|
|
| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
ADAMTS13 Activity and Inhibitor Profile
Test CodeADM13
Alias/See Also
Protease Activity Inhibitor for TTP
CPT Codes
85397 (reflex to 85335 x2)
Includes
ADAMTS13 Activity and reflex to Bethesda Assay
Preferred Specimen
(2) 4.5 mL Sodium Citrate tubes (blue tops). For plasma specimens see instructions
Minimum Volume
(1) 4.5 mL Sodium Citrate (blue tops). For plasma specimens see instructions
Instructions
Collection Instructions for Plasma:
1. Specimen must be drawn prior to replacement therapy.
2. Spin down, remove plasma, and spin plasma again.
3. Freeze specimens immediately at < or =-40 degrees C, if possible.
4. The sample should be separated into two separate vials with a minimumof at least 1 mL in each vial.
5. Send specimens in the same shipping container.
Additional Information:
1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
1. Specimen must be drawn prior to replacement therapy.
2. Spin down, remove plasma, and spin plasma again.
3. Freeze specimens immediately at < or =-40 degrees C, if possible.
4. The sample should be separated into two separate vials with a minimumof at least 1 mL in each vial.
5. Send specimens in the same shipping container.
Additional Information:
1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
Transport Container
Sodium citrate (blue top)
Transport Temperature
Inpatient specimens must be sent to the laboratory immediately.
Outpatient specimens should be shipped frozen (see instructions)
Outpatient specimens should be shipped frozen (see instructions)
Specimen Stability
Room Temperature: Unacceptable
Refrigerated: Unacceptable\
Frozen: 2 weeks
Refrigerated: Unacceptable\
Frozen: 2 weeks
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis, lipemia, icterus
Methodology
Fluorescence resonance energy transfer (FRET)
Report Available
ADAMTS13 Activity Assay: 24 hours, ADAMTS13 Inhibitor Assay: 3-5 days, ADAMTS13 Bethesda Titer: 3-5 days upon receipt at Mayo Medical Laboratories
Reference Range
ADAMTS13 ACTIVITY ASSAY
> or =70%
ADAMTS13 INHIBITOR SCREEN
Negative
ADAMTS13 BETHESDA TITER
<0.4 BU
Clinical Significance
<10% ADAMTS13 activity is highly indicative of thrombotic thrombocytopenic purpura (TTP) in an appropriate clinical setting. The presence of ADAMTS13 inhibition (positive inhibitor screen) with a measurable antibody titer is most consistent with an acquired TTP.
Performing Laboratory
Mayo Medical Laboratories
