Antiphospholipid syndrome

Modulation of the activation of endothelial nitric oxide synthase and nitrosative stress biomarkers by aspirin triggered lipoxins: A possible mechanism of action of aspirin in the antiphospholipid syndrome

PROBLEM

Antiphospholipid syndrome (APS) is characterized by the clinical manifestation of vascular thrombosis (VT) or pregnancy morbidity (PM) and antiphospholipid antibodies (aPL) that can modify the nitric oxide production. Low-dose aspirin is used in the prevention and treatment of diverse alterations of pregnancy. One of the mechanisms of action of aspirin is to induce the production of aspirin-triggered-lipoxins (ATL). The aim of this study was to evaluate the modulatory effect of ATL over the activation of endothelial nitric oxide synthase (eNOS) and nitrosative stress biomarkers induced by aPL.

METHODS

We used polyclonal IgG and sera from women with aPL and PM/VT or VT only, and from women with PM only and positive for non-criteria aPL (SN-OAPS). In these sera, biomarkers of nitrosative stress (nitrites and nitrotyrosine) were measured. The protein expression of nitrotyrosine and the phosphorylation of eNOS (at Ser1177) were estimated in human umbilical vein endothelial cells (HUVECs) stimulated with polyclonal IgG with or without ATL.

RESULTS

Women with SN-OAPS showed increased circulating levels of nitrites and nitrotyrosine. Likewise, polyclonal IgG from either SN-OAPS or VT patients stimulated nitrotyrosine expression in HUVECs. ATL decreased the nitrotyrosine expression induced by polyclonal IgG from the SN-OAPS group. ATL also recovered the reduced eNOS phosphorylation at Ser1177 in HUVECs stimulated with polyclonal IgG from women with PM/VT or SN-OAPS.

CONCLUSIONS

Increased nitrosative stress present in serum of women with SN-OAPS is associated with IgG-mediated impaired endothelial NO synthesis in endothelial cells. ATL prevent these cellular changes.

Antiphospholipid Antibodies Overlapping in Isolated Neurological Syndrome and Multiple Sclerosis: Neurobiological Insights and Diagnostic Challenges

Antiphospholipid syndrome (APS) is characterized by arterial and venous thrombosis, pregnancy morbidity and fetal loss caused by pathogenic autoantibodies directed against phospholipids (PL) and PL-cofactors. Isolated neurological APS may represent a significant diagnostic challenge, as epidemiological, clinical and neuroimaging features may overlap with those of multiple sclerosis (MS). In an open view, MS could be considered as an organ-specific anti-lipid (phospholipid and glycosphingolipid associated proteins) disease, in which autoreactive B cells and CD8+ T cells play a dominant role in its pathophysiology. In MS, diverse autoantibodies against the lipid-protein cofactors of the myelin sheath have been described, whose pathophysiologic role has not been fully elucidated. We carried out a review to select clinical studies addressing the prevalence of antiphospholipid (aPL) autoantibodies in the so-called MS-like syndrome. The reported prevalence ranged between 2% and 88%, particularly aCL and aβ2GPI, with predominant IgM isotype and suggesting worse MS prognosis. Secondarily, an updated summary of current knowledge on the pathophysiological mechanisms and events responsible for these conditions is presented. We draw attention to the clinical relevance of diagnosing isolated neurological APS. Prompt and accurate diagnosis and antiaggregant and anticoagulant treatment of APS could be vital to prevent or at least reduce APS-related morbidity and mortality.

Systemic Lupus Erythematosus and Antiphospholipid Syndrome

Antiphospholipid syndrome is an autoimmune disorder defined as association of vascular thrombosis and/or pregnancy complications with presence of antiphospholipid antibodies (lupus anticoagulant, anticardiolipin and anti-β2 glycoprotein I). It is the most common cause of acquired thrombophilia, and can occur as an independent entity or in relation with other diseases, especially systemic lupus erythematosus. Presence of antiphospholipid syndrome in systemic lupus erythematosus is additional vaso occlusive factor in already present inflammation, bringing further risk for thrombotic events. Clinical and serological manifestations of antiphospholipid syndrome and systemic lupus erythematosus are very similar, so possible connection for these two autoimmune disorders is assumed.

