RESUMO
A hemofilia A (HA) congênita é um distúrbio hemorrágico com transmissão hereditária ligado a deficiência do fator VIII (FVIII). O tratamento da HA é baseado na reposição do FVIII, requerendo infusões intravenosas de concentrados de FVIII exógeno. Durante o tratamento, alguns pacientes desenvolvem uma resposta imune que produz anticorpos anti-FVIII (inibidores). Os inibidores neutralizam a atividade procoagulante do FVIII e diminuem a eficiência do tratamento. Apesar da relevância dos inibidores, os mecanismos imunológicos associados aos inibidores ainda não foram completamente elucidados. Neste trabalho analisou-se o perfil de citocinas intracitoplasmáticas de células do sistema imune inato e adaptativo de pacientes com HA e inibidores [HAalfa-FVIII(+)] e com HA sem inibidores [HAalfa-FVIII(−)]. Os resultados mostraram uma menor frequência de monócitos e neutrófilos TNF-alfa positivo, monócitos IL-5+ e neutrófilos IL-4+ e uma maior frequência de neutrófilos, linfócitos T CD4+, T CD8+ e T CD19+ IL-10+em pacientes do grupo HAalfa-FVIII(+). Em pacientes do grupo HAalfa-FVIII(−) observou-se uma maior frequência de monócitos TNF-alfa+e linfócitos B IL-4+e uma menor frequência de linfócitos T CD4+ e T CD8+ IL-10+.
Observou-se o predomínio de um padrão anti-inflamatório/regulador no grupo HAalfa-FVIII(+) e um padrão pró-inflamatório no grupo HAalfa-FVIII(−), sugerindo que o microambiente celular pode ser um elemento importante associado à capacidade de desenvolvimento de inibidores. Analisou-se também a presença de micropartículas plasmáticas (MPs) em pacientes com HA. Os resultados mostraram uma maior frequência de MPs derivadas de células endoteliais, granulócitos e linfócitos T em pacientes do grupo HAalfa-FVIII(−) e uma maior frequência de MPs derivadas de hemácias em pacientes do grupo HAalfa-FVIII(+). O predomínio de MPs no grupo HAalfa-FVIII(−) pode ser relacionado ao aumento da ativação celular e influência do microambiente pró-inflamatório.
MPs derivadas de hemácias induziram a investigação da presença de anticorpos em hemácias de pacientes com HA. Os resultados demonstraram que pacientes do grupo HAalfa-FVIII(+) têm uma maior frequência de anticorpos na superfície de hemácias. Em função deste resultado, investigou-se a presença de anticorpos anti-FVIII em concentrados de hemácias de pacientes do grupo HAalfa-FVIII(+). Foi possível detectar anticorpos anti-FVIII em concentrados de hemácias, sugerindo que essas células podem interagir com anticorpos anti-FVIII. Determinou-se ainda, a avidez de anticorpos anti-FVIII de pacientes do grupo HAalfa-FVIII(+). Os resultados demonstraram avidez superior de anticorpos IgG total e IgG1 anti-FVIII quando comparados a IgG4. Foi observada também uma correlação negativa entre os índices de avidez de anticorpos IgG4 anti-FVIII de pacientes graves aos títulos de Bethesda, sugerindo que existem variações na avidez dos anticorpos anti-FVIII dependendo do perfil dos pacientes com HA. No contexto da avaliação da resposta imune contra o FVIII, foi possível identificar biomarcadores fenotípicos celulares e humorais característicos de pacientes com e sem inibidores que podem contribuir para o monitoramento do desenvolvimento e manutenção de anticorpos inibidores do FVIII. Palavras-chave: Hemofilia A, Fator VIII, Coagulação Sanguínea.
Assuntos
Masculino , Feminino , Humanos , Coagulação Sanguínea/imunologia , Fator VIII/uso terapêutico , Hemofilia A/imunologiaRESUMO
Sepsis is one of the major health problems all over the word. Its pathophysiological mechanisms are not completely understood, but coagulation alterations are a hallmark of this syndrome. There is a clear exacerbation of coagulation and a suppression of control mechanisms of this process, including a reduction in fibrinolysis with consequent impairment of fibrin removal. The leading cause of these alterations is the proinflammatory state of those patients, characterized by high cytokine levels, increase in adhesion molecules expression, endothelial and platelets activation, release of microparticles and other related phenomena. Moreover, coagulation and inflammation are linked in a variety of pathways with mutual activation that ultimately contributes for its maintenance. The components of this process will be herein discussed as well as therapeutical alternatives that have excessive coagulation as a target.
