Anti-Platelet Factor 4
Test Mnemonic
PLATF4
CPT Codes
- 86022 - QTY (2)
Aliases
- Heparin Dependent Antibody
- PF4
- Platelet Antibody Heparin
- Platelet Antibody LMW Heparin
- PLTAB1
- PLTAB2
Performing Laboratory
Cleveland Clinic Laboratories
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 3 mL | Plasma | Sodium citrate (Lt. Blue) | Frozen | Separate plasma from cells ASAP. |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL | Serum | No additive (Red) | Frozen | Separate serum from cells ASAP. Specimen must be labeled as serum. Serum not preferred, as it cannot be used for positive confirmatory reflex test. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | Remove plasma from cells ASAP. Plasma good for 4 hours ambient. |
| Refrigerated | Unacceptable |
| Frozen | 2 weeks |
Days Performed
Sun - Sat
Turnaround Time
1 day
Methodology
| Name | Description |
|---|---|
| Enzyme-Linked Immunosorbent Assay (ELISA) |
Reference Range
| Anti-Platelet Factor 4 | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Years | 99 Years | Normal | < 0.400 | OD | Years | 99 Years | Urgent | >0.400 OD reading with more than 50% inhibition with excess heparin after Pathologist review. | OD |
| PF4 Interpretation | |||||
| Sex | Age From | Age To | Type | Range | Range Unit |
| Normal | Negative | Urgent | Positive(*) |
Special Info
3.2 % sodium citrate is the preferred anticoagulant recommended by CLSI. All positive specimens (OD>= 0.400) will have confirmatory platelet aggregation testing (PLHEPP or PLLMWP) ordered and charged. If Heparin Induced Thrombocytopenia is due to low molecular weight heparin (LMWH), contact the lab at 216-444-2519.
Clinical Info
Test to detect IgG anti-PF4/heparin antibodies, observed in patients with heparin-induced thrombocytopenia. OD > = 0.400 with positive heparin confirmation step suggests presence of anti-PF4/heparin antibody, but does not confirm a diagnosis of heparin-induced thrombocytopenia (HIT), which should include clinical findings.