patients. Thus, innate immune cells may play an important role in the initiation of inflammatory processes underlying both diseases. This review summarizes the recent advances in our understanding of the innate cell-mediated immunopathology of BD and RP, with a focus on the common and distinct features of these mechanisms.

Intestinal Behcet's Disease: A Review of the Immune Mechanism and Present and Potential Biological Agents

Behcet's disease (BD) is a chronic and recurrent systemic vasculitis involving almost all organs and tissues. Intestinal BD is defined as BD with predominant gastrointestinal involvement, presenting severe complications such as massive gastrointestinal hemorrhage, perforation, and obstruction in some cases. To some extent, intestinal BD is classified as a member of inflammatory bowel disease (IBD), as it has a lot in common with classical IBD including Crohn's disease (CD) and ulcerative colitis (UC). Certainly, the underlying pathogenesis is not the same and dysregulation of immune function is believed to be one of the main pathogeneses in intestinal BD, although the etiology has not been clear up to now. Biological agents are an emerging category of pharmaceuticals for various diseases, including inflammatory diseases and cancers, in recent decades. Based on the deep understanding of the immune mechanism of intestinal BD, biological agents targeting potential pathogenic cells, cytokines and pathways are optimized options. Recently, the adoption of biological agents such as anti-tumor necrosis factor agents has allowed for the effective treatment of patients with refractory intestinal BD who show poor response to conventional medications and are faced with the risk of surgical treatment. In this review, we have tried to summarize the immune mechanism and present potential biological agents of intestinal BD.

Comprehensive Genetic Analysis of Druze Provides Insights into Carrier Screening

BACKGROUND

Druze individuals, like many genetically homogeneous and isolated populations, harbor recurring pathogenic variants (PV) in autosomal recessive (AR) disorders.

METHODS

Variant calling of whole-genome sequencing (WGS) of 40 Druze from the Human Genome Diversity Project (HGDP) was performed (HGDP-cohort). Additionally, we performed whole exome sequencing (WES) of 118 Druze individuals: 38 trios and 2 couples, representing geographically distinct clans (WES-cohort). Rates of validated PV were compared with rates in worldwide and Middle Eastern populations, from the gnomAD and dbSNP datasets.

RESULTS

Overall, 34 PVs were identified: 30 PVs in genes underlying AR disorders, 3 additional PVs were associated with autosomal dominant (AD) disorders, and 1 PV with X-linked-dominant inherited disorder in the WES cohort.

CONCLUSIONS

The newly identified PVs associated with AR conditions should be considered for incorporation into prenatal-screening options offered to Druze individuals after an extension and validation of the results in a larger study.

Candidate Drugs Screening for Behcet’s Disease Based on Bioinformatics Analysis and Mouse Experiments

Background

Behcet’s disease (BD) is a chronic immune disease that involves multiple systems. As the pathogenesis of BD is not clear, and new treatments are needed, we used bioinformatics to identify potential drugs and validated them in mouse models.

Methods

Behcet’s disease-related target genes and proteins were screened in the PubMed and UVEOGENE databases. The biological functions and pathways of the target genes were analyzed in detail by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. A protein-protein interaction (PPI) network was constructed by the STRING database, and hub genes were identified by the Cytoscape plug-in CytoHubba. Gene-drug interactions were identified from the DGIdb database. Experimental autoimmune uveitis (EAU) mice were used as an animal model for drug validation.

Results

A total of 249 target genes and proteins with significant differences in BD were screened, and the results of functional enrichment analysis suggested that these genes and proteins were more located on the cell membrane, involved in regulating the production of cytokines and affecting the activity of cytokines. They mainly regulated “Cytokine- Cytokine receptor interaction”, “Inflammatory bowel disease (IBD)” and “IL-17 signaling Pathway”. In addition, 10 hub genes were obtained through PPI network construction and CytoHubba analysis, among which the top 3 hub genes were closely related to BD. The DGIdb analysis enriched seven drugs acting together on the top 3 hub genes, four of which were confirmed for the treatment of BD or its complications. There is no evidence in the research to support the results in omeprazole, rabeprazole, and celastrol. However, animal experiments showed that rabeprazole and celastrol reduced anterior chamber inflammation and retinal inflammation in EAU mice.

Conclusions

The functional analysis of genes and proteins related to BD, identification of hub genes, and validation of potential drugs provide new insights into the disease mechanism and potential for the treatment of BD.

Behçet's Syndrome Apart From the Triple Symptom Complex: Vascular, Neurologic, Gastrointestinal, and Musculoskeletal Manifestations. A Mini Review

Behçet‘s Syndrome (BS) is a variable vessel vasculitis according to the Chapel Hill Consensus Nomenclature (1) and may thus affect any organ, including major and minor arterial and venous vessels to a varying degree and with varying frequency. Although the main features of BS are recurrent oral and genital aphthous ulcers, cutaneous lesions, ocular inflammation and arthritis—major vessel and life—or organ threatening involvement of internal organs and the central and peripheral nervous system occur. In general, BS in Europe appears to form six phenotypes of clinical manifestations (2), which are (1) mucocutaneous only, (2) predominant arthritis/articular involvement, (3) vascular phenotype, (4) ocular manifestations, which are most likely associated with CNS manifestations and HLA-B51, (5) dominant parenchymal CNS manifestations (being associated with the ocular ones), and (6) gastrointestinal involvement. Mucocutaneous manifestations are present in almost all patients/all phenotypes. In the following review, we summarize the current knowledge concerning vascular, neurologic, gastrointestinal and musculoskeletal manifestations of the disease.

