The histopathology of pathergy: a chronologic study of skin hyperreactivity in Behçet's disease

Fetal cardiac functional changes in pregnancies with Behcet's disease: A case-control study

BACKGROUND

Behcet's disease usually progresses with remission during pregnancy, but early subtle changes might be detected in the heart of these fetuses due to inflammation.

AIMS

We aimed to evaluate the cardiac functions in fetuses of pregnant women with Behcet's disease (BD).

STUDY DESIGN

Prospective case-control study.

SUBJECTS

This prospective study enrolled pregnant women diagnosed with Behcet's disease before pregnancy. Twenty-four pregnancies with Behcet's disease and 48 healthy pregnancies were included at 32-34 gestational weeks.

OUTCOME MEASURES

Pulsed-wave Doppler and tissue Doppler imaging (TDI) were used to assess cardiac functions.

RESULTS

Right ventricle (RV) E (early) wave and left ventricle (LV) E were significantly increased in pregnancies with BD (p = .008, p = .041, respectively). Decreased right ventricle E' (peak systolic velocity) was detected with TDI in the case group (6.2 ± 0.5, p < .001). E/E' ratios for RV and LV were significantly increased in the case group (p < .001, p = .001, respectively). The correlation between the duration of the disease and fetal cardiac functions was also evaluated. For RV, E (r = 0.735, p < .001), E' (r = -0.735, p < .001), E/E' (r = 0.894, p < .001), were strongly correlated with the disease duration. The study also showed the correlation between disease duration and LV E' (r = -0.735, p = .005), LV E (r = 0.750, p < .001), and LV E/E' (r = 0.820, p < .001).

CONCLUSION

This is the first study to evaluate the fetal cardiac functions in fetuses of pregnancies with BD. Although BD usually progresses with remission during pregnancy, early subclinical diastolic changes might occur in the heart of these fetuses due to inflammation.

Innate immune responses in Behçet disease and relapsing polychondritis

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

Neutrophil, NETs and Behçet's disease: A review

Behçet's disease (BD) is a chronic systemic vasculitis characterized by recurrent oral and genital ulcers, skin lesions, articular, neurological, vascular and sight-threatening ocular inflammation. BD is thought to share both autoimmune and autoinflammatory disease features. BD is triggered by environmental factors such as infectious agents in genetically predisposed subjects. Neutrophils seem to play an instrumental role in BD and recent works regarding the role of neutrophils extracellular traps (NETs) provides new insight in the pathophysiology of BD and the mechanisms involved in immune thrombosis. This review provides a recent overview on the role of neutrophils and NETs in the pathogenesis of BD.

Vascular complications of Behçet disease

Behçet disease is a multi-systemic complex vasculitis with unknown etiology characterized by different clinical involvements, including mucocutaneous, ocular, vascular, articular, neurological, and gastrointestinal manifestations. Growing evidence supports that different phenotypes, characterized by clusters of co-existing involvements, can be distinguished. Namely, the vascular phenotype identifies a specific group of patients who suffer from recurrent inflammatory thrombosis and arterial involvement. Vascular disease develops in up to 40% with a definite male preponderance and is usually an early manifestation. Venous involvement is significantly more common than arterial disease, and lower extremity deep vein thrombosis is its most frequent manifestation. Arterial disease involves mostly pulmonary arteries and aorta and manifests mainly in the form of aneurysms. Glucocorticoids and immunosuppressants are the recommended first-line treatments in vasculo-Behçet. Furthermore, controlled trials are still needed to assess the role of adding anticoagulation to the treatment regimen, with an accent on new oral anticoagulants. Treatment with anti-TNF alpha agents seems promising, but the management strategies are not clear yet.

Histopathological comparison of pathergy positive and negative areas of newly diagnosed Behçet patients

BACKGROUND

Behcet's disease is an inflammatory vasculitis, and pathergy reaction is a compulsory element of the diagnostic criteria. In the literature, there is no study comparing the histopathology of negative pathergy tests and positive pathergy tests in newly diagnosed Behcet's patients. The primary goal was to investigate the frequency of vasculitis, which is an important finding of Behcet's disease, in pathergy histopathology.

METHODS

The histopathology of patients with positive and negative pathergy tests revealed vasculitis or vasculopathy. In histopathology, neutrophils, lymphocytes, eosinophils, and mast cells in the perivascular area were counted and recorded as a percentage.

RESULTS

Of the 88 Behcet's patients who participated in the study, 45 were female and 43 were male. The rate of vasculitis in the histopathology of those who were positive for the pathergy test was not statistically different than those of those with negative pathergy tests (P = .14). In our study, although the relationship between the male gender and uveitis was significant at the border, and the relationship between pathergy positivity and uveitis was not found to be significant, a significant relationship was found between vasculitis in histopathology and uveitis (P = .023).

