Acometimento vascular na doença de Behçet: o processo imunopatológico / Vascular involvement in Behçet's disease: the immunopathological process

Resumo A doença de Behçet constitui uma forma rara de vasculite sistêmica, que acomete de pequenos a grandes vasos. É caracterizada por manifestações mucocutâneas, pulmonares, cardiovasculares, gastrointestinais e neurológicas. Sua apresentação clínica é bastante ampla, variando de casos mais brandos a casos graves, com acometimento multissistêmico, caracteristicamente com exacerbações e remissões. Suas causas ainda são desconhecidas; entretanto, há evidências genéticas, ambientais e imunológicas, como a associação com o alelo HLA-B51. Todas essas, em conjunto, apontam para um processo imunopatológico anormal, com ativação de células da imunidade inata e adaptativa, como as células natural killer, neutrófilos e células T, que geram padrões de respostas e citocinas específicos capazes de gerar mediadores que podem lesionar e inflamar o sistema vascular, resultando em oclusões venosas, arteriais e/ou formação de aneurismas.

Abstract Behçet's disease is a rare form of systemic vasculitis that affects small to large vessels. It is characterized by mucocutaneous, pulmonary, cardiovascular, gastrointestinal, and neurological manifestations. Its clinical presentation is quite wide, ranging from milder cases to severe cases, with multisystemic involvement, characteristically with exacerbations and remissions. Its etiopathogenesis is still unclear, although there is evidence of genetic, environmental, and immunological factors, such as the association with the HLA-B51 allele. In conjunction, all of these point to an abnormal immunopathological process, with activation of cells of innate and adaptive immunity, such as NK cells, neutrophils, and T cells, which generate specific response patterns and cytokines capable of generating mediators that can damage and inflame blood vessels, resulting in venous and arterial occlusions and/or aneurysm formation.

Subpopulations of Regulatory T Cells in Rheumatoid Arthritis, Systemic Lupus Erythematosus, and Behcet's Disease

Recently, subpopulations of regulatory T (Treg) cells, resting Treg (rTreg) and activated Treg (aTreg), have been discovered. The authors investigated the relationship between the change of Treg, aTreg and rTreg and autoimmune diseases. Treg cells and those subpopulations were analyzed by using the human regulatory T cell staining kit and CD45RA surface marker for 42 rheumatoid arthritis (RA), 13 systemic lupus sclerosis (SLE), 7 Behcet's disease (BD), and 22 healthy controls. The proportion of Treg cells was significantly lower in RA (3.8% +/- 1.0%) (P < 0.001) and BD (3.3% +/- 0.5%) (P < 0.01) compared to healthy controls (5.0% +/- 1.3%). The proportion of aTreg cells was also significantly lower in RA (0.4% +/- 0.2%) (P = 0.008) and BD (0.3% +/- 0.1%) (P = 0.013) compared to healthy controls (0.6% +/- 0.3%). The rTreg cells showed no significant differences. The ratio of aTreg to rTreg was lower in RA patients (0.4% +/- 0.2%) than that in healthy controls (0.7% +/- 0.4%) (P = 0.002). This study suggests that the decrement of aTreg not rTreg cells contributes the decrement of total Treg cells in peripheral blood of RA and BD autoimmune diseases. Detailed analysis of Treg subpopulations would be more informative than total Treg cells in investigating mechanism of autoimmune disease.

Serum Anti-Saccharomyces Cerevisiae Antibodies in Greek Patients with Behcet's Disease

We tested 59 Greek patients with Behcet's Disease (BD) for serum anti-Saccharomyces cerevisiae antibodies. No increase of these antibodies was detected in the cases compared to 55 healthy unrelated blood donors from the same population. This finding is in contrast with the correlation between Saccharomyces cerevisiae antibodies and BD as reported in other populations. It seems that environmental factors may contribute to disease expression in different populations, producing different effects according to the individual's genetic predisposition. Saccharomyces cerevisiae antibodies do not seem to be of any significance in the Greek population.

