Catastrophic antiphospholipid syndrome: clues to the pathogenesis from a series of 80 patients

[Nasal septal perforation and systemic disease]

INTRODUCTION

Nasal septal perforations are mainly due to trauma. Our review highlights systemic diseases leading to this disorder.

CURRENT KNOWLEDGE AND KEY POINTS

Various systemic diseases may be responsible of nasal septal perforation: Wegener's granulomatosis, systemic lupus erythematosus, antiphospholipid syndrome, sarcoidosis, cryoglobulinaemia. But, very few data are available about the frequency of septum nasal perforation in each disease. Clinical manifestations are numerous and not specific: obstruction, epistaxis, postnasal discharge, whistling, crusting. Asymptomatic forms are frequent. Biopsy of nasal septum is poorly useful for the diagnosis except when granuloma or vasculitis is found. Pathophysiologic mechanisms of nasal septal perforation are ischemic, infectious or inflammatory.

FUTURE PROSPECTS AND PROJECTS

Systemic disease may be suspected in unclear nasal septal perforation. More, in systemic disease, even when symptoms are absent, intranasal examination is required.

Low-molecular weight heparin: treatment failure in a patient with primary antiphospholipid antibody syndrome

Antiphospholipid antibody syndrome is an acquired autoimmune disorder characterized by vascular thrombosis and/or recurrent pregnancy losses along with laboratory evidence of antiphospholipid antibodies. Anticoagulation rather than immunosuppression is the mainstay of treatment. Despite the effectiveness of oral anticoagulation for the prevention of recurrent thromboembolic episodes, thrombotic complications in the setting of apparently therapeutic oral anticoagulation have been observed; this may at times be due to difficulties in maintaining a consistently therapeutic level of anticoagulation. Low-molecular-weight heparin has been a useful alternative for long-term anticoagulation when there is difficulty in managing oral anticoagulant therapy and has the advantage of a consistent anticoagulant effect. In this report, we describe a woman with primary antiphospholipid antibody syndrome who developed extensive pulmonary embolism despite receiving a proven therapeutic dosage of low molecular weight heparin.

Catastrophic antiphospholipid syndrome in the intensive care unit

CAPS is characterized by development of widespread microvascular thrombosis. Patients at risk are those with positive aCL or LA factor. Precipitating events, such as infection, trauma, surgical procedures, or reduction in anticoagulation therapy, may contribute to the development of CAPS. Presentation to the ICU can be dramatic, with progressive multiorgan failure and need for rapid institution of life-supporting measures. Cardiopulmonary failure has been the major contributor to mortality. A variety of therapeutic modalities have been used in an attempt to offset the widespread thrombosis and organ damage from high aCL levels. Anticoagulation therapy and high dosages of steroids seem to have a positive effect on survival.

"Black swan in the kidney": renal involvement in the antiphospholipid antibody syndrome

The antiphosphospholipid antibody syndrome (APS) describes a clinical entity with recurrent thrombosis, fetal loss, thrombocytopenia in the presence of lupus anticoagulant and/or antibodies to cardiolipin. These antibodies may be associated with connective tissue diseases such as systemic lupus erythematosus (secondary APS) or be found in isolation (primary APS). Renal syndromes increasingly being reported in association with these antibodies include thrombotic microangiopathy, renal vein thrombosis, renal infarction, renal artery stenosis and/or malignant hypertension, increased allograft vascular thrombosis, and reduced survival of renal allografts. Although much has been understood concerning the biology of these antibodies and the pathogenesis of thrombosis, the optimal therapy remains to be elucidated. This article presents a historical review of the renal involvement in the antiphospholipid syndrome and discusses therapeutic options. Further research is needed.

