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Factor Inhibitor Screen
| Item | Value |
|---|---|
| Approval req'd? | Yes, contact Hematology, x3-1747. |
| Available Stat? | No |
| Test code | INHB |
| Test group | Factor Inhibitor Screen |
| Performed by | Parnassus Hematology |
| In House Availability | Test run 0800-1500 Monday-Friday |
| Collection Instructions | Specify whether Factor Inhibitor Screen is being requested on PT or PTT. Factor Inhibitor Screen on PT will be performed only if PT > 18 seconds. Factor Inhibitor Screen on PTT will be performed only if PTT > 33.7 seconds. If test is ordered on samples with shorter clotting times, the inhibitor screen cannot yield a positive result; "test not indicated" will be sent. 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. Deliver immediately to the laboratory. 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. |
| Container type | Blue top filled to full extent of vacuum x3 |
| Amount to Collect | 8 mL blood |
| Sample type | Citrated plasma |
| Preferred volume | 4 mL plasma |
| Min. Volume | 3 mL plasma |
| UCSF Rejection Criteria | Samples collected in outdated blue top vacutainer. Over-filled or under-filled tubes may be rejected |
| Processing notes | Freeze in plastic at -20C. |
| Normal range | Negative |
| Synonyms | Circulating anticoagulant; Factor VIII inhibitor; Factor IX inhibitor; Porcine factor VIII inhibitor screen; F8 inhibitor; F9 inhibitor; mixing study |
| Turn around times | Same day or next weekday |
| Additional information | Specify whether Factor Inhibitor Screen is being requested on PT or PTT. Factor Inhibitor Screen on PT will be performed only if PT > 18 seconds. Factor Inhibitor Screen on PTT will be performed only if PTT > 33.7 seconds. If test is ordered on samples with shorter clotting times, the inhibitor screen cannot yield a positive result; "test not indicated" will be sent. Collecting three tubes assures that enough specimen is available if the Factor Inhibitor Titer must be performed in addition to the Factor Inhibitor Screen. |
| LOINC code | 40744-5 |
| LDT or Mod FDA? | Yes |
| Last Updated | 11/27/2012 5:20:47 PM |
| Entry Number | 355 |
If you have additional questions regarding this test, please call: 415-353-1667