Differential Gene Expression Patterns in Blood and Cerebrospinal Fluid of Multiple Sclerosis and Neuro-Behçet Disease

Inflammatory demyelinating disorders of the central nervous system are debilitating conditions of the young adult, here we focus on multiple sclerosis (MS) and neuro-Behçet disease (NBD). MS is an autoimmune disorder of the central nervous system. NBD, a neurological manifestation of an idiopathic chronic relapsing multisystem inflammatory disease, the behçet disease. The diagnosis of MS and NBD relies on clinical symptoms, magnetic resonance imaging and laboratory tests. At first onset, clinical and imaging similarities between the two disorders may occur, making differential diagnosis challenging and delaying appropriate management. Aiming to identify additional discriminating biomarker patterns, we measured and compared gene expression of a broad panel of selected genes in blood and cerebrospinal fluid (CSF) cells of patients suffering from NBD, MS and non inflammatory neurological disorders (NIND). To reach this aim, bivariate and multivariate analysis were applied. The Principal Analysis Component (PCA) highlighted distinct profiles between NBD, MS, and controls. Transcription factors foxp3 in the blood along with IL-4, IL-10, and IL-17 expressions were the parameters that are the main contributor to the segregation between MS and NBD clustering. Moreover, parameters related to cellular activation and inflammatory cytokines within the CSF clearly differentiate between the two inflammatory diseases and the controls. We proceeded to ROC analysis in order to identify the most distinctive parameters between both inflammatory neurological disorders. The latter analysis suggested that IL-17, CD73 in the blood as well as IL-1β and IL-10 in the CSF were the most discriminating parameters between MS and NBD. We conclude that combined multi-dimensional analysis in blood and CSF suggests distinct mechanisms governing the pathophysiology of these two neuro-inflammatory disorders.

Safety of systemic treatments for Behçet's syndrome

INTRODUCTION

Treatment of Behçet's syndrome (BS) is aimed at controlling all symptoms of such a complex disorder, ensuring a good quality of life and preventing life-threatening complications. A better understanding of the pathogenic role of different chemokines has improved our knowledge of BS and elicited a more specific use of therapies currently available, minimizing the burden of potential side-effects related to treatment.

AREAS COVERED

This work aims to provide a detailed overview of the safety profile for current therapies available in the treatment of BS, focusing on the main side-effects, toxicity and contraindications.

EXPERT OPINION

The greatest experience in the management of BS has been achieved with the employment of monoclonal anti-tumor necrosis factor antibodies which have been advocated for BS refractory manifestations. Moreover, interleukin-1 inhibitors have proven to be effective as well as safe, despite escalation of their dosage, especially to manage the most severe and difficult-to-treat ocular manifestations. However, general treatment of BS patients remains awkward as protean clinical features may respond differently to the same treatment or even worsen. Therefore, patients' safety for therapies used in BS promotes the implementation of precision medicine, which could help targeting accurately the pathogenetic mechanisms concealed behind specific clinical phenotypes.

Behҫet's Disease, and the Role of TNF-α and TNF-α Blockers

In this both narrative and systematic review, we explore the role of TNF-α in the immunopathogenesis of Behçet's disease (BD) and the effect of treatment with TNF-α blockers. BD is an auto-inflammatory disease, characterized by recurrent painful oral ulcerations. The pathogenesis of BD is not yet elucidated; it is assumed that TNF-α may play a key role. In the narrative review, we report an increased production of TNF-α, which may be stimulated via TLR-signaling, or triggered by increased levels of IL-1β and IFN-γ. The abundance of TNF-α is found in both serum and in sites of inflammation. This increased presence of TNF-α stimulates T-cell development toward pro-inflammatory subsets, such as Th17 and Th22 cells. Treatment directed against the surplus of TNF-α is investigated in the systematic review, performed according to the PRISMA guideline. We searched the Pubmed and Cochrane database, including comparative studies only. After including 11 studies, we report a beneficial effect of treatment with TNF-α blockers on the various manifestations of BD. In conclusion, the pivotal role of TNF-α in the immunopathogenesis of BD is reflected in both the evidence of their pro-inflammatory effects in BD and in the evidence of the positive effect of treatment on the course of disease in BD.

Ultrasonographic assessment of femoral cartilage thickness in patients with and without uveitis in Behçet's disease

The objective for this study is to evaluate the femoral cartilage thickness in patients with/without uveitis in Behçet's disease (BD). Patients with BD aged 18-70 years were included. The demographic and clinical characteristics of the patients were recorded. The thickness of femoral articular cartilage was measured with musculoskeletal ultrasound. Cartilage thickness was measured bilaterally from the central points of medial condyle (MFC), lateral condyle (LFC), and intercondylar area (ICA). 20 patients with uveitis [uveitis (+)] and 20 patients without uveitis [uveitis (-)] were included. Both right and left MFC and LFC had statistically significant thinner cartilage in uveitis (+) group (p < 0.05). For the ICA, uveitis (+) patients had thinner femoral cartilage than uveitis (-) patients; however, in the left side, statistically significance could not be detected. Femoral cartilage was thinner in uveitis (+) patients than in uveitis (-) patients in BD. This relationship between uveitis and femoral cartilage thickness may be helpful in the prevention and early treatment of cartilage degeneration.

