Use of Plasmapheresis and Rituximab in Probable Catastrophic Antiphospholipid Syndrome: A Case Report

Document Type

Conference Proceeding

Publication Date

5-2026

Publication Title

American Journal of Respiratory and Critical Care Medicine

Abstract

Introduction: Antiphospholipid Syndrome (APS) is an acquired prothrombotic state that presents as venous thrombosis, arterial thrombosis and obstetric complications like abortion and fetal demise. Catastrophic Antiphospholipid Syndrome (CAPS) is a rare and rapid occurrence of microvascular thrombosis and multi-system injury associated with Antiphospholipid Syndrome. Case Presentation: 60 year old Female with recent history of right lower extremity deep vein thrombosis on Apixaban and family history of Factor V Leiden mutation presented with dyspnea, worsening right lower extremity discoloration and bilateral leg swelling. She was noted to have tachycardia, bilateral pitting pedal edema and black discoloration of right leg and foot. Mild normocytic anemia and thrombocytopenia was noted in initial laboratory tests. Vascular ultrasound of extremities demonstrated extensive proximal and distal thrombosis of veins but no arterial clots, and Computed Tomography Angiography of chest revealed pulmonary embolism of right upper lobe. Antiphospholipid panel was positive with high Cardiolipin IgG and Beta 2 Glycoprotein IgG antibodies (more than 40 units / ml). Antinuclear antibody was positive and Complement level (C3 and C4) was low. Management and hospital courseIntravenous Heparin was started. While intermediate-high risk Pulmonary Embolism based on clinical, laboratory and imaging findings, catheter directed interventions were not pursued. She was offered above-knee-amputation for limb ischemia, which she declined. There was concern for microangiopathy due to down-trending platelets with elevated bilirubin and acute kidney injury, and after discussion with Hematology, Nephrology and Rheumatology, decision to pursue management for potential CAPS was made. Intravenous glucocorticoid, Plasmapheresis and Rituximab were started, following which antiphospholipid antibody levels decreased and improvement in thrombocytopenia was noted. Discussion: Combination therapy with systemic anticoagulation, high-dose intravenous glucocorticoids, and either plasmapheresis or intravenous immunoglobulin (IVIG) constitutes the recommended management for CAPS, with reported mortality reduction from 50% to 25%. Although definitive CAPS classification requires evidence of microvascular thrombosis, current literature supports initiating this regimen in patients with high suspicion for CAPS and life-threatening clinical presentations, even if diagnostic criteria is not met. Rituximab may be considered in cases of immune thrombocytopenia and microangiopathic hemolytic anemia related to antiphospholipid syndrome; however, evidence in CAPS is limited to case reports and small registry-based studies, and its efficacy remains to be established. Conclusion: More evidence is needed to determine the utility of Rituximab in patients with CAPS.

Volume

212

Issue

S1

First Page

S3799

Comments

American Thoracic Society International Conference, May 15-20, 2026, Orlando, FL

Last Page

S3799

DOI

10.1093/ajrccm/aamag162.5062

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