Childhood-onset systemic lupus erythematosus and immune thrombocytopenia: Prevalence and risk factors.

BACKGROUND:There are few studies examining the prevalence and clinical risk factors for subsequent systemic lupus erythematosus (SLE) development after long-term follow-up in childhood immune thrombocytopenia (ITP). The aims of this study were to evaluate the prevalence and risk factors for subsequent SLE development in childhood ITP. METHODS:The medical records of childhood ITP patients aged under 15 years in a major tertiary care center in Southern Thailand were retrospectively reviewed. The Kaplan-Meier method was used to estimate the cumulative probability of subsequent SLE development after ITP. Logistic regression analysis was used to identify independent risk factors for SLE development. RESULTS:A total of 473 childhood ITP cases were included in the study. During a mean follow-up time of 6.1 ± 6.7 years, the prevalence of subsequent SLE development was 2.96%. Older age at ITP diagnosis (odds ratio [OR]: 1.24, 95% CI: 1.07-1.45) and chronic ITP (OR: 24.67, 95% CI: 3.14-100.0) were independent risk factors. The cumulative probabilities of subsequently developing SLE at 5 and 10 years after diagnosis of ITP were 3.8% (95% CI: 1.4-6.2) and 6.5% (95% CI: 2.9-9.8), respectively. CONCLUSION:Older age at ITP diagnosis and chronic ITP were risk factors for subsequent SLE developed in childhood ITP.