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Factor XIII, Qualitative, with Reflex to Factor XIII 1:1 Mix

Mnemonic:    [FactXIII Scr]
Name:    Factor XIII, Qualitative, with Reflex to Factor XIII 1:1 Mix
Specimen:    2 mL plasma from a FULL sodium citrate Blue top tube. Allow tube to fill to proper capacity. Mix immediately by gentle inversion 4 times. The sample must be centrifuged immediately in a precalibrated, authorized centrifuge. The sample must be doubly spun to insure that it is platelet poor plasma. We recommend that patients be sent to the outpatient phlebotomy lab, so the samples can be processed appropriately.

Hemolyzed specimens are not acceptable.
Minimum Spec:    1 mL
Transport Temp:    Critical Frozen sample. Freeze immediately and transport frozen.
Spec Stability:    Stable 4 hours ambient.
Ref Lab/Code:    ARUP 2002819
  Method:    Solubility
Note:    This is a qualitative screening test; clot lysis only occurs in specimens with severe factor XIII deficiency (less than 1 percent of normal activity). Severe deficiency may be inherited or acquired (typically due to a factor XIII antibody). If clot lysis occurs in the initial testing, then Factor XIII 1:1 Mix will be added where the test is repeated using a 1:1 mix of patient plasma and pooled normal plasma to distinguish between FXIII deficiency and a FXIII inhibitor. Additional charges apply.

False-positive results (lysis) can be caused by heparin (therapy with unfractionated or low molecular weight heparin or contamination from a line), decreased or abnormal fibrinogen, increased fibrinolysis (inherited or acquired fibrinolytic disorders), fibrinolytic drugs, or other factors that affect clot structure or stability.
Processing Info:    Give samples to coagulation tech to be spun in the calibrated centrifuge.

Each coagulation test sample must be separately frozen. Send separate specimens when multiple tests are ordered.