Catastrophic antiphospholipid syndrome: report of 4 cases.

Catastrophic antiphospholipid syndrome (CAPS), described by Asherson in 1992, is a rare form of antiphospholipid syndrome resulting in multiorgan failure with a mortality rate of about 50%. The syndrome occurs in patients with either systemic lupus erythematosus and other rheumatic diseases (systemic sclerosis, rheumatoid arthritis, primary Sjogren syndrome) or alone. Whereas in "classic" antiphospholipid syndrome (APS), medium-large vessels are involved, a diffuse small vessel ischemia and thrombosis (microangiopathic disease) leading to a severe multiorgan dysfunction is predominant in CAPS. "Trigger" factors have been demonstrated in 45% of patients, but in the majority, they remain unknown. Not infrequently, CAPS arises in patients without any previous thrombotic history. The kidney is the organ most commonly affected, followed by the lung, the central nervous system, the heart and the skin. Disseminated intravascular coagulation occurs in approximately 13% of patients. The present study reports the clinical and serological features of 4 patients affected by this rare form of antiphospholipid syndrome. Nephrologists should be aware of the possibility of this syndrome as a cause of multiorgan failure since prompt recognition is essential for effective treatment.