Behçet's disease: An immunogenetic perspective

Behçet's disease (BD) is a chronic and rare multisystemic disorder defined by autoimmunity and inflammatory characteristics, manifested by ocular lesions, recurrent genital and oral ulcers, skin symptoms and arthritis as well as neurological, intestinal, and vascular involvement. Despite the unknown cause of BD, there is some strong documentation for immunological, genetic, environmental, and infectious factors playing a role in the pathogenesis of BD. While the nature of the genetic variants remains unidentified, many genetic risk factors are considered to contribute to BD susceptibility. Along with human leukocyte antigen gene encoding B*51 (HLA-B*51) and areas including the major histocompatibility complex class I, genome-wide association studies have recognized numerous other BD susceptibility genes including those encoding interleukin (IL)-10, IL-12 receptor β 2 (IL-12RB2), IL-23 receptor (IL-23R), C-C chemokine receptor 1 gene, signal transducer and activator of transcription 4 (STAT4), endoplasmic reticulum aminopeptidase (ERAP1), and genes encoding killer cell lectin-like receptor family members (KLRC4-KLRK1). It is believed that BD could be considered as a disorder lying in between autoimmune and autoinflammatory syndromes. The positive responses to classical immunosuppressive agents like azathioprine and cyclosporine and involvement of autoantigens in the initiation of the disorder are the main BD features that reflect the autoimmune nature of the disorder. In this review, we address recent findings on the role of common cytokines, antibodies and immunogenetic factors in BD.

Vasculitis Pathogenesis: Can We Talk About Precision Medicine?

Precision medicine is designing the medical care by taking into account the individual variability for each person. We have tried to address whether the existing data may guide precision medicine in primary systemic vasculitides (PSV). We have reviewed genome-wide association studies (GWAS) data, lessons from monogenic mimics of these diseases, and biomarker studies in immunoglobulin A vasculitis/Henoch–Schönlein purpura, Kawasaki disease, anti-neutrophil cytoplasmic antibody-associated vasculitis, polyarteritis nodosa (PAN), Takayasu arteritis, and Behçet’s disease (BD). GWAS provide insights about the pathogenesis of PSV while whole exome sequencing studies lead to discovery of monogenic vasculitides, phenotype of which could mimic other types of vasculitis such as PAN and BD. Monogenic vasculitides form a subgroup of vasculitis which are caused by single gene alterations and discovery of these diseases has enabled more specific therapies in these patients. With increasing number of studies on biomarkers, new targets for treatment appear and better and structured follow-up of PSV patients will become possible. Proteomics and metabolomics studies are required to better categorize our patients with PSV so that we can manage them appropriately and offer more targeted therapy.

Role of N-acetyl galactosamine-4-SO4, a ligand of CD206 in HSV-induced mouse model of Behçet's disease

CD206 is a macrophage mannose receptor involved in variety of autoimmune and inflammatory diseases. This study aimed to identify the pathogenic role of CD206 in a herpes simplex virus (HSV) induced Behçet's disease (BD) mouse model. CD206 positive cells were detected in peripheral blood mononuclear cells and quantified by flow cytometry. Levels of cytokines were measured by ELISA. CD206 was found to be down-regulated both in vitro (10^-6M) and in vivo (200μg/mouse) after treatment with N-acetylgalactosamine (GalNAc), a ligand for CD206. The down-regulation of CD206 was correlated with improvement in BD symptoms. Colchicine (2μg/mouse) or pentoxifylline (400μg/mouse) treated mice displayed improvement in BD symptoms with fewer CD206 positive cells. The prevalence of CD206-positive cells differed between ligand-responsive and non-responsive BD mice. Inhibition of CD206 was associated with down-regulated serum level of interleukin-17 in GalNAc-treated BD mice. These results suggest that the expression of CD206 is correlated with HSV-induced BD symptoms in mice, implicating that CD206 might have a pathogenic role in BD.

Treatment of mucocutaneous manifestations in Behçet's disease with anakinra: a pilot open-label study

BACKGROUND

The effect of IL-1 blocking therapy on mucocutaneous manifestations of Behçet's disease is incompletely understood.

METHODS

Six patients with Behçet's disease and ongoing oral/genital ulcers for ≥1 month were enrolled into an adaptive, two-phase clinical trial and included in the analysis. Study duration was 6 months with extension up to 16 months. All were treated non-blinded with anakinra 100 mg subcutaneous daily with the option to escalate the dose to 200 mg in partial responders after 1 month and 300 mg after 6 months. Patients recorded the number and severity of ulcers in daily diaries. The primary outcome was remission defined as no ulcers on physical exam for two consecutive monthly visits between months 3 and 6. Secondary outcomes included the number and severity of patient-reported ulcers, patient/physician global scores, and standardized disease activity scores.

RESULTS

Two of six patients achieved the primary outcome. Five of six patients had improvement in the number and severity of ulcers. Non-statistically significant improvements were seen in secondary outcomes. Over the entire study, patients reported ≥1 oral and ≥1 genital ulcer on 665 (66%) and 139 (14%) days, respectively. On anakinra 200 mg vs 100 mg, patients reported fewer days with oral ulcers (65% vs 74% of days, p = 0.01) and genital ulcers (10% vs 22% of days, p < 0.001) and milder oral ulcer severity (p < 0.001). Increase of anakinra to 300 mg did not result in further improvements. Adverse events were notable for mild infections.

CONCLUSION

Anakinra at an optimal dose of 200 mg daily had an acceptable safety profile and was partially effective in the treatment of resistant oral and genital ulcers in Behçet's disease.

TRIAL REGISTRATION

Clinicaltrials.gov. NCT01441076 . Registered on 24 September 2011.

Leptin promotes apoptosis and inhibits autophagy of chondrocytes through upregulating lysyl oxidase-like 3 during osteoarthritis pathogenesis

OBJECTIVE

Leptin has been found highly expressed in human osteoarthritis. We aimed to explore the possible effects and mechanisms of leptin on the apoptosis and autophagy of chondrocytes during osteoarthritis pathogenesis.

