Diagnosing catastrophic antiphospholipid syndrome: the necessity for clinical awareness

Abstract

The catastrophic variant of antiphospholipid syndrome (APS) is the most severe form of the syndrome. Patients with this variant present with the following characteristics: clinical evidence of multiple organ involvement that develops over a very short period of time (usually less than a week); histopathological features of small vessel occlusions; and laboratory confirmation of the presence of antiphospholipid antibodies (aPL) [1]. Described by Ronald A Asherson in 1992, this subset is now also referred to as Asherson’s syndrome, thus honoring the author who passed away in 2008 [2]. Although less than 1% of patients with APS develop this catastrophic variant [3], its high mortality (currently higher than 30% in the acute event [4]) emphasizes its importance in clinical medicine today. The majority of patients with this condition end up in intensive care units with multiorgan failure. Unless considered in the differential diagnosis by the attending physicians, the condition may be completely missed, resulting in a potentially lethal outcome. From a histopathological point of view, catastrophic APS is a thrombotic microangiopathic condition. However, at present, there are no studies on its pathophysiologic mechanisms. Two possible explanations include: extensive thromboses being responsible for the ongoing thrombosis by generating thrombin, depressing fibrinolysis and consuming the natural anticoag ulant proteins; and the manifestations of the systemic inflammatory response syndrome, which are presumed to be due to excessive cytokine release from ischemic and necrotic tissues [5]. Although it is still unclear what the pathophysiologic reason for why some patients develop recurrent thromboses of medium/large vessels