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Antithrombin Activity
| Item | Value | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Approval req'd? | No | ||||||||
| Available Stat? | No | ||||||||
| Test code | AT | ||||||||
| Test group | Antithrombin | ||||||||
| Performed by | Parnassus Hematology | ||||||||
| Method | Chromogenic substrate | ||||||||
| Collection Instructions | 1. Check the expiration date on the label of the blue top vacutainer before drawing the patient. 2. For blood collection in a sodium citrate blue top, the tube must be filled to above the Minimum Fill Indicator on the tube. It is crucial to wait and allow the tube to stop filling before removing it from the needle. 3. With use of a butterfly needle, draw about 1 cc using a separate blue top to remove air from tubing, discard the first tube and then draw a second blue top tube filled to the full extent of the vacuum. 4. Tubes should not be filled past the Maximum Fill dashed line by either using a syringe or removing the tube cap. For patients with Hct's ≥ 55% please contact Hematology (x3-1747) to obtain blue top tubes with adjusted citrate volumes in order to maintain the proper citrate to plasma ratio for coagulation studies. |
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| Container type | Blue top filled to full extent of vacuum | ||||||||
| Amount to Collect | 2.7 mL blood | ||||||||
| Sample type | Citrated plasma | ||||||||
| Preferred volume | 1 mL plasma | ||||||||
| Min. Volume | 0.5 mL plasma | ||||||||
| UCSF Rejection Criteria | Samples collected in outdated blue top vacutainer. Over-filled or under-filled tubes may be rejected | ||||||||
| Processing notes | Deliver sample to Hematology asap for processing. Test specimens within four hours of collection or freeze plasma in a plastic tubes at -20C. | ||||||||
| Units | % activity | ||||||||
| Normal range |
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| Synonyms | ATIII; AT3; AT III; AT Activity; Anithrombin III Activity | ||||||||
| Turn around times | 1-2 weeks. | ||||||||
| Additional information | There is no published pediatric reference range for Antithrombin activity, which generally parallels the level of antigen. The following table gives age-adjusted reference ranges for Antithrombin antigen:
Reference: Andrew M. Et al. Development of the Human Coagulation System in the Full Term Infant. Blood July 1987, 70(1):165-172. A low level of antithrombin may be associated with an inherited deficiency or with secondary causes such as acute venous thrombosis, liver disease, disseminated intravascular coagulation, heparin therapy, pregnancy, estrogen therapy, and nephropathy with proteinuria |
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| LOINC code | 27811-9 | ||||||||
| Last Updated | 5/18/2011 12:18:32 PM | ||||||||
| Entry Number | 65 |
If you have additional questions regarding this test, please call: 415-353-1667