METHODS

Gene expression profile from osteoarthritis affected and preserved cartilage were downloaded from NCBI's Gene Expression Omnibus database (GSE57218). Lysyl oxidase-like 3 (LOXL3) mRNA expression in cartilage tissues and leptin concentration in joint synovial fluid (SF) was measured in samples from 45 osteoarthritis patients and 25 healthy donors by real-time PCR and radioimmunoassay, respectively. Rat osteoarthritis model was induced by anterior cruciate ligament transection (ACLT). The expression of apoptosis regulators and autophagy markers were detected by Western blot. Cell survival and cell apoptosis were identified by CCK-8 and flow cytometry, respectively.

RESULTS

Re-analysis on GSE57218 indicated that LOXL3 mRNA was upregulated in osteoarthritis affected cartilage. LOXL3 mRNA was upregulated in osteoarthritis patients, which was positively correlated with SF leptin concentration. Similar results were obtained in rat osteoarthritis model. Moreover, ACLT surgery led to a significant increase in the protein levels of cleaved caspase 3, and a notable decrease in the protein levels of Bcl-2, LC3 II/LC3 I and Beclin1. Silencing of LOXL3 in ACLT and leptin treated primary chondrocytes significantly inhibited cell apoptosis, and promoted cell proliferation and autophagy. Moreover, overexpression of LOXL3 remarkably inhibited autophagy of chondrocytes via activating mTORC1.

CONCLUSIONS

LOXL3, a downstream of leptin, stimulated the apoptosis, but inhibited the autophagy of chondrocytes. LOXL3 is a potential therapy target for osteoarthritis.

Mucocutaneous Involvement in Behçet's Disease: How Systemic Treatment Has Changed in the Last Decades and Future Perspectives

Behçet's disease (BD) is a multisystemic disorder of unknown etiology characterized by the "triple symptom complex" consisting of recurrent oral aphthosis, genital ulcers, and chronic relapsing bilateral uveitis. Recurrent mucocutaneous lesions are generally considered the hallmark of the disease, being the most common symptoms presenting at the onset of disease. Although the improvement of knowledge about the pathogenetic mechanism added important changes in the treatment management of BD clinical manifestations, thus avoiding the appearance of serious life-threatening complications which are disease related, the mucocutaneous lesions are still the most nagging clinical manifestations to be treated. In this work we reviewed the current state of knowledge regarding the therapeutic approaches for mucocutaneous lesions of BD mainly based on controlled studies to provide a rational framework for selecting the appropriate therapy for treating these troublesome features of the disease.

mRNA Expression Level of Interleukin Genes in the Determining Phases of Behçet's Disease

Background

Behçet's disease (BD), first described in 1937 as a triadic complex of symptoms (oral aphthae, genital ulcers, and hypopyon uveitis), is a chronic, relapsing, multisystemic idiopathic inflammatory disease.

Objective

The objective of this study was to investigate the usability of messenger RNA (mRNA) expression of cytokine genes for following up patients with BD and also assess polymorphisms in these genes as to how they influence mRNA expression.

Methods

This study investigated the role of the IL1A -889(C/T), IL1B -511(C/T), and IL2 -330(T/G) polymorphisms by polymerase chain reaction (PCR)-restriction fragment length polymorphisms and the expression levels of the genes by real-time PCR in BD.

Results

The frequency of the IL2 -330 G allele was found to be significantly higher in patients with BD. A decreased level of IL1A gene expression was found in the patient group with clinically active BD compared to controls. Increased IL1B gene expression levels werefound in patient groups with active, inactive, or ocular BD (p<0.001). IL2 gene expression level manifested no significant change compared to controls in the patient group with clinically active BD; it increased in the groups with clinically inactive BD or ocular involvement.

Conclusion

IL1A, IL1B, and IL2 gene expression, and IL2 promoter polymorphisms, may be valuable markers for predicting risk in the development of BD. We believe that the results reveal the importance of achieving a better understanding of BD and the prospects of developing future therapeutic strategies.

Ultrasonographic Measurement of the Femoral Cartilage Thickness in Patients with Behçet's Disease

OBJECTIVE

To evaluate femoral cartilage thickness in patients with Behçet's disease (BD) by using ultrasonography.

METHODS

Thirty-one patients with BD (18 M, 13 F; mean age: 32.87 ± 8.5 years) and 31 age-, gender- and body mass index-matched healthy subjects were enrolled. Demographic features and medications of the patients were recorded. The femoral cartilage thicknesses of both knees were measured with a 7-12 MHz linear probe while subjects' knees were held in maximum flexion. Three mid-point measurements were taken from both knees: lateral femoral condyle (LFC), intercondylar area (ICA) and medial femoral condyle (MFC).

RESULTS

Cartilage measurements of BD patients were significantly thinner at the ICA (p = 0.009) and LFC (p = 0.007) on the left knee, and at the MFC on both sides (both p < 0.05). Left knee cartilage thickness value at MFC (p = 0.005) was decreased in BD patients with arthritis compared to the healthy control group.

CONCLUSION

These preliminary findings of decreased femoral cartilage thickness in BD patients with arthritis should be complemented with future studies. However, the possibility of early knee joint degeneration and eventual osteoarthritis in BD should also be kept in mind.

Interleukin-1 as a common denominator from autoinflammatory to autoimmune disorders: premises, perils, and perspectives

A complex web of dynamic relationships between innate and adaptive immunity is now evident for many autoinflammatory and autoimmune disorders, the first deriving from abnormal activation of innate immune system without any conventional danger triggers and the latter from self-/non-self-discrimination loss of tolerance, and systemic inflammation. Due to clinical and pathophysiologic similarities giving a crucial role to the multifunctional cytokine interleukin-1, the concept of autoinflammation has been expanded to include nonhereditary collagen-like diseases, idiopathic inflammatory diseases, and metabolic diseases. As more patients are reported to have clinical features of autoinflammation and autoimmunity, the boundary between these two pathologic ends is becoming blurred. An overview of monogenic autoinflammatory disorders, PFAPA syndrome, rheumatoid arthritis, type 2 diabetes mellitus, uveitis, pericarditis, Behçet's disease, gout, Sjögren's syndrome, interstitial lung diseases, and Still's disease is presented to highlight the fundamental points that interleukin-1 displays in the cryptic interplay between innate and adaptive immune systems.