CONCLUSIONS

Based on the results of our study, we think that a pathergy test of histopathology will contribute to the clinical diagnostic evaluation in cases with suspicious clinical pathergy tests and especially in cases with negative pathergy tests.

Behçet syndrome

Behçet syndrome is a systemic vasculitis with an unknown aetiology affecting the small and large vessels of the venous and arterial systems. The presence of symptom clusters, regional differences in disease expression and similarities with, for example, Crohn's disease suggest that multiple pathological pathways are involved in Behçet syndrome. These disease features also make formulating disease criteria difficult. Genetic studies have identified HLA-B*51 as a genetic risk factor. However, the low prevalence of HLA-B*51 in many patients with bona fide disease, especially in non-endemic regions, suggests that other factors must also be operative in Behçet syndrome. Despite lacking a clear aetiological mechanism and definition, management of manifestations that include major vascular disease, eye disease and central nervous system involvement has improved with the help of new technology. Furthermore, even with our incomplete understanding of disease mechanisms, the prognoses of patients with Behçet syndrome, including those with eye disease, continue to improve. New treatment options and a better understanding of the underlying pathogenesis for various manifestations of this condition are required to further improve the management of the disease, which will improve patient quality of life.

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.

Pathergy Phenomenon

Skin pathergy reaction (SPR) is a hyperreactivity response to needle induced trauma which is characterized by a papule or pustule formation, 24-48 h after sterile-needle prick. It is affected by a wide array of factors, including the physical properties of the needles being used, number of pricks and disease related factors such as male gender, active disease. There is a great variation in reactivity among different populations with very low positivity rate in regions of low prevalence like Northern Europe, and higher prevalance mainly in communities living along the historical Silk Road, like Turkey, China and Middle Eastern countries. SPR is not constant during the disease course, has lost its sensitivity over decades and can be positive in various disorders including Sweet's syndrome, pyoderma gangrenosum, Crohn's diesease, A20 haploinsufficiency, deficiency of IL-1-receptor antagonist and few others. Nevertheless, it is a criteria included into many currently used diagnostic or classification criteria for Behçet's disease. Although, not being fully uncovered yet, available data points to the activation of both innate and adaptive immune system with an inflammatory response mediated by polymorphonuclears and T-cells. In addition to its utility in diagnosis of Behçet's Disease, SPR may serve as a model for investigating the inflammatory pathways involved in the etiopathogenesis of this complex disease.

Leukocyte toll-like receptor expression in pathergy positive and negative Behçet's disease patients

Objectives

To investigate whether the auto-inflammatory nature and the pathergic reaction in Behçet’s disease (BD) are driven by a disturbed toll-like receptor (TLR) response.

Methods

We compared both TLR expression by flow-cytometry and TLR response by stimulation assay in 18 BD patients (both pathergy positive and pathergy negative) with 15 healthy controls.

Results

Expression of TLR1 and 2 was significantly elevated in B-lymphocytes of BD patients compared with healthy controls. TLR1, 2 and 4 were significantly more highly expressed in both CD4⁺ and CD8⁺ T-lymphocytes of BD patients. Granulocytes of BD patients displayed significantly higher expression of TLR1, 2, 4 and 6. TLR2, 4 and 5 expression was significantly increased on classical monocytes of BD patients. Intermediate monocytes of BD patients showed an increase in expression of TLR2. Furthermore, TLR2 and 5 were significantly more highly expressed in non-classical monocytes of BD patients. In pathergy positive patients, TLR5 was even more highly expressed compared with pathergy negative patients on B- and T-lymphocytes and granulocytes. Furthermore, TLR2 and 5 showed an elevated TNF-α response to stimulation with their cognate ligands.

Conclusion

Immune cells of BD patients overexpress TLR1, 2, 4, 5 and 6. Furthermore, after stimulation of TLR2 and 5, BD patients demonstrate a more potent TNF-α response. Although this is a small cohort, in the pathergy positive patients, TLR5 expression is even further augmented, suggesting that a microbial (flagellin) or damage (HMGB1) associated signal may trigger the exaggerated immune response that is characteristic for the pathergy phenomenon in BD. In conclusion, these results point to an exaggerated TLR response in the auto-inflammatory nature of BD.

