[Evaluation and perspective of 20 years of neonatal screening in Galicia. Program results.] / Evaluación y perspectiva de 20 años de cribado neonatal en Galicia. Resultados del programa.

Galician newborn screening program for early detection of endocrine and metabolic diseases began in 1978 and was a pioneer in expanded newborn screening in Spain with the incorporation of mass spectrometry in July 2000. As a primary objective, 28 diseases are screened, including those recommended SNS except sickle cell anemia which is in the inclusion phase. In its 20-year history, 404,616 newborns (nb) have been analyzed, identifying 547 cases affected by the diseases included, with a global incidence of 1: 739 newborns and 1: 1.237 of the screened inborn errors of metabolism (IEM) (1:1.580 nb if excluding benign hyperphenylalaninemia-HPA), with an average participation of 99.35%, progressively higher during the analyzed period. Among the pathologies screened, congenital hypothyroidism (1:2.211 nb), cystinuria (1:4.129 nb) and HPA (1:5.699 nb), followed by phenylketonuria and cystic fibrosis (1:10,936 nb) stand out for their incidence. Sixty-six cases of false positives were identified (seventeen of them in relation to maternal pathology) and five false negatives, being the overall PPV and NPV of the program respectively of 89.2% and 99.99%, with a sensitivity of 99.09% and a specificity of 99.98%. The mortality rate of diagnosed CME patients is 1.52%, with eleven cases presenting symptoms prior to the screening result (2%). The intelligence quotient of IEM patients at risk of neurological involvement is normal in more than 95% of cases.

El Programa Gallego para la Detección Precoz de Enfermedades Endocrinas y Metabólicas se inició en 1978 y fue pionero en España en el cribado neonatal ampliado con la incorporación de la espectrometría de masas en julio de 2000. Como objetivo primario se criban veintiocho enfermedades, incluyendo las de la cartera básica del Servicio Nacional de Salud excepto la anemia de células falciformes, que está en fase de inclusión. En sus veinte años de trayectoria se analizaron 404.616 recién nacidos (RN), identificando 547 casos afectos de las enfermedades incluidas, con una incidencia global de 1:739 RN vivos y de 1:1.237 RN de las enfermedades metabólicas congénitas (EMC) cribadas (1:1.580 RN excluyendo la hiperfenilalaninemia benigna-HPA), con una participación media del 99,35%, progresivamente creciente durante el período analizado. Entre las patologías cribadas destacan por su incidencia el hipotirodismo congénito (1:2.211 RN), la cistinuria (1:4.129 RN) y la HPA (1:5.699 RN), seguida de fenilcetonuria y fibrosis quística (1:10.936 RN). Se identificaron sesenta y seis casos de falsos positivos (diecisiete de los mismos en relación con patología materna) y cinco falsos negativos, siendo el VPP (valor predictivo positivo) y el VPN (valor predictivo negativo) global del programa del 89,2% y 99,99%, respectivamente, con una sensibilidad de 99,09% y una especificidad del 99,98%. La tasa de mortalidad de los pacientes con EMC diagnosticados fue del 1,52%, presentando once casos sintomatología previa al resultado del cribado (2%). El cociente intelectual de los pacientes con EMC y riesgo de afectación neurológica es normal en más del 95% de los casos.

Preclinical screening for retinopathy of prematurity risk using IGF1 levels at 3 weeks post-partum.

Following current recommendations for preventing retinopathy of prematurity (ROP) involves screening a large number of patients. We performed a prospective study to establish a useful screening system for ROP prediction and we have determined that measuring serum levels of IGF1 at week three and the presence of sepsis have a high predictive value for the subsequent development of ROP. A total of 145 premature newborn, with birthweight <1500 g and/or <32 weeks gestational age, were enrolled. 26.9% of them showed some form of retinopathy. A significant association was found between the development of retinopathy and each of the following variables: early gestational age, low birthweight, requiring mechanical ventilation, oxygen treatment, intracranial haemorrhage, sepsis during the first three weeks, bronchopulmonary dysplasia, the need for erythrocyte transfusion, erythropoietin treatment, and low levels of serum IGF1 in the third week. A multiple logistic regression analysis was used to obtain curves for the probability of developing ROP, based on the main factors linked with ROP, namely serum levels of IGF1 and presence of sepsis. Such preclinical screening has the ability to identify patients with high-risk of developing retinopathy and should lead to better prediction for ROP, while at the same time optimising the use of clinical resources, both human and material.

Determination of iodine in human milk and infant formulas.

The aim of this study was to develop a method to determine iodine in human milk and infant formulas using ICP-MS. The milk samples were digested using an alkaline digestion (5% NH(3), 45 W, 2 min and 30s), and the method was validated using a certified reference material (CRM) BCR CRM151. On the other hand the milk was separated in three fractions, whey, fat and caseins using ultracentrifugation (15 min, 4 degrees C, 50,000 rpm) and the iodine was determined in the different fractions. About 27 samples of different infant formulas and 14 samples of human milk have been studied. In the human milk the values found were between 144+/-93.2 microg kg(-1), whereas in the infant formulas the values were 53.3+/-19.5. For both types of samples the bigger amount of iodine is in the whey fraction, between 80% and 90%, whereas in the fat there is about a 2% of the total iodine and in the casein fraction the levels are between 5% and 10% depending on the type of sample.

Selenium levels in related biological samples: human placenta, maternal and umbilical cord blood, hair and nails.

A study on selenium levels has been carried out in human placenta, maternal and umbilical cord blood, hair and nails of a group of 50 mothers and in the hair of the newborns. The determinations were perfomed by electrothermal atomic absorption spectrometry. The selenium concentration obtained for each sample type was as follows: For the human placenta the values obtained were between 0.56 and 1.06 microg/g (mean +/- standard deviation: 0.81 +/- 0.02 microg/g). The levels for the umbilical cord blood were 51.1-104.2 microg/l (76.3 +/- 6.5 microg/l). For the maternal blood the values measured were between 57.3 and 117.9 microg/l (90.0 +/- 15.2 microg/l), and for hair and nails were 0.22-1.5 microg/g (0.60 +/- 0.37 microg/g) and 0.46-1.57 microg/g (0.90 +/- 0.27 microg/g), respectively. For the hair of the newborns the values obtained were between 0.40 and 2.53 microg/g (1.04 +/- 0.48 microg/g). The effect of different variables as age, habitat, nutritional index or gestation age of the mothers on the selenium concentration in the samples was studied. The influence of the habitat is significant with a confidence level of 95% for the selenium concentration in maternal blood and umbilical cord blood samples. The influence of the mothers' age is significant with a confidence level of 95% for the selenium concentration in the umbilical cord blood samples. For the placenta samples, the effect of the nutritional index is significant with a confidence level of 95%. There is a positive correlation between samples of umbilical cord blood and the newborns' hair, between placenta and umbilical cord, and between cord blood and maternal blood.