Phases of acute HIT
| Phases . | Platelet count . | Functional assay . | Immunoassay . | Time from discontinuation of heparin . |
|---|---|---|---|---|
| Suspected HIT | Decreased | ? | ? | NA |
| Acute HIT | Decreased | + | + | NA |
| Subacute HIT A | Normal | + | + | Majority recover platelet count by 7 days |
| Subacute HIT B | Normal | − | + | Median 50 days for functional assay to become negative |
| Remote HIT | Normal | − | − | Median 85 days for PF4/H antibodies to become undetectable |
| Phases . | Platelet count . | Functional assay . | Immunoassay . | Time from discontinuation of heparin . |
|---|---|---|---|---|
| Suspected HIT | Decreased | ? | ? | NA |
| Acute HIT | Decreased | + | + | NA |
| Subacute HIT A | Normal | + | + | Majority recover platelet count by 7 days |
| Subacute HIT B | Normal | − | + | Median 50 days for functional assay to become negative |
| Remote HIT | Normal | − | − | Median 85 days for PF4/H antibodies to become undetectable |
Adapted from Cuker19 with permission from Georg Thieme Verlag KG.
NA, not applicable.