The antiphospholipid-thrombosis syndromes. Fact, fiction, confusion, and controversy.

Anticardiolipin antibodies and the lupus anticoagulant are strongly associated with thrombosis and appear to be the most common of the acquired blood protein defects causing thrombosis. Although the precise mechanism(s) whereby antiphospholipid antibodies alter hemostasis to induce a hypercoagulable state remain unclear, several theories have been advanced. Because the aPTT is unreliable in patients with lupus anticoagulant and is not usually prolonged in patients with anticardiolipin antibodies, definitive tests, such as ELISA for IgG, IgA, and IgM anticardiolipin antibodies and the dRVVT (followed by cephalin correction for confirmation) for lupus anticoagulant, should be immediately ordered when suspecting antiphospholipid syndrome in persons with otherwise unexplained thrombotic or thromboembolic events or fetal wastage syndrome. The laboratory diagnosis of APL-T syndrome is summarized in Figure 1.