Clinical Features and Survival of Asian Pediatric Patients with Paroxysmal Nocturnal Hemoglobinuria: Results from a Single Center in China

OBJECTIVE: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease, especially in children. To characterize the clinical presentations and survival, we performed a retrospective analysis of pediatric patients. METHODS: We reviewed 55 pediatric patients with PNH referred to our hospital from January 1990 through June 2012 to assess clinical presentations, survival, and differences among subcategories. RESULTS: The overall survival 10 years after diagnosis estimated via the Kaplan-Meier method was 77.6%. The cohort of patients was divided into subcategories of classic PNH, PNH/aplastic anemia (AA), and subclinical PNH (PNH-sc)/AA based on the recently proposed PNH working clinical classification. We found that patients with classic PNH and PNH/AA had larger PNH clones and many more parameters of hemolysis, but patients with PNH-sc/AA had smaller PNH clones, fewer parameters of hemolysis, and a higher rate of bone marrow failure. Our results revealed a high rate of bone marrow failure and a low rate of hemoglobinuria at presentation. Furthermore, thrombotic events were not observed in our patients, which is significantly different from the rate seen in Caucasian patients. Additionally, pediatric patients with PNH may develop bone marrow cytogenetic abnormalities. CONCLUSION: This study provides insight into Chinese pediatric PNH patients and may aid in setting up individualized therapeutic regimens.