Cardiovascular risk factors in the antiphospholipid syndrome

A major cause of morbidity and mortality in the context of the antiphospholipid syndrome (APS) is the occurrence of thrombotic events. Besides the pathogenic roles of antiphospholipid antibodies (aPL), other risk factors and medical conditions, which are conditions for traditional risk of an individual without the APS, can coexist in this patient, raising their risk of developing thrombosis. Therefore, the clinical and laboratory investigation of comorbidities known to increase cardiovascular risk in patients with antiphospholipid antibody syndrome is crucial for the adoption of a more complete and effective treatment. Experimental models and clinical studies show evidence of association between APS and premature formation of atherosclerotic plaques. Atherosclerosis has major traditional risk factors: hypertension, diabetes mellitus, obesity, dyslipidemia, smoking, and sedentary lifestyle that may be implicated in vascular involvement in patients with APS. The influence of nontraditional risk factors as hyperhomocysteinemia, increased lipoprotein a, and anti-oxLDL in the development of thromboembolic events in APS patients has been studied in scientific literature. Metabolic syndrome with all its components also has been recently studied in antiphospholipid syndrome and is associated with arterial events.

Rheumatic fever associated with antiphospholipid syndrome: systematic review

Objective. To evaluate the clinical associations between rheumatic fever and antiphospholipid syndrome and the impact of coexistence of these two diseases in an individual. Methods. Systematic review in electronics databases, regarding the period from 1983 to 2012. The keywords: “Rheumatic Fever,” “Antiphospholipid Syndrome,” and “Antiphospholipid Antibody Syndrome” are used. Results. were identified 11 cases described in the literature about the association of rheumatic fever and antiphospholipid syndrome. Clinical presentation of rheumatic fever was characterized by the predominance of carditis (11/11) and chorea (7/11). Regarding the manifestations of APS, the stroke was observed in 7/11 (63.6%), with one of them having probable embolic origin. Conclusion. The present study brings the information that the association between APS and RF is quite rare, however, is of great clinical importance. Doctors who deal with the RF should include in their differential diagnosis the APS, especially in the presence of stroke in patients with RF and whose echocardiogram does not show intracavitary thrombi.

[Alveolar haemorrhage associated with the primary antiphospholipid syndrome]

INTRODUCTION

Thrombotic events, particularly pulmonary embolism, are well known presentations of the antiphospholipid syndrome. Other pulmonary manifestations of the disease like alveolar haemorrhage are rare but can represent a catastrophic aspect of this disease. Alveolar haemorrhage in this context is important to recognize since it can be either a complication of anticoagulation therapy or a manifestation of the disease. The therapeutic implications are then very different.

CASE PRESENTATION

We present the case of a woman with massive pulmonary embolism treated with thrombolytic therapy. This was complicated by alveolar hemorrhage initially attributed to thrombolytics and recurrent bleeding considered to be a manifestation of the antiphospholipid syndrome. The complicated course necessitated a protracted stay in the intensive care unit, mechanical ventilation, and treatment with intravenous corticosteroids and plasmapheresis.

CONCLUSION

Alveolar haemorrhage associated with the antiphospholipid syndrome can be catastrophic and require prompt and aggressive therapy. Plasmapheresis, usually reserved for the catastrophic aspects of this condition, was felt to be useful in this case.

Antibodies against the N-terminal domain of annexin A2 in antiphospholipid syndrome

Annexin A2 (ANXA2, an endothelial cell receptor for plasminogen and tissue plasminogen activator) has been identified as a new autoantigen in antiphospholipid syndrome (APS). The aim of the present study was to evaluate the presence of antibodies against the N-terminal domain of annexin A2 (ANXA2) in primary APS (PAPS). By using a synthetic peptide corresponding to the 31N-terminal amino acids of ANXA2 (ANXA2(N31)) as an antigen, we performed an enzyme-linked immunosorbent assay (ELISA) to measure anti-ANXA2(N31) IgG and IgM antibodies in the serum of PAPS patients (n=19), systemic lupus erythematosus (SLE) patients (n=50) and healthy blood donors (n=106). We did not find any statistically differences between the three groups in terms of IgG and IgM anti-ANXA2(N31) titres. Elevated IgG anti-ANXA2(N31) titres were not observed in the serum of PAPS or SLE patients who had previously tested positive for anti-ANXA2 antibodies. Thus, the ANXA2 N-terminal domain does not appear to be the target antigen for anti-ANXA2 antibodies in APS.

