Serum of patients with Behçet's disease induces classical (pro-inflammatory) activation of human macrophages in vitro

Macrophage Activation Syndrome in the Setting of Rheumatic Diseases

Patients with established rheumatic disorders may develop complications of macrophage activation syndrome due to severe flares of the underlying disease (adult-onset Still's disease, SLE); however, in most other rheumatic disorders, MAS develops in association with identified viral or other infectious triggers. It is therefore important to pursue appropriate studies to identify potential infectious triggers in rheumatic disease patients who develop MAS. Management is best directed toward treatment of the triggering infections and combinations of high-dose corticosteroids, calcineurin inhibitors, and biologic therapies targeting IL-1 and/or IL-6 to suppress the associated cytokine storm.

The roles of immune cells in Behçet's disease

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

Saliva and Serum Cytokine Profiles During Oral Ulceration in Behçet's Disease

Behçet's disease (BD) is a chronic, multi-systemic disorder of unknown aetiology typified by recurrent oral and genital mucocutaneous lesions, uveitis and vasculitis. Innate and adaptive immune system dysregulation has been implicated in pathogenesis with alterations in serum cytokine profiles. Few studies have investigated salivary cytokines in BD, despite more than 90% of BD patients first presenting with oral ulceration. The aim of this pilot study was twofold; firstly to investigate whether cytokine levels in matched serum and saliva samples show a differential profile in BD (with and without oral ulcers), recurrent aphthous stomatitis (RAS) and healthy controls (HCs), and secondly, to explore if any differential profiles in serum and/or saliva could provide a panel of cytokines with diagnostic and therapeutic potential for BD. Concentrations of 12 cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IFN-γ, TNF-α, TNF-β) were measured using the Human Th1/Th2 11-Plex FlowCytomix™ kit with IL-17A, in BD (N=20), RAS (N=6) and HCs (N=10). A differential range of cytokines was detected in serum and saliva with the majority of cytokine levels higher in saliva. The most prevalent salivary cytokines were IL-1β, IL-2, IL-8, IL-10 and TNF-α present in all samples in contrast to serum where the most prevalent cytokine detected was IL-8 (91.9%). The least abundant cytokine was IFN-γ in both saliva (43.2%) and serum (2.7%). After normalizing saliva for protein content, BD patients with oral ulcers (BD-MA) had significantly higher levels of salivary IL-1β (p=0.01), IL-8 (p=0.02), TNF-α (p=0.004) and IL-6 (p=0.01) than HCs. Notably, BD patients without oral ulcers (BD-MQ) also had significantly higher salivary IL-1β, IL-8 and TNF-α (p ≤ 0.05) than HCs. During relapsed (BD-RE) and quiet (BD-Q) systemic episodes, salivary IL-β and TNF-α were also significantly increased with IL-8 significantly higher only in BD-Q (p=0.02). BD oral ulcers signify a potential reactivation of systemic inflammation. Identifying cytokines released during asymptomatic episodes and oral ulceration might lead to targeted drug therapy to prevent recurrent oral ulcers and possible disease relapse. This is the first study to report salivary cytokine levels in BD. The detectable levels suggests cytokine profiling of BD saliva may provide an alternative, less invasive, sensitive procedure for frequent monitoring of disease activity and progression.

Macrophage polarization toward M1 phenotype through NF-κB signaling in patients with Behçet’s disease

Background

Macrophages are key innate immune cells implicated in the pathogenesis of Behçet’s disease (BD), and macrophage polarization plays a pivotal role in inflammatory response. This study aimed to investigate the role of BD serum on the phenotypes and functions of macrophage polarization.

Methods

BD or HC serum-treated human monocyte-derived macrophages (HMDMs) were examined M1/M2 phenotypes using flow cytometry and ELISA. The phagocytic capacity of HMDMs and CD4⁺T cell differentiation facilitated by HMDMs were measured by flow cytometry. Transcriptome analysis of BD and HC serum-stimulated HMDMs was conducted to identify differentially expressed genes. NF-κB signaling was examined using western blot to explore the mechanism of macrophage polarization induced by BD serum.

Results

BD serum-treated macrophages expressed a higher level of CD86, IL-12, and TNF-α and a lower level of CD163, which were compatible with the M1-like phenotype. Furthermore, BD serum-treated macrophages showed enhanced phagocytic capacity and promoted more Th1 cell differentiation. Sixty-one differentially expressed genes were identified between BD and HC serum-treated macrophages and were enriched in NF-κB signaling. BD serum-treated macrophages showed upregulated p-p65 and downregulated IκBα, and NF-κB inhibitor attenuated BD serum-stimulated M1-like phenotype.

Conclusions

BD serum promoted macrophage polarization toward a proinflammatory M1-like phenotype through NF-κB signaling and potentially facilitated inflammation in BD. M1 polarized macrophages may be a potential therapeutic target for BD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02938-z.

Plasma microparticles from patients with systemic lupus erythematosus modulate the content of miRNAs in U937 cells

In systemic lupus erythematosus (SLE), the clearance of apoptotic cells and microparticles (MPs) is reduced. Some MPs contain molecules that can modulate immune responses. This study aimed to evaluate the presence of miR-126 and miR-146a in plasma MPs of patients with SLE (SLE MPs) and analyse the ability of MPs to modulate some events in the promonocytic U937 cell line. Circulating MPs were isolated from plasma samples of healthy controls (HCs), patients with SLE and other autoimmune diseases (OAD). MPs were analysed for size and cell origin by flow cytometry and content of miR-126 and miR-146a by RT-qPCR. MPs were then added to U937 cell cultures to evaluate changes in cell phenotype, cytokine expression, content of miR-126 and miR-146a, and levels of IRF5. Patients with active SLE (aSLE) showed an increase in concentration of plasma MPs that positively correlated with the SLEDAI (SLE Disease Activity Index) score. CD14+ MPs were significantly more abundant in patients with SLE than HCs. SLE MPs contained decreased levels of miR-146a, but the miR-126 content in aSLE MPs was increased. The miR-126 content in SLE MPs correlated positively with the SLEDAI score. The treatment of U937 cells with MPs from HCs and patients induced reduced expression of HLA-DR, CD18 and CD119, increased frequency of IL-6+ and TNF-α+ cells, accumulation of IL-8 in culture supernatants, increased miR-126 levels and decreased miR-146a content, but no change in the expression of IRF5. These findings suggest that plasma MPs, especially SLE MPs, could modulate some biological events in U937 cells.

