Cribado neonatal de anemia falciforme en la Comunidad Autónoma Balear. Estudio piloto anónimo no relacionado / Neonatal screening of sickle cell disease in the Balearic Islands Autonomous Community. Pilot study in anonymous unrelated population

Introducción: La anemia falciforme, fenotipo FS, es la más común de las hemoglobinopatías estructurales. Es un trastorno hereditario causado por la presencia de hemoglobina S (HbS), resultado de una mutación puntual que afecta al codón 6 de la cadena betaglobina. En condiciones de hipoxia, se produce la polimerización de la HbS y da lugar a crisis vasoclusivas y a anemia hemolítica. Debido a que los fenómenos de inmigración han aumentado considerablemente en España y a que la mayoría de los inmigrantes pertenecen a poblaciones de riesgo para distintas hemoglobinopatías, nuestro objetivo es determinar la incidencia de la anemia falciforme y de otras hemoglobinopatías estructurales en los recién nacidos de esta Comunidad Autónoma (Islas Baleares), mediante un estudio piloto no relacionado y evaluar la necesidad de incluir esta enfermedad dentro del programa de cribado neonatal. Material y métodos: Para esto, se ha utilizado el mismo espécimen de sangre capilar usado para la detección precoz de hipotiroidismo congénito, fenilcetonuria y fibrosis quística. La separación de variantes de hemoglobina (Hb) se llevó a cabo mediante cromatografía líquida de alta resolución y se utilizó el sistema automático Variant® (Bio-Rad). Resultados: La incidencia global de variantes de Hb ha sido de 9,9 por cada 1.000 recién nacidos analizados, con una incidencia de anemia falciforme (fenotipo FS) de uno cada 6.756 casos analizados y de portadores (fenotipo FAS) de uno cada 199 casos. Conclusiones: Tanto la tasa global de variantes observadas como la incidencia de rasgo falciforme justifican plantearse la inclusión del estudio de hemoglobinopatías en el programa de cribado neonatal de la Comunidad (AU)

Introduction: Sickle cell disease (SCD) describes a group of inherited disorders caused by the presence of the sickle haemoglobin (HbS) which results from a point mutation affecting codon 6 of the â globin chain (â codon 6, Glu 6 Val).The pathophysiology involves polymerisation of HbS under low oxygen conditions causing vaso-occlusion and chronic haemolysis and anaemia. Due to increase in immigrants within our population and the majority of this group being a risk population for different haemoglobinopathies, the aim of our study is to determine the incidence of SCD and others structural haemoglobinopathies in the neonatal population of the Balearic Islands Autonomous Community, by means of an unrelated pilot study and determine the need to include this pathology in a newborn screening program. Material and methods: The study was performed with the same blood spot specimen dried on filter paper used for congenital hypothyroidism, phenylketonuria and cystic fibrosis screening. High-performance liquid chromatography (HPLC), using the VARIANTs (Biorad) automated system, was used to detect variants haemoglobin variants. Results: The overall incidence was 9.9 per 1000 specimens. The incidence of SCD was 1/6756 (FS) and the incidence of sickle cell traits was 1/199 (FAS). Conclusion: These results confirm the need to include screening for SCD and other haemoglobinopathies in our neonatal screening program (AU)

[Neonatal screening of sickle cell disease in the Balearic Islands Autonomous Community. Pilot study in anonymous unrelated population]. / Cribado neonatal de anemia falciforme en la Comunidad Autónoma Balear. Estudio piloto anónimo no relacionado.

