HSP 60 expression in mucocutaneous lesions of Behçet's disease

Behçet's Disease: A Comprehensive Review on the Role of HLA-B*51, Antigen Presentation, and Inflammatory Cascade

Behçet's disease (BD) is a complex, recurring inflammatory disorder with autoinflammatory and autoimmune components. This comprehensive review aims to explore BD's pathogenesis, focusing on established genetic factors. Studies reveal that HLA-B*51 is the primary genetic risk factor, but non-HLA genes (ERAP1, IL-10, IL23R/IL-12RB2), as well as innate immunity genes (FUT2, MICA, TLRs), also contribute. Genome-wide studies emphasize the significance of ERAP1 and HLA-I epistasis. These variants influence antigen presentation, enzymatic activity, and HLA-I peptidomes, potentially leading to distinct autoimmune responses. We conducted a systematic review of the literature to identify studies exploring the association between HLA-B*51 and BD and further highlighted the roles of innate and adaptive immunity in BD. Dysregulations in Th1/Th2 and Th17/Th1 ratios, heightened clonal cytotoxic (CD8+) T cells, and reduced T regulatory cells characterize BD's complex immune responses. Various immune cell types (neutrophils, γδ T cells, natural killer cells) further contribute by releasing cytokines (IL-17, IL-8, GM-CSF) that enhance neutrophil activation and mediate interactions between innate and adaptive immunity. In summary, this review advances our understanding of BD pathogenesis while acknowledging the research limitations. Further exploration of genetic interactions, immune dysregulation, and immune cell roles is crucial. Future studies may unveil novel diagnostic and therapeutic strategies, offering improved management for this complex disease.

Immunopathogenesis of Behçet's disease

Behçet's disease (BD) is a multi-system inflammatory disorder with vasculitic features. It does not suit any of the current pathogenesis-driven disease classifications well, a unifying concept of its pathogenesis is not unanimously conceivable at present, and its etiology is obscure. Still, evidence from immunogenetic and other studies supports the notion of a complex-polygenic disease with robust innate effector responses, reconstitution of regulatory T cells upon successful treatment, and first clues to the role of an, as of yet, underexplored adaptive immune system and its antigen recognition receptors. Without an attempt to be comprehensive, this review aims to collect and organize impactful parts of this evidence in a way that allows the reader to appreciate the work done and define the efforts needed now. The focus is on literature and notions that drove the field into new directions, whether recent or more remote.

Infectious agents and pathogenesis of Behçet's disease: An extensive review

Behçet's disease (BD) is a multisystemic chronic vasculitis. Sustained and enhanced immune responses were reportedly associated with active BD. Although genetic polymorphisms increase development risk, genetic factors alone cannot account for BD development, suggesting the involvement of exogenous factors. Also, how various infectious agents promote BD in high-risk populations is not fully understood. In this review, we summarized the current findings on the associations of infectious agents with BD pathogenesis. The review also highlights the potential microbial risk factors and their pathogenic role in BD progression. Interactions between genetic and infectious risk factors was also discussed. Furthermore, evidence implied that after the eradication of infectious agents, BD symptoms and recurrence decreased, thus highlighting that combined use of antibiotics may be an effective therapy for BD. Finally, we summarized the main limitation of the current related studies, providing valuable insights and a basis for future studies on BD pathogenic factors.

Alarmins in autoimmune diseases

Alarmins are endogenous, constitutively expressed, chemotacting and immune activating proteins or peptides released because of non-programmed cell death (i.e. infections, trauma, etc). They are considered endogenous damage-associated molecular patterns (DAMPs), able to induce a sterile inflammation. In the last years, several studies highlighted a possible role of different alarmins in the pathogenesis of various autoimmune and immune-mediated diseases. We reviewed the relevant literature about this topic, for about 160 articles. Particularly, we focused on systemic autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, idiopathic inflammatory myopathies, ANCA-associated vasculitides, Behçet's disease) and cutaneous organ-specific autoimmune diseases (vitiligo, psoriasis, alopecia, pemphigo). Finally, we discussed about future perspectives and potential therapeutic implications of alarmins in autoimmune diseases. In fact, identification of receptors and downstream signal transducers of alarmins may lead to the identification of antagonistic inhibitors and agonists, with the capacity to modulate alarmins-related pathways and potential therapeutic applicability.

IL-17A and IFN-γ are Up-regulated in CD4 and γδ T Cells in Active Behcet's Disease Patients

Involvement of γδ T cells is implicated in the pathogenesis of Behçet's disease (BD) as a bridge between innate and adaptive responses. IL-17 and IL-22 have also been shown to participate in the BD pathogenesis in addition to IFN-γ. Mainly CD4⁺ T cells are investigated previously for the production of these inflammatory cytokines. In this study, the role of γδ T cells in cytokine-related mechanisms was evaluated in BD in comparison to CD4⁺ T cells. Surface expression of markers for functional states of both CD4⁺ and γδ T cells were compared in ex vivo samples collected from patients with BD and healthy controls (HC). Sixteen active BD (a-BD), 9 inactive BD (i-BD) patients and 25 HC were investigated. The expression of CD161, CCR6 as markers for IL-17 producing cells were analyzed on γδ and CD4⁺ T cells. IFN-γ, IL-17A, IL-22, as well as CD107a (LAMP1) and CD16 (FcγRIII) were evaluated in both cell subtypes after in vitro stimulation. Only IFN-γ production was increased in γδ T cells of a-BD patients. There was no difference in increase of CD107a or decrease of CD16 surface expression on γδ T cells upon stimulation between the groups. Ex vivo IL-17A and both IL-17A/IFN-γ production and expression of CD161, CCR6 by CD4⁺ T cells were increased in a-BD. Along with CD4⁺ T cells, γδ T cells have complementary roles in cytokine production in BD. Higher IFN-γ production of γδ T cells suggests the role of an environmental triggers in BD pathogenesis, whereas IL-17 related activity is mainly provided by CD4⁺ T cells.

