Factor VIII inhibitor assay

Alphabetical Test listing

Factor VIII inhibitor assay-994

Test name:

Test number:

994

Excellian order number:

LAB994

Abbreviation:

MSO

Alternate names:

Bethesda Titer
Factor 8 inhibitor assay

Tests included:

Activated partial thromboplastin time (aPTT)
aPTT 1:1 mix with normal plasma
aPTT 1:1 incubated mix with normal plasma
aPTT 1:1 mix with saline
Factor VIII activity
Factor VIII Bethesda titer

Useful for:

Confirmation and characterization of factor VIII inhibitor

Patient preparation information:

The patient should not be anticoagulated

Specimen type:

Sodium citrate (Na cit) plasma

Collection container:

Lt blue Sodium citrate (NaCit) - 2.7mL x 3

Volume:

3 mL

Collection instructions:

Do not draw from an arm with a heparin lock or heparinized catheter

Processing instructions:

Centrifuge for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells.
Deliver to a plastic transport tube, cap, and recentifuge for 10 minutes.
Use a second plastic pipette to remove plasma, staying clear of the platelets at the bottom of the tube.
Transfer the plasma into a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as Na cit plasma and freeze immediately.

Transport container:

Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)

Transport and stability:

Frozen (strict)

Ambient - 4 hours

Performing lab:

Esoterix Coagulation Lab (300701) via LabCorp (500350): R-NX

Days set up:

Mo - Fr

TAT:

2 - 3 days

Method:

Clot

Reference ranges:

An interpretive report will be provided

CPT codes:

85240
85335
85730
85732 x 3

Subject to medical necessity (Y/N):

Yes

LCD/NCD:

Medical necessity

LOINC code:

Result:
500347 APTT 1:1 Normal Pool Mix 5946-9
500349 APTT 1:1 NP Mix, 60 Min,Incub. 30323-0

Date created:

05/29/2019

Revised date:

02/17/2021

Review date:

01/08/2024