The enigmas of the lupus anticoagulant: mechanisms, diagnosis, and management.
Lupus anticoagulant (LA) is a laboratory abnormality associated with the antiphospholipid syndrome. It is a paradoxical phenomenon in which one or more in vitro diagnostic clotting tests are prolonged and thus seem due to an anticoagulant, whereas the antiphospholipid syndrome is manifest clinically as inappropriate or excessive thrombosis. LA should be suspected when thrombosis, recurrent fetal loss, or a prolonged phospholipid (PL)-dependent clotting test is present without other identifiable causes. Despite the heterogeneity of LA antibodies, a consensus has evolved to identify the LA. Four conditions must be met for this laboratory diagnosis: 1) prolongation of a PL-based clotting test, 2) confirmation of an inhibitor-like pattern in the clotting test, 3) confirmation of PL dependence in coagulation tests, and 4) exclusion of a specific factor inhibitor. Even with an extensive armamentarium for LA diagnosis and treatment, it is still a formidable task.
Marlar
Richard A
RA
Laboratory Services #113, Oklahoma City Veterans Administration Medical Center, 921 Northeast 13th Street, Oklahoma City, OK 73104, USA. richard-marlar@ouhsc.edu
Husain
Sanam
S
D000465:Algorithms; D000925:Anticoagulants / Q000627:therapeutic use; D016736:Antiphospholipid Syndrome / Q000097:blood* / Q000175:diagnosis; D001780:Blood Coagulation Tests / Q000379:methods; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006801:Humans; D016682:Lupus Coagulation Inhibitor / Q000097:blood* / Q000187:drug effects / Q000276:immunology; D008297:Male; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000188:drug therapy; D013927:Thrombosis / Q000097:blood / Q000188:drug therapy / Q000209:etiology
D000925:Anticoagulants; D005343:Fibrinolytic Agents; D016682:Lupus Coagulation Inhibitor