Assuntos
Anticoagulantes/sangue , Coagulação Sanguínea/imunologia , Plaquetas/imunologia , Coagulação Intravascular Disseminada/sangue , Sepse/sangue , Animais , Anticoagulantes/imunologia , Coagulação Intravascular Disseminada/imunologia , Coagulação Intravascular Disseminada/terapia , Humanos , Mediadores da Inflamação/sangue , Sepse/complicações , Sepse/imunologiaRESUMO
Sipunculans, a small phylum of coelomated marine worms closely related to polychaete annelids, lack a true circulatory system. We have previously shown that the sipunculan Themiste petricola can form a cellular clot, without congealing, of cell-free coelomic fluid. The clot is formed by the aggregation of large granular leukocytes (LGLs) and may serve not only haemostatic but immune functions, since dissimilar particles may become entrapped within it. We have now evaluated the capacity of a massive clot, induced in vitro by sea water contact, to stop coelomic fluid flow. We have further studied smaller clots induced on glass-slides either with or without the presence of bacteria placed for entrapment within the clot. The fate of clotting LGLs is cell death while forming a cohesive mass, although cytoplasmic and nuclear remnants are shed from the clot. These remnants and any bacteria that avoid clot entrapment or are detached from the clot are engulfed by non-clotting cells that include small granular leukocytes (SGLs) and large hyaline amebocytes (LHAs). Both cell types can be found other than in the clot but SGLs also occur around the clot edges heavily loaded with engulfed material. The cytoskeletal arrangement of SGLs evaluated with phalloidin-rhodamine correspond to motile cells and contrast with that of clotting LGLs that form a massive network of F-actin. Thus, the complementary roles between clotting LGLs and non-clotting SGLs and LHAs act a central immune strategy of Themiste petricola to deal with body wall injury and pathogen intrusion into the coelomic cavity.
Assuntos
Coagulação Sanguínea/imunologia , Hemostasia/imunologia , Nematoides/citologia , Nematoides/imunologia , Animais , Bactérias/metabolismo , Morte Celular , Linhagem Celular , Núcleo Celular/metabolismo , Citoesqueleto/metabolismo , Fragmentação do DNA , Citometria de Fluxo , Hemorreologia , Humanos , Leucócitos/citologia , Leucócitos/microbiologia , Fagócitos , Fagocitose , Água do Mar , Leveduras/metabolismoRESUMO
OBJECTIVES: Rare patients with systemic lupus erythematosus (SLE) patients exhibit anticoagulants that interfere in the earlier stages of the intrinsic coagulation pathway, such as those involving factor XI (FXI). The objectives of our study were to describe the presence of an acquired inhibitor to FXI causing a life-threatening bleeding disorder in an SLE patient and to review the association of this coagulopathy with SLE. METHODS: We describe the clinical presentation of an SLE patient with an acquired FXI inhibitor. We reviewed the scientific literature using the MEDLINE database searching the following combinations of terms: "SLE and Factor XI," "SLE and Factor XI inhibitor," and "Factor XI inhibitor," from 1964 to 2007. RESULTS: A 20-year-old woman with a 6-year history of SLE was admitted to the hospital because of severe life-threatening abdominal bleeding due to a ruptured ovarian cyst. This hemorrhagic event was related to the presence of an FXI inhibitor. We reviewed another 13 SLE patients with this condition, 8 of whom had bleeding events. Most patients had manifestations of active SLE, and prednisone was used as the primary treatment. CONCLUSIONS: SLE activity seems to be associated with the production of antibodies directed against FXI, which may cause important coagulopathies, especially bleeding events. The inhibitor disappeared after immunosuppressive therapy for SLE in most cases, suggesting that the appearance of this inhibitor is immune mediated. Although the majority of cases with the FXI inhibitor are not fatal, it should be suspected and investigated in SLE patients, especially those with abnormal clotting tests.
