Background Catastrophic antiphospholipid syndrome (CAPS) is a rare variant that accounts for 1% of patients with antiphospholipid syndrome.

Methods The current knowledge of this potential devastating entity comes from the International Registry of patients with CAPS, named ‘CAPS Registry’. This presentation shows the results of the most recent analysis of the registry.

Results Small vessel thrombosis, laboratory features of microangiopathic haemolytic anemia, and development of multisystem involvement in a very short period of time are the main characteristics of this syndrome. Clinical manifestations are due to thrombosis but also, although the evidences are indirect, to excess of proinflammatory cytokines. Therefore, treatment strategy is based on the combination of anticoagulation, glucocorticoids, plasma exchange and/or intravenous immunoglobulins, the so-called triple therapy. In refractory cases or in those with initial life-threatening situation, rituximab may be an effective option. Recently, some cases of CAPS have been effectively treated with the addition of eculizumab to the triple therapy.

Conclusions Despite its low frequency, the mortality-related is still very high, ranging from 50% of patients in the first series to 37% in the most recent data.