Use

This test detects IgA isotype anticardiolipin antibodies, which may be implicated in antiphospholipid syndrome (APS), particularly when other isotypes are negative. Though IgA is not formally included in APS diagnostic criteria, it may be elevated in certain populations, such as African American patients with systemic lupus erythematosus, and can support APS evaluation in concert with clinical findings and other laboratory tests. (Quest Diagnostics context)