Anti-Phospholipid Screen

Key Features and Values

– Same sample type can be used across all assays to simplify inclusion into routine serology work-up
– Ready to use reagents reduces hands-on time for assay preparation
– Long shelf life cost-effective solution by reducing wastage due to expired kits
– Suitable for inclusion on automated plate systems simplifies scale-up of test volume
– Supported by a complete panel of assays for diagnosis of thrombosis risk associated with SLE and APS

Product Description

Anti Phospholipid Screen is an indirect solid phase immunoassay kit for the quantitative measurement of IgG and IgM class auto-antibodies directed against β2-glycoprotein mediated anionic phospholipids in human serum or plasma, including Cardiolipin, Phosphatidyl serine, Phosphatidyl inositol, Phosphatidic acid, Phosphatidyl choline, Lyso-phosphatidyl choline, Phosphatidyl ethanolamine. The assay is intended for in vitro diagnostic use only as an aid in the diagnosis of increased risk of thrombosis in patients with Systemic Lupus Eritematosus (SLE) or similar disorders.  Anti Phospholipid Screen kit is intended for laboratory use only.

Scientific Description
The first study on the anti-phospholipid antibodies began in 1906 when Wasserman introduced a serological test for syphilis.  In 1942 it was discovered that the active component is a phospholipid called Cardiolipin.  In the 1950’s it was observed that a large number of people appeared to be positive for syphilis tests but did not show any evidence of disease.  Initially the phenomenon was classified as a series of false positive syphilis tests, before a more accurate analysis revealed, for this group of patients, a high prevalence of autoimmune disorders including SLE and Sjögrens syndrome.  The term lupus anticoagulant (LA), used for the first time in 1972, derived from experimental observations in which an increased risk of thrombosis was observed, paradoxically, with the presence of some anticoagulants factors; the term LA is not totally correct, in fact the disease is present more frequently in patients without lupus and it is associated with thrombosis rather than to abnormal bleeding.
Some years later the role of a cofactor was investigated, the β2-glycoprotein I (apolipoprotein H) also called β2GPI and its interactions with anionic phospholipids in human serum / plasma.  This cofactor is a β-globulin with a molecular weight of 50 kDa that has a concentration of 200 μg / mL in plasma.  The β2GPI is involved in the regulation of blood coagulation, inhibiting the intrinsic way.  β2GPI in vivo is associated with negatively charged substances such as anionic phospholipids, heparin and lipoproteins.
The region that binds phospholipids is in its fifth domain.  The acronym “aPL” (anti-phospholipid antibodies) indicates improperly antibodies directed against negatively charged phospholipids like Cardiolipin (CL), Phosphatidyl serine (PS) Phosphatidyl inositol (PI) and phosphatidic acid (PA); more correctly the term anti-phospholipid antibodies indicates those antibodies directed against the complex between β2GPI and anionic phospholipids that can bind to the fifth domain of β2GPI. Among these, the Cardiolipin is the most commonly used phospholipid as an antigen for determining the aPL by ELISA method.
Diagnostic laboratories measure the antibodies directed against the complex between β2GPI and negatively charged phospholipids, as Phosphatidyl serine (PS) Phosphatidyl inositol (PI) and phosphatidic acid (PA).  Some researchers suggest the use of PS instead of Cardiolipin in ELISA assays, for a more precise diagnosis. However, these antibodies against phospholipids are less commonly used, even if their use may increase the clinical sensitivity of patient samples with suspected anti-phospholipid Syndrome (APS), but it can’ t replace the determination of autoantibodies anti-Cardiolipin.
Publications

1. Hughes G.R.V., Harris E.N., Gharavi A.E.: The AntiCardiolipina Syndrome. J. Rheumat. 13, 3: 486-489, 1986.
2. Harris E.N. et al.: Evaluation of the anti-Cardiolipn antibody test: report of an international Workshop held 4 April 1986. Clin. Exp. Immunol. 68: 215-222, 1987.
3. Domke N., Siegert G.: Phospholipidantikörper und ihre klinische Bedeutung. Zeitschrift für Klinische Medizin 16: 1399-1401, 1988.
4. Pengo V. et al.: Immunological Specificity and Mechanism of Action of IgG Lupus Anticoagulants. Blood, Vol. 70. N. 1: 69-76, 1987.

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Code: DKO114
Clinical Area: ,
Incubation: 60+30+15 min
Sensitivity: 92.3% IgG; 68.8% IgM
Specificity: 84.6 IgG; >99.9% IgM
Classification: IVD, CE
Number of Tests: 96
Sample Type: Serum/Plasma
Sample Volume: 10 µL (1:100 predilution)
Assay Range: N/A