Dépistage néonatal de la drépanocytose

Neonatal screening for sickle cell disease (SCD), the most common of recessive autosomic hemoglobin disorders, allows detection of affected babies (homozygous sickle cell disease, compound heterozygote SC, and S b-thalassemia) in a target population. A dry blood sample is obtained by heel stick and analyzed by high-performance liquid chromatography as a first-line method, followed by isoelectric focusing for confirmation, whenever a variant haemoglobin is observed on first-line method. Screening is only a component of a comprehensive system of care, including medical care. We conducted a retrospective evaluation (1995-2009) of SCD newborns outcome followed in a multicenter hospital-based network between a referral center and local specialized teams in the Northern Area of Paris. We evaluated patient's outcomes, medical care, and its adequacy to national guidelines published since 2005. Initial retrieval of SCD babies diagnosed through newborn screening was very efficient with 98.7% starting follow-up at a median age of 2 months. Data from 1 033 subjects with 6 776 patient-years of follow-up were analyzed among whom 742 had SS or Sβ0 thalassemia. Mean age of the cohort is 7.1 ± 3.9 years. Seventeen patients died at a median age 14.9 months (range 0.23-89) with 13 SCD related deaths at a median age of 23 months (range 5.5-89), all with sickle cell anemia (SS). Overall survival in SS/Sb0 patients was 97.1% at 15.8 years (95%IC : [95.2 ; 98.3]). In the cohort, preventive strategy was applied as recommended. All patients were under Peni V prophylaxis with 81% of long term optimal schedule of pneumococcal immunization. The cumulative risk of overt stroke was 0.25 per 100 patient years (0.11 ; 0.39). 97.3% of the patients with abnormal TCD have correct intensification therapy. The good results on SCD mortality and morbidity could be improved in this recently immigrated population by programs combining a territorial team with educated multi-ethnic staff and web-conferences on all at risk patients between referral center and local teams.