Hemostasis Reference Laboratory

Factor XIII Screen (by Urea Solubility)

• Transaction Code: 3200-07
• CPT Code (Suggested): 85291

Factor XIII forms covalent cross links between fibrin chains. In the absence of Factor XIII, the fibrin clot will be dissolved by 5 M urea which disrupts the hydrogen bonds. This assay will be abnormal only if the factor XIII level is <2-5%. Hereditary factor XIII deficiency, an autosomal recessive disorder, should be suspected in a patient with delayed post-surgical or traumatic bleeding, unexplained CNS hemorrhage, poor wound healing, or recurrent abortions.

• Sample Required: 0.5 ml frozen plasma x4 or (2) 3.2% sodium citrated tubes, 5 ml each.
• See Sample Requirements when ordered with other tests.
• Normal Test Value: Insoluble in urea
• Analytic Time: Within 5 working days