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ADAMTS13 Activity, Plasma
Test CodeADAMN
Alias/See Also
Epic: LAB13759
Preferred Specimen
Specimen Type: Platelet-poor plasma
Collection Container: Light blue top (citrate)
Specimen Volume: 2 x 1 mL
Minimum Volume
0.5 mL
Instructions
- Draw blood into a light blue (sodium citrate) tube. Be sure to fill tubes completely.
- Mix gently 5 to 6 times (do not over mix).
- Centrifuge the sample for 10 minutes.
- Using a pipette, aliquot plasma into a plastic vial being careful not disturb the buffy coat.
- Centrifuge the plasma sample a second time for 10 minutes
- Using a pipette, aliquot the top portion of plasma into a plastic vial. Be careful not to disturb the sediment at the bottom (leave approx. 0.25 mL of plasma at the bottom).
- Label each tube as "Plasma."
- Immediately freeze samples
Transport Container
Plastic vial
Specimen Stability
Room temperature: 4 hours
Refrigerated: Unacceptable
Frozen: 6 months
Methodology
Fluorescence resonance energy transfer (FRET)
Setup Schedule
Monday - Friday
Report Available
Next day
Limitations
Results are not acceptable if positive control is out of ±2SD.
If R2 of standard calibration curve is <0.98, results are not acceptable.
Patient results with %CV of >20 is not acceptable. Exceptions: if result is less than 50, CV of >20% is acceptable.
If R2 of standard calibration curve is <0.98, results are not acceptable.
Patient results with %CV of >20 is not acceptable. Exceptions: if result is less than 50, CV of >20% is acceptable.
Reference Range
>=75%
Clinical Significance
ADAMTS13, also known as von Willebrand Factor (vWF) cleaving protease, is a zinc metalloproteinase that cleaves ultra large vWF multimers (UL -_vWF) at the Tyr(1605)- Met(1606) bond located in the A2 region of VWF. An ADAMTS13 activity level below 5 % of normal leads to an accumulation of UL- vWF multimers in plasma. The UL- vWF multimers bind to receptors on platelets inducing platelet aggregation and formation of intravascular microthrombi.
Congenital TTP is a rare heritable disorder caused by mutations within the ADAMTS13 gene which result in the production of non-functional ADAMTS13 protein. The acquired form of TTP is an autoimmune-like disorder caused by the development of autoantibodies to ADAMTS13 that inhibit enzyme activity.
Congenital TTP is a rare heritable disorder caused by mutations within the ADAMTS13 gene which result in the production of non-functional ADAMTS13 protein. The acquired form of TTP is an autoimmune-like disorder caused by the development of autoantibodies to ADAMTS13 that inhibit enzyme activity.
Performing Laboratory
Inova Laboratories
2832 Juniper Street
Fairfax, VA 22031
Last Updated: November 22, 2023
Last Review: N. Wolford, November 22, 2023