Newborn Screening Program for Cystic Fibrosis in Cuba: Three Years' Experience

ABSTRACT In Cuba, newborn screening (NBS) for cystic fibrosis (CF) was introduced in January 2019. The results from the first three years of the CF NBS program are presented. An IRT/IRT protocol was followed using a cut-off value of 50 ng/mL. In this period 281,717 neonates were screened, 2,197 samples had increased IRT values, and a second sample was necessary (recall rate=0.78%). In 686 (0.24%) neonates, IRT was still elevated, and they were referred for clinical evaluation. Twenty-one children were confirmed by sweat test and molecular biology. Eighteen newborns presented variant F508del. A false negative case was reported. Demographic data of 32,764 neonates were collected. The average age of sampling was six days with results available at 11 days of life, but 1.7% of the samples were collected 20 days after birth. The mean IRT value was 12.7±11.7 ng/mL (ranging 0-283 ng/mL) with a calculated 98.5 percentile value of 42.4 ng/mL. On average, the samples were processed five days after collection and two days after they were received at the laboratory. Although CF NBS program in Cuba is just beginning, it can be predicted that CF will be one of the most frequent inherited-metabolic diseases in the Cuban population.

Evaluación de ensayos ultramicroanalíticos para la detección de anticuerpos contra el SARS-CoV-2 / Evaluation of ultramicroanalytic assays to detect antibodies against SARS-CoV-2

Introducción: En el presente trabajo se muestran los resultados de la validación de los ensayos serológicos in vitro para la detección de anticuerpos IgM, IgG y anticuerpos totales contra el SARS-CoV-2 UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 y UMELISA SARS-CoV-2 IgG desarrollados por el Centro de Inmunoensayo (CIE). Métodos: Se utilizaron paneles de muestras de suero de individuos negativos y de casos confirmados de COVID-19 para determinar el desempeño analítico de cada ensayo. Resultados: La especificidad clínica de los ensayos UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 y UMELISA SARS-CoV-2 IgG fue del 100 por ciento en todos los ensayos y la especificidad analítica fue de 100 por ciento para los dos primeros ensayos y del 93,1 por cientopara el último. La sensibilidad clínica fue de 64,3, 80,8 y 97,5 por ciento, respectivamente. El valor predictivo positivo fue de 100 por ciento en todos los ensayos, en tanto que el negativo osciló entre 83,3 y 95,2 por ciento. La concordancia fluctuó entre 92,4 y 96,9 por ciento y el índice kappa de todos los ensayos fue muy bueno. La sensibilidad de los ensayos se incrementó a 82,76, 96,5 y 100 por ciento, respectivamente, en las muestras de suero colectadas con más de 14 días de iniciado el cuadro clínico. Conclusiones: Los ensayos demostraron una elevada sensibilidad y especificidad, lo que permite contar con herramientas basadas en una tecnología desarrollada en Cuba que posibilita la realización de estudios serológicos, vigilancia epidemiológica y de otro tipo, incluyendo los relacionados con vacunas en una plataforma con amplia distribución nacional(AU)

Introduction: This paper shows the results obtained in the validation of in vitro serological assays to detect IgM, IgG antibodies, and total antibodies against SARS-CoV-2 UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 and UMELISA SARS-CoV-2 IgG developed by the Immunoassay Center. Methods: Panels of serum samples from negative and COVID-19 confirmed patients were used to determine the analytical performance of each assay. Results: UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 and UMELISA SARS-CoV-2 IgG assays demonstrated 100 percent clinical specificity for all assays; and 100 percent analytical specificity for the first two assays, and 93.1 percent for the last one. Clinical sensitivity was 64.3 percent, 80.8 percent and 97.5 percent, respectively. The positive predictive value was 100 percent in all assays, while the negative predictive value ranged from 83.3 percent to 95.2 percent. Concordance varied from 92.4 percent to 96.9 percent, and kappa index in every assay was very good. Assays sensitivity increased to 82.7 percent, 96.5 percent and 100 percent, respectively for serum samples collected more than 14 days after onset of the symptoms. Conclusions: The assays demonstrated high sensitivity and specificity, which allows us to have Cuban technology-based tools for serological, epidemiological surveillance, and other types of studies, including those related to vaccines on a platform with wide national distribution(AU)

