Pediatric catastrophic antiphospholipid syndrome: descriptive analysis of 45 patients from the "CAPS Registry"

Given the lack of information about catastrophic antiphospholipid syndrome (APS) in pediatric patients, the objective of the current study was to describe the clinical characteristics, laboratory features, treatment, and outcome of pediatric patients with catastrophic APS and compare them with the adult patients with catastrophic APS. We identified patients who were under 18years of age at time of catastrophic APS diagnosis included in the international registry of patients with catastrophic APS (CAPS Registry). Their main demographic and clinical characteristics, laboratory features, treatment, and outcome were described and compared with those of adult patients with catastrophic APS. From the 446 patients included in the CAPS Registry as of May 2013, 45 (10.3%) patients developed 46 catastrophic events before 18years of age (one patient presented two episodes). Overall, 32 (71.1%) patients were female and the mean age was 11.5±4.6years (range, 3months-18years). A total of 31 (68.9%) patients suffered from primary APS and 13 (28.9%) from systemic lupus erythematosus (SLE). The main differences between the two groups of patients were the higher prevalence of infections as precipitating factor for catastrophic event in the pediatric population (60.9% versus 26.8% in the adult population, p<0.001) and of peripheral vessel thrombosis (52.2% versus 34.3%, p=0.017). In addition, catastrophic APS was the first manifestation of APS more frequently in pediatric patients (86.6% versus 45.2%, p<0.001). Interestingly, pediatric patients showed a trend of lower mortality, although the difference was not statistically significant (26.1% versus 40.2%; odds ratio, 1.9; 95% confidence interval, 0.96-3.79; p=0.063). No differences were found neither in the laboratory features nor in the isolated or combination treatments between groups. Catastrophic APS in pediatric patients is a rare disease. There are minimal differences in the clinical and laboratory features, treatment, and outcome of pediatric and adult catastrophic APS patients.