Behçet disease: From pathogenesis to novel therapeutic options

Behçet disease (BD) is a complex, multi-systemic inflammatory condition mainly hallmarked by oral and genital ulcers which can also affect the vessels, gastrointestinal tract, central nervous system and even the axial skeleton. Without a clear classification among autoimmune or autoinflammatory conditions, BD has been recently classified as a MHC-I-opathy. BD aetiology is still obscure, but it is thought that certain microorganisms can elicit an aberrant adaptive immune response in the presence of a permissive genetic background. Altered T-cell homeostasis, mostly Th1/Th17 expansion and Treg impairment, could lead to an overactivation of the innate immunity, which underlies tissue damage and thus, signs and symptoms. Immunosuppression and/or immunomodulation are central to the BD management. A complex armamentarium ranging from classical synthetic disease-modifying antirrheumatic drugs to new-era biologic agents or small molecules is available in BD, with different therapeutic outcomes depending on disease manifestations. However, the precise disease mechanisms that underlie BD symptoms are not fully deciphered, which may limit their therapeutic potential and add a significant layer of complexity to the treatment decision-making process. The aim of the present review is to provide an exhaustive overview of the latest breakthroughs in BD pathogenesis and therapeutic options.

Evaluation of DNA methylation status of toll-like receptors 2 and 4 promoters in Behcet's disease

BACKGROUND

Altered innate immune function plays an important role in the initiation of inflammatory response in Behcet's disease (BD). Toll-like receptors (TLRs) are the master regulators of the innate immune system. Because the role of TLRs remains unknown in the pathogenesis of BD, the present study aimed to evaluate the expression levels and methylation status of the TLR2 and TLR4 promoters in patients with BD.

METHODS

In the present study, Iranian Azeri BD patients (n = 47) with an active (n = 22) and inactive (n = 25) period, and healthy controls (n = 61), were matched according to age, sex and ethnicity. TLR2 and TLR4 genes promoter CpG islands were predicted with the Eukaryotic Promoter Database (https://epd.vital-it.ch). Methylated DNA immunoprecipitation (MeDIP) was conducted.

RESULTS

The results showed that mRNA of TLR4 was significantly increased in the peripheral blood mononuclear cells (PBMCs) of BD patients with an active phase compared to the control group. Differences in mRNA of TLR4 between the inactive BD and control groups were not significant. Differences in TLR2 mRNA levels in the PBMCs of the active and inactive phase BD and control groups were not significant. The methylation rate of TLR4 gene promoter was significantly lower in the active and inactive BD groups compared to the control group. The difference between the active and inactive BD groups was not significant. There was no significant difference in the methylation rates of the TLR2 gene between studied groups.

CONCLUSIONS

Our preliminary findings suggest that the hypomethylation of TLR4 gene may be involved in the pathogenesis of BD via increasing TLR4 expression.

Immunopathogenesis of Behçet Disease

BACKGROUND

Behçet's Disease (BD, OMIM 109650) is a chronic relapsing inflammatory disease of unknown etiology with unpredictable exacerbations and remissions. First described in 1937 by the Turkish dermatologist HulusiBehçet, as a trisympton complex (oral and genital ulcers and uveitis), it is now recognized as a multisystemic disease. The syndrome can manifest in diverse ways and can involve nearly every organ system. Several studies have implicated T cells and monocytes in the pathogenesis of BD especially when these cells are stimulated by heat shock proteins and streptococcal antigen. This article presents a review of the relevant published literature about the immunopathogenesis of BD.

RESULT

The authors used MeSH terms "Behçet's disease" with "pathophysiology," "pathogenesis," "genetic", "epigenetic", "immunogenetic" or "immune response" to search the PubMed database. All the relevant studies identified were included.

Immunopathogenesis of Behcet's Disease

Behcet's disease (BD) is a chronic systemic inflammatory vasculitis of unknown etiology characterized by recurrent episodes of oral aphthous ulcers, genital ulcers, skin lesions, ocular lesions, and other manifestations. Although the pathogenesis of BD is unclear, some studies have shown that immunological aberrations play an important role in the development and progression of BD. Infection-related trigger factors, including antigens and autoantigens, are believed to mediate the development of BD in patients with a genetic predisposition and subsequently activate the innate and adaptive immune systems, resulting in the production of numerous cytokines and chemokines to combat the infection-related factors. The study of the immunological mechanism of BD paves the way for the development of innovative therapies. Recently, novel biotherapy approaches, including interferon-α (IFN-α), tumor necrosis factor-α (TNF-α) antagonists, and other agents that target interleukins and their receptors, have shown promising results in the treatment of patients with refractory BD and have improved the prognosis of BD. In this review, we provide the current concepts of BD immunopathogenesis.

Behçet's disease: New insights into pathophysiology, clinical features and treatment options

Behçet's disease (BD) is a rare systemic vasculitis characterized by oral aphthous ulcers, genital ulcers, ocular lesions and other systemic manifestations. BD occurs most frequently in Eurasian populations along the ancient trading route known as the "Silk Road" which extends from eastern Asia to the Mediterranean basin. The causes of BD are unknown: it is believed to be due to an autoimmune process triggered by an infectious or environmental agent in genetically predisposed individuals. HLA-B51 allele located in the MHC locus, on chromosome 6p, has been the most strongly associated risk factor for BD in areas along the Old Silk Route. Herpes simplex virus-1 and Streptococcus have been postulated as possible environmental triggers of BD. T cell homeostasis perturbation, especially Th1 and Th17 expansion and decreased regulation by Tregs are now supposed to be the cornerstone of BD pathogenesis. The histology shows vasculitis that involves both arteries and veins, and vessels of any size. BD is a systemic vasculitis with significant neutrophil infiltration, endothelial cell swelling, and fibrinoid necrosis. The diagnosis of BD is only supported by clinical criteria and requires the exclusion of other diagnoses based on clinical presentation. There are no pathognomonic laboratorial findings of BD. This rare disease often leads to blindness and fatal systemic involvement. Main causes of death include major vessel disease and central nervous system involvement. Corticosteroids are commonly used to treat clinical manifestations of BD in combination with immunosuppressant drugs. Tumor necrosis factor (TNF)-blocking agents such as Infliximab, Etanercept, and Adalimumab have been reported to have success in patients with BD.