Behçet syndrome: from pathogenesis to novel therapies

Behçet syndrome is a chronic disease hallmarked by inflammation of the blood vessels that is related to an autoimmune reaction caused by inherited susceptibility due to specific genes and environmental factors, probably components of infectious microorganisms, which turn on or get going the disease in genetically susceptible subjects. The more common clinical expression of the disease is represented by a triple-symptom complex of recurrent oral aphthous ulcers, genital ulcers, and uveitis, sometimes associated with inflammatory arthritis, phlebitis, iritis, as well as inflammation of the digestive tract, brain, and spinal cord. The treatment strategies used to manage the manifestations of Behçet syndrome have gradually progressed, and a number of new therapeutic resources have been implemented in recent years, allowing better control of pathogenic mechanisms, reducing symptoms and suffering, and ameliorating patient's outcome.

Effectiveness and tuberculosis-related safety profile of interleukin-1 blocking agents in the management of Behçet's disease

Behçet's disease (BD) is a multi-systemic disorder of unknown etiology characterized by relapsing oral-genital ulcers, uveitis, and involvement of the articular, gastrointestinal, neurologic, and vascular systems. Although the primum movens of this condition remains unknown, a tangled plot combining autoimmune and autoinflammatory pathways has been hypothesized to explain its start and recurrence. In-depth analysis of BD pathogenetic mechanisms, involving dysfunction of multiple proinflammatory molecules, has opened new modalities of treatment: different agents targeting interleukin-1 have been studied in recent years to manage the most difficult and multi-resistant cases of BD. Growing experience with anakinra, canakinumab and gevokizumab is discussed in this review, highlighting the relative efficacy of each drug upon the protean BD clinical manifestations. Safety and tolerability of interleukin-1 antagonists in different doses have been confirmed by numerous observational studies on both large and small cohorts of patients with BD. In particular, the potential for Mycobacterium tuberculosis reactivation and tuberculosis development appears to be significantly lower with interleukin-1 blockers compared to tumor necrosis factor-α inhibitors, thus increasing the beneficial profile of this approach.

Biological treatments in Behçet's disease: beyond anti-TNF therapy

Behçet's disease (BD) is universally recognized as a multisystemic inflammatory disease of unknown etiology with chronic course and unpredictable exacerbations: its clinical spectrum varies from pure vasculitic manifestations with thrombotic complications to protean inflammatory involvement of multiple organs and tissues. Treatment has been revolutionized by the progressed knowledge in the pathogenetic mechanisms of BD, involving dysfunction and oversecretion of multiple proinflammatory molecules, chiefly tumor necrosis factor- (TNF-) α, interleukin- (IL-) 1β, and IL-6. However, although biological treatment with anti-TNF-α agents has been largely demonstrated to be effective in BD, not all patients are definite responders, and this beneficial response might drop off over time. Therefore, additional therapies for a subset of refractory patients with BD are inevitably needed. Different agents targeting various cytokines and their receptors or cell surface molecules have been studied: the IL-1 receptor has been targeted by anakinra, the IL-1 by canakinumab and gevokizumab, the IL-6 receptor by tocilizumab, the IL12/23 receptor by ustekinumab, and the B-lymphocyte antigen CD-20 by rituximab. The aim of this review is to summarize all current experiences and the most recent evidence regarding these novel approaches with biological drugs other than TNF-α blockers in BD, providing a valuable addition to the actually available therapeutic armamentarium.

Behçet's syndrome pathophysiology and potential therapeutic targets

Behçet syndrome is a systemic inflammatory disorder characterized by multiorgan involvement such as oral and genital ulcers, uveitis, skin lesions as well as by less frequent, but often more severe, central nervous system and vascular manifestations. The pathogenetic mechanisms are still incompletely known; however the interaction between a specific genetic background and environmental or infectious factors certainly contributes to the immune dysregulation that characterizes this disease. The discovery of new immunological pathways in Behçet syndrome pathogenesis may help us to set up new treatments. In this review, we will focus our attention on the possible mechanisms underlying Behçet syndrome pathogenesis and their potential role as novel therapeutic targets.

[Pathophysiology of Behçet's disease]

Although the precise pathogenesis and etiology of Behçet's disease (BD) still remains unknown, current evidence suggests that inflammatory reaction in BD arises from disruption of homeostasis in genetically susceptible individuals, resulting in altered innate and adaptive immunity responses, pathogenic T cell activation in the peripheral blood, and in inflammatory sites. Association with HLA-B51 is known as the strongest genetic susceptibility factor for BD. Recent GWAS (genome-wide association studies) have confirmed this relationship, and reported new susceptibility genes (IL-10, IL-23R, IL-12RB2) for the disease. A triggering infectious agent could operate through molecular mimicry, and the disease could subsequently be perpetuated by an abnormal immune response to an auto-antigen in the absence of ongoing infection. Several potential bacteria have been investigated but the most commonly implicated microorganism is Streptococcus sanguis. Recent data have showed that the T cell homeostasis perturbation consisted mainly of Th1 and Th17 expansions, while regulatory T cell response was suppressed. Cytokine such as IL-17, IL-23 and IL-21 play a significant role in the pathogenesis of BD. Inflammatory cells within BD inflammatory lesions include mostly neutrophils, CD4(+) T cells, and cytotoxic cells. Lastly, endothelium dysfunction has been clearly established. This improved understanding of the pathophysiology of BD will certainly lead to the development of new therapeutic agents, potentially more effective than current therapy. In this review, we have studied the etiopathogenesis of BD in the light of recent advances.

