Toward harmonized interpretation of anticardiolipin and anti–β2-glycoprotein I antibody detection for diagnosis of antiphospholipid syndrome using defined level intervals and likelihood ratios: communication from the ISTH SSC Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibodies

Improving harmonization of the clinical interpretation of anticardiolipin (aCL) and anti-β2-glycoprotein I (aβ2GPI) antibodies immunoglobulin G (IgG)/immunoglobulin M (IgM) in the diagnosis of antiphospholipid syndrome (APS) is desirable. Likelihood ratios (LRs) with corresponding test-result intervals can identify the power of a test to discriminate between a diseased and nondiseased patient and may be useful for the semiquantitative interpretation of aCL/aβ2GPI results.