ADAMTS 13 Activity

Also Known as (Alias) ATS-13
Indications TTP/HUS
Method Flourescence Resonance Transfer Assay(FRET), 
Test Information ADAMTS13 activity is measured by a Fluorescence Resonance Transfer (FRET) Assay in which fluorescence is detected when a synthetic von Willebrand Factor peptide (VWF73) is cleaved by ADAMTS13
Additional Test Information ADAMTS13 is a plasma protein that cleaves ultra-large VWF multimers, thus regulating the interaction of platelets with von Willebrand. Low ADAMTS13 activity is found in patients with thrombotic thrombocytopenia purpura (TTP).   In classic acquired antibody-mediated TTP, an  the ADAMTS13 activity level is usually less than 10% at presentation.  Very low levels are also seen in congenital TTP.  Modestly decreased levels have been reported in a number of clinical settings. ADAMTS13 activity levels may help differentiate TTP from other microthrombolytic disorders such as HUS or atypical HUS.
Caution should be exercised in the interpretation of any assay for ADAMTS13; the results should only be considered in the conjunction with the patient's clinical condition. Previous transfusion, plasma infusion, plasma exchange, or free hemoglobin in the plasma (>2g/L) may affect the level of ADAMTS13 as well as any inhibitors that are present.
Sample Requirements Citrate (blue top)
Requested Volume 5cc citrate (blue top)
Shipping Information Spin within 4 hours and freeze plasma at -20C then ship frozen specimen on dry ice

Send samples to:
Bloodworks Northwest
Attn:  Platelet Immunology Lab, Rm 619
921 Terry Avenue
Seattle, WA 98104

For additional information please see Ordering Information
Requisition Form RFT- Immunogenetics/HLA and Platelet Immunology Labs
RFT Hemostasis Reference Laboratory
Transaction Code 3260-01
CPT Codes 85397
Test Schedule Monday, Wednesday, and Friday unless special request
Turn around Time (analytic time) 2-3 business days
Report/Results Fax number required to receive report