Combinaciones más frecuentes y características clínicas y de estudios complementarios de pacientes pediátricos con dengue / Most common symptom combinations, clinical features and supplementary test characteristics of pediatric

Introducción: el dengue es una enfermedad viral, con un amplio espectro clínico. Objetivos: describir las características clínicas y de laboratorio, y determinar las combinaciones de síntomas y signos más frecuentes halladas en pacientes pediátricos con sospecha de dengue, internados en el Hospital Docente Pediátrico del Cerro. Métodos: se realizó un estudio analítico, transversal, retrospectivo, a un universo de 1 300 pacientes ingresados entre enero y diciembre de 2012, con una muestra de 260 enfermos. Se estudiaron las variables síntomas y signos, además se hallaron las medianas de los valores de laboratorio hematócrito, conteo leucocitario y plaquetario. Se establecieron asociaciones predictivas de tener dengue según grupo de edades, para lo cual se determinó odds ratio (OR). Resultados: los síntomas más frecuente estuvieron representados por: cefalea, artromialgias, dolor retroocular y rash; los complementarios solo mostraron tendencia a la leucopenia. Las combinaciones predictivas de dengue halladas fueron: fiebre, exantema y prueba del lazo positiva en todas las edades. La fiebre, exantema y artromialgias para adolescentes (OR= 28,7; IC 95 por ciento 3,98-58,3; p= 0,0001) y escolares (OR= 13,32; IC 95 por ciento 1,74-28,0; p= 0,0001); mientras que la fiebre, cefalea, dolor retroocular y exantema en el grupo adolescentes (OR= 9,57; IC 95 por ciento; 3,63-26,85; p= 0,00001). Conclusiones: en este estudio la clínica varía con la edad, sin incluir síntomas respiratorios, no así los análisis. La asociación de síntomas y signos deben ser tenidas en cuenta de acuerdo con los grupos de edad, y resultaron semejantes los encontrados en los adolescentes con lo reportado en adultos(AU)

Introduction: dengue is a viral disease of broad clinical spectrum. Objectives: to describe the clinical and laboratory characteristics, and to determine the most common sign and symptom combinations found in pediatric patients suspected of dengue, who had been admitted to the teaching pediatric hospital in Cerro municipality. Methods: a retrospective, cross-sectional and analytical study was conducted in a sample of 260 patients from a universe of 1 300 patients admitted to hospital from January to December 2012. The study variables were symptoms and signs in addition to estimating the medians of hematocrit, leukocyte and platelet count values at lab. Predictive associations of having dengue were set according to age groups for which odds ratios were determined. Results: the most frequent symptoms were headache, arthromyalgias, retroocular pain and rash whereas the supplementary tests just showed tendency to leucopenia. The predictive combinations for dengue were fever, exanthema and positive tourniquet test at all ages; fever, exanthema and arthromyalgias for adolescents(OR= 28.7; 95 percent CI 3.98-58,3; p= 0.0001) and schoolchildren (OR= 13.32; 95 percent CI 1.74-28.0; p= 0.0001) and fever, headache, retroocular pain and exanthema for the adolescent group (OR= 9.57; IC 95 percent; 3.63-26.85; p= 0.00001). Conclusions: in this study, the clinical characteristics vary with the age, excluding the respiratory symptoms, but it is not the same in the supplementary tests. The associations of symptoms and signs should be taken into account depending on the age group and those found in adolescents were similar to the ones reported in adults(AU)