Screening of differentially expressed proteins in psoriasis vulgaris by two-dimensional gel electrophoresis and mass spectrometry

The aim of the present study was to elucidate differentially expressed proteins in lesional tissues of psoriasis vulgaris (PV) and normal tissues. Lesional skin tissues were collected from PV patients, along with normal skin tissues from healthy individuals. The protein content of the samples was extracted and then separated by two-dimensional gel electrophoresis (2-DGE). Any proteins that were differentially expressed in the lesional skin of PV patients compared with the healthy controls were analyzed by mass spectrometry and bioinformatics. In the stratum corneum and dermis of PV patients, the total number of proteins identified by 2-DGE was 1,969±21 and 1,928±49, respectively. Of these, 30 proteins were differentially expressed in the PV patients, of which 14 were identified as: Type 1 keratin cytoskeleton proteins (including K1C10, K1C14, K1C15 and K1C16); the type 2 keratin cytoskeleton protein, K2C1; actin-associated proteins (including ARP3, ACTA and ACTBM); prohibitin; heat shock proteins (HSPB1 and CH60); centrosome protein, CP135; and membrane associated proteins (including ANXA4 and ANXA5). The differential expression of protein between PV lesions and normal tissue can be considered as pathological biomarker. Elucidating the abnormal regulation of these proteins can provide mechanism of the development of PV and may contribute to significant approaches for PV treatments.

Evaluation of the relationship between salivary concentration of anti-heat shock protein immunoglobulin and clinical manifestations of Behçet's disease

OBJECTIVE

This study investigated the relationship between the concentration of anti-heat shock protein (HSP) 60 antibody in resting saliva and the severity of Behçet's disease (BD).

METHOD

Sixty-five patients diagnosed with BD at Tokyo Medical and Dental University Hospital were enrolled in this study. Based on clinical severity scores, patients were categorized as having mild, moderate, or severe BD. Periodontal status was evaluated with the Community Periodontal Index (CPI), and anti-HSP60 antibody concentrations in resting saliva were measured with an enzyme-linked immunosorbent assay.

RESULTS

The mean antibody concentration in patients in the moderate group was significantly higher than concentrations in the mild and severe groups. No significant difference was found between the mild and severe groups. Gingival inflammation, identified with the CPI, was associated with a higher antibody concentration. The antibody concentration in patients who had stomatitis for more than 2 weeks was significantly higher than in those with stomatitis for less than 2 weeks. The antibody concentration in patients who had taken colchicine was significantly lower than that in subjects who had not.

CONCLUSION

These results suggest that the concentration of anti-HSP60 antibody in resting saliva may be effective as a non-invasive indicator for the diagnosis (screening) and prognostication of BD.

Behcet’s disease: from heat shock proteins to infections

Background: Behcet’s disease (BD) is a chronic, inflammatory multisystemic condition of unknown etiology. Although the cause of BD is not clear, it is believed to be the result of an autoimmune process triggered by an infectious or environmental agent (possibly local to a geographic region) in a genetically predisposed individual.

Objective: To detail current knowledge of the role of microorganisms in the pathogenesis of BD and review the infectious etiology of this disease.

Methods: The review based on publication in SCOPUS, Science direct, and PubMed.

Results: A microbial infection has been implicated in the development of the disease to explain the strong inflammatory reactions observed, the activation of monocytes and macrophages, and the induction of proinflammatory cytokines and chemokines detected. Common factors linking some of the possible pathogenetic agents are extrinsically induced tissue stress or heat shock proteins, which react with host tissues and elicit significant T-helper type 1 cell responses.

Conclusion: Based on collected data, we conclude that the microorganisms discussed seem to participate and, at least in part, act as triggers during the course of BD. By clarifying the microbial associations of BD and finding its etiology, particularly the causative antigens leading to BD, it would be easier to suggest more effective treatment and preventive strategies for this disease.

Behçet’s Disease: A Review

Behçet’s disease (BD) is a multi-system inflammatory disorder dominated clinically by recurrent oral and genital ulceration, uveitis, and erythema nodosum. Behçet’s disease runs a chronic course, with unpredictable exacerbations and remissions whose frequency and severity may diminish with time. Behçet’s disease typically arises in young adults, although childhood-onset BD has also been reported. The disease can affect both genders and has a worldwide distribution, although it is more prevalent in countries of the ancient Silk Route. The cause of BD remains unknown, although an autoimmune reaction triggered by an infectious agent in a genetically predisposed individual has been suggested. The treatment of BD is symptomatic and empirical, but generally specific to the clinical features of each patient. The majority of affected individuals do not have life-threatening disease, although mortality can be associated with vascular-thrombotic and neurological disease.

Gamma Delta (γδ) T Cells and Their Involvement in Behçet's Disease

Behçet's disease (BD) is a multisystem inflammatory disorder characterized by orogenital ulcerations, ocular manifestations, arthritis, and vasculitis. The disease follows a relapsing-remitting course and its pathogenesis is unknown. Genetic predisposition and immune-dysregulation involving gamma delta (γδ) T cells are reported to have a role. γδ T cells are atypical T cells, which represent a small proportion of total lymphocytes. They have features of both innate and adaptive immunity and express characteristics of conventional T cells, natural killer cells, and myeloid antigen presenting cells. These unconventional T cells are found in the inflammatory BD lesions and have been suggested to be responsible for inducing and/or maintaining the proinflammatory environment characteristic of the disease. Over the last 20 years there has been much interest in the role of γδ T cells in BD. We review the literature and discuss the roles that γδ T cells may play in BD pathogenesis.

Molecular Dynamics Simulation Reveals the Selective Binding of Human Leukocyte Antigen Alleles Associated with Behçet's Disease

Behçet’s disease (BD), a multi-organ inflammatory disorder, is associated with the presence of the human leukocyte antigen (HLA) HLA-B*51 allele in many ethnic groups. The possible antigen involvement of the major histocompatibility complex class I chain related gene A transmembrane (MICA-TM) nonapeptide (AAAAAIFVI) has been reported in BD symptomatic patients. This peptide has also been detected in HLA-A*26:01 positive patients. To investigate the link of BD with these two specific HLA alleles, molecular dynamics (MD) simulations were applied on the MICA-TM nonapeptide binding to the two BD-associated HLA alleles in comparison with the two non-BD-associated HLA alleles (B*35:01 and A*11:01). The MD simulations were applied on the four HLA/MICA-TM peptide complexes in aqueous solution. As a result, stabilization for the incoming MICA-TM was found to be predominantly contributed from van der Waals interactions. The P2/P3 residue close to the N-terminal and the P9 residue at the C-terminal of the MICA-TM nonapeptide served as the anchor for the peptide accommodated at the binding groove of the BD associated HLAs. The MM/PBSA free energy calculation predicted a stronger binding of the HLA/peptide complexes for the BD-associated HLA alleles than for the non-BD-associated ones, with a ranked binding strength of B*51:01 > B*35:01 and A*26:01 > A*11:01. Thus, the HLAs associated with BD pathogenesis expose the binding efficiency with the MICA-TM nonapeptide tighter than the non-associated HLA alleles. In addition, the residues 70, 73, 99, 146, 147 and 159 of the two BD-associated HLAs provided the conserved interaction for the MICA-TM peptide binding.

