Clinical Information

Lupus anticoagulant (LA) is one of several antibodies referred to as antiphospholipid antibodies (APA). Lupus anticoagulants are immunoglobulins (IgG, IgM, IgA, or a combination of these) that interfere with specific coagulation factor-phospholipid interactions, typically causing prolongation of one or more phospholipid-dependent clotting time tests (eg, activated partial thromboplastin time [aPTT]; dilute Russell's viper venom time due to inhibition). The characteristic in vitro inhibition caused by the presence of LA inhibitors can be overcome by additional phospholipid, which can be used to confirm the presence of LA. However, the most common in-vivo clinical manifestations of presence of APA are vascular thrombosis and recurrent miscarriage, among other organ manifestations. The combination of clinical manifestations and persistent presence of APA satisfies the criteria for APA syndrome. The hexagonal LA assay system enhances the sensitivity and specificity of aPTT-based LA detection by employing:

1. A partial thromboplastin that is more responsive to LA than many other reagents.

2. Inverted hexagonal phase phospholipid for neutralization of LA inhibition.