The purinergic P2×7 receptor is expressed on monocytes in Behçet's disease and is modulated by TNF-α

The P2×7 receptor (P2×7r) is expressed in innate immune cells (e.g. monocyte/macrophages), playing a key role in IL-1β release. Since innate immune activation and IL-1β release seem to be implicated in Behçet's disease (BD), a systemic immune-inflammatory disorder of unknown origin, we hypothesized that P2×7r is involved in the pathogenesis of the disease. Monocytes were isolated from 18 BD patients and 17 healthy matched controls. In BD monocytes, an increased P2×7r expression and Ca(2+) permeability induced by the selective P2×7r agonist 2'-3'-O-(4-benzoylbenzoyl)ATP (BzATP) was observed. Moreover, IL-1β release from LPS-primed monocytes stimulated with BzATP was markedly higher in BD patients than in controls. TNF-α-incubated monocytes from healthy subjects almost reproduced the findings observed in BD patients, as demonstrated by the increase in P2×7r expression and BzATP-induced Ca(2+) intake. Our results provide evidence that in BD monocytes both the expression and function of the P2×7r are increased compared with healthy controls, as the possible result, at least in part, of a positive modulating effect of TNF-α on the receptor. These data indicate P2×7r as a new potential therapeutic target for the control of BD, further supporting the rationale for the use of anti-TNF-α drugs in the treatment of the disease.

Common MEFV gene mutations in Turkish patients with Behcet's disease

Behcet's disease (BD) is a chronic systemic inflammatory disorder whose etiology has not been fully established yet. The MEditerranean FeVer (MEFV) gene has been identified as the cause of Familial Mediterranean Fever (FMF). BD shows similarities with FMF, in terms of clinical findings and treatments, as well as their geographical and ethnic co-occurrence. In this study we investigated common MEFV gene mutation frequencies in Turkish patients with BD in an area of Turkey where both diseases are frequently encountered. We screened 207 BD patients who had no symptoms and family history for FMF and 200 healthy subjects for five common MEFV gene mutations (E148Q, M680I, M694V, V726A, P369S) and clinical features. Seventy-five patients were found to carry a single MEFV mutation, and six patients were compound heterozygous. The difference in the frequency of the MEFV mutation between the BD and control groups was statistically significant (p<0.001, odds ratio [OR] 2.74, 95% confidence interval [CI] 1.75-4.29). The frequencies of E148Q and M680I mutations were significantly higher in the BD group (p=0.001, p=0.046, respectively). The frequency of uveitis was significantly lower in patients with the mutation than in patients without the mutation (p=0.029, OR 0.54, 95% CI 0.30-0.98). There was no statistical significance between carriers and non-carriers with respect to gender and other manifestations of BD. The frequency of the MEFV mutation was significantly higher in patients with BD compared to the healthy control group. Based on our results, MEFV mutations appear to have a role in the pathogenesis of BD.

A functional variant of pre-miRNA-196a2 confers risk for Behcet's disease but not for Vogt-Koyanagi-Harada syndrome or AAU in ankylosing spondylitis

This study aimed to investigate the predisposition of common pre-miRNA SNPs with Behcet's disease (BD), Vogt-Koyanagi-Harada (VKH) syndrome and acute anterior uveitis (AAU) associated with ankylosing spondylitis (AS). A two-stage association study was carried out in 859 BD, 400 VKH syndrome, 209 AAU(+)AS(+) patients and 1,685 controls all belonging to a Chinese Han population. Genotyping, the expression of miR-196a and Bach1 (the target gene of miR-196a), cell proliferation, cytokine production were examined by PCR-RFLP, real-time PCR, CCK8 and ELISA. In the first stage study, the results showed significantly increased frequencies of the miR-196a2/rs11614913 TT genotype and T allele in BD patients (adjusted P(c) = 0.024, OR = 1.63; adjusted P(c) = 5.4 × 10(-3), OR = 1.45, respectively). However, no significant association of the tested SNPs with VKH and AAU(+)AS(+) patients was observed. The second stage and combined studies confirmed the association of rs11614913 with BD (TT genotype: adjusted P(c) = 6×10(-5), OR = 1.53; T allele: adjusted P(c) = 8×10(-6), OR = 1.35; CC genotype: adjusted P(c) = 0.024, OR = 0.68). A stratified analysis showed an association of the rs11614913 TT genotype and T allele with the arthritis subgroup of BD (P(c) = 5.3 × 10(-3), OR = 1.89; P(c) = 0.015, OR = 1.56, respectively). Functional experiments showed a decreased miR-196a expression, an increased Bach1 expression and an increased production of IL-1β and MCP-1 in TT cases compared to CC cases (P = 0.023, P = 0.0073, P = 0.012, P = 0.002, respectively). This study shows that a functional variant of miR-196a2 confers risk for BD but not for VKH syndrome or AAU(+)AS(+) by modulating the miR-196a gene expression and by regulating pro-inflammatory IL-1β and MCP-1 production.

Differential effects of colchicine in blood mononuclear cells of patients with Behçet disease in relation to colchicine responsiveness

BACKGROUND

Colchicine, a first-line drug for the treatment of Behçet disease (BD), inhibits caspase-1 activation and inflammatory cytokine production. However, therapeutic and preventive effects are not observed in some patients with BD.

OBJECTIVE

To explore whether the effects of colchicine on proinflammatory cytokine expression and cell death in peripheral blood mononuclear cells (PBMCs) from patients with BD are associated with responsiveness to colchicine.