Behçet Disease: An Update for Dermatologists

Behçet disease (BD) is a chronic, relapsing, systemic vasculitis of unknown etiology with the clinical features of oral and genital ulcers, cutaneous vasculitic lesions, ocular, articular, vascular, gastrointestinal, neurologic, urogenital and cardiac involvement. BD usually appears around the third or fourth decade of life. Gender distribution is roughly equal. The disease is much more frequent in populations along the ancient 'Silk Road', extending from Eastern Asia to countries in the Middle East and the Mediterranean, compared with Western countries, but has universal distribution. Mucocutaneous manifestations are the clinical hallmarks of BD. The diagnostic criteria widely used in the disease's diagnosis are based on mucocutaneous manifestations because of their high sensitivity and/or specificity. Genetic factors are the key driver of BD pathogenesis, and HLA-B51 antigen is the strongest genetic susceptibility factor. Streptococcus sanguinis (S. sanguinis) or microbiome change can trigger innate immune system-mediated inflammation sustained by adaptive immune responses. Epistatic interaction between HLA-B51 and endoplasmic reticulum aminopeptidase 1 (ERAP1) in antigen-presenting cells disrupt T-cell homeostasis leading to downregulation of Tregs and expansion of Th1 and Th17. Thus, neutrophil activation and intense neutrophil infiltration of the affected organs develop in the early stage of inflammation. BD has a variable clinical course with unpredictable exacerbations and remissions. The disease is associated with a high mortality rate, especially in young male patients, and large-vessel, neurological, gastrointestinal system and cardiac involvement are the most important causes of death. The principal aim of treatment should be to prevent irreversible organ damage, especially during the disease's early, active phase. A better understanding of the disease's pathogenesis has provided important information on its management. New drugs, especially apremilast and anti-TNF-α agents are effective in the management of BD and have the potential to improve patients' quality of life, prognosis and survival.

Increased Urinary CD163 Levels in Systemic Vasculitis with Renal Involvement

Objectives

Systemic vasculitis includes a group of disorders characterized by inflammation of the vessel wall, involving multiple systems, and can cause malignant hypertension. CD163 is a specific marker of anti-inflammatory macrophages. This study is aimed at evaluating the CD163 levels in relation to systemic vasculitis and renal involvements.

Methods

Urinary CD163 levels were retrospectively measured by enzyme-linked immunosorbent assay (ELISA) in 51 patients with systemic vasculitis, 42 essential hypertensions, and 36 healthy volunteers. The associations between urinary CD163 levels and clinical indicators were analyzed.

Results

Urinary CD163 levels were significantly higher in patients with systemic vasculitis [68.20 (38.25~158.78) (pg/ml)] compared to essential hypertension [43.86 (23.30-60.71) (pg/ml)] (p = 0.003) and the healthy volunteers [30.76 (9.30-54.16) (pg/ml)] (p < 0.001). Furthermore, systemic vasculitis patients with renal involvement had significantly higher urinary CD163 levels relative to patients without renal involvement [86.95 (47.61 and 192.38) pg/ml] vs. [41.99 (17.70 and 71.95) pg/ml, p = 0.005]. After control factors age, sex, and BMI, urinary CD163 levels in systemic vasculitis patients were positively correlated with serum creatinine, blood urea nitrogen, and β-2 microglobulin (r = 0.45, 0.48, and 0.46; p = 0.001, 0.001, and 0.002, respectively). In addition, we found the level of urinary CD163 in granulomatous vasculitis (including TA, GPA, and EGPA) was significantly higher than that in necrotizing vasculitis (including PAN) [86.95 (41.99 and 184.82) pg/ml] vs. [45.73 (21.43 and 74.43) pg/ml, p = 0.016].

Conclusion

Urinary CD163 levels were significantly higher in patients with systemic vasculitis, especially in patients with renal involvement. Thus, urinary CD163 has the potential to be a biomarker for systemic vasculitis with renal involvement.

Treatment of Behçet's Disease: An Algorithmic Multidisciplinary Approach

Behçet's disease (BD) is a chronic, relapsing inflammatory, multisystem disease of unknown etiology. The disease has a wide clinical spectrum of mucocutaneous lesions and ocular, vascular, articular, neurologic, gastrointestinal and cardiac involvement. Although the number of effective drugs used in the disease's treatment has increased in recent years, BD is still associated with severe morbidity because of mainly mucocutaneous, articular and ocular symptoms and an increased mortality because of large vessel, neurological, gastrointestinal and cardiac involvement. Many factors are associated with a more serious course, such as male gender and a younger age of onset. While the severity of the disease is more pronounced in the first years of the disease, it decreases in most patients after the age of forties. The primary goal of treatment should be the prevention of irreversible organ damage. Therefore, early diagnosis and appropriate treatment and close follow-up are mandatory to reduce the morbidity and mortality of the disease. Treatment varies depending on the organ involved and the severity of the involvement. For all these reasons, the treatment should be personalized and arranged with a multidisciplinary approach according to the organs involved. Treatment is mainly based on suppression of the inflammatory attacks of the disease using local and systemic immunomodulatory and immunosuppressive drugs. In this review, based on the mainly controlled studies and personal experience in clinical practice and basic research in this field, we propose a stepwise, symptom-based, algorithmic approach for the management of BD with a holistic perspective.

Genetic Association of Interleukin 33/ST2 Polymorphisms With Behcet's Uveitis

Interleukin (IL)33, a member of the IL1 superfamily, functions as a nuclear factor and mediates biological effects by interacting with the ST2 receptor. Recent studies have described IL33 as an emerging pro-inflammatory cytokine in the immune system, and IL33/ST2 gene polymorphisms have been implicated in the pathogenesis of various immune diseases. However, the underlying mechanisms of IL33/ST2 in Behcet's disease (BD) remain to be defined. Here, we investigated the association between IL33/ST2 gene polymorphisms and BD in 585 BD uveitis (BDU) patients and 834 healthy controls using Agena MassARRAY iPLEX platform. We found that rs3821204 was associated with the development of BDU. Moreover, the frequency of rs2210463 G allele was lower in patients with genital involvement. Association analysis revealed a much greater genetic difference between complete-type and incomplete-type BD groups, including three SNPs (rs7044343, rs1048274, and rs2210463). Our findings suggest that IL33/ST2 gene polymorphisms are involved in the pathogenesis of BDU. Different genetic backgrounds may exist in complete-type and incomplete-type BD patients.

