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Test Code VWFGPIBM vWF, Gplb Binding (vWF:GplbM)

Specimen and Container/Tube

Specimen Type: Plasma

Preferred Specimen: Light Blue Top Tube, 3.2% Sodium Citrate

Other Acceptable specimens: N/A

Specimen Handling and Transport Instructions

UCMC Onsite Instructions: 

Collect specimen per standard collection procedure and send to laboratory immediately. 

 

NOTE: Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.

 

UCMC Offsite and UC MedLab Outreach Instructions: 

  • Collect specimen per standard collection procedure.
  • Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.
  • Centrifuge specimens at >2500 x g for 10 minutes at room temperature.
  • Carefully remove plasma from cells using a plastic transfer pipette avoiding buffy coat.
  • Aliquot removed plasma into 2 plastic tubes containing a minimum of 0.5 mL of specimen in each tube.
  • Plasma samples must then be frozen at -20oC.
  • Once solidly frozen, they must be shipped on dry ice. Samples that have thawed in transit will be rejected.

Rejection Criteria

  • Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits. 
  • Specimens that have wrong ratio of blood to anticoagulant (fill volume), clotted or grossly hemolyzed.

Reference Values

 

Test

Age

Sex

Reference Range

vWF, Gplb

ALL

ALL

50 - 203%

Critical Values

Analyte

Unit

Low

High

Age

N/A

N/A

N/A

N/A

N/A

CPT Codes

85397

LOINC Codes

73978-9

Volume

Preferred Volume: 2.0 mL

 

Minimum Volume: 1.0 mL

Specimen Stability

Storage Temperature

Stability

Room temperature

4 hours

Refrigerated

not acceptable

Frozen

30 days

Collection Instructions

Collect specimen per standard laboratory collection procedures. 

 

NOTE: Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.

 

Test Components

vWF GpIb Binding Activity

Clinical Indications

Diagnosis of von Willebrand disease (VWD)

Methodology

Immunoturbidimetric (latex immuno-assay)

Additional Information

  • Locally defined normal reference range for funtional vWF is 50-203%. This local range was developed using a population of adult donors of all blood groups. 
  • It is known that group O individuals have lower vWF levels than individuals of non-group O blood type. The assay manufacturer reports the following reference ranges by blood group:
    • Group O: 49-179%. 
    • Non-group O (Groups A, B, and AB): 60-214%

  • This test was validated by the University of Chicago Medicine Coagulation Laboratory.  This test has not been cleared or approved by the FDA. The laboratory is regulated under CLIA as qualified to perform high-complexity testing.

  • 3.2% sodium citrate light blue top tubes must have 9 to 1 ratio of blood to anticoagulant.

  • Not allowed to be shared with other tests.

  • Not avaliable for add ons. 

Turnaround Time

Turnaround times are relative to the time the specimen is received in the test laboratory. 

STAT Turnaround Time: N/A

 

Routine Turnaround Time: 72 hours

 

Testing Schedule: Tuesday and Thursday, day shift only.

 

Please consult Lab medicine resident on-call (pager 7910) if more rapid test performance is deemed necessary.

Synonyms/Keyword Search

VWD; VWF GPIB Binding Activity; vWF functional; vWF activity

Last Review Date

10/30/2024