(510) Asherson Syndrome: A Rare Case of Catastrophic Antiphospholipid Syndrome

Introduction: Described by Asherson in 1992, catastrophic antiphospholipid antibody syndrome (CAPS) represents a rare entity with incidence less than 1% and a 48% mortality. It is characterized by multi-vessel thrombi in antiphospholipid positive patients. Because of its rare occurrence and overlap with other thrombotic microangiopathies, it remains a diagnostic dilemma. Herein, we review such a case.

Description: A 24-year-old man with medical history of systemic lupus erythematosus, antiphospholipid syndrome (APLA) was admitted to the ICU with septic shock secondary to MSSA bacteremia. His stay was complicated by multifocal ischemic stroke and metabolic encephalopathy requiring mechanical ventilation. Transthoracic echocardiogram revealed an ejection fraction of 20% and a large mass on the aortic valve. Treatment with Nafcillin was initiated. Lab results included low complement levels, positive anti-β2GPI antibodies, and thrombocytopenia. Although microangiopathic hemolytic anemia was a differential, lab parameters were not indicative of this. Cerebral angiogram for vasculitis was inconclusive, and a lumbar puncture was negative for CNS infection. These findings raised suspicion for CAPS. The patient was started on plasma exchange, high-dose pulse steroids and therapeutic anticoagulation. Timely treatment with triple therapy for CAPS led to rapid stabilization with hemodynamic stability and liberation of mechanical ventilation. Treatment continued with antibiotics and aortic valve surgery. Patient continued to improve, progressing towards recovery.

Discussion: Catastrophic antiphospholipid syndrome is characterized by the presence of autoantibodies directed against phospholipid-binding proteins, which activate pro-thrombotic cascades leading to microvascular thrombi. Diagnosis requires the presence of microvascular thrombi within a week of insult, lab confirmation of APLA and histopathological confirmation of small vessel occlusion. It often follows an acute trigger such as infection, surgery or trauma. 3-5 days of treatment with anticoagulation, steroids, and plasma exchange has the best survival rate, with Rituximab reserved for refractory cases. Our patient showed significant improvement within three days of treatment. Timely diagnosis is often impeded by the complexity of clinical presentation.