SUMA Technology and Newborn Screening Tests for Inherited Metabolic Diseases in Cuba: An Overview of the First 30 Years

Abstract The ultramicroanalytic system (SUMA), created in the 1980s, is a complete system of reagents and instrumentation to perform ultramicroassays combining the sensitivity of the micro-enzyme-linked immunosorbent assay (ELISA) tests with the use of ultramicrovolumes. This technology permitted establishing large-scale newborn screening programs (NSPs) for metabolic and endocrine disorders in Cuba. This article summarizes the main results of the implementation during the 30 years of SUMA technology in NSP for 5 inherited metabolic diseases, using ultramicroassays developed at the Department of Newborn Screening at the Immunoassay Center. Since 1986, SUMA technology has been used in the Cuban NSP for congenital hypothyroidism, initially studying thyroid hormone in cord serum samples. In 2000, a decentralized program for the detection of hyperphenylalaninemias using heel dried blood samples was initiated. These successful experiences permitted including protocols for screening congenital adrenal hyperplasia, galactosemia, and biotinidase deficiency in 2005. A program for the newborn screening of CH using the thyroid-stimulating hormone Neonatal ultramicro-ELISA was fully implemented in 2010. Nowadays, the NSP is supported by a network of 175 SUMA laboratories. After 30 years, more than 3.8 million Cuban newborns have been screened, and 1002 affected children have been detected. Moreover, SUMA technology has been presented in Latin America for over 2 decades and has contributed to screen around 17 million newborns. These results prove that developing countries can develop appropriate diagnostic technologies for making health care accessible to all.

Desenvolvimento do UMELISA-TSH neonatal para dosagem de TSH em sangue coletado em papel filtro / Development of the ultramicroelisa for determination of neonatal TSH from blood spots on filter paper

O hipotireoidismo congênito, causado pela ausência anatômica ou funcional da glândula tireóide, apresenta freqüência mundial de aproximadamente 1:4000 recém-nascidos. A principal implicação da doença, o retardo mental, somente pode ser evitada se o tratamento se iniciar nas primeiras semanas de vida. Por isso, o diagnóstico precoce constitui a chave de êxito no tratamento da enfermidade. O Umelisa – TSH neonatal é um ensaio heterogêneo imunoenziomático tipo sanduíche, cuja fase sólida são micropoços de 10mL em tiras/placas pré-sensibilizadas com anticorpos policlonais anticadeia Beta do TSH. As amostras de sangue são eluídas com um conjugado anti_TSH policlonal/fosfatase alcalina e transferidas para placas de reação. A reação é revelada com substrato fluorigênico e a intensidade da fluorescência emitida é proporcional à concentração de TSH presente na amostra. A leitura é realizada automaticamente por um leitor fluorímetro-fotômetro computadorizado. A curva padrão validada contra ao padrão 80 558 da OMS varia dentro de uma faixa de 10-200 µUI/L, com limite de detecção de 2 µUI/L. Posteriormente, a curva foi ajustada para medir valores a partir de 0,1 µUI/L. A avaliação analítica mostrou uma precisão intra e inter-ensaio no ponto de corte (25 µUI/L) de 6,2 e 7,4 por cento, respectivamente. A correlação entre o Umelisa – TSH neonatal e o Delfia neonatal TSH foi boa (r = 0,99), além de não ser detectadas interferências significativas com outros hormônios hipofisários e proteínas séricas. A recuperação do teste foi de 101,1 +/- 3,7 por cento. Na prova de paralelismo, as concentrações calculadas de 3 amostras, após a correção com o fator de diluição, foi de +/- 6,4 por cento da concentração original da amostra pura. O Umelisa- TSH neonatal mostrou-se um método rápido e sensível, podendo ser utilizado como uma opção para programas de rastreamento em massa, já que permite operar com grandes quantidades de amostras garantindo eficiência e custo compatível com a tabela de exames complementares do Sistema Único de Saúde (SUS).