Experimental Therapeutic Solutions for Behcet's Disease

Behcet's disease (BD) is a chronic systemic vasculitis with inflammation attacks that involve multiple organs. In addition to numerous mucocutaneous symptoms, notably recurrent oral and genital ulcers, ocular, articular, vascular, gastrointestinal, cardiac, and neurological system involvement can be observed. Mucocutaneous lesions are the primary symptom of the disease in most patients, and they usually occur before major organ involvement and other symptoms of the disease. Recognizing the disease's mucocutaneous lesions is very important to diagnose at an early stage, control with appropriate treatment and close follow-up, and prevent major organ involvement. Genome-wide association studies (GWAS) in recent years have confirmed that HLA-B*51 is the most significant genetic predisposing factor. The majority of gene polymorphisms have been detected in molecules that respond to microorganisms and genes encoding cytokines and adhesion molecules. The infectious agent S. sanguinis -commonly found in the oral mucosa of patients with BD- or the differences in the salivary or intestinal microbiome composition can trigger innate immune-mediated inflammation sustained by acquired or adaptive immune responses. In antigen-presenting cells (APCs), epistatic interactions between HLA-B*51 and endoplasmic reticulum aminopeptidase 1 (ERAP1) variants lead to the disruption of T-cell homeostasis, especially the activation of Type1 T-helper and Th17 pathway and suppression of regulatory T-cells. Recent developments to clarify the disease's etiopathogenesis provided us with a better understanding of the mechanism of action of the relatively old drugs while opening a way for many new treatment methods. Apremilast has become an important option in the treatment of mucocutaneous symptoms with its high efficacy and safety. The disease increases the mortality rate, especially in young male patients. New treatments, especially anti-TNF-α agents, have provided significant progress and decreased the mortality rates with their rapid effect and high efficacy in patients with severe organ involvement and resistance to traditional immunosuppressive and immunomodulatory therapies. The use of IL-1, IL-6, IL-17, IL-12/IL-23 antagonists in different organ involvement has gradually increased, and the quality of life has significantly improved in many patients.

Understanding Behçet's Disease in the Context of Innate Immunity Activation

Behçet´s disease (BD) is a heterogeneous condition consisting of idiopathic systemic vasculitis affecting large and small blood vessels of different types (i.e., arteries, veins, or capillaries). The disease frequently occurs in young adults without gender predilection, differently from several other autoimmune conditions. This challenging illness has recently been proposed by some authors as an example of complex autoinflammatory syndrome. Although much remains unanswered about BD pathogenesis, recent understanding of some aspects of innate immunity have clarified a few issues (and raised others). HLA-B*51 represents the strongest genetic risk factor for BD to date, albeit several other HLA-independent loci have also been associated with the disease. The consistent hyper-reactivity against Streptococcus sanguinis antigens and alterations in oral and gut microbioma suggests that infectious agents may play an important role. Moreover, functional abnormalities of pattern recognition receptors, especially Toll-like receptors in monocytes, have been demonstrated in patients with BD and can be associated with the development of the disease. Neutrophil hyperactivity is one of the most consistent findings in BD pathogenesis, as demonstrated by exacerbated constitutive oxidative burst, chemotaxis and NET formation. However, some studies suggest that the phagocyte-activated status in BD is not primary to the disease itself, but rather restricted to a fraction of patients with severe disease activity, and probably secondary to activating soluble factors carried by serum/plasma from BD patients. Herein we review the state of the art on BD etiopathogenesis with special emphasis on the participation of the innate immune system

Regulating the Polarization of Macrophages: A Promising Approach to Vascular Dermatosis

Macrophages, a kind of innate immune cells, derive from monocytes in circulation and play a crucial role in the innate and adaptive immunity. Under the stimulation of the signals from local microenvironment, macrophages generally tend to differentiate into two main functional phenotypes depending on their high plasticity and heterogeneity, namely, classically activated macrophage (M1) and alternatively activated macrophage (M2). This phenomenon is often called macrophage polarization. In pathological conditions, chronic persistent inflammation could induce an aberrant response of macrophage and cause a shift in their phenotypes. Moreover, this shift would result in the alteration of macrophage polarization in some vascular dermatoses; e.g., an increase in proinflammatory M1 emerges from Behcet's disease (BD), psoriasis, and systemic lupus erythematosus (SLE), whereas an enhancement in anti-inflammatory M2 appears in infantile hemangioma (IH). Individual polarized phenotypes and their complicated cytokine networks may crucially mediate in the pathological processes of some vascular diseases (vascular dermatosis in particular) by activation of T cell subsets (such as Th1, Th2, Th17, and Treg cells), deterioration of oxidative stress damage, and induction of angiogenesis, but the specific mechanism remains ambiguous. Therefore, in this review, we discuss the possible role of macrophage polarization in the pathological processes of vascular skin diseases. In addition, it is proposed that regulation of macrophage polarization may become a potential strategy for controlling these disorders.

Dysregulation of glycerophospholipid metabolism during Behçet's disease contributes to a pro-inflammatory phenotype of circulating monocytes

Behçet's disease (BD) is a relapsing, multisystem and inflammatory condition characterized by systemic vasculitis of small and large vessels. Although the etiopathogenesis of BD remains unknown, immune-mediated mechanisms play a major role in the development of the disease. BD patients present leukocyte infiltration in the mucocutaneous lesions as well as neutrophil hyperactivation. In contrast to neutrophils, whose involvement in the pathogenesis of BD has been extensively studied, the biology of monocytes during BD is less well known. In this study, we analyzed the phenotype and function of circulating monocytes of 38 BD patients from Hospital of Braga. In addition, we evaluated the impact of inflammatory and metabolomic plasma environment on monocyte biology. We observed a worsening of mitochondrial function, with lower mitochondrial mass and increased ROS production, on circulating monocytes of BD patients. Incubation of monocytes from healthy donors with the plasma of BD patients mimicked the observed phenotype, strongly suggesting the involvement of serum mediators. BD patients, regardless of their symptoms, had higher serum pro-inflammatory TNF-α and IP-10 levels and IL-1β/IL-1RA ratio. Untargeted metabolomic analysis identified a dysregulation of glycerophospholipid metabolism on BD patients, where a significant reduction of phospholipids was observed concomitantly with an increase of lysophospholipids and fatty acids. These observations converged to an enhanced phospholipase A2 (PLA2) activation. Indeed, inhibition of PLA2 with dexamethasone or the downstream cyclooxygenase (COX) enzyme with ibuprofen was able to significantly revert the mitochondrial dysfunction observed on monocytes of BD patients. Our results show that the plasma inflammatory environment coupled with a dysregulation of glycerophospholipid metabolism in BD patients contribute to a dysfunction of circulating monocytes.