Anti-endothelial cell antibodies and central nervous system involvement in Behçet's disease

INTRODUCTION: Previous studies have detected the presence of anti-endothelial cell antibodies (AECA) in patients with Behçet's disease (BD). However, no real evidence exists whether these antibodies exert any influence on clinical presentation and/or activity of this disease. OBJECTIVES: To determine the frequency of AECA in patients with BD and analyze possible clinical associations. METHODS: 50 patients with BD who fulfilled diagnostic criteria were selected. Thirty-seven patients were females, and 13 were males; the mean age was 44 ± 9 years with a mean follow-up time of 10 ± 7.5 years. AECA were assayed by ELISA using ECV-304 cells as the antigenic substrate. The prevalence of AECA was determined, and their possible relationships with present and past clinical features were investigated. RESULTS: AECA were detected in the sera of 38 percent of the patients (IgG in 13, IgM in four, and IgG plus IgM in two). An association was observed between AECA and a previous history of central nervous system involvement (OR= 5.4, p= 0.03). This association was more evident for IgG-AECA (OR= 6.0, p= 0.02). A trend of an increased risk of aneurysms was also observed in patients with IgG-AECA (OR= 2.58, p= 0.77). None of the other clinical characteristics showed a relevant association with these antibodies. CONCLUSION: Our data suggest that IgG-AECA may be a marker of more severe lesions in patients with BD based on the higher frequency of previous central nervous system manifestations in patients who presently display circulating AECA.

INTRODUÇÃO: Estudos anteriores detectaram a presence de anticorpos anti-célula endotelial (AACE) em pacientes com doença de Behçet, porém não há nenhuma evidência se a presença destes anticorpos exerce alguma influência na apresentação clínica ou atividade da doença. OBJETIVOS: Determinar a freqüência de AACE em pacientes com doença de Behçet e analisar possíveis associações clínicas. MÉTODOS: Foram selecionados 50 pacientes que preencheram corretamente os critérios diagnósticos para a doença de Behçet. Trinta e sete pacientes eram do sexo feminino e 13 do sexo masculino, média de idade de 44 ± 9 anos e tempo médio de seguimento de 10 ± 7,5 anos. O AACE foram analisados por ELISA utilizando células ECV-304 como substrato antigênico. A prevalência de AACE foi determinada e foram investigadas possíveis relações com características clínicas atuais e pregressas. RESULTADOS: Os AACE foram detectados no soro de 38 por cento dos pacientes (13 na forma IgG, 4 IgM e 2 nas formas IgG e IgM). Observamos uma associação entre o AACE e história pregressa de envolvimento de sistema nervoso central (OR=5,4; p=0,03). Esta associação era mais evidente para o AACE na forma IgG (OR=6,0; p=0,02). Observamos também uma tendência de risco aumentado de aneurismas em pacientes com AACE na forma IgG (OR=2,58; p=0,77). Nenhuma outra característica clínica mostrou-se relevante com o anticorpo estudado. CONCLUSÃO: Nossos dados sugerem que o AACE na forma IgG pode ser uma marcador de lesão mais grave em pacientes com doença de Behçet baseado no fato de encontrarmos uma maior freqüência de história pregressa de manifestação de sistema nervoso central em pacientes com AACE circulante.

Mimetisme moleculaire entre l'antigene-s et les peptides viraux

Experimental autoimmune uveitis [EAU], was induced in Lewis rats after injection of S- Antigen [S-Ag]. In this study we found an amino acid sequence homology between a uveitopathogenic site of S-Ag and two viral proteins. Based on our findings, we conclude that a viral infection may sensitize the mononuclear cells that can cross- react with self proteins by a mechanism termed molecular mimicry

Behcet's disease sera containing antiendothelial cell antibodies promote adhesion of T lymphocytes to cultured human dermal microvascular endothelial cells

Antiendothelial cell antibodies (AECA) have been detected in the sera of patients of autoimmune diseases showing vasculitis. Using IgM-ELISA, we found AECA in 42 (56%) of 75 sera samples from patients with Behcet's disease in a previous study. All of the 15 AECA-positive sera of Behcet's disease patients had an increased expression of the intercellular cell adhesion molecule-1 (ICAM-1), 93.3% of the sera induced the vascular cell adhesion molecule-1 (VCAM-1), and 100% of the serum induced the E-selectin molecule on human dermal microvascular endothelial cells (HDMEC). After stimulation of HDMEC with AECA-positive sera of Behcet's disease patients, the expression of ICAM-1 and VCAM-1 on HDMEC increased significantly at 4 hours, reaching a peak at 16 hours. Expression of E-selectin was induced at 1 hour after stimulation with a peak at 4 hours and it decreased thereafter. Adherence of T lymphocytes to HDMEC increased significantly after stimulation with AECA-positive sera from Behcet's disease patients. Also, the adherence of T lymphocytes to HDMEC increased at 4 hours and returned to its normal level at 48 hours. These results show that AECA-positive sera of Behcet's disease patients are capable of activating HDMEC to promote the adherence of T lymphocytes to increase the expression of ICAM-1, VCAM-1, and E-selectin on the cell surfaces. The whole process may play an important role in the pathogenesis of vasculitis in Behcet's disease.

