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Pathogenic mechanisms mediating antiphospholipid syndrome
Antiphospholipid antibodies are the marker for antiphospholipid syndrome. There is evidence that these autoantibodies lead to both thrombotic diathesis and obstetrical manifestations. Besides the known interaction with soluble coagulation factors, in vitro and in vivo experimental models and studies in humans recently have shown the ability of antiphospholipid antibodies to modulate functions of cells involved in coagulation homeostasis. These findings support a new hypothesis to explain the paradox of the prolongation of coagulation assays in vitro and the association with thrombophilic diathesis in vivo. Obstetrical manifestations have been linked to a direct antibody effect on the trophoblast leading to defective placentation that is not necessarily associated with thrombotic phenomena. Phospholipid binding proteins such as beta 2 -glycoprotein I appear to behave as a bridge between circulating antiphospholipid antibodies and cellular targets
Statins and autoimmune diseases
Besides the well-known lipid-lowering effect, statins display nonlipid-lowering pharmacological activities. In vitro and in vivo studies suggest that statins have direct anti-inflammatory, antithrombotic and plaque-stabilizing effects via a number of mechanisms. A direct immunomodulatory effect has been also demonstrated in in vitro and in vivo experimental models. In addition to traditional risk factors, systemic inflammation, immune-mediated responses and thrombophilia have been suggested to play a major role in sustaining the premature atherosclerosis in autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. This review focuses on the anti-inflammatory and immunomodulating mechanisms of statins as demonstrated in in vitro and in vivo experimental models, providing new insights for the use of statins in treating systemic autoimmune diseases both for their anti-atherosclerotic activity and for their pleiotropic effects on inflammation, haemostasis and the immune responses. (copyright) 2005 Edward Arnold (Publishers) Ltd
Pidotimod : a reappraisal
Pidotimod (Polimod ®) is a synthetic dipeptide molecule with biological and immunological activity on both the adaptive and the innate immune responses. In vitro studies, both from animal and human specimens, have documented a good activity on innate and adaptive immune responses and have been confirmed by in vivo studies. These activities have been applied in clinical studies demonstrating the efficacy of pidotimod in reducing the rate of recurrent infections of the upper respiratory and urinary tracts in children. The same results were obtained in recurrent respiratory tract infections in adults. Interestingly, these effects are more evident in the setting of immune defects such as senescence, Down's syndrome, and cancer. Copyrigh
Pathogenic mechanisms of antiphospholipid syndrome : a new autoimmune disease
Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by the triad of recurrent thrombosis, fetal losses and thrombocytopenia associated with phospholipid binding proteins. The syndrome is a rare example of an autoimmune disease in which the diagnostic autoantibodies are also pathogenic. Owing to the widespread distribution of the target antigens, autoantibodies can interfere with coagulation homeostasis as well as with placentation sustaining the thrombophilia and the miscarriages, respectively. Recent advances in etiology and pathogenesis are changing the knowledge the treatment of the syndrome
Up-date on the antiphospholipid syndrome
Antiphospholipid syndrome is defined by recurrent thrombotic events and fetal losses in the presence of anti-phospholipid antibodies detectable by beta 2 glycoprotein I-dependent anti-cardiolipin and/or lupus anticoagulant assays. Thrombosis can occur in any vascular district but deep veins and cerebral arteries represent the most frequent sites. Both early and late fetal losses have been reported in women affected by the syndrome as well as pre-eclampsia. Beta 2 glycoprotein I-dependent anti-cardiolipin and lupus anticoagulant are the formal laboratory diagnostic tools; new assays appear to improve the diagnostic power, but larger validation studies are needed before accepting them on a routine basis. In spite of the improvement in our knowledge on the pathogenic mechanisms of the syndrome, the standard therapy is still based on anti-platelet or anticoagulant drugs both for vascular and obstetrical problems
Cardiac involvement in systemic autoimmune diseases
The heart and the vascular system are frequent and characteristic targets of several systemic autoimmune diseases, in particular Systemic Lupus Erythematosus (SLE), Rheumatoid Arthritis (RA) and Systemic Sclerosis (SSc). In this chapter we review the classic cardiac abnormalities and the more recent data about cardiovascular involvement as part of a major disease complication determining a substantial morbidity and mortality. In addition to the classic cardiac abnormalities involving the heart structures, acute and chronic ischemic heart disease and cerebrovascular accidents are threatening clinical manifestations of SLE and RA associated to an early accelerated atherosclerosis. Immune-mediated inflammation is now recognized as an important factor involved in the pathogenesis of atherosclerosis. Ongoing clinical studies are being devised to find specific risk factors associated with systemic autoimmune diseases and/or treatment regimens. Hopefully, prophylactic measures should be available within the next few years
Rheumatoid arthritis : a female challenge
Rheumatoid arthritis (RA) is two- to three-fold more frequent in women than in men and a strong association with sex hormones has been demonstrated. There is strong evidence that autoimmunity is under genetic control, and genes in sexual chromosomes can play a role in supporting the female prevalence. On the other hand, it is widely accepted that sex hormones - estrogens in particular - may regulate the immune response by favoring the survival of forbidden autoreactive clones and ultimately the prevalence of autoimmunity in women. Accordingly, estrogens have been suggested to be associated with the development of RA. Pregnancy in RA women is a common situation and most pregnant patients experience a remission. This has been closely related to a switch from Th1 to Th2 immune responses and to a decreased production of proinflammatory cytokines, at least in part supported by the changes of the hormonal profile in pregnancy. Pregnancy planning is required in RA in order to avoid unwanted complications. In particular, the need to control the disease requires safe use of antirheumatic drugs both during the pregnancy itself and in the breastfeeding period. Hormonal treatment for contraception is contraindicated in the case of positivity for antiphospholipid antibodies owing to the increased thrombophilic risk. Similarly, replacement hormonal treatment in postmenopausal women with RA to control osteoporosis is no longer recommended as a result of its ability to increase the cardiovascular risk closely associated with RA itself
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