MATHEMATICAL MODELING OF BEHÇET'S DISEASE: A DYNAMICAL SYSTEMS APPROACH

Behçet's Disease (BD) is a multi-systemic, auto-inflammatory disorder that is characterized by recurrent episodes of inflammatory manifestations affecting skin, mucosa, eyes, blood vessels, joints and several other organs. BD is classified as a multifactorial disease with an important contribution of genetics. Genetic studies suggest that there is a strong association of BD with a Class I major histocompatibility complex antigen, named HLA-B*51, along with several other weaker associations with genes encoding proteins involved in inflammation. However, pathogenic mechanisms associated with these genetic variations and their interactions with the environment have not been elucidated yet. In this paper, we present a mathematical model for BD based on a dynamical systems perspective that captures especially the relapsing nature of the disease. We propose a disease progression mechanism and construct a model, in the form of coupled ordinary differential equations (ODEs), which reveals the occurrence pattern of the disease in the population. According to our model, the disease has three distinct modes describing different phenotypes of people carrying HLA-B*51 tissue antigen, namely, the Healthy Carrier, the Potential Patient and the Active Patient. We herein present an exemplary mathematical model for BD, for the first time in the literature, that concisely captures the actions of many cell types together with genetic and environmental effects. The proposed model provides insight into this complex inflammatory disease which may lead to identification of new tools for its treatment and prevention.

Various forms of tissue damage and danger signals following hematopoietic stem-cell transplantation

Hematopoietic stem-cell transplantation (HSCT) is the most potent curative therapy for many malignant and non-malignant disorders. Unfortunately, a major complication of HSCT is graft-versus-host disease (GVHD), which is mediated by tissue damage resulting from the conditioning regimens before the transplantation and the alloreaction of dual immune components (activated donor T-cells and recipient’s antigen-presenting cells). This tissue damage leads to the release of alarmins and the triggering of pathogen-recognition receptors that activate the innate immune system and subsequently the adaptive immune system. Alarmins, which are of endogenous origin, together with the exogenous pathogen-associated molecular patterns (PAMPs) elicit similar responses of danger signals and represent the group of damage-associated molecular patterns (DAMPs). Effector cells of innate and adaptive immunity that are activated by PAMPs or alarmins can secrete other alarmins and amplify the immune responses. These complex interactions and loops between alarmins and PAMPs are particularly potent at inducing and then aggravating the GVHD reaction. In this review, we highlight the role of these tissue damaging molecules and their signaling pathways. Interestingly, some DAMPs and PAMPs are organ specific and GVHD-induced and have been shown to be interesting biomarkers. Some of these molecules may represent potential targets for novel therapeutic approaches.

Intravascular immunity as a key to systemic vasculitis: a work in progress, gaining momentum

Vascular inflammation contributes to the defence against invading microbes and to the repair of injured tissues. In most cases it resolves before becoming apparent. Vasculitis comprises heterogeneous clinical entities that are characterized by the persistence of vascular inflammation after it has served its homeostatic function. Most underlying mechanisms have so far remained elusive. Intravascular immunity refers to the surveillance of the vasculature by leucocytes that sense microbial or sterile threats to vessel integrity and initiate protective responses that entail most events that determine the clinical manifestations of vasculitis, such as end-organ ischaemia, neutrophil extracellular traps generation and thrombosis, leucocyte extravasation and degranulation. Understanding how the resolution of vascular inflammation goes awry in patients with systemic vasculitis will facilitate the identification of novel pharmacological targets and bring us a step closer in each patient to the selection of more effective and less toxic treatments.

Innate and Adaptive Responses to Heat Shock Proteins in Behcet's Disease

Behcet's disease (BD) is a systemic, chronic inflammatory disorder with both innate and adaptive immune responses. Heat shock proteins (HSP) are highly conserved molecules in different species with scavenger activity and involved in correct folding of newly synthesized proteins. T and B cell responses against HSPs are observed in BD patients in both αβ and γδ T-cell populations. 60-kD HSP (HSP60) is also shown to be recognized by pattern recognition receptors such as toll-like receptors (TLR) and is suggested to be an endogenous "danger" signal to the immune system with rapid inflammatory cytokine releases and enhancement of adaptive Th1-type responses. Elucidating the exact role of HSPs in BD pathogenesis might pave the way to less toxic therapeutic approaches to BD, such as antibacterial therapies and immunomodulation.

Skewed Helper T-Cell Responses to IL-12 Family Cytokines Produced by Antigen-Presenting Cells and the Genetic Background in Behcet's Disease

Behcet's disease (BD) is a multisystemic inflammatory disease and is characterized by recurrent attacks on eyes, brain, skin, and gut. There is evidence that skewed T-cell responses contributed to its pathophysiology in patients with BD. Recently, we found that Th17 cells, a new helper T (Th) cell subset, were increased in patients with BD, and both Th type 1 (Th1) and Th17 cell differentiation signaling pathways were overactivated. Several researches revealed that genetic polymorphisms in Th1/Th17 cell differentiation signaling pathways were associated with the onset of BD. Here, we summarize current findings on the Th cell subsets, their contribution to the pathogenesis of BD and the genetic backgrounds, especially in view of IL-12 family cytokine production and pattern recognition receptors of macrophages/monocytes.

Serum IgA reactivity against GroEL of Streptococcus sanguinis and human heterogeneous nuclear ribonucleoprotein A2/B1 in patients with Behçet disease

BACKGROUND

Infectious agents, especially Streptococcus sanguinis and herpes simplex virus, have long been postulated as major triggering factors for Behçet disease (BD).

OBJECTIVES

To identify an anti-S. sanguinis antigen reacting with serum IgA antibody in patients with BD.

METHODS

We detected a target protein by proteomics analysis and evaluated serum IgA reactivity of 100 patients with BD against the identified streptococcal target protein and human heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1. Homologous epitope sequences between the streptococcal target protein and human hnRNP A2/B1 were also evaluated.

