Antiphospholipid antibody associated thrombocytopenia and the paradoxical risk of thrombosis

Abstract

The pathogenesis of thrombocytopenia in patients with antiphospholipid syndrome (APS) is heterogeneous. Patients with antiphospholipid antibodies (aPL) and thrombocytopenia in the absence of clinical manifestations of APS will be diagnosed and treated as idiopathic thrombocytopenic purpura. However, the presence of aPL places those individuals at particular risk for developing both bleeding and thrombotic complications. Therefore, we propose the inclusion of such patients in the subgroup 'aPL-associated thrombocytopenia'. More attention should be devoted to this subgroup of patients to elucidate the role of aPL in the development of thrombocytopenia and to facilitate the adequate monitoring of its potential thrombotic risk.

Antiphospholipid-associated thrombocytopenia or autoimmune hemolytic anemia in patients with or without definite primary antiphospholipid syndrome according to the Sapporo revised classification criteria: a 6-year follow-up study

“…Even more, some authors have proposed that this subgroup of patients might indeed represent a prethrombotic state preceding the onset of APS. 27 In agreement with this notion, Diz-Küçükkaya et al 28 reported that 60% of aPL-positive patients diagnosed as having immune thrombocytopenic purpura (ITP) developed thrombosis in a 5-year follow-up study.…”

Thromboembolic events among adult patients with primary immune thrombocytopenia in the United Kingdom General Practice Research Database

“…The latter exhibit a high prevalence in adult patients with primary immune thrombocytopenia 27 and have been hypothesized to trigger increased platelet activation and decreased production of prostacylcin, nitric oxide, and protein C. 28 In a study of 82 consecutive adults with primary immune thrombocytopenia, for example, Diz-Küçükkaya et al report a statistically significant difference in 5-year, thrombosis-free survival between APA-positive and negative patients. 29 Knowledge of an elevated risk of venous thrombosis among adult patients with primary immune thrombocytopenia may possibly support increased utilization of thromboprophylactic treatment in patients at lower risk of hemorrhage.…”

Endothelial cell activation by immunoglobulins from patients with immune thrombocytopenic purpura or with antiphospholipid syndrome

“…The presence of APLA in patients with ITP puts them at an increased risk of thrombosis rather than hemorrhage, even when thrombocytopenia is severe. 12 In conclusion, our data show that some APLA in patients with ITP may be able to activate EC. Such a mechanism may have clinical significance because it may increase the risk of thrombosis, particularly when correction of thrombocytopenia is obtained.…”