How do you manage a DOAC if interested in testing for lupus anticoagulant?

Testing for anti-phospholipid antibodies encompasses two broad categories of testing. One is an ELISA based (aka solid phase) set of tests that include anti-cardiolipin and anti-beta 2 glycoprotein I antibodies. ELISA assay are not affected by DOACs. For the second lupus anticoagulant (aka fluid phase) testing, it would be prudent to interrupt the DOAC for at least 48 hours prior to sample collection. DOACs may result in an indeterminate or false positive test result.

Agree with Dr. @Dr. First Last; the serologic tests for AcL and anti-B2GPI antibodies are not affected by anticoagulants whereas the functional tests, e.g., the LAC (lupus anticoagulant), etc., will look positive if done while the patient is receiving them, any anticoagulant but not aspirin or HCQ. Even a drop of heparin to flush an intravenous line may affect the LAC test. Some laboratories adjust their tests to account for the use of anticoagulants but these are not widely available.

LA Testing in the setting of DOACs, Heparin or Vitamin K antagonist.

# DOACs

Some labs try to remove DOACs via charcoal. Inhibitors of apixaban, rivaroxaban, and dabigatran are available, but not commercially available to use in laboratories. So they can give rise to false positive LA tests in both APTT based and DRVVT based testing. This was proven by random LA testing done on Afib patients who were on DOACs. I would avoid LA testing while on DOACs. When they are interrupted for at least 48 ...

Agree with my colleagues.

ELISA tests are not affected by DOAC.

For LAC testing, I hold it for 48 hours before test. Since it requires interruption of anticoagulants, I wait at least 6-8 weeks before testing for LAC unless clinical suspicion is very high.