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Factor XII (12) Activity

Justification

Factor XII deficiencies are not associated with excess bleeding risk, even after major surgery; however, some patients with FXII deficiency may experience poor wound healing. Factor XII deficiencies are typically discovered as part of a prolonged aPTT workup.

STAT: < 24 hours (7 days a week)

Clot-based

Draw Tube: Blue Top

Sample Type: Citrated Plasma

Specimen Requirements

Sample Type Volume Required Minimum Volume Stability
PREFERRED Citrated Plasma 1mL 0.5mL Frozen (-20C): 2 weeks
Frozen (-80C): 6 months
ALTERNATIVE - - - -
REJECTION CRITERIA Thawed in transit, refrozen or clotted sample
SPECIAL INSTRUCTIONS -

General Information

METHODOLOGY Clot-based
STAT TAT < 24 hours (7 days a week)
STAT TAT Performance > 90% of results released in 24 hours 7 days a week
ROUTINE TAT < 3 days (M-F)
ALTERNATIVE NAMES Hageman Factor, F12, FXII
DESCRIPTION This is a clot-based assay for the determination of Factor XII Activity level in citrated plasma. Patient sample at three different dilutions is mixed with Factor XII Deficient plasma containing normal levels of all other factors, such that the resulting activated Partial Thromboplastin Time is dependent only on the level of Factor XII present in the patient sample. This value is compared to a reference curve generated from calibrators with known levels of Factor XII Activity.
LIMITATIONS -
NORMAL RANGE 57-165%
ASSOCIATED TESTING -
REFERENCES -
SAMPLE REPORT Upon request
NEW YORK STATE APPROVED Yes

Test Codes

ORDER CODE P3059
CPT CODE 85280
LOINC CODE 3232-6