**Antiphospholipid Syndrome and Thrombocytopenia**

DOI: 10.5772/intechopen.72509

Antiphospholipid Syndrome and Thrombocytopenia

Klara Gadó and Gyula Domján

Additional information is available at the end of the chapter Klara Gadó and Gyula Domján

http://dx.doi.org/10.5772/intechopen.72509 Additional information is available at the end of the chapter

#### Abstract

Antiphospholipid syndrome is characterised by arterial and venous thromboembolic events and pregnancy morbidity (mainly, recurrent foetal losses), in the presence of antiphospholipid antibodies. Diagnosis is based on the presence of at least one laboratory and at least one clinical manifestation of antiphospholipid syndrome. There are also socalled "non-criteria" clinical features, and thrombocytopenia is one of the most important among them. Thrombocytopenia has been reported with a prevalence between 30 and 46% among patients with antiphospholipid syndrome. The pathogenesis of thrombocytopenia related to antiphospholipid antibodies is not absolutely clear. Binding of antiphospholipid antibodies to platelets and the promotion of platelet activation and aggregation thus thrombus formation must be an important mechanism as well as the immune-mediated clearance of platelets. Thrombocytopenia in antiphospholipid syndrome is usually mild and does not require clinical intervention. The presence of thrombocytopenia in patients with antiphospholipid syndrome is typically associated not with haemorrhagic complications, rather it can trigger thrombotic events. Other causes of thrombocytopenia, such as TTP, SLE, MDS, and ITP should be excluded. As thrombocytopenia is usually mild and it predicts later thrombosis, patients may be given platelet aggregation inhibitors and/ or anticoagulant therapy. Anti-thrombotic treatment should be stopped only in case of severe thrombocytopenia.

Keywords: antiphospholipid syndrome, APS, antiphospholipid antibody, thrombocytopenia, thrombosis, SLE, pregnancy