The molecular and clinical evidence of vitamin D signaling as a modulator of the immune system: Role in Behçet's disease

Various tissues and cell types are the targets of vitamin D. However, the major targets of vitamin D in the immune system are monocytes/macrophages, dendritic cells (DCs), as well as B and T cells. Vitamin D plays an important role in the immune system modulation via regulating the expression of genes that generate pro-inflammatory mediators and inhibiting the proliferation of pro-inflammatory cells, both of which have been implicated in the pathophysiology of the inflammatory diseases. Recent studies have revealed the important relations between vitamin D and Behçet's disease (BD). Vitamin D function and its deficiency have been linked to a wide range of metabolic disorders including malignant, cardiovascular, infectious, neuromuscular, and autoimmune diseases. Here, we provide a brief analysis of the recent literature regarding immune-regulatory effects as well as clinical evidence of vitamin D influence on the molecular level in BD.

Soluble CD40L is associated with increased oxidative burst and neutrophil extracellular trap release in Behçet's disease

Background

Studies have suggested that soluble factors in plasma from patients with active (aBD) and inactive (iBD) Behçet’s disease (BD) stimulate neutrophil function. Soluble CD40 ligand (sCD40L) is an important mediator of inflammation in BD. Its expression and effect on neutrophil oxidative burst and neutrophil extracellular trap (NET) release have not been characterized. In this study, we sought to investigate the role of plasma and the CD40L pathway on NET release and the oxidative burst profile in patients with aBD and iBD.

Methods

Neutrophils and peripheral blood mononuclear cells (PBMCs) were obtained from patients with aBD (n = 30), patients with iBD (n = 31), and healthy control subjects (HCs; n = 30). sCD40L plasma concentration was determined in individual samples. A pool of plasma for each group was created. In some experiments, plasma pools were treated with recombinant CD40 (rhCD40-muIg) for sCD40L blockade. NET release and H₂O₂/O₂⁻ production were determined after stimulation with phorbol 12-myristate 13-acetate, sCD40L, or plasma pool. Flow cytometric analysis was performed to evaluate the expression of (1) CD40, Mac-1, and phosphorylated NF-κB p65 on neutrophils and monocytes and (2) CD40L on activated T cells and platelets. CD40L gene expression in PBMCs was determined by qRT-PCR.

Results

sCD40L plasma levels were significantly higher in patients with iBD (median 17,234, range 2346–19,279 pg/ml) and patients with aBD (median 18,289, range 413–19,883 pg/ml) than in HCs (median 47.5, range 33.7–26.7 pg/ml; p < 0.001). NET release was constitutively increased in BD compared with HC. NET release and H₂O₂/O₂⁻ were higher after stimulation with sCD40L or BD plasma and decreased after sCD40L blockade. Mac-1 expression was constitutively increased in neutrophils of patients with aBD (88.7 ± 13.2% of cells) and patients with iBD (89.2 ± 20.1% of cells) compared with HC (27.1 ± 18.8% of cells; p < 0.01). CD40 expression on phagocytes and CD40L expression on platelets were similar in the three groups. PBMCs as well as nonactivated and activated CD4⁺ T cells from patients with BD showed higher CD40L expression.

Conclusions

Plasma from patients with aBD exerts a stimulus on NET release and oxidative burst, probably induced by sCD40L.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1443-5) contains supplementary material, which is available to authorized users.

The macrophages in rheumatic diseases

Macrophages belong to the innate immune system giving us protection against pathogens. However it is known that they are also involved in rheumatic diseases. Activated macrophages have two different phenotypes related to different stimuli: M1 (classically activated) and M2 (alternatively activated). M1 macrophages release high levels of pro-inflammatory cytokines, reactive nitrogen and oxygen intermediates killing microorganisms and tumor cells; while M2 macrophages are involved in resolution of inflammation through phagocytosis of apoptotic neutrophils, reduced production of pro-inflammatory cytokines, and increased synthesis of mediators important in tissue remodeling, angiogenesis, and wound repair. The role of macrophages in the different rheumatic diseases is different according to their M1/M2 macrophages phenotype.

Polymorphisms of interleukin 6 and interleukin 10 in Egyptian people with Behcet's disease

Cytokines play critical roles in the pathogenesis of Behçet's disease (BD). They mediated many of the effectors and regulatory functions of immune and inflammatory responses. Many studies have linked Interleukin-6 (IL-6) and Interleukin-10 (IL-10) pathologically to BD. Thus, this study aimed to investigate the associations between IL-6 and IL-10 promoter single-nucleotide polymorphisms (SNPs) and the susceptibility to BD and their implication on plasma levels. We genotyped IL-6 -174 G/C (rs1800795) using Mutagenically Separated Polymerase Chain Reaction PCR (MS-PCR) and IL-10 -1082 G/A (rs1800896) and -819 C/T (rs1800871) using Sequence Specific Primer PCR (SSP-PCR) in 87 Egyptian patients and 97 controls. The plasma levels of IL-6 and IL-10 were measured using Enzyme-linked Immunosorbent Assay (ELISA). Significant increase in the frequency of -1082 GG genotype (P<0.05, OR=2.25, 95%CI=1.03-4.91) and significant decrease in the frequency of -1082 GA genotype (P<0.05, OR=0.53, 95%CI=0.29-0.96) was demonstrated in BD patients compare to controls. Patients with genital ulcer had significantly lower frequency of -1082 GG (P<0.05, OR 0.2, 95% CI=0.04-0.99) and G allele (P<0.05, OR=0.28, 95%CI=0.08-0.93), while patients with ocular manifestations had significantly higher frequency of -1082 G allele (P<0.01, OR=2.28, 95%CI=1.19-4.36). BD patients had significantly higher level of IL-6 (P<0.001) and significantly lower level of IL-10 (P<0.001) compared to controls. The changes in the level of cytokines were independent of any genotype of IL-6 or any genotype/haplotype of IL-10. Patients with active disease state had significantly higher level of IL-6 compared to patients in remission (P<0.05). In conclusion, our preliminary study indicates that the polymorphism at IL-10 -1082 G/A may play a role in BD susceptibility. The significant increase in IL-6 level and the significant decrease in IL-10 level in BD patients were independent of any particular genotype in IL-6 or any particular genotype/haplotype in IL-10.

