P1502: LONG-TERM FOLLOW-UP OF DUTCH PATIENTS WITH SICKLE CELL DISEASE DIAGNOSED BY NEONATAL SCREENING – EFFECT ON THE MORBIDITY AND MORTALITY IN THE NETHERLANDS.

Abstract

Background: Sickle cell disease (SCD) is associated with increased morbidity and mortality compared to the general population. To initiate early preventive measures, newborn screening for SCD has been introduced in January 2007 in the Netherlands. Aims: The objective of this study is to assess the effectiveness of this neonatal screening for SCD by describing the residual risks of death and major disease-related events during the first fourteen years of life in children diagnosed with SCD at birth in the Netherlands. Methods: Here we report the first data of the largest center (Amsterdam UMC) of this prospective, national multicenter cohort study. Following informed consent, data were collected from medical files of all children diagnosed by neonatal screening. Descriptive data on SCD genotype and occurrence of major disease-related events are presented, including hospitalization for vaso-occlusive crisis (VOC), acute chest syndrome, severe infections and neurological complications. Overall survival and survival without specific SCD-related complications were analyzed by Kaplan-Meier curves. Results: Up until now, 98 (56%) out of 174 eligible subjects from this institution were included, with a total follow-up of 805 patient-years. The majority (55%) had the severe genotype (HbSS/ beta0-thalassemia), the remainder had genotypes HbSC or HbS/beta+-thalassemia. Survival by the age of 14 was 98.9%, with 1 death at the age of 1 years due to sepsis, most likely related to SCD. Seven patients (7.1%) had a severe infection (meningitis, sepsis, osteomyelitis) caused by Streptococcus Pneumoniae in 3/7 cases. Antibiotic prophylaxis was prescribed for all 7 patients before they reached the age of 1 year, and 6/7 patients had been fully vaccinated with the 23 valent pneumococcal vaccine. Two patients experienced a symptomatic cerebral infarction at the age of 11 months and 1.5 years, respectively. At the age of 10 years the survival without hospitalization for vaso-occlusive crisis was 27% (95% CI: 12.7 – 43.14%) and 51% (25.3 – 72.0%) for the SS/Sβ0 and SC/Sβ+ genotype, respectively. Image:Summary/Conclusion: In this cohort of neonatally screened patients with SCD, the SCD-related mortality and morbidity is still impressive with 1% mortality, 7 severe infections, and 2 patients with a CVA. A final analysis of the effect of neonatal screening for SCD will follow after completion of data collection in all participating centers in the Netherlands.