Treatment of the antiphospholipid syndrome

Despite increasing knowledge of the immunology and pathophysiology of the antiphospholipid syndrome, treating this condition remains challenging. Because of a paucity of randomized controlled trials, many of the treatment recommendations are not evidence-based. Retrospective case series suggest that a high level of oral anticoagulation is needed to prevent recurrent thrombosis. The combination of heparin and low-dose aspirin is effective in significantly increasing the chances of a successful pregnancy in woman with recurrent pregnancy failure associated with antiphospholipid antibodies. Primary prevention with aspirin is justified in patients with antiphospholipid antibodies but without a prior history of thrombosis. Interesting and controversial issues in the treatment of the antiphospholipid syndrome include the use of less intensive anticoagulation or antiplatelet agents in some patient subsets, anticoagulation for certain nonstroke neurologic conditions, the role of other agents (hydroxychloroquine, antioxidants), and novel immunomodulatory strategies.

Bacterial induction of autoantibodies to beta2-glycoprotein-I accounts for the infectious etiology of antiphospholipid syndrome

The antiphospholipid syndrome (APS) is characterized by the presence of pathogenic autoantibodies against beta2-glycoprotein-I (beta2GPI). The factors causing production of anti-beta2GPI remain unidentified, but an association with infectious agents has been reported. Recently, we identified a hexapeptide (TLRVYK) that is recognized specifically by a pathogenic anti-beta2GPI mAb. In the present study we evaluated the APS-related pathogenic potential of microbial pathogens carrying sequences related to this hexapeptide. Mice immunized with a panel of microbial preparations were studied for the development of anti-beta2GPI autoantibodies. IgG specific to the TLRVYK peptide were affinity purified from the immunized mice and passively infused intravenously into naive mice at day 0 of pregnancy. APS parameters were evaluated in the infused mice on day 15 of pregnancy. Following immunization, high titers of antipeptide [TLRVYK] anti-beta2GPI Ab's were observed in mice immunized with Haemophilus influenzae, Neisseria gonorrhoeae, or tetanus toxoid. The specificity of binding to the corresponding target molecules was confirmed by competition and immunoblot assays. Naive mice infused with the affinity-purified antipeptide Ab's had significant thrombocytopenia, prolonged activated partial thromboplastin time and elevated percentage of fetal loss, similar to a control group of mice immunized with a pathogenic anti-beta2GPI mAb. Our study establishes a mechanism of molecular mimicry in experimental APS, demonstrating that bacterial peptides homologous with beta2GPI induce pathogenic anti-beta2GPI Ab's along with APS manifestations.

Bacterial induction of autoantibodies to beta2-glycoprotein-I accounts for the infectious etiology of antiphospholipid syndrome

The antiphospholipid syndrome (APS) is characterized by the presence of pathogenic autoantibodies against beta2-glycoprotein-I (beta2GPI). The factors causing production of anti-beta2GPI remain unidentified, but an association with infectious agents has been reported. Recently, we identified a hexapeptide (TLRVYK) that is recognized specifically by a pathogenic anti-beta2GPI mAb. In the present study we evaluated the APS-related pathogenic potential of microbial pathogens carrying sequences related to this hexapeptide. Mice immunized with a panel of microbial preparations were studied for the development of anti-beta2GPI autoantibodies. IgG specific to the TLRVYK peptide were affinity purified from the immunized mice and passively infused intravenously into naive mice at day 0 of pregnancy. APS parameters were evaluated in the infused mice on day 15 of pregnancy. Following immunization, high titers of antipeptide [TLRVYK] anti-beta2GPI Ab's were observed in mice immunized with Haemophilus influenzae, Neisseria gonorrhoeae, or tetanus toxoid. The specificity of binding to the corresponding target molecules was confirmed by competition and immunoblot assays. Naive mice infused with the affinity-purified antipeptide Ab's had significant thrombocytopenia, prolonged activated partial thromboplastin time and elevated percentage of fetal loss, similar to a control group of mice immunized with a pathogenic anti-beta2GPI mAb. Our study establishes a mechanism of molecular mimicry in experimental APS, demonstrating that bacterial peptides homologous with beta2GPI induce pathogenic anti-beta2GPI Ab's along with APS manifestations.