Newborn Screening for Sickle Cell Disease in Brussels, a Program with an Ongoing Clinical Outcome Improvement

Abstract 4757

Early identification of sickle cell disease (SCD) by newborn screening (NS) is well established to be an efficient and practical tool in enhancing the health care of affected patients with SCD. The aim of our study, conducted in Brussels Region, was to assess whether there is an ongoing improvement of clinical outcome of children with SCD detected by the NS program.

Universal NS was progressively implemented in Brussels starting within a few maternity wards in 1994 and extending to all maternity wards in 2000. Children identified with SCD progressively benefited from comprehensive expert medical care in three dedicated reference centers. Care included education, prevention, emergency and specific out-patient and in-patient treatments. To evaluate the improvement in comprehensive care, we reviewed data of children born from January 1^st 2000 to December 31^st 2003 (group A) and from January 1^st 2005 to December 31^st 2008 (group B). All data were recorded from January 1^st 2000 to December 31^st 2005 for group A and from January 1^st 2005 to December 31^st2010 for group B. Both groups had the same follow-up period accounting for 118 patient-years in group A and 259 patient-years in group B. Median follow-up was 3.5 yrs (range 2.06–5.83 yrs) and 4.1 yrs (range 2.08–5.96 yrs) in group A and B respectively. The major events such as septicemia, anemia, dactylitis, vaso-occlusive event (VOC), acute chest syndrome (ACS), symptomatic neurological events and hospital days were reviewed and compared during the study follow-up between the two groups. The reasons for hospitalization that were selected were: septicemia, pneumonia, urinary tract infection, osteomyelitis, gastroenteritis, VOC crisis, dactylitis, ACS, acute splenic sequestration, aplastic episodes and neurologic events. Several biological parameters were also reviewed.

Among the 98 patients identified with SCD at birth, 33 (16 girls and 17 boys) and 65 (37 girls and 28 boys) belonged to group A and B, respectively. In group A, 25 children were HbSS, 2 HbSβ⁺ and 6 HbSC. In group B, 53 were HbSS, 5 HbSβ°, 5 HbSβ⁺ and 2 had an other genotype. Most of the patients developed at least one major adverse event during the study period. The proportion of patients having presented severe anemia and acute chest syndrome was significantly lower in group B than in group A (table 1). The higher rate of septicemia in group A could be due to the delayed implementation of national vaccination for Streptococcus pneumonia or to the poor prophylactic penicillin compliance. No difference was observed between both groups for dactylitis, VOC and clinical neurological event. No patient died during the study period. Hematological parameters at one year of age were not different between both groups.

In conclusion, newborn screening is obviously recognized as a precious tool to identify patients with SCD. However, it must be part of a comprehensive care program. Our results demonstrated that its sustained effectiveness is really and clearly proven when it is coupled with a comprehensive and dedicated treatment program including close and regular parent education. This ongoing assessment should be performed to monitor and improve the screening program. Thereby the progressively implementation of comprehensive care has improved over time the quality of SCD management and then the outcome of patients in Brussels Region.