RESULTS

Four protein bands were detected by immunoprecipitation, and chaperonin GroEL was identified by a proteomics analysis. Reactivity of serum IgA against recombinant S. sanguinis GroEL was detected in 77 of 100 patients with BD (77%) and in 21 of 70 healthy controls (30%). In addition, reactivity of serum IgA against human recombinant hnRNP A2/B1 was seen in 79 of 100 patients with BD (79%) and in eight of 70 healthy controls (11%). Among the eight distinctive epitopes with significant homology between S. sanguinis GroEL and human hnRNP A2/B1, the serum IgA reactivity of patients with BD was markedly higher with epitope 3 (hnRNP A2/B1 peptide 33-46 and GroEL peptide 57-70) and epitope 6 (hnRNP A2/B1 peptide 177-188 and GroEL peptide 347-358).

CONCLUSION

We identified an S. sanguinis GroEL protein as a target of serum anti-S. sanguinis IgA antibody reactivity in patients with BD. In addition, patients with BD exhibited serum IgA reactivity against homologous epitope regions between S. sanguinis GroEL and human hnRNP A2/B1.

[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.

Aberrant expression and secretion of heat shock protein 90 in patients with bullous pemphigoid

The cell stress chaperone heat shock protein 90 (Hsp90) has been implicated in inflammatory responses and its inhibition has proven successful in different mouse models of autoimmune diseases, including epidermolysis bullosa acquisita. Here, we investigated expression levels and secretory responses of Hsp90 in patients with bullous pemphigoid (BP), the most common subepidermal autoimmune blistering skin disease. In comparison to healthy controls, the following observations were made: (i) Hsp90 was highly expressed in the skin of BP patients, whereas its serum levels were decreased and inversely associated with IgG autoantibody levels against the NC16A immunodominant region of the BP180 autoantigen, (ii) in contrast, neither aberrant levels of circulating Hsp90 nor any correlation of this protein with serum autoantibodies was found in a control cohort of autoimmune bullous disease patients with pemphigus vulgaris, (iii) Hsp90 was highly expressed in and restrictedly released from peripheral blood mononuclear cells of BP patients, and (iv) Hsp90 was potently induced in and restrictedly secreted from human keratinocyte (HaCaT) cells by BP serum and isolated anti-BP180 NC16A IgG autoantibodies, respectively. Our results reveal an upregulated Hsp90 expression at the site of inflammation and an autoantibody-mediated dysregulation of the intracellular and extracellular distribution of this chaperone in BP patients. These findings suggest that Hsp90 may play a pathophysiological role and represent a novel potential treatment target in BP.

Diagnostic yield of heat shock protein 70 (HSP-70) and anti-HSP-70 in Behcet-induced uveitis

Heat shock proteins (HSPs) are intracellular proteins with pro- and anti-inflammatory actions, playing an important role in the pathogenesis of Behcet's disease (BD). Diagnosis of BD uveitis in early stages is still problematic, thus this study was undertaken to determine diagnostic values of serum HSP- and anti-HSP-70 in BD uveitis. Serum levels of HSP- and anti-HSP-70 were measured in 53 patients with BD (26 with and 27 without uveitis). In control group, 25 age- and sex-matched idiopathic uveitis patients were enrolled consecutively. Both groups had no medical problems save uveitis at the time of sampling. Confounders like medications were analysed subsequently. HSP- and anti-HSP-70 values were measured by commercial ELISA kits. Data were analysed by spss 11.5 and medcalc 11.5.1 software. The Mean HSP-70 serum levels were different among aforementioned subgroups (P = 0.001, anova). They were elevated in BD uveitis compared with BD without uveitis (4.84 ± 4.21 versus 2.24 ± 2.08 ng/ml; P = 0.045). HSP-70 in sera of BD uveitis was also higher than that parameter in patients with idiopathic uveitis (4.84 ± 4.21 versus 2.37 ± 3.30 ng/ml; P = 0.001; cut-off point value 1.0 9 ng/ml, 95% CI 0.61-0.86, P = 0.0002, ß = 0.06). However, there was not any statistical difference among those groups in the serum anti-HSP-70 levels (P = 0.63, anova). Multiple regression analysis demonstrated that among different confounders, only prednisolone increases and BD uveitis decreases HSP-70 levels independently. This prospective cross-sectional study suggested that HSP-70 serum level is impressed over the course of BD uveitis, and it could be utilized to diagnose or predict developing it.

Expression of regulatory receptors on γδ T cells and their cytokine production in Behcet's disease

INTRODUCTION

Behcet's disease (BD) is a multi-systemic disorder with muco-cutaneous, ocular, arthritic, vascular or central nervous system involvement. The role of γδ T cells is implicated in BD. The activation status of γδ T cells and their cytokine secretion against phosphoantigens are evaluated in BD.

METHODS

NKG2A, NKG2C, NKG2D, CD16 and CCR7 molecules on γδ T cells were analyzed in 70 BD, 27 tuberculosis (TB) patients and 26 healthy controls (HC). Peripheral γδ T cells were expanded with a phosphoantigen (BrHPP) and IL-2, restimulated with BrHPP and a TLR3 ligand, and cytokine production was measured.

RESULTS

γδ T cells were not increased in both BD and TB patients, but the proportions of TCRVδ2+ T cells were lower (58.9 and 50.7 vs. 71.7%, P=0.04 and P=0.005) compared to HC. Higher proportion of TCRVδ2+ T cells were CD16+ (26.2 and 33.9 vs. 16.6%, P=0.02 and P=0.001) and CCR7- (32.2 and 27.9 vs. 17.7%, P<0.0001 and P=0.014) in BD and TB patients compared to HC. NKG2C+ γδ+ T cells were relatively increased (0.5 and 0.6 vs. 0.3%, P=0.008 and 0.018), whereas NKG2D positivity was decreased in patients with BD and TB (77.7 and 75.8 vs. 87.5%, P=0.001 and 0.004). Expansion capacity of γδ T cells in BD and TB as well as production of IL-13, IFN-γ, granulocyte monocyte colony stimulating factor (GM-CSF), TNF-α, CCL4 and CCL5 in BD was lower compared to HC, when restimulated by TLR3 ligand and BrHPP.

