Device Description
INTENDED USE
For the detection and semi-quantitation of IgG anti-β2GPl antibodies in individuals with systemic lupus erythematosus (SLE) and lupus-like disorders (anti-phospholipid syndrome). For In Vitro Use Only.
SUMMARY AND EXPLANATION OF THE I TEST
Anti-phospholipid antibodies are a heterogeneous group of immunoglobulins that bind to several anionic phospholipids, including cardiolipin and phosphatidylserine. High serum levels of anti-phospholipid antibodies are frequently detected in patients with autoimmune (e.g., SLE) and non-autoimmune diseases, as well as in apparently healthy individuals. Patients with positive reactions to both anti-phospholipid and anti-β2GPl assays were more likely to have clinical complications than those positive for only one. Higher prevalence and mean serum levels of IgG anti-β2GPl antibodies have been reported in autoimmune patients. In addition, anti-β2GPl antibodies in SLE patients correlated with clinical manifestations of anti-phospholipid syndrome.
PRINCIPLE OF THE TEST
The test is s an indirect ELISA. Diluted serum/ plasma samples, calibrator sera, and controls are incubated in microwells coated with purified human β2GPl. After the removal of unbound serum/plasma proteins by washing, antibodies specific for human IgG, labeled with horseradish peroxidase (HRP), are added forming complexes with the β2GPl bound antibodies. Following another wash step, the bound enzyme-antibody conjugate is assayed by the addition of a single solution containing tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) as the chromogenic substrate. Color develops in the wells at intensity proportional to the serum concentration of anti-β2GPl antibodies. Results are obtained by reading the O.D. of each well in a spectrophotometer. Calibrator sera are provided, with the IgG anti-β2GPl antibody concentrations expressed in G units.. Controls and patient results are determined from the calibration curve. Refer to Product Package Insert.