Assuntos
Coagulação Sanguínea/imunologia , Fator XI/antagonistas & inibidores , Lúpus Eritematoso Sistêmico/sangue , Transtornos da Coagulação Sanguínea/sangue , Transtornos da Coagulação Sanguínea/tratamento farmacológico , Transtornos da Coagulação Sanguínea/imunologia , Fator XI/imunologia , Feminino , Humanos , Imunossupressores/uso terapêutico , Lúpus Eritematoso Sistêmico/imunologia , Adulto JovemRESUMO
Phospholipases A(2) are components of Bothrops venoms responsible for disruption of cell membrane integrity via hydrolysis of its phospholipids. This study used a large nonimmune human scFv library named Griffin.1 (MRC, Cambridge, UK) for selection of recombinant antibodies against antigens present in Bothrops jararacussu venom and identification of specific antibodies able to inhibit phospholipase activity. Four clones were identified as capable of inhibiting this activity in vitro. These clones were able to reduce in vivo the myotoxic activity of BthTX-I and BthTX-II PLA(2), but had no effect on the in vitro anticoagulant activity of BthTX-II. This work shows the potential of using recombinant scFv libraries in the search for antibodies that neutralize relevant venom components.
Assuntos
Anticorpos/imunologia , Anticorpos/metabolismo , Bothrops/metabolismo , Venenos de Crotalídeos/enzimologia , Venenos de Crotalídeos/toxicidade , Coração/efeitos dos fármacos , Fosfolipases A/toxicidade , Animais , Anticorpos/genética , Anticorpos/isolamento & purificação , Coagulação Sanguínea/imunologia , Venenos de Crotalídeos/imunologia , Ensaio de Imunoadsorção Enzimática , Expressão Gênica , Fosfolipases A2 do Grupo II , Humanos , Cinética , Camundongos , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/isolamento & purificação , Fragmentos de Peptídeos/metabolismo , Fosfolipases A/imunologia , Fosfolipases A/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas de Répteis , SolubilidadeRESUMO
OBJECTIVE: The effect of Lactobacillus casei CRL 431 immunomodulatory activity on inflammation and coagulation during pneumococcal pneumonia was investigated in malnourished mice. METHODS: Weaned mice were malnourished after they consumed a protein-free diet for 21 d. Malnourished mice were treated for 7 d with a balanced conventional diet (BCD) with L. casei supplementation (BCD+Lc) or without it. The malnourished control group received only a protein-free diet whereas well-nourished control (WNC) mice consumed BCD ad libitum. Mice were challenged by the intranasal route with pneumococci at the end of each dietary treatment. Lung injury, leukocyte recruitment, cytokine production, coagulation tests, and fibrin(ogen) deposition in lungs were evaluated. RESULTS: Malnourished control mice showed impaired leukocyte recruitment and cytokine production, and more severe lung injuries when compared with WNC mice. Coagulation tests were significantly impaired in malnourished control group versus WNC group. Repletion with BCD or BCD+Lc improved these parameters, but only BCD+Lc mice achieved the values of WNC mice. In addition, the interleukin-10 level was higher in the BCD+Lc group than in the WNC group. CONCLUSION: Repletion with supplemental L. casei accelerated recovery of the defense mechanisms against pneumococci by inducing different cytokine profiles. These cytokines would be involved in the improvement of the immune response and in the induction of a more efficient regulation of the inflammatory process, limiting the injury caused by infection.
Assuntos
Coagulação Sanguínea/imunologia , Inflamação/imunologia , Lacticaseibacillus casei/imunologia , Pneumonia Bacteriana/imunologia , Probióticos/uso terapêutico , Deficiência de Proteína/complicações , Animais , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Citocinas/análise , Citocinas/biossíntese , Fibrina/análise , Fibrinogênio/análise , Imunidade/imunologia , Imunoglobulina A/análise , Inflamação/patologia , Leucócitos/imunologia , Pulmão/química , Pulmão/imunologia , Pulmão/patologia , Masculino , Camundongos , Neutrófilos , Pneumonia Bacteriana/complicações , Pneumonia Bacteriana/patologia , Infecções Estreptocócicas/complicações , Infecções Estreptocócicas/imunologiaRESUMO
Sepsis is a complex disease and coagulation derangements are part of this context. The inflammatory storm is ultimately responsible for coagulation derangements. It is characterized by exacerbated coagulation, impaired anticoagulation and decreased fibrin removal. These derangements are implicated in the generation of microcirculation thrombosis, with deposition of microclots and obstruction of circulation, impairing blood flow and contributing to tissue hypoperfusion and consequently, organ dysfunction. This review will address the main issues regarding coagulation disorders in the context of sepsis.
