It is not the platelet count but the clinical aspect, whether or not there is a hemorrhagic diathesis (pathologically increased bleeding tendency), that determines therapy (see table below).
Furthermore, it is important whether it is an isolated thrombocytopenia with otherwise normal values of hemoglobin (Hb) and leukocytes (incl. differential blood count), or a thrombocytopenia that is part of a two- or three-line cytopenia (dicytopenia or pancytopenia). In pancytopenia (synonym: tricytopenia), there is a severe reduction of all three rows of cells in the blood. Thus, anemia (anemia), leukopenia (reduced number of white blood cells (leukocytes) in the blood compared to the norm), and thrombocytopenia exist simultaneously.
Grade | Bleeding | Description | Therapy |
0 | none |
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1 | low |
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2 | mild |
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3 | Medium |
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4 | heavy |
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* First-line treatment:
- Glucocorticosteroids: dexamethasone, methylprednisolone, or prednisone.
- Intravenous immunoglobulins
HIT (heparin-induced thrombocytopenia)
- Most common form of drug-induced thrombocytopenia.
HIT type I | HIT type II | |
Affected group | Sensitized patients only | Non-sensitized patients also |
Frequency | 10-25 % | 0.5-3 %(UFH: NMH* = 9:1) |
Mechanism | Heparin-platelet interaction (dose-dependent). | Antibody-induced platelet activation (dose-independent). |
Onset | Day 1-5 after initiation of heparin therapy. | Day 5-20 after initiation of heparin therapyOn re-exposure for a few hours. |
Platelets | Mostly > 100,000/µl | Mostly 40-60,000/µl(drop > 50% of baseline) |
Complications | / | Thromboembolism |
Diagnostics | Diagnosis of exclusion | HIT antibodies (resulting in massive thrombin formation!). |
Therapy | No therapy required; self-limiting course; heparin can be continued | Discontinue heparin immediately if suspected (then normalize values)Anticoagulation with lepirudin, danaparoid sodium, or argatrobanPatients must not receive heparin in the future! |
* UFH: unfractionated heparinNMH: low-molecular-weight heparin.