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Uses: Order to diagnose hemophilia A, acquired factor VIII deficiency, or as part of a diagnostic workup for von Willebrand disease (VWD). Also useful for monitoring treatment in patients with factor VIII deficiency or VWD. Not recommended when screening for thrombophilia.
Method: Electromagnetic Mechanical Clot Detection
Category: Coagulation Disorders, Hematology
Reference: Normal
| Age | Reference Interval |
|---|---|
| 0-6 years | 56-191% |
| 7-9 years | 76-199% |
| 10-11 years | 80-209% |
| 12-13 years | 72-198% |
| 14-15 years | 69-237% |
| 16-17 years | 63-221% |
| 18 years and older | 56-191% |
Abnormal in hemophilia >5% Mild, 1-5% Moderate, <1% Severe
Pre-test Information: Overnight fasting is preferred. Give a brief clinical history. It is recommended that patient discontinues Heparin for 1 day & Oral Anticoagulants for 7 days prior to sampling as these drugs may affect test results. Discontinuation should be with prior consent from the treating Physician.
Specimen Collection: 3 mL Whole blood in 1 Blue tube (Sodium Citrate). Mix thoroughly by inversion. Transport to Lab within 4 hrs. If this is not possible, make PPP within 1 hour of the collection as follows: Centrifuge sample at 3600 rpm for 15 min & transfer supernatant to a clean plastic tube. Centrifuge this supernatant again at 3600 rpm for 15 mins & finally transfer the supernatant (PPP) to 1 labelled clean plastic screw-capped vial. FREEZE IMMEDIATELY. Ship frozen. DO NOT THAW. Overnight fasting is preferred. Duly filled Coagulation Requisition Form is mandatory.
Storage: Critical frozen
Stability: Stability Room 4 hrs
Stability Refrigerated 4 hrs
Stability Frozen 2 weeks
Report Availability: 1-3 days
More Details: Other names that describe the test. Antihemophilic Factor (AHF), Factor VIII:C (Coagulant Portion) Coagulation Factor VIII Activity Assay,Plasma Factor VIII Activity Assay, Intrinsic Factor Proteins, Intrinsic Factors, Factor 8 deficiency test. Ageing, pregnancy, OCP use & oestrogen replacement therapy can increase Factor VIII levels.