Antinuclear antibody status and risk of death in children and adolescents

Objectives: The association between the presence of antinuclear antibodies (ANA) and mortality has been rarely reported. The present study explored the value of ANA as a predictor of overall survival in children and adolescents. Methods: Patients younger than 20 years who underwent ANA testing in Chang Gung Memorial Hospital (CGMH) from 2000 to 2008 were enrolled in this study. Mortality was ascertained by using the National Death Registry of Taiwan. Positive ANA titres were categorized as low (1:40 to 1:80), medium (1:160 to 1:320), and high (≥ 1:640). Results: A total of 13 345 subjects (6579 males, 6766 females) were enrolled during the 9-year study period. The overall prevalence of low, medium, and high ANA titres was 20.8% (n = 2774), 6.0% (n = 804), and 2.5% (n = 338), respectively. During 45 140 person-years of follow-up, 146 deaths were identified and the crude mortality rates were 3.8 and 3.0 per 1000 person-years for subjects with positive and negative ANA test results, respectively (p = 0.130). Compared with ANA-negative subjects, the adjusted hazard ratio (HR) for all-cause mortality among those with a high ANA titre was 5.18 [95% confidence interval (CI) 3.138.57]. A low-to-medium ANA titre was not associated with increased mortality. Among the 18 deaths in individuals with a high ANA titre, 14 were due to systemic lupus erythematosus (SLE). In comparison, five out of 34 deaths among those with low-to-medium titres of ANA and none of those with negative ANA were related to SLE. Conclusions: Children and adolescents with high ANA titres should receive greater attention and monitoring to prevent unfavourable outcomes because they have a higher mortality risk than those with negative ANA results.