METHODS

Activation of caspase-1, transcription and secretion of interleukin (IL)-1β, tumour necrosis factor (TNF)-α and IL-6, and release of lactate dehydrogenase (LDH) in PBMCs isolated from healthy controls and patients with BD were analysed in the presence or absence of colchicine and upon stimulation with lipopolysaccharide (LPS) plus a caspase-1 activator.

RESULTS

Colchicine significantly modulated monosodium urate-induced IL-1β release, LPS-stimulated LDH release, and basal transcript levels of TNF-α and IL-6 in healthy controls and BD colchicine responders, but not in BD colchicine nonresponders. Notably, colchicine showed contrasting effects on LPS-stimulated IL-1β transcription, i.e. it increased in responders but decreased in nonresponders. Also, higher levels of TNF-α and IL-6 transcripts were observed in LPS-stimulated PBMCs from nonresponders compared with responders.

CONCLUSIONS

This study shows different effects of colchicine on PBMCs from patients with BD according to their responsiveness to colchicine. Predicting responsiveness to colchicine in patients with BD may, therefore, be possible by examining alterations in IL-1β transcript levels in LPS-stimulated PBMCs after colchicine treatment.

Behçet's disease: immunological relevance with arthritis of ankylosing spondylitis

Behçet's disease (BD) is a multi-system inflammatory disorder, in which cytokine balance is polarized to Th1. In this study, the cell surface molecule expression, Th1/Th2, inflammatory cytokine levels in blood, and synovial fluid of CD3(+) T lymphocytes in BD were investigated. The study group consisted of 10 BD, 10 ankylosing spondylitis (AS) patients with peripheral arthritis, and 10 healthy subjects. Expression of cell surface molecules, intracellular IL-2, IL-5, IL-8, IL-10, IL-12, IFN-γ, and TNF-α levels in CD3(+) T lymphocytes were determined by flow cytometry in synovial and peripheral blood mononuclear cells (PBMCs). Synovial and plasma cytokine levels were measured by ELISA and CBA. In PBMCs, CD4, CD25, HLA-DR expression and intracellular IL-12, and TNF-α levels of CD3(+) T lymphocytes were statistically increased in BD patients compared to healthy subjects. Compare to AS patients, CD25 and HLA-DR surface expression and intracellular IFN-γ and TNF-α levels in T cells were significantly elevated in BD patients. In BD patients, there was an increase in IL-8 secretion; however, in AS patients, both Th1- and Th2-type cytokines were increased compare to healthy subjects. Intracellular cytokine expression did not show any difference in BD patients; however, IL-12 content of synovial fluid was significantly increased compared to AS patients. Our findings revealed that Th1 polarization occurred in both peripheral blood and synovial fluid of BD patients with arthritis. It is found no difference between synovial fluid analysis of BD and AS patients, showing the similarities in the pathogenesis of both diseases.

Cytokines and Behcet's disease

Behcet's Disease (BD) is a systemic vasculitis of unknown etiology. Increasing studies find that a sophisticated interlacing cytokine network is closely implicated in the onset, evolution and even organ damages of the disease. Cytokines involved can be categorized as Th1 type, Th2 type, Th17 type, chemokines and other proinflammatory cytokines, etc. The vicious cycle of cytokine network plays a substantial role in the disease pathogenesis and even in organ lesions, and might be disorganized by blocking one of the key links of the cytokines, which in turn may provide essential clues to outlook the target therapy regimen of cytokine agents in BD. There have been a number of case reports of the positive efficacies of cytokine (and cytokine blocker) agents including Infiximab (Human murine chimeric Anti-TNF α monoclonal antibody), Anakinra (recombinant, non-glycosylated human IL1 receptor antagonist) etc in BD. IFN-α had been used clinically in treating BD with uveitis with beneficial efficacy ever since the 1980s. The studies to date suggested that IL6, IP10 are involved in BD with nervous system lesions, IL17, IL18 are relevant to the superimposed uveitis in patients with BD. Some cytokines i.e. IL8, RANTES, MIP-1α are associated with the disease activity, whereas others are exemplified by that of IL10, whose level shows negative relevance to the disease activity, might be potentially cytokine of protecting effect. According to the related genetic study, the SNPs of numerous cytokines including IL1, TNFα, IFNγ, IL12, and IL18 are pertinent to BD. The recent GWAS (Genome Wide Association Studies) demonstrated that SNPs in the IL10 and IL23R-IL12RB2 region are associated with the disease. Most studies nowadays are confined within the cytokines in the peripheral blood levels, owing to the potentially significant roles of certain cytokines in local lesions. It warrants further in-depth study to address this issue. Moreover, it deserves multi-centre study considering the unique geographical "silk road" display picture of the disease.

Squamous metaplasia amplifies pathologic epithelial-mesenchymal interactions in COPD patients

Squamous metaplasia (SM) is common in smokers and is associated with airway obstruction in chronic obstructive pulmonary disease (COPD). A major mechanism of airway obstruction in COPD is thickening of the small airway walls. We asked whether SM actively contributes to airway wall thickening through alteration of epithelial-mesenchymal interactions in COPD. Using immunohistochemical staining, airway morphometry, and fibroblast culture of lung samples from COPD patients; genome-wide analysis of an in vitro model of SM; and in vitro modeling of human airway epithelial-mesenchymal interactions, we provide evidence that SM, through the increased secretion of IL-1beta, induces a fibrotic response in adjacent airway fibroblasts. We identify a pivotal role for integrin-mediated TGF-beta activation in amplifying SM and driving IL-1beta-dependent profibrotic mesenchymal responses. Finally, we show that SM correlates with increased severity of COPD and that fibroblast expression of the integrin alpha(v)beta(8), which is the major mediator of airway fibroblast TGF-beta activation, correlated with disease severity and small airway wall thickening in COPD. Our findings have identified TGF-beta as a potential therapeutic target for COPD.

