Factor V Deficiency Workup

Updated: Mar 09, 2021
  • Author: Olga Kozyreva, MD; Chief Editor: Perumal Thiagarajan, MD  more...
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Workup

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. [21] However, this test is not routinely ordered to diagnose factor V deficiency. A factor V inhibitor panel should also be ordered.

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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.

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