Etiopathology of Behcet's disease: immunological aspects

Behcet's disease is recognized as a systemic inflammatory disease of unknown etiology. The disease has a chronic course with periodic exacerbations and progressive deterioration. Previous reports have shown at least three major pathophysiologic changes in Behcet's disease; excessive functions of neutrophils, vasculitis with endothelial injuries, and autoimmune responses. Many reports suggested that immunological abnormalities and neutrophil hyperfunction may be involved in the etiology and the pathophysiology of this disease. HLA-B51 molecules by themselves may be responsible, in part, for neutrophil hyperfunction in Behcet's disease. T cells in this disease proliferated vigorously in response to a specific peptide of human heat shock protein (hsp) 60 in an antigen-specific fashion. T cells reactive with self-peptides produced Th1-like proinflammatory and/or inflammatory cytokines. This leads to tissue injury, possibly via delayed-type hypersensitivity reaction, macrophage activation, and activation and/or recruitment of neutrophils. These data shed new light on the autoimmune nature of Behcet's disease; molecular mimicry mechanisms may induce and/or exacerbate Behcet's disease by bacterial antigens that have activated T cells which are reactive with self-peptide(s) of hsp. This would lead to positive selection of autoreactive T cells in this disease.

Streptococcal infection in the pathogenesis of Behcet's disease and clinical effects of minocycline on the disease symptoms

Although the precise pathoetiology of Behcet's disease (BD) remains obscure, patients with BD have a high incidence of chronic infectious foci, indicating an enhanced susceptibility to chronic tonsillitis, and dental caries. Sometimes, clinical symptoms appear after treatment of these foci in BD patients. It is believed that BD might be related to an allergic reaction to a bacterial infection in view of the many clinical symptoms, especially the presence of aphthous and genital ulcerations. An attempt to obtain cutaneous responses to bacterial antigens has been carried out using various vaccines developed from bacteria isolated from the ulcerative lesions and oral cavities of BD patients. BD patients often show intense hypersensitivity to various strains of streptococci, not only by their cutaneous reactions but also by in vitro testing. In this report, we describe our previous studies on the correlation between streptococcal antigens and the pathogenesis of BD and also discuss the recent reports of other authors. The intense hypersensitivity to streptococcal antigens acquired after streptococcal infection is thought to play an important role in the appearance of symptoms in BD patients since the production of pro-inflammatory cytokines by peripheral blood mononuclear cells (PBMC) was enhanced when stimulated with streptococcal antigen in a culture system. Minocycline, an antibiotic to which certain strains of streptococci are sensitive, reduced the frequency of clinical symptoms in BD patients as well as the production of pro-inflammatory cytokines by BD-PBMC stimulated with streptococcal antigen.

Quantificaçäo da interferência do soro na fagocitose de imunocomplexos nas espondiloartropatias soronegativas, lúpus eritematoso sistêmico e doença reumatóide / Quantification of serum interference in the immune complexes phagocytosis in seronegative spondylarthropaties, systemic lupus erythematosus and rheumatoid disease

Cinqüenta e cinco soros de pacientes portadores de espondiloartropatias soronegativas, lúpus eritematoso sistêmico e artrite reumatóide foram selecionados para o estudo. Todos os soros mostravam fator reumatóide negativo pela prova de látex. A determinaçäo da interferência na fagocitose de gamaglobulina agregada por macrófagos de cobaia foi obtida por uma fórmula. A caracterizaçäo dos soros foi discriminada pela reaçäo daqueles que mostraram resultados mais expressivos na interferência sobre a fagocitose, facilitando ou inibindo-a. Os resultados, em valores absolutos e percentuais, mostraram a predominância do fenômeno da interferência na fagocitose, com valores significantes estatisticamente (p<0,05), quando comparado com soro normal. A análise comparativa entre as doenças estudadas na quantificaçäo da interferência do soro na fagocitose de imunocomplexo näo mostrou diferença significativa. A inibiçäo da fagocitose ocorreu com mais predominância no soro de pacientes com síndrome de Reiter e artrite psoriática; no soro de pacientes com síndrome de Reiter houve uma diferença estatisticamente significante na inibiçäo da fagocitose (p=0,0247). A caracterizaçäo da fraçäo sérica responsável pela interferência na fagocitose näo foi demonstrada. No estado atual dos conhecimentos, näo há uniformidade nas curvas de diluiçäo estudadas. É enfatizada a possibilidade de existência de mais de um elemento interferindo na fagocitose de imunocomplexos.

