Abstract Number: PB1925
Meeting: ISTH 2020 Congress
Background: Catastrophic antiphospholipid syndrome (CAPS) is a life threatening complication of APS characterized by simultaneous intravascular and microvascular thrombosis involving three or more organs in presence of antiphospholipid antibodies. recent studies have demonstrated significant complement activation in patients with thrombotic APS and clinical manifestations of CAPS TMA is similar to complement- mediated TMA.
Aims: To evaluate the efficacy of Eculizumab in refractory CAPS patient. To perform molecular sequencing of complement regulatory genes and screening for antibodies against CFH.
Methods: Six APS patients who presented with Clinical manifestation fulling CAPS criteria The genomic DNA was used as a template for a highly multiplexed polymerase chain reaction scheme. Sequence data were aligned to the human reference genome (Hg19) to identify nucleotide variants.
Results: Six APS patients, all triple positive, five males and one female ages 36 to 71 who fulfilled criteria for CAPS with three or more organ systems involved and all with renal insufficiency and thrombocytopenia on presentation. Three were considered secondary with a diagnosis of Lupus. One with a prior diagnosis of ITP. All were treated with corticosteroids and heparin and 4 received plasmapheresis. Three were treated with Eculizumab, two with disease progression while on plasmapheresis. All three rapidly improved with complement inhibition.
Complement gene molecular variants were identified in 4 patients, two with multiple variants. Two of the tree patients treated with Eculizumab has variants identified.
Conclusions: Our finding support a role for complement dysregulation in APS patients who developed the Catastrophic form of the disease. Complement inhibition in three patients with worsening clinical manifestation resulting in clinical improvement most noted in improved renal function similar to patients with aHUS. The efficacy of heparin in CAPS may also be related to its documented anti-complement inhibitory activity in addition to its anticoagulant activity.
To cite this abstract in AMA style:Liebman H, Weitz I. Complement Regulatory Abnormalities are Frequent in Patients with Catastrophic APS and Refractory Patients Respond Rapidly to Eculizumab Treatment [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/complement-regulatory-abnormalities-are-frequent-in-patients-with-catastrophic-aps-and-refractory-patients-respond-rapidly-to-eculizumab-treatment/. Accessed March 4, 2024.
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