Immunopathogenesis of Behçet's disease with special emphasize on the possible role of antigen presenting cells

Behçet's disease (BD) is a systemic vasculitis with unclear etiology and pathogenesis. Although several viral and bacterial causes have been investigated in detail for several years, of late it is widely accepted that microorganisms may play a role as a trigger, or as a cross-reactive antigens that interfere with self-antigens, such as heat-shock proteins. Genes such as HLA-B51, MICA and TNF, considered to play a crucial role in the pathogenesis of BD, are located in the major histocompatibility complex (MHC). However, it has been accepted that, only HLA-B51 is directly related with pathogenesis of the disease, and others have strong linkage disequilibrium with HLA-B51. Some other genes such as IL1, Factor V and ICAM-1, KIR and eNOS assumed to take a part in the pathogenesis are settled out of the MHC region. In patients with BD, several abnormalities in innate and acquired immunity were detected. Mainly, the hypersensitivity of T lymphocytes to different types of antigens plays a critical role in the pathogenesis. However, it is not clear that whether defective signal transduction or antigen presenting cell (APC) dysfunction is responsible for T cell hypersensitivity. Cytokines and chemokines secreted from APCs and T cells are suggested to cause the neutrophil hyperactivation. Activated neutrophils secrete some cytokines, which prime themselves and also stimulate Th1 cells. These relationships among APCs, Th1 lymphocytes and neutrophils constitute the basis of immune responses in BD. In this review, we focus on the possible role of APC in the pathogenesis of BD with an attempt to take attention of researchers in this field to these cells at the crossroads of innate and adaptive immunity, and discuss other potential contributors including cells of the immune system and mediators.

Synovial angiostatic non-ELR CXC chemokines in inflammatory arthritides: does CXCL4 designate chronicity of synovitis?

In our previous studies, we found higher synovial fluid (SF) levels of angiogenic ELR(+) CXC chemokines such as CXCL1, CXCL5, CXCL6 and CXCL8, which play an important role in neutrophil migration and angiogenesis, and more abundant synovial CXCR2 chemokine receptor expression in patients with rheumatoid arthritis (RA) than those with Behçet's disease (BD), familial Mediterranean fever and osteoarthritis (OA). As a continuation of our previous studies, we investigated synovial levels of angiostatic non-ELR CXC chemokines (CXCL4, CXCL9 and CXCL10) in patients with RA, BD, spondyloarthritis (SpA), and OA. Seventy (17 RA, 15 BD, 19 SpA, and 19 OA) patients were enrolled in the study. The levels of CXCL4, CXCL9, and CXCL10 were measured by ELISA. The SF levels of CXCL4 in patients with RA were higher than those of the patients with BD, SpA, and OA (P = 0.007, P = 0.022, and P = 0.017, respectively). No difference was found with respect to CXCL4 levels among the BD, SpA, and OA patients. The synovial CXCL9 levels of patients with RA and SpA were found to be higher than those of the patients with OA (P = 0.002 and P = 0.005, respectively), while no statistically significant difference was detected among the other groups. With regard to SF CXCL10 levels, patients with RA had higher levels as compared to patients with OA (P = 0.002), but no significant difference was found among the other groups. CXCL9 correlated with CXCL4 and CXCL10 (P < 0.05 for both) in patients with RA. No correlation was found in other parameters. The angiostatic non-ELR CXC chemokines were expressed in synovial inflammation. We proposed that angiostatic non-ELR CXC chemokines may increase to balance angiogenic ELR (+) CXC chemokines in which increased levels were shown in patients with inflammatory arthritides and CXCL4 may contribute to designate the chronicity of synovitis in patients with RA. In addition, as CXCL-9 and CXCL-10 play crucial role in inflammation characterized by Th1 polarization, we suggested that they may contribute to the commencement and the perpetuation of synovitis seen in these groups of arthritides.

Interleukin-18 Promoter Polymorphisms in Patients With Behçet’s Disease

Behçet's disease (BD) is an idiopathic systemic inflammatory disease and is considered to be a T helper 1 (Th1) type cytokine driven disorder. Moreover, levels of interleukin-18 (IL-18), a pivotal mediator of Th1 cytokine response, have been reported to be upregulated in BD. Therefore, we investigated the distribution of IL-18 promoter -607 C/A and -137 G/C polymorphisms in 103 BD patients (mean age 41.0 years; 48 male, 55 female) using allele-specific-polymerase chain reaction. As compared with healthy control subjects, BD patients had a significantly higher frequency of the -607 CC genotype (42.7% vs 23.3%, odds ratio [OR] = 2.455, 95% confidence interval [CI] = 1.350-4.461, p(c) = 0.021) and a higher frequency of the -607 C allele (60.7% vs 48.1%, OR = 1.668, 95% CI = 1.129-2.464, p = 0.0101). Haplotype analysis showed that BD patients had significantly less -607A/-137G haplotype (27.3% vs 44.2%, OR = 0.469, 95% CI = 0.268-0.820, p(c) = 0.032) and -607A/-137G haplotype homozygote (5.8% vs 20.4%, OR = 0.242, 95% CI = 0.096-0.612, p(c) = 0.014) than control subjects. In addition, the frequency of -607C/-137G haplotype homozygote was significantly higher in BD patients than control subjects (48.5% vs 20.4%, OR = 3.684, 95% CI = 1.997-6.791, p(c) = 0.0014). Although there were no associations between the polymorphisms and clinical manifestations or severity, patients with the -607 CC genotype or -607C/-137G haplotype homozygote showed significantly earlier symptom development (p = 0.034 by ANOVA; p = 0.009 by t-test, respectively) than those with other genotypes or diplotypes. These results suggest that the IL-18 promoter gene is a candidate susceptibility gene in BD patients.