Until first half of the XX century, sickle cell disease was practically limited to the malaria endemic areas and countries having known an important surge of African slaves. Today, migratory flows and progress of medicine have modified considerably the distribution of sickle cell disease which is from now on a frequent affection in Western Europe. The preventive implementation of medical care makes it possible to reduce morbidity and mortality associated with this pathology. Stake of a medical policy and economic interests, neonatal screening for hemoglobin disorders justifies then fully the implementation of powerful and adapted means. In order to initiate a newborn screening programme in our centre, we developed various immunological tests allowing to identify the sickle hemoglobin. We first of all developed an indirect immunoassay and led a population study on 46082 Belgian newborns and 1825 neonates from Central Africa. The performances of this assay were improved thereafter by conceiving a competitive test. Next, for reasons independent of our will, we had unfortunately to abandon the immunological approach. This methodology was thus supplanted in our center by an innovative method for this indication: the mass spectrometry. Our promising results currently authorize us to perennialize our policy in the neonatal screening for sickle cell disease and open the way for new developments in other fields. / Jusquà la première moitié du XXe siècle, la drépanocytose se limitait pratiquement aux zones dendémie palustre et aux pays ayant connu un important afflux desclaves dorigine africaine. Aujourdhui, les flux migratoires et les progrès de la médecine ont considérablement modifié la distribution de cette maladie qui est désormais une affection fréquente en Europe occidentale. La prise en charge précoce permet de réduire la morbidité et la mortalité associées à cette maladie. Enjeu dune politique sanitaire et dintérêts économiques, le dépistage néonatal de la drépanocytose justifie donc ainsi pleinement la mise en uvre de moyens performants et adaptés. Afin dinitier un programme de dépistage au sein de notre centre, nous avons initialement développé divers tests immunologiques permettant didentifier lhémoglobine anormale. Nous avons tout dabord mis au point un immunoessai indirect et conduit une étude de population sur 46082 nouveau-nés belges et 1825 bébés originaires dAfrique centrale. Les performances de lessai ont par la suite été améliorées en concevant un test compétitif. Lapprovisionnement laborieux danticorps nécessaires aux tests de détection a par la suite entravé notre programme. En effet, la commercialisation en a été interrompue et la production danticorps monoclonaux par nos moyens propres na pas été couronnée du succès escompté. Lapproche immunologique du dépistage néonatal de la drépanocytose a ainsi été supplantée dans notre centre par une méthode novatrice pour cette indication : la spectrométrie de masse. Nos résultats prometteurs nous autorisent actuellement à pérenniser notre nouvelle façon de faire dans le dépistage néonatal de la drépanocytose et ouvre la voie pour de nouveaux développements dans dautres domaines.

The aim of this study was to evaluate the National Neonatal Screening Program in Sergipe State in Brazil Northeastern (PNTN/SE) for phenylketonuria (PKU). It was performed a cross-sectional study. Variables assessed were: phenylalanine blood concentrations at filter paper collected from the heel of 43.449 children (PKUneo); blood phenylalanine concentrations obtained by venipuncture in the children with abnormal PKUneo; children s age in the different program phases from January 2007 to June 2008; and the coverage in 2007. The suspected children were selected when PKUneo were above the cut-off level of 5 mg/dL. Furthermore, these children were classified by the venous concentration of phenylalanine in according to the literature, thereby obtaining the prevalence of hyperphenylalaninemy (HPA) and phenylketonuria from January 2007 to June 2008. The cases diagnosed before 2007 were not analysed. Finally, we verified the venous concentrations of phenylalanine at those children on dietetic treatment for the disease as much as the amount of phenylalanine present on their diet. The children s age at PKUneo collection was 107 days (MDP), the age when the assay was done was 2813 days and at the venous collection in the diagnosis confirmation was 5317 days. Twelve children were called based on the PKUneo cut-off. From these, the concentrations of phenylalanine collected by venipuncture were normal in five children, one child was classified as hyperphenylalaninemy and five as PKU with the prevalence of 1/43449 and 1/8690, respectively. The treatment for PKU began with 5112 days. The coverage of PNTN/SE/2007 was 78.93%, besides, 11% of the Sergipe´s children that have private health care. In conclusion, PNTN/SE presented satisfactory coverage, PKU and hyperphenylalaninemy prevalences compatible with the literature and adequate cut-off. On the other hand, the collection of PKUneo is late and the onset of treatment is delayed. / O objetivo deste trabalho foi avaliar o Programa Nacional de Triagem Neonatal no Estado de Sergipe no Nordeste do Brasil (PNTN/SE) para a fenilcetonúria (PKU). Foi realizado um estudo transversal. As variáveis estudadas foram: concentrações de fenilalanina no sangue coletado em papel-filtro do calcanhar de 43.449 crianças (PKUneo); concentrações de fenilalanina no sangue coletado por punção venosa realizada nas crianças convocadas após resultado de PKUneo alterado; idade das crianças nas diferentes fases do PNTN/SE, no período entre janeiro de 2007 a junho de 2008, e a cobertura do programa no ano de 2007. As crianças suspeitas foram selecionadas quando apresentavam concentrações de PKUneo acima do ponto de corte de 5 mg/dL. Além disso, classificamos estas crianças segundo as concentrações venosas de fenilalanina de acordo com a literatura, calculando, assim, a prevalência de PKU e da hiperfenilalaninemia (HPA) no período de janeiro de 2007 a junho de 2008, não utilizando os casos diagnosticados antes de janeiro de 2007 e depois de junho de 2008. Por fim, foram acompanhadas as concentrações venosas de fenilalanina das crianças classificadas como fenilcetonúricas e hiperfenilalaninêmicas em tratamento dietético, assim como a quantidade de fenilalanina ingerida na alimentação. A idade das crianças, na coleta do PKUneo, foi de 107 dias (MDP), na realização do ensaio foi de 2813 dias e na coleta para confirmação do diagnóstico foi de 5317 dias. Foram convocadas doze crianças após resultado de PKUneo alterado, das quais cinco tiveram concentrações venosas normais de fenilalanina, uma foi classificada como hiperfenilalaninêmica e cinco como fenilcetonúricas com prevalência de 1/43449 e 1/8690, respectivamente. A terapia nas cinco crianças com PKU foi iniciada com 5112 dias. A cobertura do PNTN/SE em 2007 foi de 79%, não sendo considerados nesse resultado os 11% da população coberta por planos privados de saúde. Deste modo, o PNTN/SE apresentou no período estudado cobertura satisfatória, prevalências de PKU e HPA compatíveis com àquelas encontradas na literatura e ponto de corte adequado. Em contrapartida, a coleta do PKUneo é tardia e o início do tratamento é demorado.