Unusual manifestations of the antiphospholipid syndrome

The classical clinical picture of the antiphospholipid syndrome (APS) is characterized by venous and arterial thromboses, fetal losses and thrombocytopenia, in the presence of antiphospholipid antibodies (aPL), namely lupus anticoagulant (LA), anticardiolipin antibodies (aCL), or antibodies to the protein “cofactor” b2 glycoprotein I. Single vessel involvement or multiple vascular occlusions may give rise to a wide variety of presentations. Any combination of vascular occlusive events may occur in the same individual and the time interval between them also varies considerably from weeks to months or even years. Deep vein thrombosis, sometimes accompanied by pulmonary embolism, is the most frequently reported manifestation in this syndrome. Cerebrovascular accidents—either stroke or transient ischemic attacks—are the most common arterial thrombotic manifestations. Early and late fetal losses, premature births and pre-eclampsia are the most frequent fetal and obstetric manifestations. Additionally, several other clinical features are relatively common in these patients, i.e., thrombocytopenia, livedo reticularis, heart valve lesions, hemolytic anemia, epilepsy, myocardial infarction, leg ulcers, and amaurosis fugax. However, a large variety of other clinical manifestations have been less frequently described in patients with the APS, with prevalences lower than 5%. These include, among others, large peripheral or aortic artery occlusions, Sneddon's syndrome, chorea, transverse myelopathy, intracardiac thrombus, adult respiratory distress syndrome, renal thrombotic microangiopathy, Addison's syndrome, Budd-Chiari syndrome, nodular regenerative hyperplasia of the liver, avascular necrosis of the bone, cutaneous necrosis or subungual splinter hemorrhages. In this article, some of these “unusual” manifestations are reviewed.