An insight into the pathophysiology of thrombosis in antiphospholipid syndrome.

The antiphospholipid syndrome (APS) is a disorder which is characterized by the presence of autoimmune antiphospholipid antibodies (APL) and increased risk of thrombosis and fetal loss. APL are associated with recurrent abortions in APS patients and participate in the pathogenesis of venous or arterial thrombosis, although the underlying mechanisms are poorly understood. Antigens that are targeted by APL include beta 2 glycoprotein I and prothrombin. Pathological mechanisms of APL encompass inhibition of natural anticoagulants (protein C system, tissue factor pathway inhibitor, and annexin A5), inhibition of the fibrinolytic system, activation of endothelial cells, monocytes and platelets, and complement activation. In this review, we discuss the main targets of APL and prothrombogenic mechanisms of APL.

Prevalence of antiphospholipid antibodies is not different in Chilean diabetic patients and normal individuals.

Diabetes mellitus (DM) is complicated by vascular and neurological events. Antiphospholipid (aPL) antibodies have already been associated with many clinical conditions, including venous and arterial thrombosis, as well as recurrent fetal loss. However, a significant association between aPL antibodies and DM has not been widely reported yet. In the present study, we investigated the prevalence of aPL antibodies in diabetic patients. This study included 100 Chilean diabetic patients (67 of them with some complications and 33 without complications; 28 with Type 1 and 72 with Type 2 DM) and 100 healthy blood donor controls. Each sample was analyzed for IgG, IgM and IgA anticardiolipin (aCL), anti-beta(2) glycoprotein I (anti-beta(2)GPI), antiprothrombin (aPT) antibodies, and lupus anticoagulant (LA). Fourteen out of 100 (14%) diabetic patients presented some type of aPL antibodies. Four patients were positive for aCL antibodies, two for anti-beta(2)GPI antibodies, and nine for aPT antibodies. All patients were LA negative. The incidence of different isotypes was similar in each of the aPL antibodies studied, and their activities were low. No significant correlation was observed between aPL antibodies and vascular complications.