ABSTRACT
The literature on nonspecific circulating anticoagulants generally appears rather confusing because of the difficulty of precisely characterizing such abnormalities in the laboratory. Lack of real clinical information resulted in lupus anticoagulants (LA) being considered a mere laboratory curiosity for a number of years. The “cofactor” pattern may occur because on mixing with normal plasma the platelet bypassing effect is diminished more readily than the LA with consequent reappearance of LA in the mixtures. The regular prothrombin time (PT) test is usually quite insensitive to most LA. An abnormal PT associated with an LA usually indicates a frank deficiency of prothrombin which could cause bleeding. The hypothesis that LA bind the phospholipid normally converted to prostacyclin, thereby compromising this antithrombotic pathway seemed most plausible. In most comparisons of tests for LA the outcome appears to be dependent on the initial screening procedure used and such comparisons are meaningful only if a group of patients with a particular clinical feature are studied.
