Anti-Beta2 Glycoprotein 1 Screen ELISA
The Anti-Beta2 Glycoprotein 1 Screen ELISA is For Research Use Only
Size: 1×96 wells
Sensitivity: 0.47 AU/mL
Dynamic Range: 10 – 160 AU/ml
Incubation Time: 2 hours
Sample Type: Serum, Plasma
Sample Size: 100 µL
The antiphospholipid syndrome (APS) is a disorder that presents peculiar symptoms: arterial and venous thrombosis, thrombocytopenia, ulcers of the lower limbs, hemolytic anemia, loss of the fetus during pregnancy and is associated with the presence of antiphospholipid antibodies. Antiphospholipid antibodies represent a large and heterogeneous immunoglobulins group, including anticardiolipin antibodies and lupus anticoagulant. The former are diagnosed by on their reactivity with cardiolipin or other anionic phospholipids in ELISA test, while the latter is detected in phospholipid-dependent coagulation tests (aPTT, KCT, dRVVT).
In the early ’90s it was observed that antiphospholipid antibodies are not directed against anionic phospholipids, as long it was considered, but they react with plasma proteins bound to anionic (phospholipidic) surfaces. In fact about cardiolipin, it was observed the need for a cofactor for antibodies binding, this cofactor was identified in β2 glycoprotein 1 (β2-GP1). The β2 glycoprotein 1 is a plasma glycoprotein of molecular weight of 50 kD, which is complexed to lipoproteins for 40%. A patient with clinical suspicion of APS, who has a high titre of anti-beta2GP1 antibodies, even if LAC or anti-cardiolipin antibodies are negative, has a strong chance of having the antiphospholipid syndrome, because these antibodies recognize β2-GP1 bound to the surface of phospholipid (cardiolipin). These proteins seem to express their antigenicity only after contact with specific areas such as the anionic phospholipid surface or very hydrophilic plastic surfaces. The importance of ELISA anti-phospholipids test, including the anti-β2-GP1 test, lies in the fact that a positive test if associated with one or more of the symptoms can confirm a diagnosis of APS.