Avaliação da agregação plaquetária em presença de anticorpos antifosfolípides: anti-β2GP1 e anticardiolipina / Evaluation of platelet aggregation in the presence of antiphospholipid antibodies: anti-β2GP1 and anticardiolipin

INTRODUÇÃO: A síndrome antifosfolípide (SAF) é uma condição autoimune que apresenta fenômenos trombóticos arteriais e venosos de repetição além de complicações obstétricas. Sua patogênese está associada à presença de anticorpos antifosfolípides e/ou anti-β2 glicoproteína I (β2GPI) que aparentemente modificam o efeito anticoagulante da β2GPI. A dimerização da β2GPI induzida por anticorpos parece estar relacionada à indução da agregação plaquetária contribuindo para o estado trombofílico na SAF. OBJETIVOS: O presente trabalho objetiva demonstrar a influencia dos anticorpos antifosfolípides em testes de agregação plaquetária com diferentes agonistas (ADP, colágeno e adrenalina). MÉTODOS: Foram analisados testes de agregação de plaquetas normais com diferentes agonistas (ADP, colágeno, adrenalina) na presença de soro contendo anticorpos antifosfolípides em diferentes concentrações. RESULTADOS: As análises obtidas mostraram uma inibição significativa (P < 0,05) nas curvas de agregação plaquetária induzidas por ADP e adrenalina quando comparadas ao controle. O paradoxo entre o estado protrombótico e a presença de autoanticorpos que in vitro apresentam atividade anticoagulante foi demonstrado na literatura, dificultando o entendimento patofisiológico da síndrome antifosfolípide. CONCLUSÃO: Os resultados obtidos demonstraram que o soro rico em anticorpos anticardiolipina e anti-β2GPI, ambas da classe IgG, interferem em testes de curvas de agregação plaquetária.

INTRODUCTION: The antiphospholipid syndrome (APS) is an autoimmune condition characterized by recurrent arterial and venous thrombosis, besides obstetric complications. The pathogenesis is associated with the presence of antiphospholipid and/or anti-b2-glicoprotein I (anti-b2GPI) antibodies that appear to change the anticoagulant activity of b2GPI. Antibody-induced dimerization of b2GPI seems to be related to the induction of platelet aggregation, contributing to the development of thrombosis in APS. OBJECTIVES: The objective of the present study is to demonstrate the influence of antiphospholipid antibodies in platelet aggregation tests with different agonists (ADP, collagen, and adrenaline). METHODS: We analyzed platelet aggregation tests with different agonists (ADP, collagen, adrenalin) when normal platelets were exposed to serum with different concentrations of antiphospholipid antibodies. RESULTS: Results demonstrated a significant inhibition in adrenalin- and ADP-induced platelet aggregation curves (P < 0.05) in all antibody concentrations tested when compared to the control. The paradox between the prothrombotic state and the presence of autoantibodies that show anticoagulant activity in vitro was demonstrated in the literature, making it difficult to understand the pathophysiologic mechanism of the antiphospholipid syndrome. CONCLUSION: Results showed that anticardiolipin and anti-b2GPI antibodies-rich serum, both of which belonging to the IgG class, can interfere with platelet aggregation curves.

Anticardiolipin antibodies from syphilis and systemic lupus erythematosus induce leakage in cardiolipin vesicles

Anticardiolipin antibodies from sera of patients with systemic lupus erythematosus or syphilis induced leakage of entrapped carboxyfluorescein (CF) from cardiolipin (CL)/phosphatidylcholine(PC) vesicles prepared by sonication of equimolar mixtures of CL:PC. The sera dilution used here was 1:7500. IgG (5-20 mug/ml) from the same sera, not containing beta2GPI, also produced a concentration-dependent leak. Vesicle leakage was inhibited by salt and was not detected with vesicles prepared exclusively with phosphatidylcholine. The demonstration of antibody-induced vesicle leakage offers a convenient system to investigate the mechanism of antibody-lipid binding as well as a potential diagnostic tool.