Vascular Behçet's syndrome: an update

Behçet's syndrome (BS) is a complex vasculitis, characterised by peculiar histological, pathogenetic and clinical features. Superficial venous thrombosis (SVT) and deep vein thrombosis (DVT) are the most frequent vascular involvements, affecting altogether 15-40% of BS patients. Atypical thrombosis is also an important clinical feature of BS, involving the vascular districts of the inferior and superior vena cava, suprahepatic veins with Budd-Chiari syndrome, portal vein, cerebral sinuses and right ventricle. On the other hand, arterial involvement, although affecting only 3-5% of patients, represents a unique feature of BS, with aneurysms potentially affecting peripheral, visceral and pulmonary arteries. Vascular events in BS are promoted by inflammation, with neutrophils playing a key role in the pathogenesis of thrombotic events; in turn, coagulative components such as fibrinogen, thrombin, factor Xa and factor VIIa amplify the inflammatory cascade. Understanding the contribution of inflammatory and coagulation components in the pathogenesis of BS vascular events is crucial to define the most effective therapeutic strategy. Control of vascular thrombosis is achieved with immunosuppressants drugs rather than anticoagulants. In particular, use of azathioprine and cyclosporine in association with low-dose corticosteroids should be considered in DVT and SVT cases, while treatment with cyclophosphamide together with anti-TNF-α agents can be effectively used in arterial involvement. More recently, the anti-TNF-α drugs have also been reported as a valid alternative for the treatment also of venous events, especially DVT. An exception to the use of anticoagulant in BS could be represented by cerebral veins thrombosis. In this review, we will depict the main characteristics of the vascular involvement in BS, briefly describing histological and pathogenetic features, while focusing on the clinical and therapeutical approaches of the vascular manifestations of BS.

Critical role of neutrophil extracellular traps (NETs) in patients with Behcet's disease

OBJECTIVES

Behçet's disease (BD) is a chronic systemic vasculitis. Thrombosis is a frequent and life-threatening complication. The pathogenesis of BD is poorly understood and evidence supporting a role for primed neutrophils in BD-associated thrombotic risk is scant. To respond to inflammatory insults, neutrophils release web-like structures, known as neutrophil extracellular traps (NETs), which are prothrombotic. We evaluated the role of NETs and markers of NETs in BD.

METHODS

Blood samples were collected from patients with BD, according to the International Study Group Criteria for Behçet's disease, and healthy donors (HD). NET components, including cell-free DNA (CfDNA) and neutrophil enzymes myeloperoxidase (MPO), were assessed in serum or in purified neutrophils from patients with BD and HD.

RESULTS

Patients with active BD had elevated serum cfDNA levels and MPO-DNA complexes compared with patients with inactive BD and to HD. In addition, levels of cfDNA and MPO-DNA complexes were significantly higher in patients with BD with vascular involvement compared with those without vascular symptoms. Purified neutrophils from patients with BD exhibited spontaneous NETosis compared with HD. Thrombin generation in BD plasma was significantly increased and positively correlated with the levels of MPO-DNA complexes and cfDNA. Importantly, DNAse treatment significantly decreased thrombin generation in BD plasma but not in HD plasma. In addition, biopsy materials obtained from patients with BD showed NETs production in areas of vasculitic inflammation and thrombosis.

CONCLUSIONS

Our data show that NETs and markers of NETS levels are elevated in patients with BD and contribute to the procoagulant state. Targeting NETs may represent a potential therapeutic target for the reduction or prevention of BD-associated thrombotic risk.

Behçet's syndrome as a tool to dissect the mechanisms of thrombo-inflammation: clinical and pathogenetic aspects

Behçet's syndrome (BS) is a complex disease with different organ involvement. The vascular one is the most intriguing, considering the existence of a specific group of patients suffering from recurrent vascular events involving the venous and, more rarely, the arterial vessels. Several clinical clues suggest the inflammatory nature of thrombosis in BS, especially of the venous involvement, thus BS is considered a model of inflammation-induced thrombosis. Unique among other inflammatory conditions, venous involvement (together with the arterial one) is currently treated with immunosuppressants, rather than with anti-coagulants. Although many in-vitro studies have suggested the different roles of the multiple players involved in clot formation, in-vivo models are crucial to study this process in a physiological context. At present, no clear mechanisms describing the pathophysiology of thrombo-inflammation in BS exist. Recently, we focused our attention on BS patients as a human in-vivo model of inflammation-induced thrombosis to investigate a new mechanism of clot formation. Indeed, fibrinogen displays a critical role not only in inflammatory processes, but also in clot formation, both in the fibrin network and in platelet aggregation. Reactive oxygen species (ROS)-derived modifications represent the main post-translational fibrinogen alterations responsible for structural and functional changes. Recent data have revealed that neutrophils (pivotal in the pathogenetic mechanisms leading to BS damage) promote fibrinogen oxidation and thrombus formation in BS. Altogether, these new findings may help understand the pathogenetic bases of inflammation-induced thrombosis and, more importantly, may suggest potential targets for innovative therapeutic approaches.

