Factor V Deficiency Workup

Updated: Apr 04, 2023
  • Author: Olga Kozyreva, MD; Chief Editor: Perumal Thiagarajan, MD  more...
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Laboratory Studies

The presence of a mild prolongation of the prothrombin time (PT) and activated partial thromboplastin time (aPTT) may be the first indication of factor V deficiency. Coagulation study results are as follows:

  • Bleeding time can be prolonged in severe cases
  • aPTT - Prolonged
  • PT - Prolonged
  • Thrombin time - Normal
  • Stypven time (Russell viper venom time [RVVT]) - Prolonged
  • Mixing study - Correction of PT or partial thromboplastin time (PTT) with the mixing of equal amounts of normal and patient plasma

Use specific factor V activity and antigen assays for confirmation. The factor V antigen assay quantifies factor V levels but does not test for functional factor V. Some patients have factor V deficiency caused by dysfunctional factor V while the level of factor V protein, estimated by factor V antigen levels, is normal. [24] However, this test is not routinely ordered to diagnose factor V deficiency. A factor V inhibitor panel should also be ordered.


Imaging Studies

Early and aggressive imaging studies are indicated, even with low suspicion for hemorrhage, after coagulation therapy is initiated, and may include the following:

  • Head computed tomography (CT) scan (noncontrast) - To assess spontaneous or traumatic hemorrhage
  • Body CT scan - Perform as indicated by clinical suspicion and anatomical location, to assess spontaneous or traumatic hemorrhage. May be performed with or without intravenous contrast, oral contrast, or both.
  • Head and spinal column MRI - To further assess spontaneous or traumatic hemorrhage
  • Radiograph for joint assessment - This is of limited value in an acute setting of hemarthrosis. Chronic degenerative joint disease is often present.
  • Special studies - Perform angiography and nucleotide bleeding scan as clinically indicated.