Sign in →

Epic Code LAB306 Factor VIII Activity

Important Note

To monitor emicizumab (Hemlibra) therapy please request the Chromogenic Factor VIII Activity. Hemlibra interferes with APTT clot-based assays.

Please take steps to ensure specimen integrity to reduce recollection. Specimen Tube Shortage (link)

Test Name Alias

Factor VIII (8) Activity | Hemophilia A | 8384 | Factor 8

Interface Order Alias

10135

Quick Collect

+(1)S10POx3/F

Clinical Information

Used to evaluate congenital or acquired factor deficiencies.  In addition, used to diagnose von Willebrand disease when measured with the von Willebrand Factor antigen and von Willebrand Ristocetin cofactor.   May be employed in clarifying the cause of a prolonged partial thromboplastin time.  It is useful in the monitoring substitution therapy with Factor VIII concentrates for hemophilia A.   

Icons & Photos

3.2% Na. Citrate

Collection Instructions

Specimen Collection: Blood

 

Container(s): Blue top (3.2% Na. Citrate)

Preferred Volume to Collect: 2.7 mL (full tube)

Minimum Volume to Collect: 1.8 mL (full tube)

Capillary collect ok: No

Microtainer acceptable: No

 

Collection Instructions:

  • Detailed instructions (link): Anticoagulant Correction for High Hematocrit

  • Detailed instructions (link): Blue Citrate Tube

  • Tube must be full. Do not over fill or under fill; look for the fill indicator lines.

  • Gently invert 8 - 10 times to mix anticoagulant with blood.
  • Specimen should be processed within 1 hour – See Processing Instructions below.
  • +(1)S10/POx3/F

 

PROCESSING INSTRUCTIONS (Laboratory, Outpatient or Off-site collection)

 

Processed Specimen: Platelet Poor Plasma with a platelet count <10 X 109/L

Centrifuge/Spin: Yes

Aliquot: Yes

Processing Instructions:

  • Centrifuge and remove plasma within 1 hour of collection.
  • Separate plasma into 2-3 aliquots, minimum of 0.5 mL each.
  • Freeze aliquots in plastic transport tubes immediately.

Transport Temperature:

  • Ambient (up to 1 hour in whole blood state)
  • Frozen (plasma only >4 hours)

Rejection Criteria

  • Hemolysis
  • Specimen has been thawed

Specimen Stability

Ambient: 1 hour

Frozen: 2 months

Laboratory Retention: 2 months

Test Frequency

Available Monday – Friday, usual TAT 1-4 days.

Reference Range

Adult: 55 - 180%

Pediatric reference ranges have not been established.

 

Critical Values Table

Performing Department

Coagulation

Performing Department Laboratory Location

Corewell Health Reference Laboratory, Grand Rapids, MI

Methodology

Activated Partial Thromboplastin (APTT) clot based assay with plasma deficient substrate

CPT

85240

CDM Code

3058524002

Epic Test ID

1230100671

LOINC

Factor VIII Activity: 3209-4

Mayo Access Code

SHO8384

Additional Information

This test is part of the panel von Willebrand Profile

Reviewed Date

3/23/2023

Updated Date

9/5/24 - Processing Instructions