CONCLUSION

The changes on γδ T cells of BD as well as TB patients implicate that γδ T cells have already been exposed to regulatory effects, which changed their activity. Lower cytokine response of γδ T cells implicates down modulation of these cells in BD.

Recognition of self-heat shock protein 60 by T cells from patients with atopic dermatitis

Heat shock protein 60 (hsp60) is a highly conserved stress protein and target of self-reactive T cells in various inflammatory diseases. Not much is known about a possible role in atopic disease. As atopic diseases are considered to be the result of a disturbance in the balance between T helper cells type 2 and regulatory T cells, it is of interest to know whether hsp60 acts as a bystander antigen in atopic disease. Our aim was to investigate whether hsp60 is involved in the chronicity of inflammation of atopic dermatitis (AD). We studied the expression of hsp60 in skin tissue of adults with AD by immunohistochemistry. Peripheral blood mononuclear cells (PBMC) of children with AD were cultured with hsp60 and proliferative responses, cytokine secretion, surface markers, and functional assays were compared to responses of PBMC of healthy controls (HC). Hsp60 was detected more in lesional skin of AD patients compared to nonlesional skin. Furthermore, PBMC of children with AD proliferated more strongly in response to hsp60 compared to HC. hsp60-reactive T cells of atopic children produced high levels of IFNγ and low levels of IL-10. In vitro activation with hsp60 leads to the induction of CD4(+)CD25(bright) T cells expressing FOXP3 in both HC as well as in atopic children. However, despite their regulatory phenotype, hsp60-induced CD4(+)CD25(bright)CD127(-)FOXP3(+) T cells of AD patients were incapable of suppressing effector T cells in vitro. hsp60 is recognized by proinflammatory (IFNγ high, IL-10 low) T cells in atopic patients and is more present in lesional AD skin. This suggests that hsp60-specific T cell responses contribute to local inflammation in AD.

Aberrant Activation of Heat Shock Protein 60/65 Reactive T Cells in Patients with Behcet's Disease

Behcet's disease (BD) is a multisystemic inflammatory disease and is characterized by recurrent attacks on eyes, brain, skin, and gut. There is evidence that skewed T-cell responses contributed to its pathophysiology in patients with BD. We found that heat shock proteins (HSPs) reactive T cells were prevalent in patients with BD. Here, we summarize current findings on HSP reactive T cells and their contribution to the pathogenesis in patients with BD.

HSP: Bystander Antigen in Atopic Diseases?

Over the last years insight in the complex interactions between innate and adaptive immunity in the regulation of an inflammatory response has increased enormously. This has revived the interest in stress proteins; proteins that are expressed during cell stress. As these proteins can attract and trigger an immunological response they can act as important mediators in this interaction. In this respect, of special interest are proteins that may act as modulators of both innate and adaptive immunity. Heat shock proteins (HSPs) are stress proteins that have these, and more, characteristics. More than two decades of studies on HSPs has revealed that they are part of intrinsic, “natural” mechanisms that steer inflammation. This has provoked comprehensive explorations of the role of HSPs in various human inflammatory diseases. Most studies have focused on classical autoimmune diseases. This has led to the development of clinical studies with HSPs that have shown promise in Phase II/III clinical trials. Remarkably, only very little is yet known of the role of HSPs in atopic diseases. In allergic disease a number of studies have investigated the possibility that allergen-specific regulatory T cell (Treg) function is defective in individuals with allergic diseases. This raises the question whether methods can be identified to improve the Treg repertoire. Studies from other inflammatory diseases have suggested HSPs may have such a beneficial effect on the T cell repertoire. Based on the immune mechanisms of atopic diseases, in this review we will argue that, as in other human inflammatory conditions, understanding immunity to HSPs is likely also relevant for atopic diseases. Specifically, we will discuss why certain HSPs such as HSP60 connect the immune response to environmental antigens with regulation of the inflammatory response. Thus they provide a molecular link that may eventually even help to better understand the immune pathological basis of the hygiene hypothesis.

Ocular Behçet disease: current therapeutic approaches

PURPOSE OF REVIEW

To alert physician to timely recognition and current treatment of recurrent hypopyon iridocyclitis or panuveitis in ocular Behçet disease (OBD).

RECENT FINDINGS

Interferon-α, rituximab, intravitreal triamcinolone, and biological response modifiers by tumor necrosis factor inhibitors such as infliximab and adalimumab are being used increasingly for the treatment of severe sight-threatening ocular inflammation including retinal vasculitis and cystoid macular edema (CME).

SUMMARY

Biological agents offer tremendous potential in the treatment of OBD. Given that OBD predominantly afflicts the younger adults in their most productive years, dermatologist, rheumatologist, internist, or general practitioners supervising patients with oculo-articulo-oromucocutaneous syndromes should be aware of systemic Behçet disease. Early recognition of ocular involvement is important and such patients should strongly be instructed to visit immediately an ophthalmologist, as uveitis management differs from extraocular involvements with high ocular morbidity from sight-threatening complications due to relapsing inflammatory attacks in the posterior segment of the eye. A single infliximab infusion should be considered for the control of acute panuveitis, whereas repeated long-term infliximab infusions were proved to be more effective in reducing the number of episodes in refractory uveoretinitis with faster regression and complete remission of CME.

New insights into the pathogenesis of Behçet's disease

Behçet's disease (BD) is a recurrent systemic inflammatory disorder of unknown origin characterized by oral and genital mucous ulcer, uveitis, and skin lesions. Involvement of large vessels, central nervous system (CNS), gastrointestinal tract and thrombotic events are less frequent but can be life threatening. The aim of this review is to provide new insights into the pathogenesis of BD. Over the past year substantial advances have been done in the understanding of the genetic [1,2] and immunology [3] of BD. BD is at the crossroad between autoimmune and autoinflammatory syndromes. In common with autoimmune diseases BD shares class I MHC association. However, in contrast to autoimmune disorders, BD has clinical features that seem to be mostly autoinflammatory. The pathogenesis of BD is still unknown, but major determinants of the genetic and immune system abnormalities have been reported recently. Triggering infectious factors are supposed to participate in the outbreak of BD in genetically predisposed patients. Two recent large genome-wide association study (GWAS) conducted in Turkey and Japan reported association between single nucleotide polymorphism (SNP) of interleukin (IL)-10 and IL-23R/IL-12RB2 genes and BD. New insights into the perturbations of T cell homeostasis of BD recently emerged. We have recently demonstrated the promotion of Th17 responses and the suppression of regulatory T cells (Tregs) that were driven by interleukin (IL)-21 production and that correlates with BD activity. Inflammatory cells within BD inflammatory lesions included mostly neutrophils, Th1 and Th17 cells, and cytotoxic CD8+ and γδ T cells. Altogether, the recent progresses in the knowledge of BD pathogenesis pave the way for innovative therapy.