'MHC-I-opathy'-unified concept for spondyloarthritis and Behçet disease

The spondyloarthropathies comprise ankylosing spondylitis (AS), reactive arthritis, psoriatic arthritis (PsA) and arthritis associated with inflammatory bowel disease. In this Perspectives article, we describe how Behçet disease and several clinically distinct spondyloarthropathies-all associated with MHC class I (MHC-I) alleles such as HLA-B(*)51, HLA-C(*)0602 and HLA-B(*)27 and epistatic ERAP-1 interactions-have a shared immunopathogenetic basis. As a unifying concept, we propose that barrier dysfunction in environmentally exposed organs such as the skin, and aberrant innate immune reactions at sites of mechanical stress, can often trigger secondary adaptive immune CD8(+) T-cell responses with prominent neutrophilic inflammation that culminate in exacerbation and recurrence of these diseases. Of note, these 'MHC-I-opathies' show a differential immunopathology, probably reflecting antigenic differences within target tissues: HLA-B(*)51 is linked to ocular and mucocutaneous disease but not gut involvement, and HLA-C(*)0602 is linked to type I psoriasis but not scalp or nail disease.

Histopathologic Study of Pathergy Test in Behçet's Disease

Background:

The pathergy test (PT) is important in the diagnosis of Behçet's disease (BD). However, misinterpretation of the test might cause false-positive or false-negative results. Therefore, immunopathologic and histopathologic tests are recommended with PT.

Aims and Objectives:

The aim of this study is to determine histopathologic findings of positive pathergy reaction at BD.

Materials and Methods:

This study was performed on 23 patients with BD. All patients were in active period of the disease. After 48 h from the injection, biopsy was performed on positive pathergy lesions.

Results:

Of the specimen from positive PT lesions of patients with BD, nine revealed mixed type inflammatory cell infiltration (39.1%), two revealed lobular panniculitis without vasculitis (8.7%), two revealed neutrophil rich infiltration (8.7%), and five revealed lymphocyte rich infiltration (21.7%) at the subcutaneous tissue. Mixed type inflammatory cell infiltration (43.4%), endothelial swelling and thickening (17.3%), erythrocyte extravasation (26.0%), perivascular cell infiltration (13.0%), lymphocytic vascular reaction (8.6%), lymphocytic vasculitis (13.0%), and leukocytoclastic vasculitis (21.7%) were detected in dermis by histopathologic examinations. There was no statistically significant difference between histopathologic findings and sex, family history, and systemic involvement except uveitis.

Conclusion:

This is an exceptional study since it is the first study that determines subcutaneous tissue findings of positive pathergy reaction in Behçet patients. In our study, uveitis was found to be statistically significant in the patients who had vasculitis in dermis. It can be a clue for prediction of disease severity and course. Further, studies that include wide number of patients will better illuminate the correlation between subcutaneous tissue findings and disease severity and clinical course.

WITHDRAWN: Neutrophil activation in Behçet's Disease

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.intimp.2013.07.017. The duplicate article has therefore been withdrawn.

Histopathological Evaluation of Behçet's Disease and Identification of New Skin Lesions

Behçet's disease (BD) is a multisystemic, relapsing inflammatory disorder with an obscure etiology and pathogenesis. Diagnosis depends on the clinician's ability to identify a group of nonspecific mucocutaneous lesions, which also manifest in a number of other diseases. In recent years, there has been an increase in the studies focusing on the histopathological aspects of Behçet's disease diagnostic mucocutaneous lesions. Their results emphasize the value of histopathology and direct immunofluorescence (DIF) in the differential diagnosis of Behçet's disease.

CXC chemokine expression profiles in aqueous humor of patients with different clinical entities of endogenous uveitis

Aqueous humor (AH) samples from patients with Behçet's disease (BD) (n=29), Vogt-Koyanagi-Harada (VKH) disease (n=21), and HLA-B27-associated uveitis (n=8), and 42 control patients were assayed for the neutrophil chemoattractants CXCL1/GRO-α and CXCL8/IL-8 and the lymphocyte chemoattractants CXCL9/MIG, CXCL10/IP-10 and CXCL12/SDF-1 with the use of a multiplex chemokine assay. Chemokine levels except SDF-1 were significantly higher in the 3 disease groups than in normal controls. Considering all patients, mean GRO-α levels were 15-fold higher than IL-8 levels and mean IP-10 levels were 22-fold higher than MIG levels. In patients with the same disease activity, AH levels of GRO-α and IP-10 were significantly higher in patients with BD than in patients with VKH disease and HLA-B27-associated uveitis (p=0.0474; p<0.001, respectively). These data suggest that GRO-α and IP-10 are the predominant CXC chemokines involved in neutrophil and activated T lymphocyte chemoattraction in endogenous uveitis, particularly in BD.