Síndrome antifosfolípide e trombocitopenia na infância

OBJETIVO: Relatar o caso de uma criança com diagnóstico de síndrome do anticorpo antifosfolípide associada à trombocitopenia grave e realizar uma revisão de literatura sobre o assunto. DESCRIÇÃO DO CASO: Criança de nove anos e oito meses de idade com trombocitopenia grave associada a anticorpo anticardiolipina positivo. Os dados foram coletados por meio de anamnese, exame físico e exames complementares da paciente. O diagnóstico foi determinado de acordo com os critérios estabelecidos para a síndrome antifosfolípide, associados às manifestações mais comuns na faixa etária pediátrica: livedo reticular e trombocitopenia. COMENTÁRIOS: A síndrome do anticorpo antifosfolípide é uma doença incomum na população pediátrica e suas manifestações clínicas, com a redução do número de plaquetas, devem ser consideradas.

Food anaphylaxis in antiphospholipid syndrome and thrombosis

BACKGROUND

We have observed that some cases of food anaphylaxis were followed by severe thrombosis associated to anticardiolipin antibodies. Food anaphylaxis associated with antiphospholipid syndrome has seldom been published.

OBJECTIVE

The aims were: 1) to test anticardiolipin antibodies in an important number of patients with anaphylaxis due to vegetal foods and their relationship with possible thrombosis; and 2) to study seed and fruit hypersensitivity in patients with previous thrombotic events associated with antiphospholipid antibodies (aCL).

METHODS

We included 30 patients diagnosed of thrombosis associated with aCL, 52 patients who suffered from anaphylaxis due to seeds or fruits, and 120 control patients. Haematological, cardiopulmonary vascular and rheumatologic studies had been performed as needed. In vivo and in vitro allergy tests with a large battery of vegetal allergens were carried out in all the patients. Measurement of IgG aCL antibodies and specific IgE to vegetal food was done by ELISA and CAP-FEIA (Phadia). Immunodetection and inhibitions with lipoproteins belonging to seeds were performed.

RESULTS

Seventy-five percent of the patients diagnosed as having antiphospholipid primary syndrome had specific IgE against different proteins from different vegetable allergens, most of them seeds, and clearly against lipoproteins that were also recognised by the patients with food anaphylaxis but not by the control cases. Among the patients with anaphylaxis, 28% had anticardiolipin antibodies and 17.3% thrombosis.

CONCLUSION

Our study suggests that seed lipoproteins which cause severe food anaphylaxis might have a potential role in the antiphospholipid syndrome and related thrombosis.

Antiphospholipid syndrome and central nervous system

Classification criteria, etiology, pathogenesis, major central nervous system (CNS) manifestations of the antiphospholipid syndrome (APS), as well as diagnostic and therapeutic approach are discussed in the article, supported by several MRI findings to illustrate differential complexity of selected topics. Close interplay of inflammation, autoimmunity, coagulation cascade, vasculature bed, neuron physiology and demyelinization in APS is elaborated. Cerebrovascular disease, multiple sclerosis-like syndrome, seizures, cognitive disfunction, headache and migraine, chorea and catastrophic antiphospholipid syndrome (CAPS) are discussed as the most prominent CNS manifestations of the APS.

Hemostatic changes in vasculitides

The systemic vasculitides are an heterogeneous group of rare diseases characterized by inflammation and fibrinoid necrosis of blood vessel walls. Today it is well known that the inflammatory process characterizing vasculitides activates coagulation factors, inhibits anticoagulant factors, inhibits fibrinolytic processes, increases platelet activity and production and determines endothelial dysfunction. So far the mortality in vasculitides, even if falling, remains substantially high. Patients with vasculitic syndrome are at increased risk of developing atherosclerosis and in these patients prevalence of cardiovascular disease and cardiovascular events is higher than in the general population. Vasculitides can be associated with antiphospholipid syndrome. It is important to establish a strategy of antithrombotic therapy management in vasculitic patients, but this has not yet been clearly achieved.