Behçet's disease (Adamantiades-Behçet's disease)

Adamantiades-Behçet's disease (ABD) is characterized by starting with oral aphthous ulceration and developing of the systemic involvements. The pathogenesis of ABD is closely correlated with the genetic factors and the triggering factors which acquire delayed-type hypersensitivity reaction against oral streptococci mediated by IL-12 cytokine family. HLA-B51 is associated in more than 60% of the patients and its restricted CD8+ T cell response is clearly correlated with the target tissues. Bes-1 gene encoded partial S. sanguinis genome which is highly homologous with retinal protein, and 65 kD heat shock protein (Hsp-65) released from streptococci is playing an important role with human Hsp-60 in the pathogenesis of ABD. Although Hsp-65/60 has homologies with the respective T cell epitope, it stimulates peripheral blood mononuclear cells (PBMCs) from ABD patients. On the other hand, some peptides of Hsp-65 were found to reduce IL-8 and IL-12 production from PBMCs of ABD patients in active stage.

[Behçet's disease in obstetrics and gynecology]

Behçet's disease is a multisystemic disease of unknown origin characterized by a recurrent bipolar aphtosis (oral and genital) associated with vascular, digestive or articular symptoms. Gynecologists can be faced to this disease at any time of the life of their patients, including during the pregnancy. Given that the first demonstrations of the disease can be genital, they are in the front line to evoke this diagnosis. They thus have to know the main characteristics of the disease to make the diagnosis and to organize a multidisciplinary management. During pregnancy, the treatment of the disease is to be adapted to avoid teratogenic drugs, and adapt the doses of the treatment.

Etiopathogenesis of Behçet's disease with emphasis on the role of immunological aberrations

Behçet's disease (BD) is a chronic multisystemic inflammatory disorder of unknown origin consisting of oral aphthous ulcers, ocular symptoms, skin lesions, and genital ulcerations. It has many features in common with systemic vasculitides and is more prevalent in countries along the ancient Silk route. Immune-mediated mechanisms play a major role in the pathogenesis of the disease, and inflammatory mediators are also involved. BD is not considered to be an autoimmune disorder, and the character of the disease needs to be clarified. Immunological aberrations in BD have been extensively studied by many investigators; genetic factors have been related to disease susceptibility, but their exact role in the development of disease is uncertain. Environmental factors such as infectious agents have also been implicated in the etiology of BD. However, the etiopathogenesis of the disease remains to be elucidated. Factors involved in the immunopathogenesis of BD with emphasis on the role of immunological aberrations are analyzed in this review.

Behçet's disease--a contemporary review

Behçet's disease (BD) is a systemic vasculitis disorder of unknown etiology, characterized by relapsing episodes of oral aphthous ulcers, genital ulcers, skin lesions and ocular lesions. It can affect other systems including vascular, gastrointestinal and neurological systems. It occurs most frequently in an area that coincides with the Old Silk Route (between latitudes 30 degrees and 45 degrees north in Asia and Europe). BD is slightly more frequent and has a worse clinical course in men. It is believed to be due to an auto-immune process triggered by an infectious or environmental agent in a genetically predisposed individual. HLA-B51 is the most strongly associated risk factor. The International Study Group (ISG) for Behçet's Disease created a set of criteria for the diagnosis of BD. Available treatments include corticosteroids, azathioprine, cychlophosphamide, cyclosporine A, interferon-alpha, anti-tumour necrosis factor alpha agents, among others. BD has a variable course characterized by relapses and remissions. Prognosis depends on the clinical involvement. Loss of visual acuity and neurological disease are major causes of morbidity and disability.

Investigation of the association between Toll-like receptor 2 gene polymorphisms and Behçet's disease in Japanese patients

Behçet's disease (BD) is a chronic systemic inflammatory disorder characterized by recurrent ocular symptoms, oral and genital ulcers, and skin lesions. The etiology of BD is still uncertain, but genetic and environmental factors likely both play an important role in BD development. In the present study, we investigated whether polymorphisms of Toll-like receptor 2 (TLR2), previously reported to recognize BD candidate antigens, are associated with BD. Two hundred Japanese patients with BD and 128 Japanese healthy controls were recruited. We genotyped five single-nucleotide polymorphisms (SNPs) in the TLR2 gene and assessed the allele/genotype diversity between cases and controls for all SNPs. No significant differences in the frequency of TLR2 alleles, genotypes, and haplotypes in the BD cases were detected compared with the controls. These data indicate that TLR2 polymorphisms do not play an important role in the development of BD.

Comparison of expression of heat-shock protein 60, Toll-like receptors 2 and 4, and T-cell receptor gammadelta in plaque and guttate psoriasis

BACKGROUND

Psoriasis is a chronic skin disease that appears to be autoimmune in nature. Recently, it is thought that microbial pathogens of skin can affect the pathogenesis of psoriasis by inducing autoimmunity. Heat-shock proteins (HSPs) are known to play an important role in immune and inflammatory responses of the skin including psoriasis. Recent studies have suggested that Toll-like receptors (TLR) 2, 4 and gammadelta T-cell receptors (TCR-gammadelta) may recognize HSP60 as a ligand and consequently activate the immune system.

METHODS

The biopsy specimens of 12 of guttate psoriasis, 12 of plaque psoriasis and five of normal skin were studied using immunohistochemical staining. The expressions of HSP60, TLR2 and TLR4 were evaluated using an immunostaining-intensity-distribution (IID) index and TCR-gammadelta positive cells were counted.

RESULTS

The expression of HSP60 was significantly higher in guttate and plaque psoriasis than in normal skin. The expression of TLR4 was higher in guttate psoriasis than in plaque psoriasis and normal skin. The expression of TCR-gammadelta was higher in guttate and plaque psoriasis than in normal skin, but there was no correlation found between the expression of HSP60 and TLRs 2 and 4, or between that of HSP60 and TCR-gammadelta.