The skin pathergy test: innately useful?

Pathergy is the term used to describe hyper-reactivity of the skin that occurs in response to minimal trauma. A positive skin pathergy test (SPT), characterised by erythematous induration at the site of the needle stick with a small pustule containing sterile pus at its centre, is among the criteria required for a diagnosis of Behçet's disease (BD) and in certain population has been shown to be highly specific for this condition. Problems with standardising the induction manoeuvre for the SPT as well as the method of assessment of the response have limited the usefulness of the SPT in the clinical setting. Extensive investigation into histopathological and immunological aspects of pathergy has led to a number of hypotheses relating to the aetiology of the skin pathergy reaction and the disease itself, but the cause is considered to be unknown. Pathergy lesions, the development of new skin lesions or the aggravation of existing ones following trivial trauma, are also reported in pyoderma gangrenosum and has been noted in other neutrophilic dermatoses such as Sweet's syndrome. The response of such patient groups to the systematic application of the SPT has not been described. We propose that a new way of considering the pathergy reaction is to see it as an aberration of the skin's innate reactivity from a homeostatic reactive mode closely coupled to tissue healing to an abnormal destructive/inflammatory mode. Our understanding of BD and other similar conditions would profit by more detailed mechanistic knowledge of skin homeostasis to minimal trauma in both health and disease through a more structured and systematic use of the SPT.

Patient characteristics in Behçet disease: a retrospective analysis of 213 Turkish patients during 2001-4

BACKGROUND

Behçet disease (BD) is a chronic, inflammatory, multisystemic vasculitic disorder with a wide spectrum of clinical presentations. The highest prevalence is seen in Turkey. Specific diagnostic tools are yet to be discovered; thus, the diagnosis relies on physicians being acquainted with the symptoms and signs of the disease.

OBJECTIVE

To investigate the epidemiologic characteristics of BD and to emphasize the typical clinical and laboratory characteristics.

METHODS

This was a retrospective analysis of all the BD patients attending the Ankara Numune Education and Research Hospital throughout the years 2001-4. Diagnosis of BD was made according to the International Study Group criteria. A total of 213 patients were evaluated with respect to family history, clinical features, pathergy test, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), antistreptolysin O, and ferritin levels. When assessing disease activity, the active clinical manifestations on the day of the examination were taken into account. Correlations were analyzed between sex and age distribution, age of onset, disease duration, and family history; and between family history and age of onset, pathergy, clinical manifestations, and laboratory parameters. Correlations were also evaluated between pathergy positivity and clinical manifestations, and laboratory parameters. Correlations between activity scores and age of onset, duration, sex, family history, and laboratory data were also analyzed.

RESULTS

The female : male ratio was 1.04, and the mean age of onset was 27 years. Family history did not affect age of onset or disease severity. Men presented with more active disease, and there was a weak but positive correlation between disease activity and CRP. No correlation was observed between duration and age of disease onset. The most common clinical presentations were oral aphthous lesions, genital ulcers, and skin lesions. Men more commonly presented with papulopustular lesions, pathergy positivity, and vascular, eye, and renal involvement, and women presented with arthritis/arthralgia more commonly than men. Vascular lesions, ESR, and CRP showed significant relationships with pathergy reaction. Eye involvement was not affected by age of onset.

CONCLUSIONS

We believe our results indicate that the pathogenesis of BD is multifactorial. Hormonal factors seem to be of some influence, while genetic background and environmental factors seem to be the major contributors. Infections seem to be among the triggering environmental factors. Predisposing genes may affect the influence of environmental factors. Prevalence studies should be carried out periodically in those countries with a high prevalence of BD to keep up with the changing dynamics of the disease, which may also shed light on the as-yet unknown pathogenesis of BD.

Comparison of argon laser photocoagulation-induced cutaneous inflammation and skin pathergy test in Behçet's disease

Nonspecific increased inflammatory response is an important feature of Behçet's disease (BD). The skin pathergy reaction (SPR) which tests this hyperreactivity in the skin is frequently used as a diagnostic tool. This study aims to investigate the argon laser photocoagulation (ALP)-induced cutaneous inflammation in BD patients and controls and also to compare the results with the skin pathergy test (SPT). The study group consisted of 35 patients with BD and 28 healthy volunteers. The ALP was applied to the left forearms of all cases from 20-cm distance (2,000 mW, 100 microm) with exposure times ranging from 0.2 to 0.7 s with 0.1-s increments. Also, a SPT with three prics was performed to both forearms of all cases. The ALP-induced cutaneous inflammation and SPT were evaluated and scored with the same method at 48 h, and the SPR scores of 2+ and above was accepted as positive. Positive results as defined above were found in eight cases (23%) with the ALP and in nine (26%) with the SPT in patients with BD. There was no clear correlation between the ALP and SPT results and also between the exposure time to laser beam and SPR scores. The preliminary results of this study reveal that ALP can induce a skin hyperreactivity similar to the needle prick-induced SPR in patients with BD. We, herein, showed that ALP can induce skin inflammation with its thermal effect and without any inoculation of antigen in BD. This method would help to develop another experimental method to investigate the cutaneous inflammation in BD.

