| Primary Name | Factor II Assay |
| Synonym | Prothrombin Assay |
| Synonym | Factor II Functional Assay |
| UAB Procedure Number | 2500470 |
| CPT Code | 85210 |
| Specimen | Collect one (1) blue-stopper tube (3.2% sodium citrate), filled to specified volume. Do not underfill or overfill. |
| Specimen Management | Note time of collection and time of last treatment if applicable. Centrifuge blue-stopper tube within 1 hour of collection, separate plasma and test or quick-freeze at -70°C. |
| Specimen Accepted | Daily including weekends |
| Test Performed | Monday-Friday. |
| Available Stat? | Pathologist's approval required. |
| Description | Congenital factor II (prothrombin) deficiency is caused by one of several rare mutations that reduce prothrombin production or activity. Acquired prothrombin deficiency is caused by vitamin K deficiency, the use of Coumadin therapy, or prothrombin-neutralizing lupus anticoagulant. |
| Reference Interval | 50-150% |
| Critical Value | None |
| Follow-up Test | If the functional prothrombin assay indicates a deficiency, the prothrombin antigen assay may be used to distinguish qualitative from quantitative disorders. |
| Associated With | Bleeding disorders |
| Associated With | Lupus anticoagulant |
| Associated With | Vitamin K deficiency |
© Copyright by the University of Alabama at Birmingham