Anticuerpos contra mitocondrias, corazón y perinúcleo. ¿Asociación con el título de anticuerpos anticardiolipina en el síndrome antifosfolípido primario?: estudio exploratorio / Seric antibodies as antiheart, antimithocondrial and antiperinuclear. These antibodies es related to the anticardiolipin antibodies level. Exploratory study

En el suero de pacientes con síndrome antifosfolípido primario se han descrito anticuerpos antimitocondriales (AM), anticorazón (ACOR) y contra perinúcleo (AP); algunos se nagativizan al inhibir los sueros con micelas de cardilipina. Decidimos evaluar si la fecuencia de AM, ACOR y AP tiende a aumentar en proporción directa al título de anticuerpos anticardiolipina (aCL). Se incluyeron sueros de pacientes: 12 con SAFP y 3 con lupus eritematoso sistémico. Se distribuyeron en 3 grupos de 5 sueros cada uno según el título de aCL (ensayo inmunoenzimático, punto de corte densidad óptica 0.21). Grupo bajo (DO de 0.816 a 1.360) y grupo alto (DO de 1.850 a 3.000). Detección de AM, ACOR y AP por inmunofluorescencia indirecta. Los resultados fueron: positivos, grupo bajo (O), grupo medio MA y ACOR en 1/5 y AP en 1/5 respectivamente, grupo alto ACOR y AP en el 20 por ciento (1/5), ACOR en el 20 por ciento (1/5), y AP en el 40 por ciento (2/5) y AM en 0 por ciento. Observamos tendencia a mayor frecuencia de ACOR y AP en relación directa a título de aCL y aunque el tamaño de la muestra no permite ser concluyente, los resultados justifican estudios posteriores para dilucidar este aspecto

Antibodies to cardiolipins in cerebrovascular stroke

Antibodies to cardiolipin were measured in 50 consecutive patients with first stroke on admission and 10 healthy, age and sex matched control group. Elevated levels of acll antibodies were preset in none of the control group, but in 18% of patients with stroke. CAT scan of the brain among the 9 patients with acl antibodies, however 4 cases had no any other risk facto ECHO doppler heart examination was normal in all 9 cases, however ECG showed associated recent myocardial infraction [MI] in one case and old MI in another case among patients with positive acl antibodies. We suggest screening patients with stroke for acl antibodies, especially if there was no obvious risk factor or if there was associated myocardial infraction or did cerebral infract in brain CAT scan

Anticuerpos antiocardiolipina: desarrollo de una técnica inmunoenzimática / Anticardiolipin antibodies: development of the inmunoenzimatic technic

Los anticuerpos anticardiolipina son autoanticuerpos clínicamente asociados con eventos trombóticos arteriales y venosos, muerte fetal recurrente y trombocitopenia. El presente trabajo describe el desarrollo de un sistema indirecto de ELISA para la detección de anticuerpos anticardiolipina. Las placas fueron fijadas con cardiolipina a una concentración de 25 µg/ml por evaporación al vacio. Las uniones inespecificas fueron eliminadas por bloqueo de las placas con albúmina bovina al 4 por ciento en PBS. El suero a una dilución de 1:50 fue incubado en la placa por 1h. Se utilizó un conjugado anti-IgG humana marcado con peroxidasa y obtenido en conejos a una dilución 1:1000. Se estudiaron 150 sueros de donantes voluntarios para establecer los valores límites que fueron fijados en la X más 3DS. Se estudiaron 17 pacientes con Lupus Eritematoso Sistémico encontrando correlación significativa entre los niveles elevados de anticuerpos anticardiolipinas y la presencia de trombosis venosa y/o arterial, trobocitopenia y muerte fetal y/o abortos espontáneos

