Factor XII Activity
General Information
Lab Name
Factor XII Activity
Lab Code
F12
Epic Name
Factor XII Activity
Description
Factor XII (12) activity is a PTT-based factor assay and used for diagnosing deficiency of factor XII (12). Factor XII deficiency is often discovered when patients have prolonged PTT but do not exhibit any bleeding diathesis.
Emicizumab (Hemlibra) will affect all PTT-based assays and will overestimate the factor concentrations.
Outside clients should fill and submit Coagulation Patient Clinical History Form: Coagulation Patient Clinical History Form
Synonyms
Factor 12
Interpretation
Method
Stago STA Clottable Factor assay
Reference Range
Units: %
| Female | Male | ||
|---|---|---|---|
| Age | Range | Age | Range |
| 0-29d | 11-150 | 0-29d | 11-150 |
| 1m-2m | 17-150 | 1m-2m | 17-150 |
| 3m-5m | 25-150 | 3m-5m | 25-150 |
| 6m-11m | 39-150 | 6m-11m | 39-150 |
| 1y- | 30-150 | 1y- | 30-150 |
Effective date: 07/01/2004
Interferences and Limitations
Patients on bivalirudin (Angiomax), dabigatran (Pradaxa), argatroban (Novastan), rivaroxaban (Xarelto), apixaban (Eliquis), and edoxaban (Savaysa) may show prolonged clotting times. This may cause an under- estimation of the factor concentrations. Emicizumab (Hemlibra) will affect all PTT-based assays and will overestimate the factor concentrations.
Elevated factor VIII level (>250%) will result in a false increase of factor IX, XI, or XII.
Ordering & Collection
Specimen Type
Collection
3 or 5 mL BLUE TOP (CITRATE) tube
Forms & Requisitions
Outside clients should fill and submit Coagulation Patient Clinical History Form: Coagulation Patient Clinical History Form
Handling Instructions
The Laboratory MUST process specimen, within 4 hrs of blood collection.
Quantity
requested: entire specimen
Processing
UW-MT Instructions: Take specimen to UW-MT Coag lab for processing. Coag tech will freeze plasma sample for transport to HMC Coag.
HMC Instructions: Take specimen to HMC Coag lab for processing.
Outside Laboratory: Centrifuge for 10 minutes, remove plasma & re-spin plasma for another 10 minutes. Decant & Freeze plasma (minimum 1.0 mL) @ -20°C to -80°C. Send frozen on dry ice.
Performance
LIS Dept Code
Coagulation (COAG)
Performing Location(s)
| HMC |
Coagulation
206-520-4600 325 9th Ave, Rm # GWH-47, Seattle, WA 98104-2420 |
|---|
Frequency
Run Monday-Friday. Reported by end of day.
Available STAT?
No
Billing & Coding
CPT codes
85280
LOINC
Interfaced Order Code
UOW1219
Interfaced Result Code
UOW1219