Relapsing catastrophic antiphospholipid syndrome potential role of microangiopathic hemolytic anemia in disease relapses

To analyze the clinical and laboratory characteristics of patients with catastrophic antiphospholipid syndrome (APS) who suffer relapses.

We analyzed the Web site--based international registry of patients with catastrophic APS ("CAPS Registry") http://infmed.fcrb.es/es/web/caps and selected those cases that relapsed.

Relapses were reported in 9 of 282 (3.2%) patients with catastrophic APS. A total of 35 episodes of catastrophic APS were found: 6 patients presented 2 relapses, 2 patients suffered 3 relapses, and 1 patient developed 17 relapses. However, the last patient was not included in the statistical analysis because his clinical and immunologic characteristics were not fully described. Therefore, a total of 18 episodes were analyzed. In 9 (50%) episodes, a precipitating factor was identified. The most frequent precipitating factor, found in 5 (28%) episodes, was infection. Brain, kidney, heart, and lung were the most common organs involved. Laboratory features of microangiopathic hemolytic anemia (MHA) were present in 13 of 18 (72%) episodes (definitive in 9, corresponding to 4 patients, and probable in 4, corresponding to 2 patients). Three relapses did not present with features of MHA and in the remaining 2 these data were not reported. The mortality rate was 38%.

Although relapses are rare in patients with catastrophic APS, these results support the hypothesis that an association between MHA and relapsing of catastrophic APS could be present.