4050 – Anti-Phospholipid screen

Highlights

• Use of purified phospholipids (cardiolipin, phosphatidyl-serine, -inositol, -ethanolamine, phosphatidic acid) and β2-glycoprotein I as coating antigens
• Quantitative determination of IgG and/or IgM antibodies in human serum
• Aids in the diagnosis of anti-phospholipid antibody syndrome (APAS) in conjunction with clinical and laboratory findings
• Differentiates autoimmune phospholipid antibodies from those appearing in infectious diseases
• Detection of disease-relevant autoantibodies recognizing phospholipid–protein complexes
• Manual test for professional in vitro diagnostic use
• CE marked

Intended Use

The Anti-Phospholipid screen is a quantitative enzyme-linked immunosorbent assay (ELISA) for detecting IgG and/or IgM antibodies against phospholipids, including cardiolipin, phosphatidyl-serine, phosphatidyl-inositol, phosphatidylethanolamine, phosphatidic acid, and β2-glycoprotein I in human serum. The assay reliably quantifies these antibodies and aids clinicians in diagnosing anti-phospholipid antibody syndrome (APAS) and related autoimmune disorders, such as systemic lupus erythematosus (SLE). Used alongside clinical evaluation, imaging, and other laboratory tests, it helps assess the risk of thrombotic events and recurrent fetal loss. The immunoassay is designed for manual professional in vitro diagnostic use.

Diagnostic Relevance

Anti-phospholipid antibody syndrome (APAS) is an autoimmune disorder. It causes clinical symptoms such as arterial or venous thrombosis, thrombocytopenia, and recurrent fetal loss. Primary APAS occurs on its own, while secondary APAS is associated with systemic lupus erythematosus (SLE). Both forms involve autoantibodies that react with negatively charged phospholipids. These autoantibodies serve as critical biomarkers for laboratory diagnosis and help assess the risk of thrombotic or obstetric complications.

In autoimmune patients, phospholipid antibodies often recognize complexes formed between negatively charged phospholipids and plasma protein cofactors, particularly β2-glycoprotein I (β2-GP-I), a 50 kDa serum protein involved in coagulation and platelet aggregation. The interaction between cardiolipin and the positively charged fifth domain of β2-GP-I induces conformational changes in the protein, creating novel epitopes that are targeted by autoantibodies. Detection of these antibodies enables clinicians to identify patients at risk for thrombotic events, monitor disease progression, and inform therapeutic decisions such as anticoagulant management.

The assay provides a robust, reproducible, and clinically relevant method for detecting disease-associated autoantibodies, complementing other diagnostic modalities and supporting the comprehensive assessment of autoimmune and thrombotic disorders.