Oxidases and oxygenases in regulation of neutrophil redox pathways in Behçet's disease patients

This study aimed to determine plasma and neutrophil oxidase activities that may contribute to vascular inflammation in Behçet's disease (BD) patients. Cyclooxygenase (COX), NADPH oxidase and myeloperoxidase (MPO) activity was determined in neutrophils isolated from BD patients and healthy controls. Functional assay of NADPH oxidase was significantly increased in BD patients, both at basal conditions and in response to fMLP stimulation. There was a significant increase in plasma MPO activity in the disease group as compared to controls. Total COX activity was significantly increased in BD neutrophils. The increase in total COX activity was accompanied with enhanced activity of COX-2, differentiated by using the COX-1 isoform-specific inhibitor SC-560. Neutrophil nitrate/nitrite levels showed no significant difference in BD; however, plasma nitrate/nitrite contents in BD patients were significantly greater compared to controls. In conclusion, increased plasma MPO, neutrophil NADPH and COX activities may contribute to intravascular inflammation documented in BD patients.

Treatment with levamisole and colchicine can result in a significant reduction of IL-6, IL-8 or TNF-alpha level in patients with mucocutaneous type of Behcet's disease

BACKGROUND

Mucocutaneous type of Behcet's disease (MCBD) is a multisystemic inflammatory disease with oral and genital ulcers with or without skin lesions.

METHODS

A solid phase, two-site sequential chemiluminescent immunometric assay was used to measure serum levels of interleukin (IL)-6, IL-8 and tumour necrosis factor (TNF)-alpha in 54 normal control subjects and in 64 MCBD patients before and after treatment with levamisole plus colchicine.

RESULTS

We found that 67%, 83% or 67% of MCBD patients had a serum IL-6, IL-8 or TNF-alpha level greater than the upper normal limit of 4.7, 8.7 or 7.4 pg/ml, respectively. The mean serum level of IL-6 (9.9 +/- 2.4 pg/ml, P < 0.005), IL-8 (107.5 +/- 21.4 pg/ml, P < 0.001) or TNF-alpha (22.5 +/- 4.1 pg/ml, P < 0.001) in 64 MCBD patients was significantly higher than that (2.1 +/- 0.2, 5.7 +/- 0.2 or 3.8 +/- 0.2 pg/ml for IL-6, IL-8 or TNF-alpha level, respectively) in normal control subjects. In 43 MCBD patients with all the serum IL-6, IL-8 and TNF-alpha levels higher than their upper normal limits, treatment with levamisole plus colchicine for a period of 0.5-11.5 (mean, 3.2 +/- 2.4) months could significantly reduce the mean serum IL-6, IL-8 and TNF-alpha levels from 9.0 +/- 1.7 to 1.6 +/- 0.2 pg/ml (P < 0.001), 134.6 +/-28.2-6.0 +/- 0.4 pg/ml (P < 0.001) and 25.7 +/- 5.6-3.5 +/- 0.4 pg/ml (P < 0.001), respectively.

CONCLUSIONS

Treatment with levamisole and colchicine can result in a significant reduction of serum IL-6, IL-8 or TNF-alpha level in MCBD patients.

Vitamin levels in Behçet's disease

OBJECTIVE

To determine the role of oxidative stress and the antioxidant defense mechanism in the etiopathogenesis of active and inactive Behçets disease. In line with this objective, the present study aimed to examine the levels of nitric oxide (NO) and malondialdehyde (MDA), which are the end products of oxidant stress, and vitamins, which are non-enzymatic antioxidants, for the diagnosis and particularly the follow-up of Behçet's disease.

MATERIALS AND METHODS

The study group consisted of a total of 60 individuals: 40 of whom were Behçet's disease patients and 20 were healthy individuals. Of the 40 Behçet's patients, 29 had the active and 11 had the inactive (stable) form of the disease.

RESULTS

Although plasma MDA and NO (its stable form nitrite) levels in the total patient group were statistically significantly higher than those in the control group (p<0.06), there was no statistically significant difference as such between inactive Behçet's patients and the control group (p>0.05). Vitamin E, C, B1, B2 and flavin mononucleotide (FMN) values were significantly lower in the patient group in comparison with the control group (p<0.05). There was no statistically significant difference in other vitamin values.

DISCUSSION

It is contemplated that measurement of such oxidative stress factors as MDA and NO and an accompanying evaluation of the antioxidant defense system can be significant in the diagnosis and treatment follow-up of Behçet's disease.

EBV‐associated haemophagocytic syndrome in a patient with Behçet's disease

We present a case of Epstein-Barr virus (EBV)-associated haemophagocytic syndrome in a patient with Behçet's disease. A 43-year-old man, who had been receiving treatment under the diagnosis of Behçet's disease for recurrent oral ulcers, genital ulcer, ileal ulcer, and arthritis, had been admitted for fever, headache, and nausea developed 3 days ago. Laboratory data showed pancytopaenia, an increase in liver enzymes, lactate dehydrogenase (LDH) and ferritin. Haemophagocytic syndrome was diagnosed from histiocytosis and haemophagocytosis by macrophages, shown in the bone marrow aspiration and biopsy, and in situ hybridization for EBV showed a positive finding. The patient recovered rapidly after steroid therapy. This is the first report of EBV-associated haemophagocytic syndrome developed in a patient with Behçet's disease.

Significance of serum interleukin-8 levels in patients with Behcet's disease: high levels may indicate vascular involvement

BACKGROUND

Interleukin-8 (IL-8) has been shown previously to associate with different individual clinical manifestations and activity of Behcet's disease (BD), but its association with vascular involvement has not been established.

