Quantitative Risk for Single-Positive Lupus Anticoagulant Results With Different Anticoagulants.

Objectives Clinical experts recommend against testing for lupus anticoagulant (LAC) during anticoagulation. Methods We quantitated the risk of a single-positive dilute Russell viper venom time (dRVVT) result or partial thromboplastin time–based phospholipid neutralization (PN) result on anticoagulation. Results Any anticoagulation led to a fourfold greater likelihood of single-positive results, primarily by rivaroxaban (odds ratio [OR] = 8.6) and warfarin (OR = 6.6), resulting in a positive dRVVT test with a normal PN test. Heparin and apixaban were twofold more likely to show single-positive results, but enoxaparin did not show significant single positivity. Conclusions Our results quantitatively support experts' avoidance of LAC testing during anticoagulation. [ABSTRACT FROM AUTHOR]