CONCLUSIONS

HSP60 may be related to the pathogenesis of both guttate and plaque psoriasis and TLR4 may be related to the pathogenesis of guttate psoriasis.

Association of reduced heme oxygenase-1 with excessive Toll-like receptor 4 expression in peripheral blood mononuclear cells in Behçet's disease

INTRODUCTION

Toll-like receptors (TLRs) mediate signaling that triggers activation of the innate immune system, whereas heme oxygenase (HO)-1 (an inducible heme-degrading enzyme that is induced by various stresses) suppresses inflammatory responses. We investigated the interaction between TLR and HO-1 in an inflammatory disorder, namely Behçet's disease.

METHODS

Thirty-three patients with Behçet's disease and 30 healthy control individuals were included in the study. Expression levels of HO-1, TLR2 and TLR4 mRNA were semiquantitatively analyzed using a real-time PCR technique, and HO-1 protein level was determined by immunoblotting in peripheral blood mononuclear cells (PBMCs) and polymorphonuclear leukocytes. In some experiments, cells were stimulated with lipopolysaccharide or heat shock protein-60; these proteins are known to be ligands for TLR2 and 4.

RESULTS

Levels of expression of HO-1 mRNA were significantly reduced in PBMCs from patients with active Behçet's disease, whereas those of TLR4, but not TLR2, were increased in PBMCs, regardless of disease activity. Moreover, HO-1 expression in PBMCs from patients with Behçet's disease was repressed in the presence of either lipopolysaccharide or heat shock protein-60.

CONCLUSION

The results suggest that upregulated TLR4 is associated with HO-1 reduction in PBMCs from patients with Behçet's disease, leading to augmented inflammatory responses.

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.

Cytokines and chemokines in uveitis: is there a correlation with clinical phenotype?

Uveitis is a general term for intraocular inflammation and includes a large number of clinical phenotypes. As a group of disorders, it is responsible for 10% of all registered blind patients under the age of 65 years. Immune-mediated uveitis may be associated with a systemic disease or may be localized to the eye. The pro-inflammatory cytokines interleukin (IL)-1beta, IL-2, IL-6, interferon-gamma and tumor necrosis factor-alpha have all been detected within the ocular fluids or tissues in the inflamed eye together with others, such as IL-4, IL-5, IL-10 and transforming growth factor-beta. The chemokines IL-8, monocyte chemoattractant protein-1, macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and fractalkine are also thought to be involved in the associated inflammatory response. There have been a number of studies in recent years investigating cytokine profiles in different forms of uveitis with a view to determining what cytokines are important in the inflamed eye. This review attempts to present the current state of knowledge from in vitro and in vivo research on the inflammatory cytokines in intraocular inflammatory diseases.

Physiopathologie de la maladie de Behçet

SUBJECT

Pathophysiology of Behçet's disease (BD) is complex. Recent experimental data shed new light on the mechanisms leading to organ lesions.

MAIN ISSUES

Neutrophils and cytotoxic lymphocytes are now recognized as key effector cells in BD. Genetic susceptibility, environmental factors (virus and/or bacterial infections), inflammatory response abnormalities (heat shock proteins, dysregulated NO production) and abnormal immune response play also a major role in BD pathogeny.

PERSPECTIVES

Better understanding of the BD pathophysiology will allow the development of new therapies more specific of BD.

The role of heat shock protein 60, vascular endothelial growth factor and antiphospholipid antibodies in Behçet disease

BACKGROUND

Behçet disease is a systemic inflammatory disease of unknown aetiology. T cells in this disease proliferate vigorously in response to a specific peptide of heat shock protein (HSP) 60 in an antigen-specific fashion. Vascular endothelial cell growth factor (VEGF) is a cytokine participating in the inflammatory process. One of the prominent features of Behçet disease is vasculitis as a result of endothelial dysfunction. Antiphospholipid antibodies (APA) may play a role in the development of thrombosis by inhibiting production of prostacyclin by endothelial cells.

OBJECTIVES

To investigate the role of HSP60, VEGF and APA in Behçet disease and their relation to clinical manifestations and disease activity.

METHODS

Thirty patients with Behçet disease were included; 17 were in the active stage and 13 were in the inactive. Fifteen age- and sex-matched healthy subjects served as controls. Complete clinical examination and Doppler examination were done. Serum levels of HSP60, VEGF and APA were performed.

RESULTS

Serum levels of HSP60, VEGF and APA were significantly higher in patients than in controls; however, their level did not correlate with disease activity. The serum level of VEGF correlated significantly with the presence of vascular manifestations and ocular involvement. The serum level of APA was greater in patients with thrombosis. HSP60 has an important role in aetiopathogenesis of Behçet disease, which sheds new light on its autoimmune nature.

CONCLUSIONS

An elevated serum level of VEGF may be a risk factor for the development of ocular disease contributing to poor visual outcome.

New approaches in the treatment of Adamantiades-Behçet's disease

PURPOSE OF REVIEW

To update clinicians on the recent advances in the treatment of Adamantiades-Behçet's disease.

RECENT FINDINGS

Interferon-alpha-2a and infliximab have proved able to induce prompt remission in the vast majority of Adamantiades-Behçet's patients with DMARD-resistant uveoretinitis. Efficacy of interferon-alpha-2a has also been reported for mucocutaneous lesions, arthritis, and (more anecdotally) for neuro-Behçet, while results from small case series suggest that infliximab is beneficial for mucocutaneous lesions and (more anecdotally) for arthritis and gastro-intestinal manifestations. Two cases of neuro-Behçet treated with infliximab showed a complete resolution. Finally, in a randomized controlled trial of patients with mucocutaneous, arthritic manifestations, or both, etanercept effectively suppressed mucocutaneous lesions.A different approach is tolerization by oral administration of the 336-351 peptide of the human heat shock protein 60 (thought to have a pathogenic role in Adamantiades-Behçet's disease-associated uveitis), linked to recombinant cholera B-toxin B-subunit. Preliminary results have shown that tolerization is safe and effective in preventing relapses of uveitis.

SUMMARY

Biologic agents have proved effective in patients resistant to conventional treatment. However, disease subsets characterized by severe morbidity and mortality such as vasculo-Behçet and neuro-Behçet still pose major therapeutic challenges. Further studies are needed to devise better treatment strategies for severe Adamantiades-Behçet's disease.