METHODS

Forty-five untreated patients with BD and 29 healthy individuals were included in the study. The activity of patients was based on the existence of two or more symptoms and a statistically significantly high Behcet's Disease Activity Index (BDAI) at the time of the study. IL-8, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) results were evaluated with respect to activity, vascular involvement, and other specific individual clinical manifestations of the disease.

RESULTS

IL-8 levels were found to be significantly elevated in active BD compared with inactive BD (P = 0.006) and healthy controls (P = 0.000), with median values of 267 (53-2000), 137 (52-290), and 58 pg/mL (53-160 pg/mL), respectively. Unlike ESR and CRP, IL-8 levels showed a high correlation with BDAI scores (r = 0.743, P = 0.00) and the number of active clinical manifestations (r = 0.646, P = 0.00). Serum levels of IL-8 were increased in patients with oral ulcers, genital ulcers, eye lesions, and vascular lesions, with median values and significance levels of 254.5 (53-2000), P = 0.05; 254.5 (52-1400), P = 0.03; 254.5 (72-2000), P = 0.029; and 593 pg/mL (110-2000 pg/mL), P = 0.001, respectively. In addition, IL-8 levels in the active patient group with vascular involvement were significantly higher than the levels in those without vascular involvement.

CONCLUSION

Serum IL-8 levels are increased in the active phase of BD. This marker may be useful in the early detection of vascular involvement.

Serum substance P and calcitonin gene-related peptide levels in Behçet's disease and their association with disease activity

BACKGROUND

Substance P (SP) and calcitonin gene-related peptide (CGRP) are neuropeptides that have a role in several cutaneous diseases and inflammations. Aim. To evaluate SP, CGRP and serum interleukin (IL)-8 levels in Behçet's disease (BD) and to explore the relationship of these peptides with BD activity.

METHODS

The study group comprised 30 patients with BD, and 30 healthy individuals acted as controls. Serum levels of SP, CGRP and IL-8 were determined by micro-ELISA test during the active and inactive disease periods of patients with BD. These data were compared with each other and controls. Active and inactive periods of BD were established.

RESULTS

The mean +/- SD serum CGRP (ng/ml) and IL-8 levels (pg/ml) in inactive BD (5.87 +/- 2.49 and 0.62 +/- 0.24, respectively) were significantly higher than the control group (4.74 +/- 1.17 and 0.46 +/- 0.11) (P < 0.05 for both). The difference between serum CGRP and IL-8 levels in active BD were also significantly higher than in inactive BD (P < 0.05 for both). Serum SP values (ng/ml) in active BD (18.27 +/- 5.38) were significantly higher than in inactive BD (15.26 +/- 5.74) and controls (12.6 +/- 4.45) (P < 0.05 for all), whereas the difference between the serum SP values in inactive BD and the control group was not statistically significant (P > 0.05).

CONCLUSION

Serum SP and CGRP may have a role in the pathogenesis of BD. In addition, serum IL-8, SP and CGRP levels can be used as laboratory parameters indicating activity in BD.

HLA-Independent Antibacterial Host Response toward Th1 Immunity Mediated by IL-12: a New Concept for the Pathogenesis of Adamantiades–Behçet's Disease

Yanagihori et al. found an HLA-independent higher frequency of IL-12B promoter polymorphism in Adamantiades-Behçet's disease (ABD) patients than in controls. Stimulation with streptococcal antigens specifically increased expression of patients' peripheral blood mononuclear cells IL-12 p40/p70. The authors provide evidence for an antibacterial host response toward T-helper type 1 immunity mediated by IL-12 in patients with ABD, which is HLA independent.

Dexamethasone, colchicine and iodine-lithium-α-dextrin act differentially on the oxidative burst and endotoxin tolerance induction in vitro in patients with Behçet's disease

Pro-inflammatory activation of innate immune cells, such as macrophages, and neutrophils in patients with Behçet's disease (BD) results in increased production of reactive oxygen species and enhanced adhesion to endothelial cells due to increased expression of adhesion receptors. We investigated the influence of dexamethasone (DEX), colchicine (Col), and iodine-lithium-alpha-dextrin (ILalphaD), during BD, on the respiratory burst of whole blood neutrophils and monocytes, CD11a/CD18 surface expression, monocyte endotoxin tolerance and cytokine synthesis in vitro. In BD patients we observed an increase of the spontaneous, N-formyl-Met-Leu-Phe- and LPS-induced respiratory burst of monocytes and neutrophils as well as up-regulation of neutrophil CD11a/CD18 surface expression. DEX, Col and ILalphaD in vitro differentially affected the stimulus-dependent oxidative burst of BD and caused the down-regulation of CD11a/CD18 surface expression in neutrophils but not monocytes. LPS homologous tolerance induction is not altered in BD. However, DEX and Col increased tolerance to LPS-induced TNF-alpha synthesis. ILalphaD down-regulated N-formyl-Met-Leu-Phe- and LPS-induced oxidative burst and CD14 receptor expression and increased monocyte cross-tolerance to LPS. DEX induced LPS-tolerance by restoring the ratio of INF-gamma and IL-4 production, while Col caused a dramatic increase in IL-4 synthesis by monocytes. DEX, Col and ILalphaD may limit the overwhelming inflammation by differentially affecting the monocyte activation program, shifting them from ''classically" into "alternatively'' activated monocytes and may have important implications for the treatment of BD.

Hypothalamic proline-rich polypeptide is an oxidative burst regulator

The AGAPEPAEPAQPGVY proline-rich polypeptide (PRP) was isolated from neurosecretory granules of the bovine neurohypophysis; it is produced by N. supraopticus and N. paraventricularis. PRP possesses immune-modulating activity, preventing the death of Gram-negative bacteria-infected mice. Here we show that PRP does not affect human peripheral blood neutrophlis and monocytes phagocytosis but dramatically enhances spontaneous or fMLP- and PMA-induced, and also phagocytosis-dependent, oxidative burst. We demonstrated the regulatory role of PRP on the oxidative burst induction of normal and relapsing inflammatory disease (Behcet's disease and familial Mediterranean fever) neutrophils and monocytes. Our results suggest a previously undescribed role for the hypothalamic peptide within primary activated neutrophils and monocytes, since we provide evidence that PRP can differentially regulate both chemotaxis- and phagocytosis-dependent oxidative burst in normal and inflammatory disease effector cells.