Killer cell immunoglobulin-like receptor genotypes in Behçet's disease patients: any role for the 3DP1*001/002 pseudogene?

AIMS

Genotypic profiles of the natural killer cell immunoglobulin-like receptors (KIR) have been reported to vary among different ethnic groups and variable clinical entities. This study represents the second report on its distribution among patients with Behçet's disease (BD). We studied 43 unrelated Lebanese Behçet's patients, had their DNA typed using sequence-specific primer technique for the presence of 16 KIR genes and pseudogenes loci, and compared them to the general Lebanese population.

RESULTS

In addition to sharing common features with the general population, the AA genotype was still the most frequent--however, with five new KIR profiles identified. There was no statistically significant distribution of the different KIR genes between the cases (BD patients) and controls (Lebanese population); however, KIR3DP1*001/002 was found to be significantly different between the BD patients and the Lebanese population, but this significance was lost after correction for all KIR loci.

CONCLUSION

The results lead to an interesting future research question of whether or not KIR genotype is involved in the predisposition to or pathogenesis of BD especially that a pseudogene is controversially in question. This is the second report that describes the KIR genotypic profile in such an important clinical disease but the first to shed a light on the possible role of a pseudogene.

Do synovial biopsies help to support evidence for involvement of innate immunity in the immunopathology of Behçet's disease?

Behçet's disease is a complex vasculitis of unknown etiology. Abundant neutrophils suggest the involvement of innate immunity. Cytokines are skewed to the T-helper-1 pattern. Few sterile organs are easily accessible for analysis in Behçet's disease. Cañete and coworkers identify inflamed joints as a feasible model and suggest the involvement of innate immunity in Behçet's disease.

Distinct synovial immunopathology in Behçet disease and psoriatic arthritis

INTRODUCTION

The aim of the study was to investigate synovial immunopathology differences between early Behçet disease (BD) and psoriatic arthritis (PsA).

METHODS

Needle arthroscopy of an inflamed knee joint was performed in patients with early untreated BD (n = 8) and PsA (n = 9). Synovial fluid (SF) was collected for cytokines, perforin, and granzyme analysis. Eight synovial biopsies per patient were obtained for immunohistochemical analysis of the cellular infiltrate (T cells, natural killer cells, macrophages, B cells, plasma cells, mast cells, and neutrophils), blood vessels as well as expression of perforin and granzyme. The stained slides were evaluated by digital image analysis.

RESULTS

The global degree of synovial inflammation was similar in the two types of arthritis. In the analysis of the innate immune cell infiltration, there was a striking neutrophilic inflammation in BD synovitis whereas PsA displayed significantly higher numbers of cells positive for c-kit, a marker of mast cells. As for lymphocytes, CD3+ T cells, but neither CD20+ B cells nor CD138+ plasma cells, were significantly increased in BD versus PsA. Further analysis of the T-lymphocyte population showed no clear shift in CD4/CD8 ratio or Th1/Th2/Th17 profile. The SF levels of perforin, an effector molecule of cytotoxic cells, displayed a significant four- to fivefold increase in BD.

CONCLUSIONS

This systematic comparative analysis of early untreated synovitis identifies neutrophils and T lymphocytes as important infiltrating cell populations in BD. Increased levels of perforin in BD suggest the relevance of cytotoxicity in this disease.

An incidental enterocolic lymphocytic phlebitis pattern is seen commonly in the rectal stump of patients with diversion colitis superimposed on inflammatory bowel disease

Aims:

Enterocolic lymphocytic phlebitis (ELP) is an uncommon cause of bowel pathology and most frequently results in ischaemia. It is characterised by an artery-sparing, venulocentric lymphoid infiltrate that causes a phlebitis and vascular compromise. Rare cases of ELP have been encountered with lymphocytic colitis in the absence of ischaemic bowel change. The present study examined the occurrence of ELP in the setting of diversion colitis and inflammatory bowel disease, as well as in random colectomy specimens.

Methods:

The study cohort comprised the following: 26 completion proctectomy specimens for ulcerative colitis with superimposed diversion colitis in the rectal stump; 3 colectomy specimens for Crohn disease with diversion colitis; 6 colectomy specimens for adenocarcinoma and/or diverticular disease with diversion colitis; 34 resection specimens with ulcerative colitis only; 19 with Crohn disease only; and 100 random colon resection specimens for adenocarcinoma, adenoma, diverticular disease and ischaemia.

