4050 – Anti-Phospholipid screen
The Anti-Phospholipid screen is a quantitative immunoassay for the determination of IgG and / or IgM antibodies against phospholipides (cardiolipin, phosphatidyl-serine, -inositol, -ethanolamine, phosphatidic acid and ß2-glycoprotein I) in human serum. The Anti-Phospholipid screen is intended as an aid in the diagnosis of anti-phospholipid antibody syndrome (APAS) in conjunction with other clinical and laboratory findings.
APAS, an autoimmune disorder evident by clinical symptoms such as thrombocytopenia, arterial (venous) thrombosis, and recurrent foetal loss, as well as systemic lupus erythematosus (SLE) are characterized by the presence of autoantibodies reactive to negatively charged phospholipids. The detection of such autoantibodies is well established and plays an essential role in the diagnostics of systemic autoimmune diseases.
In autoimmune patients, phospholipid antibodies seem to recognize phospholipids associated with plasma protein cofactors, e.g. ß2 glycoprotein-I (ß2 GP-I), a serum protein with a molecular weight of ca. 50 kDa, that affects platelet aggregation and coagulation. Negatively charged phospholipids such as Cardiolipin interact with the positively charged fifth domain of ß2 GP-I, an interaction that leads to conformational changes of the protein and the creation of new epitopes recognized by autoimmune phospholipid autoantibodies.
The ELISA (Enzyme Linked Immunosorbent Assay) is an immunoassay for the determination of specific antibodies. The strips of the microtiter plate are coated with test-specific antigens. If antibodies are present in the patient´s sample, they bind to the antigens. A secondary antibody conjugated with the enzyme peroxidase detects the generated immune complex. A colorless substrate is converted into the colored product. The signal intensity of the reaction product is proportional to the antibody activity in the sample. After stopping the signal intensity of the reaction product is measured photometrically.
The immunoassay is designed for manual professional in vitro diagnostic use.
|Indication||Anti-phospholipid antibody syndrome (APAS)|
|Description||Enzyme immunoassay for the quantitative determination of IgG and / or IgM antibodies against phospholipids in human serum|
|Format||Microtiter plate coated purified human cardiolipin, bovine phosphatidyl-serine, -inositol, -ethanolamine, phosphatidic acid and human ß2-glycoprotein I|
|Total incubation time||105 min.|
|Sample volume||10 µL serum|
|No. of determinations||96 (89 x 1) + 5 x Calibrators + 2 x Controls|