Doença de Behçet: análise de seis casos / Behçet's disease: analysis of six cases

A doença de Behçet é uma afecçäo multissistêmica com alteraçöes mucocutâneas, oculares, intestinais, articulares, vasculares, urogenitais e neurológicas. Embora de evoluçäo clínica intermitente, a moléstia pode se estabilizar e cronificar. Os autores relatam seis casos, dando enfoque aos achados clínicos

Absence of lupus anticoagulants in Behcet's disease

The presence of a lupus anticoagulant was evaluated in patients with Bechet's disease by the kaolin clotting time method. Four percents (three patients) of 69 patients analyzed were found positive for the lupus anticoagulant. However, no statistically significant association existed between the presence of this antibody and the presence of thrombosis, clinical activity, clinical type, antinuclear antibodies and the positive VDRL test.

Detecçäo de anticorpos e anticomponentes lipídicos (cardiolipina, gangliosídios e galactocerebrosídios) em pacientes com doença de Behçet / Detection of antibodies and lipid anticomponents (cardiolipin, gangliosides and galactosilceramidas) in patients with Behçet's disease

Os autores avaliam a presença de anticorpos antifraçöes lipídicas (cardiolipina, gangliosídios e galactocerebrosídios) em 13 pacientes com doença de Behcet. Anticorpos séricos anticardiolipina do isotipo IgG foram detectados em 30// dos casos, 50// do isotipo IgM. Em nenhum dos pacientes foi observada presença de isotipo IgA. Antigalactocerebrosídio foram detectados em apenas dois (15//) dos pacientes. Com relaçäo às manifestaçöes clínicas, observou-se que a presença de anticorpos anticardiolipina configura fator de risco para o desenvolvimento do acometimento neurológico

Sindrome de Bechet: a poposito de un nuevo caso

Se estudia un nuevo caso de Enfermedad de Behcet observado en Panamá. El paciente acudió por primera vez a la consulta externa el año de 1971 por úlcera aftosa, en mucosa bucal del labio inferior, que curó con esteroides local y sistémico en pequeñas dosis. Dos anos después presentó, por primera ocasión, conjuntivitis bilateral, que tambien mejoró con el mismo tratamiento. Quince años después presentó una úlcera genital urente, que producía mal olor. El cultivo de la secreción de la úlcera bucal reveló el crecimiento de Estreptococo alfa hemolítico; y la biopsia del labio demostró que tenía inflamación crónica y erosión inespecífica. Los exámenes de laboratório revelaron aumento de las inmunoglobulinas G y A, una relación OKT4/OKT8 invertida y ausencia del antígeno HLA-B5

Enfermedad de Behcet: revisión clínica e inmunológica; presentación de un caso / Behcet's disease: clinical and immunologic review; presentation of a case

Se presenta una paciente, de 36 años de edad, padece de una enfermedad de Behcet, diagnosticada por examen histopatológico y estudio inmunológico, con hipersensibilidad a prueba cutánea o al pinchazo con aguja estéril. Se señala que comenzó a presentar lesiones de eritema nudoso desde hace 18 años, lesiones exulceradas en la mucosa vulvovaginal hace dos años y lesiones aftosas en la mucosa oral hace 10 meses, así como dolores articulares más intensos en el hemicuerpo derecho, así como fotofobia e inyección conjuntival

A Study of HLA Antigens in Behcet's Syndrome

Fifty-two Korean patients with Behcet's syndome were typed for HLA antigens. 52 apparently healthy Korean subjects were used as controls; 42 for HLA-A, B, C and all 52 for HLA-DR typing. HLA-B5 and DRw8 presented significantly high frequencies in all patiens. According to Shimizu's classification, HLA-B5 and DRw8 were significantly increased in the complete type; B5 in the incomplete type; DR3 in the suspected-possible type. According to Lehner's classification, HLA-DR3 was significantly increased in the neurological type; B5 in the ocular type; B5 in the ocular type. We confirmed the association of HLA-B5 with the severity of Beh et's syndrome. A relation might exist between DRw8, DR3 and Behcet's syndrome.