Factors in the intrinsic pathway: FXII, FXI, FIX, FVIII
The presence of an inhibitor
If a patient with thrombosis or without bleeding, a lupus anticoagulant is indicated. If bleeding is present, specific factor assays.
To determine the titer of the inhibitor
Bypassing agent: either rFVIIa or aPCC (FEIBA)
Immunosuppressive agents to eradicate the inhibitor