Review and Proposal of Alternative Technologies for Comprehensive and Reliable Newborn Screening Using Paper Borne Urine Samples for Lysosomal Storage Disorders: Glycosphingolipid Disorders

Abstract Few current methods are efficient to detect a high number of lysosomal storage disorders (LSDs) in newborn screening. Therefore, we propose a stepwise procedure that starts with the use of paper borne urine samples (Berry-Woolf specimen) for the inexpensive detection of elevated lysosomal content and the identification of which of the three majors biochemical groups -mucopolysaccharides, oligosaccharides, and glycosphingolipids- is detected. Urine samples are preferable to blood samples because of their higher concentrations of the relevant analytes. Subsequent steps would precisely determine which enzyme deficiency is involved. As a summary, following our previous papers on the detection of elevated oligosaccharides and mucopolysaccharides, here we describe how elevated urinary glycosphingolipids (GSLs) could be fluorometrically detected using the reagent 5-hydroxy-1-tetralone (HOT) and subsequently identified with precision by continuous thin layer chromatography or other techniques. We also outline the steps required for the validation of this procedure for its introduction in newborn screening programs.

[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.

[Variations in echocardiography after bariatric surgery. Biliopancreatic diversion vs vertical gastrectomy]. / Variaciones de la ecocardiografía tras la cirugía bariátrica. Derivación biliopancreática vs. gastrectomía vertical.

INTRODUCTION: Introduction: obesity has become a worldwide health problem due to its relationship with cardiovascular morbimortality, thus bariatric surgery is considered as one of the main solutions for the correction of excess weight and, consequently, the improvement of its associated heart diseases. Objective: to compare vertical gastrectomy (VG) and biliopancreatic diversion (BPD) by observing echocardiographic characteristics both before and after surgery, as well as to evaluate surgical outcome in terms of the BAROS scale. Methods: results were collected from the echocardiographic testing requested for the preoperative study of patients who underwent surgery over the course of 24 months (from January 2014 to December 2015), as well as their anthropometric data. These were compared with postoperative parameters measured at 3 years after surgery. Results: finally, 26 patients were selected (13 VG and 13 BPD) with a mean age of 42 yrs. VG: initial BMI: 44.6 ± 7.1; final BMI: 31.8 ± 11.3 (p < 0.01); BPD: initial BMI: 48.1 ± 14.2; final BMI: 32.7 ± 10.4 (p < 0.01). Echocardiography: normal systolic function: 100% vs 92%; normal diastolic function: 88.5% vs 69.2%; no valvulopathy: 80% vs 69%; normal left atrium: 76.9% vs 73.1% (p > 0.05); HTA: 38.5% vs 19.2% (p < 0.05), preoperatively and postoperatively, respectively. Conclusions: no significant differences were found between the two groups studied with different techniques, although a slight deterioration in diastolic function was found in both groups. The comorbidities associated with obesity improved in both groups, and the surgery was scored as positive. The scant variation revealed by echocardiography prompts to reconsider its systematic preoperative use in these patients given the low cost-benefit ratio.

INTRODUCCIÓN: Introducción: la obesidad se ha convertido en un problema de salud a nivel mundial por su relación con la morbimortalidad cardiovascular. La cirugía bariátrica se plantea como una de las soluciones para la corrección del exceso de peso y mejoría de las cardiopatías asociadas. Objetivo: comparar la gastrectomía vertical con la derivación biliopancreática de tipo Scopinaro para observar la repercusión de los cambios que se producen en la estructura cardiaca tras la cirugía. Además, evaluar el resultado quirúrgico en función de la escala BAROS. Material y métodos: se recogieron los resultados de la ecocardiografía incluida en el estudio preoperatorio de los pacientes candidatos a cirugía bariátrica de nuestro hospital, intervenidos en un periodo de 2 años, junto a los datos antropométricos y de comorbilidad. Estos se compararon con los resultados postoperatorios medidos a los 3 años de la cirugía. Resultados: finalmente se seleccionaron 26 pacientes (13 GV y 13 DBP), con una edad media de 42 años. GV: IMC inicial de 44,6 ± 7,1; IMC final de 31,8 ± 11,3 (p < 0,01). DBP: IMC inicial de 48,1 ± 14,2; IMC final de 32,7 ± 10,4 (p < 0,01). Ecocardiografía: función sistólica normal: 100% vs. 92%; función diastólica normal: 88,5% vs. 69,2%; sin valvulopatía: 80% vs. 69%; aurícula izquierda normal: 76,9% vs. 73,1% (p > 0,05); HTA: 38% vs. 19% (p < 0,05), en el preoperatorio y postoperatorio, respectivamente. Conclusiones: no se encontraron diferencias significativas entre los dos grupos estudiados con técnicas diferentes, si bien pudo encontrarse un ligero deterioro de la función diastólica en ambos grupos. Las comorbilidades asociadas a la obesidad mejoraron en ambos grupos y el grado de evaluación de la cirugía fue positivo. La escasa variación de la ecocardiografía hace replantearse su uso sistemático en el preoperatorio de estos pacientes por el bajo índice coste-beneficio.

Cyanotoxin level prediction in a reservoir using gradient boosted regression trees: a case study.

