THU0278 Rituximab in Catastrophic Antiphospholipid Syndrome: A Potential Therapeutic Option
Authors: H. Berman, I. Rodríguez-Pintó, G. Espinosa, R. Cervera
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> Catastrophic antiphospholipid syndrome (APS) is characterized by thrombosis in multiple organs developing over a short period of time. The combined therapy of anticoagulation plus glucocorticoids plus plasma exchange and/or intravenous immunoglobulin is the first-line treatment. Despite this regimen, the mortality remains high and new treatment options are needed. Rituximab, a chimeric monoclonal antibody against CD20, has demonstrated in observational studies that may be effective for the treatment of patients with refractory forms of systemic lupus erythematosus (SLE). <h3>Objectives</h3> To describe the main clinical manifestations, laboratory features, and outcome of patients with catastrophic APS treated with rituximab. <h3>Methods</h3> We reviewed the web-based international Catastrophic APS registry ("CAPS Registry") for rituximab-treated patients. The registry contains clinical, laboratory, and therapeutic data on all reported cases of catastrophic APS, and can be freely consulted through the Internet (http://infmed.fcrb.es/es/web/caps). <h3>Results</h3> We identified 15 patients with catastrophic APS treated with rituximab. Median age of patients was 36.4 years (range 3 months-69 years). Eleven (73%) patients were female, 9 (60%) suffered from primary APS, 4 (27%) from SLE, and the remaining two patients from splenic marginal-zone lymphoma and overlap syndrome, respectively. In 8 (53%)patients, precipitating factors were identified. The most frequent precipitating factor, found in 5 patients, was infection. Problems related to anticoagulation treatment were identified in 2 cases and trauma in the remaining case. Lupus anticoagulant was reported as positive in 9/11 patients, the IgG isotype of anticardiolipin antibodies (aCL) in 10/12 (83%) and the IgM isotype of aCL in 4 (50%). The IgM isotype of anti-β2-glycoprotein I antibodies were positive in only 5 patients and the IgG isotype in 4 patients. In 2 patients, the administration of rituximab as first or second-line was not specified in the registry. Four (31%) out of 13 patients received rituximab as first-line treatment associated with combined therapy of catastrophic APS: In 3 of them, the reason was the severity of clinical picture and in the remaining, rituximab was administered as a treatment of lymphoma. In 9 (69%) patients, rituximab was the second line-therapy due to poor response to initial treatment in form of recurrent episodes of catastrophic APS in 2 patients, worsening of thrombocitopenia in one patient and worsening of thrombotic clinical picture in 3 patients (in the remaining 3 patients, the reason for rituximab was not specified). Rituximab was used in a different fashion, including 375 mg/m<sup>2</sup> once weekly for 4 weeks (4 patients) or two infusions of 500-1000 mg one or two weeks or a month apart (3 patients). No adverse events were described in relation to the rituximab. After a mean follow-up of 14.8 ± 11.8 months, only 3 (20%) patients died. <h3>Conclusions</h3> Rituximab may be effective for the treatment of patients with severe or refractory catastrophic APS. <h3>Disclosure of Interest</h3> None Declared