Case Report
Friend or Foe: Factor XII Deficiency Discovered Incidentally during Management of NSTEMI
Table 2
Workup of baseline isolated prolonged aPTT.
| | Test | Patient’s value | Reference range |
| Heparin onboard | Mixing study | aPTT does not correct with normal plasma | | Lupus anticoagulant | Negative | Negative | Cardiolipin antibodies | Negative | Negative | Beta-2-glycoprotein I antibodies | Negative | Negative |
| Postheparin cessation | Activated clotting time (sec) | 714 | 74–137 | Heparin anti-Xa (IU/mL) | <0.10 | 0.30–0.70 | Mixing study | aPTT corrects with normal plasma | | Factor II activity (%) | 92 | 70–120 | Factor VIII activity (%) | 342 | 60–150 | Factor IX activity (%) | 143 | 60–150 | Factor X activity (%) | 63 | 70–120 | Factor XI activity (%) | 84 | 60–150 | Factor XII activity (%) | <13 | 60–150 |
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