CXCR2 Expression on neutrophils is upregulated during the relapsing phase of ocular Behcet disease

PURPOSE

To search for markers of Behcet disease (BD) activity,we measured CXCR1 and CXCR2 levels on the circulating leukocytes of patients suffering from ocular BD.

METHODS

Peripheral blood leukocytes were harvested from healthy volunteers (n = 16) and ocular BD patients (n = 35). The patients consisted of 15 individuals in relapsing phase (6 with prednisolone treatment) and 20 individuals in remission phase (9 with prednisolone treatment). Expression of CXC chemokine receptors (CXCRs) on leukocytes (including lymphocytes, monocytes, neutrophils) was measured using flow cytometry.

RESULTS

Without prednisolone treatment, CXCR2 expression (on both total leukocytes and neutrophils) in relapsing phase was significantly higher than in remission-phase patients or normal individuals. By contrast, no significant difference was detected in the expression of CXCR1 between any ofthe groups. Importantly, low-dose prednisolone therapy reduced CXCR2 expression on neutrophils.

CONCLUSIONS

CXCR2 has a potential role in promot-ing uveitis during ocular attack and might also be a useful marker for disease activity.

Therapeutic effects of gemcitabine on cutaneous manifestations in an Adamantiades-Behçet's disease-like mouse model

The aim of this work was to study the effects and side effects of gemcitabine (2',2'-difluorodeoxycytidine, dFdC), a pyrimidine synthesis inhibitor, on skin lesions of a herpes simplex virus (HSV)-induced Adamantiades-Behçet's disease (ABD)-like mouse model. For the dose-escalation study, ICR mice were treated intraperitoneally with dFdC over 5 days. For the efficacy study, ICR mice were inoculated with HSV and classified as having ABD according to a revised Japanese classification, and then 18 ABD mice were randomly assigned to placebo, 0.06 or 0.12 microg of dFdC/day over 5 days. Serum levels of interleukin-4 (IL-4), IL-6, IL-10, interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) were determined using enzyme-linked immunosorbent assay. After application of 3 microg of dFdC over 5 days, alanine aminotransferase increased (P = 0.032), but all other kidney and liver parameters were unchanged. In ABD mice, 5 days of dFdC treatment with 0.06 or 0.12 microg of dFdC/day resulted in a dose-dependent improvement of cutaneous manifestations by more than 60% (P = 0.017). There was no significant change in cytokine levels, and none of the cytokine levels correlated with response to treatment. Moreover, dFdC shows promising effects to improve cutaneous lesions in the HSV-induced ABD-like mouse model. In this animal model, effects of dFdC on the cytokine profile remained inconclusive.

Specific interleukin-1 gene polymorphisms in Turkish patients with Behcet's disease

Genetic factors that predispose individuals to Behçet's disease (BD) are considered to play important roles in the development of the disease. The pro-inflammatory cytokine interleukin-1 (IL-1) has been implicated in the pathogenesis of BD. Our aim was to determine a possible association of specific polymorphisms of IL-1alpha, IL-1beta, and IL-1 receptor antagonist genes with susceptibility for BD. We genotyped 72 patients with BD and 163 healthy controls for IL-1alpha-889, IL-1beta-511, and +3953 (nt5887) single-nucleotide polymorphisms besides IL-1 receptor antagonist variable number of tandem repeat polymorphism (for five different alleles). Comparison of the IL-1beta+3953 T allele and TT genotype frequencies showed a significant difference between patients with BD and controls (54.2 vs. 40.5%, OR = 1.74, P = 0.024, and 40.3 vs. 19.6%, OR = 2.76, P = 0.009, respectively). However, no difference was observed in the genotype or allele frequencies of IL-1alpha-889, IL-1beta-511, and IL-1 receptor antagonist between the patients with BD and the controls. Our results indicate that susceptibility to BD is increased in individuals carrying the IL-1beta+3953 T allele and TT genotype.

Hypothalamic proline-rich polypeptide is a regulator of oxidative burst in human neutrophils and monocytes

OBJECTIVE

The effects of proline-rich polypeptide (PRP) isolated from neurosecretory granules of bovine neurohypophysis produced by nuclei supraopticus and paraventricularis on phagocytosis, bacterial intracellular killing and oxidative burst induction in normal human cells and inflammatory cells from patients with Behçet's disease (BD), i.e. peripheral blood neutrophils and monocytes, were investigated.

METHODS

Intracellular killing of Staphylococcus aureus by neutrophils and monocytes of normal controls and BD patients, phagocytic activity as well as spontaneous and N-formyl-Met-Leu-Phe (fMLP)- or phorbol 12-myristate 13-acetate (PMA)-induced activation of their respiratory burst were determined by quantitative flow cytometry using highly specific fluorescence probes.

RESULTS

PRP does not affect human peripheral blood neutrophil and monocyte phagocytosis but dramatically enhances spontaneous or fMLP- and PMA-induced oxidative burst as well as the intracellular killing of S. aureus. PRP induced the upregulation of the spontaneous or fMLP- and PMA-induced oxidative burst in normal PMNs and monocytes; the number of inflammatory BD cells did neither increase further nor undergo spontaneous or PMA-stimulated oxidative burst. In BD patients, increased spontaneous production of reactive oxygen intermediates (ROIs) by neutrophils and monocytes is characterized by impaired intracellular protein-kinase-C (PKC)-dependent oxidative burst regulation as well as over-regulation of chemotaxis/inflammation-mediated respiratory burst induction. PRP restores rather the impaired intracellular PKC-dependent regulation of ROI production in inflammatory diseased cells than the chemotaxis/induction of the inflammation-mediated respiratory burst.

CONCLUSION

We demonstrated the regulatory role for PRP on oxidative burst in neutrophils and monocytes from normal controls and BD patients. Our results suggest that PRP differentially affects both chemotaxis- and PKC-dependent oxidative burst in normal and inflammatory cells from patients.

Androgen receptor levels of oral and genital ulcers and skin pathergy test in patients with Behçet's disease

BACKGROUND

Hormonal factors have long been proposed to play a role in Behçet's disease (BD). Male sex, systemic onset, HLA-B51 positivity and a younger age of onset in BD are associated with severer disease, and the disease generally runs a milder course in women. Vascular involvement is more common, and the skin pathergy test (SPT) is more strongly positive in men. BD rarely develops before puberty or after the age of 50 years. Clinical manifestations of the disease, with the exception of eye symptoms, tend to improve with time. Therefore, BD may be androgen driven to some degree.

