Anti-phospholipid antibody

In the diagnosis of systemic rheumatic diseases, the term antiphospholipid antibody includes a variety of autoantibodies with different specificities. The target antigen is a negatively charged anionic phospholipid, such as cardiolipin. Their reactivity in the serum of autoimmune patients requires cofactors (& beta; 2-glycoprotein I, or apolipoprotein H). Anti-phospholipid antibodies can cause false positive responses to syphilis tests, that is, VDRL-positive or borrelia-specific antibody tests are negative and cardiolipin-complement fixation tests are positive. In addition, it can cause lupus anticoagulation, leading to prolonged APTT.