A Case of Catastrophic Antiphospholipid Syndrome with Acute Multiorgan Thrombosis and Concerns for Re-Emergence

Objective: Rare disease Background: Catastrophic antiphospholipid syndrome (CAPS) is a rare, life-threatening form of antiphospholipid syndrome characterized by widespread thrombotic complications leading to multiorgan ischemia and failure. Although there are no standard treatment guidelines for CAPS, it often involves triple therapy with anticoagulation, corticosteroids, and plasma exchange. Recently, biologics such as rituximab and eculizumab have also shown promise as potential new therapies for CAPS, as observed in our case. Case Report: We describe a 59-year-old female patient who presented with altered mental status and diffuse weakness. Imaging studies revealed multiorgan thrombosis along with thrombocytopenia that markedly improved with plasma exchange therapy, steroids, and a heparin drip. While the exact etiology of CAPS remained unknown, it was likely precipitated by her warfarin discontinuation and confirmed Haemophilus influenzae infection. The patient's hospital course was complicated by hemorrhagic shock after a renal biopsy, followed by an acute drop in thrombocytopenia and new embolic infarcts in the brain that raised concern for CAPS re-emergence. To address the refractory nature of her condition, the patient underwent a trial of rituximab, which remarkably improved her clinical picture and platelet count by an 8-fold increase within 1 week. Conclusions: This case highlights the importance of early recognition and diagnosis of catastrophic antiphospholipid syndrome, a true rheumatological emergency that requires aggressive treatment to prevent irreversible complications. Our patient's presentation and response to treatment also underscores the complexity of managing CAPS and the use of newer biological therapies in refractory cases.