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HelpTest ID 7INHE Factor VII Inhibitor Evaluation, Plasma
Ordering Guidance
This test is for factor VII inhibitors only. If the presence or type of inhibitor is unknown, first order APROL / Prolonged Clot Time Profile, Plasma, except for patients with known hemophilia A or B. When screening studies are needed for patients with known hemophilia A or B, order 8INHE / Factor VIII Inhibitor Evaluation, Plasma; or 9 INHE / Factor IX Inhibitor Evaluation, Plasma; respectively.
Shipping Instructions
Send all vials in the same shipping container.
Necessary Information
Specimen Required
Specimen Type: Platelet-poor plasma
Patient Preparation:
1. Patient must not be receiving Coumadin (warfarin) or heparin therapy.
2. Fasting preferred
Collection Container/Tube: Light-blue top (3.2% sodium citrate)
Submission Container/Tube: Plastic vials
Specimen Volume: 3 mL in 3 plastic vials, each containing 1 mL
Collection Instructions:
1. Specimen must be collected prior to factor replacement therapy.
2. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.
3. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.
4. Aliquot plasma (1-2 mL per aliquot) into 3 separate plastic vials leaving 0.25 mL in the bottom of centrifuged vial.
5. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally, -40° C or below.
Additional Information:
1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
2. Each coagulation assay requested should have its own vial.
Useful For
Detection and quantitation of inhibitor to coagulation factor VII
This test is not useful for the detection of a lupus-like circulating anticoagulant inhibitor, a nonspecific circulating anticoagulant, or other inhibitors that are not specific for coagulation factors.
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| 7INHT | FVII Inhib Profile Tech Interp | No | Yes |
| F_7 | Coag Factor VII Assay, P | Yes | Yes |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| 7AINH | FVII Inhib Profile Prof Interp | No | No |
| F7_IS | Factor VII Inhib Scrn | No | No |
| GBETH | General Factor Bethesda Units, P | No | No |
Testing Algorithm
Testing begins with coagulation factor VII activity assay with dilutions to evaluate assay inhibition; if the factor VII activity assay is normal or increased, a technical interpretation will be provided.
If the factor VII activity assay is decreased, an inhibitor screen will be performed at an additional charge to look for specific factor VII inhibition and a professional interpretation will be provided. If specific inhibition is apparent, the titer of the inhibitor will be determined.
Special Instructions
Method Name
F_7, F7_IS, GBETH: Optical Clot-Based
7INHT: Technical Interpretation
7AINH: Medical Interpretation
Reporting Name
Factor VII Inhib Profile, PSpecimen Type
Plasma Na CitSpecimen Minimum Volume
2 Plastic vials, each containing1 mL.
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma Na Cit | Frozen | 14 days |
Reference Values
FACTOR VII ACTIVITY ASSAY
Adults: 65-180%
Normal, full-term newborn infants or healthy premature infants may have decreased levels (≥20%) that increase within the first postnatal week but may not reach adult levels for 180 days or more postnatal.*
*See Pediatric Hemostasis References in Coagulation Guidelines for Specimen Handling and Processing.
FACTOR VII INHIBITOR SCREEN:
Negative
GENERAL FACTOR BETHESDA UNITS:
≤0.5 Bethesda Units
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
85390
85230
85335 (if appropriate)
85335 (if appropriate)
85390 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| 7INHE | Factor VII Inhib Profile, P | 90225-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| F_7 | Coag Factor VII Assay, P | 3198-9 |
| 7INHT | FVII Inhib Profile Tech Interp | 69049-5 |
Forms
If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.