ADAMTS13 activity with reflex inhibitor profile

Alphabetical Test listing

ADAMTS13 activity with reflex inhibitor profile-994

Test name:

Test number:

994

Excellian order number:

LAB994

Abbreviation:

MSO

Alternate names:

Metalloprotease
Protease Activity Inhibitor for TTP
von Willebrand Factor Cleaving Protease
Microangiopathy
Thrombotic Microangiopathy
VWF protease activity and inhibitor

Tests included:

Testing begins with the ADAMTS13 activity assay to evaluate the percent activity. If the ADAMTS13 activity is less than 30%, the inhibitor titer and ADAMTS13 profile interpretation will be performed.

Useful for:

Assisting with the diagnosis of immune or acquired thrombotic thrombocytopenic purpura

Patient preparation information:

Fasting preferred

Specimen must be collected prior to replacement therapy

Specimen type:

Sodium citrate (Na cit) plasma

Collection container:

To obtain adequate sample volume please collect 2 tubes:

Lt blue Sodium citrate (Na Cit) - 2.7mL

Volume:

2 mL plasma in 2 plastic vials each containing 1 mL

Collection instructions:

Do not over or under fill tube as the ratio of anticoagulant to whole blood is critical

Coag – tube fill guidelines

Immediately following collection, mix sample thoroughly by gently inverting 8 - 10 times to prevent clotting

Processing instructions:

Centrifuge
Transfer plasma into a plastic vial
Centrifuge a second time
Aliquot plasma (one mL per aliquot) into two seperate screw cap transfer vial/tube (Mayo T914), leaving 0.25 mL in the bottom of the centrifuged vial
Freeze plasma immediately (no longer than 4 hours after collection) at -20 degrees C or, ideally, below -40 degrees C.

Transport container:

Screw cap transfer vial/tube (Mayo T914) x2

Transport and stability:

Frozen (strict)

Refrigerated - NO

Ambient - NO

Specimen retention time:

7 days

Performing lab:

Mayo Clinic Laboratories (ADAMS): R-NX

Days set up:

Mo - Fr, Su

TAT:

3 days

Method:

Fluorescence Resonance Energy Transfer (FRET)

Reference ranges:

ADAMTS13 ACTIVITY ASSAY: > or =70%

ADAMTS13 INHIBITOR TITER: <0.5 BU

Clinical information:

Less than 10% ADAMTS13 activity is highly indicative of thrombotic thrombocytopenic purpura (TTP) in an appropriate clinical setting. The presence of ADAMTS13 measurable Bethesda titer is most consistent with an acquired (autoimmune) TTP.

CPT codes:

85397
85335 (if appropriate)

Date created:

05/31/2022

Revised date:

05/24/2024

Review date:

02/28/2023