The antiphospholipid syndrome: The clinical importance of detecting antiphospholipid antibodies by immunoassays

Antiphospholipid syndrome (APS) is an autoimmune disease characterised by thrombosis and pregnancy complications with the presence of so-called antiphospholipid (aPL) antibodies. The detection of these antibodies is extremely important to establish the diagnosis of APS. This dissertation investigated the importance of testing for aPL antibodies in the APS laboratory diagnostics. Furthermore, existing aPL antibodies were reconsidered. APL antibodies not included in the classification criteria of APS have also been investigated. An important finding was that for a patient who has had thrombosis, fewer tests are needed when thrombotic APS is suspected. In addition, this study was able to conclude that the diagnosis for APS depends partly on the laboratory test used. Finally, a specific group of aPL antibodies targeting prothrombin (an important protein in blood clotting) has been shown to activate platelets and potentially contribute to the increased risk of thrombosis in patients with APS. The results provide insight into the mechanism of APS that can contribute to choosing the right anticoagulants.