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Test Code CHF8 Chromogenic Factor VIII Activity Assay, Plasma


Ordering Guidance


Coagulation testing is highly complex, often requiring the performance of multiple assays and correlation with clinical information. For that reason, a coagulation consultation is recommended.



Necessary Information


 



Specimen Required


Specimen Type: Platelet-poor plasma

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: 13-mm x 75-mm, 5-mL, plastic vials (polypropylene preferred)

Specimen Volume: 2 mL Platelet-poor plasma in 2 13-mm x 75-mm, 5-mL, plastic vials (polypropylene preferred), 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. Within 4 hours of collection , centrifuge and aliquot plasma into a plastic vial, then centrifuge plasma again.

4. Aliquot plasma (1 mL per aliquot) into 2 13-mm x 75-mm, 5-mL, plastic vials (polypropylene preferred)leaving 0.25 mL in the bottom of centrifuged vial.

5. Immediately freeze plasma (no longer than 2 hours after processing) at -20° C or, ideally, at -40° C or below.

Additional Information:

1. Double-centrifuged specimens are critical for accurate results as platelet contamination may cause spurious results.

2. Each coagulation assay requested should have its own vial.


Useful For

Monitoring coagulation factor replacement therapy of selected extended half-life coagulation factor replacements

 

Aiding in the diagnosis of hemophilia A using a 2-stage assay, especially when the 1-stage assay result was normal

Testing Algorithm

This assay is indicated in situations where there is a clinical suspicion of hemophilia A diagnosis, but the 1-stage factor VIII (FVIII) assay result is normal. However, recent guidelines recommend this assay be performed in addition to the 1-stage assay in the initial workup of hemophilia A.

 

Testing for autoantibodies to FVIII in the presence of a low FVIII activity may be clinically indicated. To add on FVIII inhibitor testing, call 800-533-1710 within 7 days to assess if adequate plasma sample is available.

 

For more information see Hemophilia Testing Algorithm.

Method Name

Chromogenic

Reporting Name

Chromogenic FVIII, P

Specimen Type

Plasma Na Cit

Specimen Minimum Volume

Platelet-poor plasma: 0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Plasma Na Cit Frozen 14 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK
IV heparin contamination Reject

Reference Values

55.0-200.0%

Reference values apply to all ages.

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Performing 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

85130

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CHF8 Chromogenic FVIII, P 49865-9

 

Result ID Test Result Name Result LOINC Value
CHF8 Chromogenic FVIII, P 49865-9

Forms

If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.