The lupus anticoagulant titer is associated with elevated antiphosphatidylserine/prothrombin immunoglobulin‐M isotype antibody levels

Clot based assays used for lupus anticoagulant (LAC) detection are typically interpreted in a qualitative fashion and may not reflect LAC potency. In this cross-sectional study, we describe a method for quantifying the LAC titer using serial (dependent) two-fold dilutions in normal pooled plasma.