OBJECTIVES

We aimed to investigate androgen receptor (AR) levels of oral ulcers (OU), genital ulcers (GU) and SPT areas and compared them with those of adjacent normal-appearing skin/mucosa from patients with BD.

METHODS

Thirty-eight patients with BD (16 female, 22 male; mean +/- SD age, 36.45 +/- 10.2 years), diagnosed according to the criteria of the International Study Group for Behçet's Disease, were included in the study with blind histological examination. Biopsies from OU of 10 patients, GU of 11 patients, SPT areas of 17 patients and adjacent (approximately 2 cm distant) normal-appearing skin/mucosa in patients with BD were performed. Nuclear AR levels were studied by an immunohistochemical technique, using monoclonal antibodies. The percentage of positively staining cells was recorded as the AR index (ARI). In addition, the prevalence and the positivity rate of SPT has also been evaluated.

RESULTS

ARI values in the lesional and control (non-lesional adjacent) skin/mucosa were found to be 14.5 versus 18% for OU, 28.7 versus 25.5% for GU and 36.3 versus 21.8% (p = 0.068) for SPT areas. The positive SPT areas in male patients showed a higher ARI than those of female patients (43.36 and 23.33%; p = 0.078). The ARI values of SPT areas in male patients but not in female patients were found to be significantly higher as compared with non-lesional skin (21.63%; p = 0.039). The SPT positivity was also more common in male patients compared with female patients (86.4% and 62.5%), although the difference was not significant (p = 0.88). SPT have been found to be more strongly positive among the males (4.63 +/- 3.3) compared with female patients (3.18 +/- 1.9), and the difference was statistically significant (p = 0.022).

CONCLUSIONS

Our findings indicate that androgens seem to play a role both in the formation and increased positivity of the SPT areas in male patients with BD.

Beh??et??s syndrome and the nervous system

PURPOSE OF REVIEW

Behçet's syndrome (BS) is a multi-system, vascular-inflammatory disease of unknown origin, involving the nervous system in a subgroup of patients. The syndrome is rare, but as patients with BS are young and frequently present with an acute or subacute brainstem syndrome or hemiparesis, as well as with other various neurological manifestations, the syndrome is often included in the differential diagnosis of multiple sclerosis, stroke of the young adult, and another wide range of neurological disorders. The present review summarizes the neurological involvement in BS, and emphasizes recent clinical concepts and ethiopathogenetic findings.

RECENT FINDINGS

Over the last years the growing clinical and imaging evidence had suggested that neurological involvement in BS may be subclassified into two major forms: one, which is seen in the majority of patients, may be characterized as a vascular-inflammatory CNS disease, with focal or multifocal parenchymal involvement; the other, which has few symptoms and a better neurological prognosis, may be caused by isolated cerebral venous sinus thrombosis and intracranial hypertension. These two types rarely occur in the same individual, and their pathogenesis is likely to be different. A nonstructural vascular type headache is relatively common, whereas isolated behavioral syndromes and peripheral nervous system involvement are rare.

SUMMARY

The involvement of the nervous system in BS is heterogeneous as clinical and imaging data reveal. Currently it is unknown which factors determine or have a role in the development of neurological involvement, but some progress has been achieved in understanding the neurological spectrum of the syndrome, which may lead to a better management of these patients.

Review of the Chronology of Clinical Manifestations in 60 Patients with Behçet’s Disease

BACKGROUND

The natural course of Behçet's disease is not fully known.

OBJECTIVE

The aim of the present study was to determine the occurrence of the symptoms retrospectively in chronologic order in patients with Behçet's disease, diagnosed according to the criteria of the International Study Group for Behçet's Disease.

METHODS

A total of 60 consecutive patients (29 male and 31 female; aged 35.87 +/- 9.84 years) were involved in the study. The symptoms of the disease were retrospectively recorded in the time order of the manifestations per patient.

RESULTS

Oral ulcer was the most commonly observed onset manifestation (51 of 60 patients: 85%), followed by genital ulcer (13 of 60 patients: 21.7%) and articular symptoms (10 of 60 patients: 16.7%). The duration between the oral ulcer and the fulfillment of diagnostic criteria was calculated to be 3.77 +/- 4.43 years. The same duration was 2.50 +/- 4.74 and 2.11 +/- 3.44 years for genital ulcer and articular symptoms, respectively. The duration between the time point of fulfillment of diagnostic criteria and the diagnosis (2.83 +/- 2.3 years) was found to be longer in female patients (3.2 +/- 2.5 years). The duration was also longer in patients having only mucocutaneous lesions (3.18 +/- 2.5 years) than in patients having serious organ involvement such as eye disease (1.63 +/- 0.7 years; p < 0.05).

CONCLUSION

Our study indicates that oral ulcer is the onset manifestation in the majority of the patients and the disease is often diagnosed with a delay of several years after the appearance of the onset sign.

Pathogenesis of Adamantiades-Behçet's disease

The aetiology of Adamantiades-Behçet's disease remains unknown and its pathogenesis is not fully understood. Linked intrinsic and extrinsic factors are thought to contribute to the development of the disease, which probably occurs by environmental triggering of a genetically determined disorder. Transmission is solely vertical, indicating that the disease is not contagious. Genetic factors have been investigated and a significant link of HLA-B51, especially of HLA-B5101, has been identified. However, none of the functional correlates of the disease appear to be restricted by HLA-B51. Recently, the role of the genes encoding TNF, Tap proteins and MICA has been emphasised. Extrinsic pathogenetic candidates have been identified, including bacterial ( Streptococcus sanguis, Mycoplasma fermentas) and viral (human herpes virus) antigens and environmental pollution, which may cross-react with oral mucosal antigens and induce immunological mechanisms. A common factor linking some of the possible pathogenetic agents is extrinsically induced tissue stress or heat shock proteins, which react with host tissues and elicit significant Th1 cell responses. Neutrophils may also play a role in the pathogenesis of the disease, as they are attracted by macrophages and activated endothelial cells, which release cytokines and chemokines (especially IL-8) at the site of the lesions, and thus contribute to tissue damage and self maintenance of inflammation. Endothelial activation leading to a chronic local inflammation process together with platelet and serum factors enhance coagulation and thrombosis.