INTRODUCTION: Sickle cell disease (SCD) describes a group of inherited disorders caused by the presence of the sickle haemoglobin (HbS) which results from a point mutation affecting codon 6 of the beta globin chain (beta codon 6, Glu 6 Val). The pathophysiology involves polymerisation of HbS under low oxygen conditions causing vaso-occlusion and chronic haemolysis and anaemia. Due to increase in immigrants within our population and the majority of this group being a risk population for different haemoglobinopathies, the aim of our study is to determine the incidence of SCD and others structural haemoglobinopathies in the neonatal population of the Balearic Islands Autonomous Community, by means of an unrelated pilot study and determine the need to include this pathology in a newborn screening program. MATERIAL AND METHODS: The study was performed with the same blood spot specimen dried on filter paper used for congenital hypothyroidism, phenylketonuria and cystic fibrosis screening. High-performance liquid chromatography (HPLC), using the VARIANTs (Biorad) automated system, was used to detect variants haemoglobin variants. RESULTS: The overall incidence was 9.9 per 1000 specimens. The incidence of SCD was 1/6756 (FS) and the incidence of sickle cell traits was 1/199 (FAS). CONCLUSION: These results confirm the need to include screening for SCD and other haemoglobinopathies in our neonatal screening program.

Regional reference values for some quantities measured with the ADVIA Centaur analyser. A model of co-operation between the in vitro diagnostic industry and clinical laboratories.

This work is a model of co-operation between the in vitro diagnostic industry and clinical laboratories for the production of reference values. Thirteen clinical laboratories having an ADVIA Centaur analyser and representing the majority of the geographical regions of Spain have shared the search for reference individuals and the production of reference values for thyrotropin, free thyroxine, free triiodothyronine, cobalamine and folate concentrations in serum. All the logistic work has been done in co-operation with the Spanish supplier of the ADVIA Centaur analyser. The reference limits produced in the virtual laboratory are derived from the blend of reference values obtained by each laboratory. The multicentre reference limits were estimated according to the recommendations of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC).

[Evaluation of a diagnostic protocol of thyroid dysfunction]. / Valoración de un protocolo diagnóstico de disfunción tiroidea.

OBJECTIVE: To assess a three-stage protocol for the study of thyroid dysfunction. DESIGN: Descriptive and retrospective. SETTING: Primary Care Centres on the island of Mallorca. PATIENTS: 8,818 non-hospital patients without any previous treatment. MEASUREMENTS AND MAIN RESULTS: In the first stage only TSH was determined. In function of its result FT4, considered a confirmation parameter, was proceeded with. Determination of T3 was reserved for the few cases of discrepancy between FT4 and TSH, when the latter was low or suppressed. We studied costs and diagnostic yield and then the possibility of improving the relationship between them by varying the cut-off used in the TSH (< 0.5 or > 4.5 microUI/ml) against the reference values (0.35-5.5 microUI/ml). The results of these two hypotheses were studied, along with a third where the significant difference of the FT4 reference limits was considered. Analytic sensitivity and specificity were acceptable in all cases. Determinations not made because they were inappropriate (FT4 and T3) comprised 45.7% of the requested or "hypothetical" determinations which would have been carried out if the protocol had not been applied, and a year's saving of 3,637,075 pesetas; which would increase by 181,753 pesetas (2.30%) if we changed the TSU cut-off to the reference values. CONCLUSIONS: This study protocol of thyroid dysfunction is adequate, although it could be improved by changing the TSH cut-offs to the reference values.

[Hypophosphoremia and meningococcal infection. Preliminary study]. / Hipofosforemia e infección meningocócica. Estudio preliminar.

Serum phosphorus showing anomaly low values: 2.47 +/- 0.41 mg/dl (p less than 0.001) were determined within the first hours of admittance in 18 children with meningococcal infection. In another 10 renal clearance was performed founding phosphatemias of 2.35 +/- 0.37 mg/dl (p less than 0.002), determining FE of electrolytes. Both groups were compared with another one without infectious pathology which presented normal phosphatemia. Most serious cases had the most severe hypophosphatemia (p less than 0.01); eight children presented hyperphosphaturia up to 52.7 mg/Kg/day and TRP lower than 80%; six asymptomatic hypocalcemia, two hypomagnesemia; FE of potassium was elevated in three children, FE of calcium in one child and FE phosphorus in eight children. Monosodium phosphate was administered to two children with myocarditis as they presented signs of hypophosphatemia. All of them normalized biochemically in 3-4 days. Possible physiopathological mechanisms of this situation are discussed, considering the possibility that hormonal and/or tubular mechanisms take part in the lowering of phosphorus. Necessity of monitoring serum and urine phosphorus in these children is emphasized.