Cyanotoxins are a type of cyanobacteria that is poisonous and poses a health threat in waters that could be used for drinking or recreational purposes. Thus, it is necessary to predict their presence to avoid risks. This paper presents a nonparametric machine learning approach using a gradient boosted regression tree model (GBRT) for prediction of cyanotoxin contents from cyanobacterial concentrations determined experimentally in a reservoir located in the north of Spain. GBRT models seek and obtain good predictions in highly nonlinear problems, like the one treated here, where the studied variable presents low concentrations of cyanotoxins mixed with high concentration peaks. Two types of results have been obtained: firstly, the model allows the ranking or the dependent variables according to its importance in the model. Finally, the high performance and the simplicity of the model make the gradient boosted tree method attractive compared to conventional forecasting techniques.

Pregnanetriolone in paper-borne urine for neonatal screening for 21-hydroxylase deficiency: The place of urine in neonatal screening.

The standard method of primary neonatal screening for congenital adrenal hyperlasia (CAH), determination of 17-hydroxyprogesterone (17OHP) in heelprick blood, is the object of recurrent controversy because of its poor diagnostic and economic efficiency. The superior ability of urinary pregnanetriolone levels to discriminate between infants with and without classical CAH has been known for some time, but has not hitherto been exploited for primary screening. Here we propose an economical neonatal CAH-screening system based on fluorimetric determination of the product of reaction between urinary pregnanetriolone and phosphoric acid.

Copper nanowires immobilized on the boards of microfluidic chips for the rapid and simultaneous diagnosis of galactosemia diseases in newborn urine samples.

Galactosemia is a rare disease that is diagnosed through the identification of different metabolite profiles. Therefore, the specific detection of galactose 1-phosphate (Gal 1-P), galactose (Gal), and uridyl diphosphate galactose (UDP-Gal) confirms type I, II, and III galactosemia diseases. Because of the low prevalence of galactosemia, sample availability is very scarce and screening methods to diagnose the illness are not commonly employed around the world. This work describes the coupling of microfluidic chips (MCs) to copper nanowires (CuNWs) as electrochemical detectors for the fast diagnosis of galactosemia in precious newborn urine samples. Conceptually speaking, we hypothesize that the inherent selectivity and sensitivity of CuNWs, toward galactosemia metabolites detection in connection with MC selectivity could allow the fast and simultaneous detection of the three galactosemia biomarkers, which implies the fast diagnosis of any galactosemia type in just one single analysis. Electrosynthesized CuNWs show a well-defined shape, with an average length of 6 µm and a width of 300 nm. The modified electrodes exhibited an enhanced electroactive surface area twice as high as the nonmodified ones. Very good intraelectrode repeatability with relative standard deviations (RSDs) of <8% (n = 10) and interelectrode reproducibility with RSDs of <12% (n = 5) were obtained, indicating an excellent stability of the nanoscaled electrochemical detector. Under optimum chemical (3 mM NaOH, pH 11.5), electrokinetic (separation voltage +750 V, injection +1500 V for 5 s) and electrochemical (E = +0.70 V in 3 mM NaOH, pH 11.5) conditions, galactosemia diseases were unequivocally identified, differentiating between type I, II, and III, using selected precious ill diagnosed newborn urine samples. Detection proceeded within less than 350 s, required negligible urine sample consumption, and displayed impressive signal-to-noise characteristics (ranging from 14 to 80) and micromolar limits of detection (LODs) much lower than the cutoff levels (Gal 1-P > 0.4 mM and Gal > 1.4 mM). Excellent reproducible recoveries (93%-107%, RSDs <6%) were also achieved, revealing the reliability of the approach. The significance of the newborn urine samples studied confirms the analytical potency of MC-CuNWs approach, enhancing the maturity of the microchip technology and opening new avenues for future implementation of screening applications in the field.

Congenital hypothyroidism with neurological and respiratory alterations: a case detected using a variable diagnostic threshold for TSH.

We report a case of congenital hypothyroidism (CH) with neurological and respiratory alterations due to a heterozygotic c.374-1G > A mutation of TITF1/NKX2-1. The hypothyroidism was detected using a neonatal screening protocol in which the thyroid stimulating hormone (TSH) threshold is re-set each day on the basis of within-day variability and between-day variation. In this case, the threshold on the day of the initial analysis was 8.2 mIU/L, and the measured TSH level in heel-prick blood was 8.3 mIU/L.

Evaluation and long-term follow-up of infants with inborn errors of metabolism identified in an expanded screening programme.

Newborn screening (NBS) by tandem mass spectrometry started in Galicia (Spain) in 2000. We analyse the results of screening and clinical follow-up of inborn errors of metabolism (IEM) detected during 10 years. Our programme basically includes the disorders recommended by the American College of Medical Genetics. Since 2002, blood and urine samples have been collected from every newborn on the 3rd day of life; before then, samples were collected between the 5th and 8th days. Newborns who show abnormal results are referred to the clinical unit for diagnosis and treatment. In these 10 years, NBS has led directly to the identification of 137 IEM cases (one per 2060 newborns, if 35 cases of benign hyperphenylalaninemia are excluded). In addition, 33 false positive results and 10 cases of transitory elevation of biomarkers were identified (making the positive predictive rate 76.11%), and 4 false negative results. The use of urine samples contributed significantly to IEM detection in 44% of cases. Clinical symptoms appeared before positive screening results in nine patients (6.6%), four of them screened between days 5 and 8. The death rate was 2.92%; of the survivors, 95.5% were asymptomatic after a mean observation period of 54 months, and only two had an intellectual/psychomotor development score less than 85. Compared to other studies, a high incidence of type I glutaric aciduria was detected, one in 35,027 newborns. This report highlights the benefits of urine sample collection during screening, and it is the first study on expanded newborn screening results in Spain.