Assuntos
Coagulação Sanguínea/imunologia , Fibrinólise/fisiologia , Sepse/sangue , Antitrombinas/imunologia , Antitrombinas/metabolismo , Coagulação Sanguínea/fisiologia , Fatores de Coagulação Sanguínea/imunologia , Fatores de Coagulação Sanguínea/metabolismo , Humanos , Lipoproteínas/sangue , Lipoproteínas/imunologia , Lipoproteínas/metabolismo , Receptores de Superfície Celular/sangue , Receptores de Superfície Celular/imunologia , Receptores de Superfície Celular/metabolismo , Sepse/imunologia , Sepse/metabolismoRESUMO
The saliva from blood-feeding arthropod vectors is enriched with molecules that display diverse functions that mediate a successful blood meal. They function not only as weapons against host's haemostatic, inflammatory and immune responses but also as important tools to pathogen establishment. Parasites, virus and bacteria taking advantage of vectors' armament have adapted to facilitate their entry in the host. Today, many salivary molecules have been identified and characterized as new targets to the development of future vaccines. Here we focus on current information on vector's saliva and the molecules responsible to modify host's hemostasis and immune response, also regarding their role in disease transmission.
Assuntos
Vetores Artrópodes/imunologia , Interações Hospedeiro-Parasita/imunologia , Saliva/imunologia , Animais , Coagulação Sanguínea/imunologia , Hemostasia/imunologia , Agregação Plaquetária/imunologiaRESUMO
A saliva de artrópodes hematófagos é rica em moléculas com funções diversas que mediam uma alimentação sangüínea bem sucedida. Estas moléculas agem não apenas como armas contra a resposta hemostática, inflamatória e imunológica do hospedeiro funcionando também como ferramentas para o estabelecimento de patógenos. Parasitas, vírus e bactérias aproveitando-se deste arsenal dos vetores adaptaram-se facilitando seu estabelecimento no hospedeiro. Hoje, várias moléculas salivares foram identificadas e caracterizadas como novos alvos para o desenvolvimento de vacinas futuras. Neste trabalho, centramos em informação recente sobre a saliva de vetores e as moléculas responsáveis por modificar a resposta hemostática e imunológica assim como seu papel na transmissão de doenças.
Assuntos
Animais , Vetores Artrópodes/imunologia , Interações Hospedeiro-Parasita/imunologia , Saliva/imunologia , Coagulação Sanguínea/imunologia , Hemostasia/imunologia , Agregação Plaquetária/imunologiaRESUMO
A severe hemorrhagic syndrome produced by contact with Lonomia obliqua caterpillars has become epidemic in southern Brazil. A significant thrombin production with intense consumption of fibrinogen and high D-dimer production indicates a consumption coagulopathy and secondary fibrinolysis in patients. Lopap is a single-chain 69kDa serine protease isolated from the crude extract of L. obliqua bristles. Experiments in mice showed that the purified protein, similar to the crude extract, causes uncoagulable blood by fibrinogen depletion. In order to characterize the effects of Lopap on cells involved with hemostatic system, we performed experiments using human umbilical vein endothelial cells (HUVECs). Our results show that Lopap exerts a direct effect on endothelial cells by increasing the liberation of molecules involved in the regulation of vascular tone, inhibiting platelet activation and chemotaxis, apart from inducing the expression of cell adhesion molecules which participate in inflammatory responses. The release or new synthesis of mediators involved in coagulation as von Willebrand factor and tissue factor, or in fibrinolysis as tissue plasminogen activator, was not affected by Lopap. Also our results demonstrated that Lopap acts on cell survival of HUVECs, regulating the expression of molecules as NO and avoiding cell death.