Clinical and therapeutic aspects associated to phospholipid binding antibodies (lupus anticoagulant and anticardiolipin antibodies).

Abstract

Antiphospholipid antibodies (APA) comprise a family of immunoglobulins characterized by their pattern of reactivity in a number of laboratory tests. Included in this family are lupus anticoagulant (LA) anticardiolipin antibodies (ACA) and antibodies causing biologic false positive serologic tests for syphilis (BFP-STS). LA and ACA occur in a variety of conditions, including other autoimmunes disorders, infectious diseases, neoplasic disorders, in association with certain drugs and in otherwise healthy individuals. Clinical interest in LA and ACA is increasing. Antiphospholipid antibody syndrome is characterized by a triad of clinical features which include fetal loss, thromboembolic disease and thrombocytopenia. Other clinical manifestations related with APA are livedo reticularis, cutaneous necrosis, hemolytic anemia, heart valve disease, chorea, migraine and obstetric problems as fetal growth retardation, pre-eclampsia, post-partum serositis or neonatal thrombosis or catastrophic antiphospholipid syndrome. Therapy is mainly directed against the widespread and diverse manifestations associated with the obstruction of small and large vessels. Long-term treatment with oral anticoagulation therapy is advised, even if the venous or arterial occlusion occurred many years previously. In patients with primary antiphospholipid syndrome there is no evidence that the prophylactic administration of steroids or immunosuppression will prevent thromboembolic events. Although the administration of more energetic immunosuppression with cyclophosphamide in pulse form is effective in reducing elevated antibody levels, there is usually a rapid rebound to pretreatment levels shortly after discontinuation of the therapy. A history of recurrent fetal loss requires mandatory treatment during pregnancy. Although the actual prospective risk of pregnancy loss in women with antiphospholipid syndrome and prior pregnancy loss is unknown, it may exceed 60%. Because of this many investigators have treated women with antiphospholipid syndrome with either antiplatelet agents, immunosuppressive agents, or anticoagulants in an attempt to improve pregnancy outcome. Unfortunately, there is no unequivocal proof that any of these therapies are fully efficacious. Despite varying treatment protocols, the live birth rate with treatment was 70%, similar to that reported in the recent randomized clinical trial. Thrombocytopenia and autoimmune hemolytic anemia in patients with APA are treated similarly as patients without APA. Treatment of asymptomatic patients isn't indicated, because only approximately 10-15% of patients with APA developed complications.