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

Anticardiopilin antibodies and disease activity in systemic lupus erythematosus

Estudamos 80 pacientes portdores de lúpus eritematoso sistêmico, 26 dos quais apresentavam-se em atividade, e detectamos anticorpos anticardiolipina da classe IgG em 28/30 (35%) e da classe IgM em 20/80 (25%). Demonstramos uma associaçäo estatística entre a presença de anticorpos anticardiolipina e atividade de doença. Do mesmo modo houve associaçäo entre a presença dos anticorpos anticardiolipina e anti-DNA que pode sugerir uma reaçäo cruzada entre esses anticorpos ou apenas uma coincidência devido a síntese policlonal de imunoglobulinas mais evidênciada em períodos de atividades da doença

Antyphospholipid antibodies in syphilis

1. An enzyme-linked immunosorbent assay was used to determine the phospholipid specificity of antibodies in sera from 35 syphilis patients. 2. Based on the cross-reaction obtained aginst a mixture of cardiolipin, phosphatidylcholine and holesterol that is standard for flocculation tests according to the Venereal Disease Research Laboratory (CECON, Säo Paulo, Brazil), all 35 patients tested positive for antibodies of the IgG class whereas 13 (37%) also had IgM antibodies for the same mixture of lipids. IgG antibodies to cardiolipin were demonstrated in 2 patients (6%) and IgM antibodies in 5 (15%). Significant levels of IgG anti-phosphatidylcholine were detected in 3 patients (9%) and IgM antibodies in 4(11%). IgG anti-phosphatidylethanolamine antibodies were found in 1 patient (3%) and IgM antibodies in 3(9%). Antibody binding to cardiolipin plus cholesterol or cardiolipin plus phosphatidycholine was as effective as when the standard mixture of all 3 lipids was used. 3. A comparison with serum from systemic lupus erythematosus patients and inhibition studies using liposomes o cardiolipin or the mixture of 3 lipids suggests that there are at least 3 groups of anticardiolipin antibodies

Neuropsychiatric manifestations of systemic lupus erythematosus: the value of anticardiolipin, antigangliosides and antigalactocerebrosides antibodies

In an attempt to find a serological marker for neuropsychiatric manifestations (NPM) of SLE sera from 66 patients (classified in three groups, according to their NPM - defined, probable and without NPM) were analysed by ELISA for IgG and antigalactocerebrosides antibodies. A strong correlation was found between IgM antigangliosides and antigalactocerebrosides antibodies and NPM, but not with IgG class. IgM and IgG antibodies anticardiolipin were not correlated with BPM in this study. Both IgM antigangliosides and seven patients with definid NPM but clinically inactive. The analysis of these autoantibodies showed an important role predictive for NPM in SLE; the negative test decreases the chance of the NPM

Association of anti-DNA and anticardiolipin antibodies in systemic lupus erythematosus

Estudos recentes tem demonstrado a possibilidade de reaçäo cruzada entre anticorpos anti-DNA e anticardiolipina. No presente estudo a análise destes anticorpos por ELISA demonstrou uma associaçäo significante da presença simultânea destes anticorpos em pacientes com LES. Oito amostras de soros com os níveis mais altos de ambos anticorpos foram usadas para determinar a possibilidade de reaçäo cruzada. Os níveis de anticardiolipina näo foram alterados por DNA denaturado em concentraçäo adequada para inibir fortemente a ligaçäo do anticorpo anti DNA. Os resultados näo confirmam estudos prévios utilizando anticorpos monoclonais, mostrando reaçäo cruzada entre estes dois grupos de anticorpos. Entretanto, uma populaçäo de anticorpos que apresente reaçäo cruzada, em alguns casos especiais, näo pode ser descartada

Lupus anticoagulant--a double misnomer.

The clinical features of thirteen Chinese patients with lupus anticoagulant were described. They were noted to conform to those reported among Caucasians and tend to suggest that the term 'lupus anticoagulant' is a double misnomer.