[Antiphospholipid antibodies]

Antiphospholipid antibodies (APA) are acquired, circulating immunoglobulins connected with thrombo-embolic diseases occurring within all organ systems. Whether the antibodies are of pathogenetic relevance for the development of thrombo-embolic states is unresolved. All materials are limited and have yielded contradictory results with regard to important aspects. An increased APTT or PTT does not increase the risk of bleeding in patients with LA, unless abnormalities in the coagulation process are present, e.g. thrombocytopenia or hypoprothrombinaemia. Many questions are unanswered: Should APA be treated in asymptomatic patients? Should patients with APA and relevant symptoms be treated? If so, which treatment should be chosen? And how long should the treatment continue? Are APA of pathogenetic importance or are they markers for another mechanism that causes an immunocoagulopathy? How can it be explained that so many persons produce autoantibodies without becoming seriously ill? In order to clarify the significance of APA it is necessary to standardize tests and to perform extensive, prospective studies, where variations of ACA titres are analysed. Until results from such studies are available, APA should be looked for in patients with recurring arterial or venous thrombosis and in patients with recurring spontaneous abortion with reference to anticoagulant and anti-platelet aggregation therapy if IgG-ACA are elevated over prolonged periods.