Results:

ELP was present in 18 of the 26 ulcerative colitis cases with diversion colitis, 3/3 Crohn disease cases with diversion colitis, 1/6 cases of diverticular disease with diversion colitis, 6/34 cases of ulcerative colitis without diversion, 2/19 Crohn disease cases without diversion colitis, and only 1 of 100 colectomy cases without inflammatory bowel disease or diversion colitis.

Conclusion:

ELP occurs most frequently in cases that have been diverted for inflammatory bowel disease. Fewer cases of ELP were noted in cases of inflammatory bowel disease in the absence of diversion colitis. It is postulated that altered bowel flora and immune dysregulation may be pivotal in the causation of this association.

Neutrophilic dermatoses in children

The neutrophilic dermatoses are rare disorders, especially in children, and are characterized by neutrophilic infiltrates in the skin and less commonly in extracutaneous tissue. The neutrophilic dermatoses share similar clinical appearances and associated conditions, including inflammatory bowel disease, malignancies, and medications. Overlap forms of disease demonstrating features of multiple neutrophilic dermatoses may be seen. The manuscript attempts to provide an up-to-date review of (i) classical neutrophilic dermatoses, focusing on distinctive features in children and (ii) neutrophilic dermatoses which may largely be pediatric or genodermatosis-associated (Majeed, SAPHO [synovitis, severe acne, sterile palmoplantar pustulosis, hyperostosis, and osteitis] syndrome, PAPA (pyogenic sterile arthritis, pyoderma gangrenosum, and acne), PFAPA (periodic fever with aphthous stomatitis, pharyngitis, and cervical adenopathy), and other periodic fever syndromes, and congenital erosive and vesicular dermatosis healing with reticulated supple scarring).

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.

Mucocutaneous lesions of Behcet's disease

Behcet's disease is particularly prevalent in "Silk Route" populations, but it has a global distribution. The diagnosis of the disease is based on clinical criteria as there is as yet no pathognomonic test, and mucocutaneous lesions, which figure prominently in the presentation and diagnosis, may be considered the diagnostic hallmarks. Among the internationally accepted criteria, painful oral and genital ulcers, cutaneous vasculitic lesions and reactivity of the skin to needle prick or injection (the pathergy reaction) are considered hallmarks of Behcet's disease, and often precede other manifestations. Their recognition may permit earlier diagnosis and treatment, with salutary results. This paper describes the various lesions that constitute the syndrome and focuses on those that may be considered characteristic.

Dermatologic signs

BACKGROUND

Dermatology signs serve as important clues to primary skin disorders and internal conditions.

OBJECTIVE AND METHODS

To highlight major cutaneous signs based on a MEDLINE literature search from 1966 to March 2006.

RESULTS AND CONCLUSIONS

A multitude of signs exist in dermatology. Appreciation and knowledge of cutaneous signs will enhance the care of patients with dermatologic manifestations.

Negative evaluation of a pathergy test in hepatitis B surface antigen carriers

The different cutaneous manifestations of hepatitis B virus infection have been described in different studies. We proposed to evaluate the frequency of skin pathergy positivity in hepatitis B surface antigen carriers. The study group consisted of 92 hepatitis B surface antigen carriers and 76 healthy individuals as a control group. The pathergy test was applied intradermally to both forearms of the patients and the control subjects. The results of the pathergy test were evaluated. Papule or pustule formation was noted as positive. Four and one of the 92 hepatitis patients and 76 control subjects, respectively, were positive for the pathergy reaction. Evidently, this pathergy test that shows non-specific skin hyper-reactivity cannot be used as a clinical marker to indicate hepatitis B surface antigen carriers. The test cannot be used to predict the cutaneous manifestations of hepatitis B infection either.

Behçet's disease: from Hippocrates to the third millennium

Behçet's disease (BD) is characterised by recurrent episodes of orogenital aphthae, systemic vasculitis, and systemic and retinal venous thrombosis. An association between HLA-B51 and BD was first identified over 20 years ago, but recently identified gene associations implicate regions both within and without the MHC in the immunological events underlying the lesions in BD. These include allelic variants within the tumour necrosis factor gene region and within the MHC class I chain related gene region, the factor V Leiden mutation, which is associated with retinal vascular occlusion, and alleles of the intercellular adhesion molecule gene. No single causative gene for BD has emerged; the evidence indicates that the underlying immune events in BD are triggered by a microbial antigen and subsequently driven by genetic influences which control leucocyte behaviour and the coagulation pathways. Knowledge of these risk factors may permit a more accurate prognosis for a given patient, and identify new pathways for more targeted intervention than is currently available.

