ADAMTS 13 Antibody
| Also Known as (Alias) | ATS-13 Antibody |
| Indications | TTP |
| Method | ELISA |
| Test Information | If ADAMTS 13 activity is less than 30%, then reflex testing for an inhibitor and antibody will be performed. The ADAMTS 13 antibody test uses microtiter wells coated with a recombinant ADAMTS 13 protease. After incubation with the patient’s plasma, a conjugated anti-human IgG is applied and the test is completed with the change of color as an indication of an antibody. Test results of 12 – 15 units/mL is borderline positive for an antibody. Results of greater than 15 units/mL is positive. |
| Additional Test Information | Strong antibody-mediated inhibition of ADAMTS13 activity (>90%) is seen in approximately half of the patients with acquired TTP. The presence of this level of inhibition strengthens the case for a diagnosis of TTP. The significance of milder ADAMTS13 inhibition is unclear, particularly when the overall ADAMTS13 level is not severely depressed. The assay used does not distinguish between antibody-mediated and non-specific ADAMTS13 inhibition.
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 | Ship to Bloodworks immediately after draw to ensure the laboratory receives specimen within 4 hours of draw time. If this is not possible, spin within 4 hours and freeze plasma at -20C, then ship frozen specimen on dry ice
NOTE: If the sample is received as whole blood after 4 hours of draw time, the sample will need to be redrawn. Send samples to: For additional information, please see Ordering Information |
| Requisition Form | RFT- Platelet Immunology Laboratory RFT- Hemostasis Reference Laboratory |
| Transaction Code | 3260-03 |
| CPT Codes | 83520 |
| Test Schedule | Reflexive |
| Turn around Time (analytic time) | 2-3 business days |
| Report/Results | Fax number required to receive report |
