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HelpTest Code FVIII Factor 8 Assay, LAB306
Methodology
Activated Partial Thromboplastin Clot Based Assay
Performing Laboratory
St. Luke's Hospital Cedar Rapids
Specimen Requirements
Container/Tube:
Preferred:Full blue-top (sodium citrate) 1.8mL tube-Hemolyzed or short draw specimen is not acceptable.
Specimen Volume: 0.5mL sodium citrate
plasma
Stability: centrifuged specimens at 2-4°C
or at 18-24°C must be tested within 4 hours from the
time of specimen collection.
Collection Instructions: Forward promptly. If there is a delay in transport of >4 hours or if mailing time exceeds 4 hours, spin down, remove plasma from cells and freeze immediately in plastic vial. Send specimen frozen. Specimen stability is ≤2 weeks when frozen at -20° C.
NOTE: Patients with a hematocrit of >55% must be recollected using an altered amount of sodium citrate
Reference Values
50 - 150% activity
Day(s) Test Set Up
Monday through Friday (days only)
Test Classification and CPT Coding
85240
Useful For
Hemophilia A is a sex-linked hemorrhagic disease caused by reduced circulating Factor VIII. In patients with the disease, the degree of Factor VIII deficiency dictates the severity of the bleeding disorder. Approximately 10-40% of normal Factor VIII activity is required for minimal hemostasis; below this range a tendency toward bleeding is apparent.
Analytic Time
1 day upon receipt