Antiphospholipid antibodies (APLA) are associated with anti-phospholipid syndrome (APS), a thrombotic disorder, but they are also frequently detected in immune thrombocytopenic purpura (ITP), a bleeding disorder [₁]. Antinuclear antibodies (ANA) and antiphospholipid antibodies (APLA) are important in the pathogenesis of systemic lupus erythematosus (SLE) and the APS respectively. Not all ANA or APL antibodies can cause clinical effects [₂]. Although APS was first fully described in the context of connective tissue diseases such as systemic lupus erythematosus, it was soon recognised that the condition can exist on its own. APS appears to represent a clinical spectrum, both in terms of APS features and the presence of other autoimmune conditions. The clinical and serological characteristics of “primary” APS (PAPS) are similar to those of secondary APS, although the clinical features are more commonly recognised in the presence of another autoimmune or inflammatory condition. Furthermore, patients with PAPS may subsequently develop SLE. APLA are found in 1% to 5% of young healthy control subjects; however, the incidence increases with age and coexistent chronic disease. The syndrome occurs most commonly in young to middle-aged adults; however, it also can occur in children and the elderly. Among patients with SLE, the prevalence of APLA is high, ranging from 12% to 30% for APL, and 15% to 34% for lupus anticoagulant antibodies. In general, APLA occur approximately five times more often then lupus anticoagulant in patients with APS [₃]. In patients with ITP, the persistent presence of APLA is an important risk factor for the development of APS [₄].

In conclusion, APLA have been suggested to play a role in the pathogenesis of thrombocytopenia.

Correspondence to

Irfan Yavasoglu, Adnan Menderes University Medical Faculty, Division of Hematology, 09100 Aydin, Turkey e-mail: dr_yavas@yahoo.com Telephone: +90-256-2120020 Fax: +90-256-2146495