14. Conclusion

Thrombocytopenia may be a symptom of APS. Paradoxically, it refers to an elevated thrombotic tendency, not bleeding risk. The causes of decreased platelet number are complex: antiphospholipid antibodies that bind to platelets activate them and induce thrombosis. Thrombocytes are consumed during this process. On the other hand, thrombocytopenia is the consequence of destruction by immune mechanisms, like in the case of ITP. Sometimes, it might be the only sign of APS.

Diagnosis is not easy; other causes of thrombocytopenia must be excluded by careful examinations.

Thrombocytopenia in APS is usually mild and per se does not require any treatment. Patients with or without thrombocytopenia require anticoagulant medication in case of venous thrombotic event while low-dose aspirin or clopidogrel is recommended after arterial thrombosis. For OAPS, the combination of anticoagulant and thrombocyte aggregation inhibitor therapy is advised. CAPS is a life-threatening disease with a rapid progression of multiorgan failure. Even application of high-dose corticosteroids, plasma exchange, intravenous immunoglobulin and complement inhibitor agent mortality is very high.