Behçet's disease

Behçet's disease is characterized by recurrent aphthous stomatitis, uveitis, genital ulcers, and skin lesions. The role of the HLA-B*51 gene has been confirmed in recent years, although its contribution to the overall genetic susceptibility to Behçet's disease was estimated to be only 19%. The production of a variety of cytokines by T cells activated with multiple antigens has been shown to play a pivotal role in the activation of neutrophils. As regards the treatment, anti-tumor necrosis factor alpha therapy has been shown to be effective for mucocutaneous symptoms as well as for sight-threatening panuveitis, although a randomized, controlled trial is required.

Identification of alpha-tropomyosin as a target self-antigen in Behçet's syndrome

Behçet's syndrome is a multi-system inflammatory disease affecting mainly the oral and urogenital mucosa and the uveal tract. The etiology and pathogenesis of Behçet's syndrome are unknown, but autoimmune mechanisms are implicated. We initiated this work to identify self-antigens targeted by patients with Behçet's syndrome. We used patient sera to immuno-blot tissue lysates, and we found that some patients manifest antibodies to a 37-kDa band. The 37-kDa band was detected in extracts of skin, tongue, vagina, muscle and heart but not in brain, kidney, lung, liver, intestine and thymus. In-gel digestion and mass spectrometry revealed the band to be alpha-tropomyosin. Autoimmunity to alpha-tropomyosin can be pathogenic; immunized Lewis rats developed lesions in the uveal tract and skin, with features of Behçet's disease.

Anti-MHC autoimmunity in Behçet's disease: T cell responses to an HLA-B-derived peptide cross-reactive with retinal-S antigen in patients with uveitis

Immune response to retinal autoantigens plays a central role in the pathogenesis of uveitis. A synthetic peptide (B27PD) from a common sequence of various HLA-B molecules associated with uveitis, such as HLA-B27 and 51, which shares amino acid homologies with a retinal-S antigen (S-Ag)-derived peptide (PDSAg), was shown to be immunogenic in human and experimental uveitis in the rat. In this study we investigated T cell responses to B27PD and PDSAg in patients with Behçet's disease and posterior uveitis (BD-posterior uveitis; n = 33) in comparison with non-Behçet anterior uveitis (AU, n = 14), Behçet's patients without uveitis (BD, n = 15) and healthy controls (HC, n = 32) in a 6-day proliferation assay. Patients with BD and posterior uveitis had significantly higher responses (stimulation index (SI) 2.8 +/- 1.3) than those with AU (SI 1.5 +/- 0.4), BD without uveitis (SI 1.1 +/- 0.4) and HC (SI 1.1 +/- 0.6) for B27PD (P < 0.0001). Responses to PDSAg were also higher in BD with posterior uveitis patients (SI 3.3 +/- 1.6) than AU (SI 1.5 +/- 0.4), BD without uveitis (SI 1.2 +/- 0.3) and HC (SI 1.1 +/- 0.6) (P < 0. 0001). A significant correlation between the responses to PDSAg and B27PD (r = 0.56, P < 0.001) was observed. Elevated levels of IL-2 and tumour necrosis factor-alpha were also observed in culture supernatants obtained from peripheral blood mononuclear cells after stimulation with the peptides, but no correlation was found between the proliferative responses and cytokine levels. These results suggest that cellular immunity to cross-reactive HLA-B and S-Ag-derived peptides might play a role in the pathogenesis of posterior uveitis in BD.

Oligoclonal T cell expansions in patients with Behçet's disease

Behçet's disease (BD) is a multisystem disorder with oral and genital ulcers, mucocutaneous, ocular, joint, vascular and central nervous system involvement. In this study, the peripheral T cell repertoire was analysed in patients with BD with MoAbs against T cell receptor (TCR) Vbeta gene products in CD4+ and CD8+ T cell compartments, and these were compared with rheumatoid arthritis (RA) patients and healthy controls (HC). In the CD4+ T cell compartment, oligoclonal TCR Vbeta expression was observed in 56% of BD (10/18), 71% of RA (5/7) patients and 21% (3/14) of HC. In the CD8+ T cell group 50% of BD (9/18), 57% of RA patients and 28% of HC (4/14) had an oligoclonal TCR repertoire. An increase of TCR Vbeta5.1 subset was observed in five BD patients among CD8+ T cells. Other elevations of TCR Vbeta subsets were heterogeneously distributed with one to three different Vbeta subsets. Our results suggest an antigen-driven oligoclonal increase of T cells in BD. There was no overall increase in any Vbeta group to suggest a superantigen effect. Analysis of the responsible antigens causing the increase in T cell subsets may give insights into the aetiopathogenesis of BD and immunomodulation of these T cells may lead to new treatments.