Inter-rater reliability assessment for the new-born screening quality assurance

IntroductionTo ensure the quality of the new-born screening (NBS), our laboratory reviewed the analytical procedure to detect subjective steps that may represent a risk to the patient. Two subjective activities were identified in the extra-analytical phases: the classification of dried blood spots (DBS) according to their quality and the assignment of haemoglobin patterns. To keep these activities under control, inter-rater studies were implemented. This study aimed to evaluate the inter-rater reliability and the effectiveness of the measures taken to improve the agreement between observers, to assure NBS results’ quality. Materials and methodsDried blood spots specimens were used for the inter-rater studies. Ten studies were performed to assess DBS quality classification, and four to assess the assignment of haemoglobin patterns. Krippendorff’s alpha test was used to estimate inter-rater reliability. Causes were investigated when alpha values were below 0.80. ResultsFor both activities, the reliability obtained in the first studies was inadequate. After investigation, we detected that the criterion to classify a DBS as scant was not consolidated, and also a lack of consensus on whether or not to report Bart’s haemoglobin depending on its percentage. Alpha estimates became higher once the training was reinforced and a consensus about the appropriate criteria to be applied was reached. ConclusionInter-rater reliability assessment helped us to ensure the quality of subjective activities that could add variability to NBS results. Furthermore, the evolution of the alpha value over time allowed us to verify the effectiveness of the measures adopted

Newborn Screening for SCID: Experience in Spain (Catalonia)

Linfocitos T; Cribado de recién nacidos; Inmunodeficiencia combinada severaLimfòcits T; Cribratge de nounats; Immunodeficiència combinada severaT-lymphocytes; Newborn screening; Severe combined immunodeficiencyNewborn screening (NBS) for severe combined immunodeficiency (SCID) started in Catalonia in January-2017, being the first Spanish and European region to universally include this testing. In Spain, a pilot study with 5000 samples was carried out in Seville in 2014; also, a research project with about 35,000 newborns will be carried out in 2021–2022 in the NBS laboratory of Eastern Andalusia. At present, the inclusion of SCID is being evaluated in Spain. The results obtained in the first three and a half years of experience in Catalonia are presented here. All babies born between January-2017 and June-2020 were screened through TREC-quantification in DBS with the Enlite Neonatal TREC-kit from PerkinElmer. A total of 222,857 newborns were screened, of which 48 tested positive. During the study period, three patients were diagnosed with SCID: an incidence of 1 in 74,187 newborns; 17 patients had clinically significant T-cell lymphopenia (non-SCID) with an incidence of 1 in 13,109 newborns who also benefited from the NBS program. The results obtained provide further evidence of the benefits of early diagnosis and curative treatment to justify the inclusion of this disease in NBS programs. A national NBS program is needed, also to define the exact SCID incidence in Spain

Identification of 22q11.2 deletion syndrome via newborn screening for severe combined immunodeficiency: two years’ experience in Catalonia (Spain)

22q11.2 deletion; Newborn screening; Severe combined immunodeficiencyeDeleción 22q11.2; Examen de recién nacidos; Inmunodeficiencia combinada graveSupressió 22q11.2; Cribratge de nounats; Immunodeficiència combinada greuBackground: The current scenario of newborn screening is changing as DNA studies are being included in the programs of several countries. Severe combined immunodeficiency (SCID) disorders can be detected using quantitative PCR assays to measure T-cell receptor excision circles (TRECs), a byproduct of correct T-cell development. However, in addition to SCID, other T-cell-deficient phenotypes such as 22q11.2 deletion syndrome 22q11.2 duplication syndrome, CHARGE syndrome, and trisomy 21 are detected. Methods: We present our experience with the detection of 22q11.2 deletion syndrome and 22q11.2 duplication syndrome in a series of 103,903 newborns included in the newborn screening program of Catalonia (Spain). Results: Thirty newborns tested were positive (low TREC levels) and five were found to have copy number variations at the 22q11 region (4 deletions and 1 duplication) when investigated with array comparative genomic hybridization technology and MLPA. Conclusion: Newborn screening for SCID enables detection of several conditions, such as 22q syndromes, which should be managed by prompt, proactive approaches with adequate counseling for families by a multidisciplinary team

First universal newborn screening program for severe combined immunodeficiency in Europe: two-years' experience in Catalonia (Spain)

Newborn screening; Severe combined immunodeficiency; T-cell receptor excision circlesCribratge de nadons; Immunodeficiència combinada greu; Cercles d'excisió de receptors de cèl·lules TCribado de recién nacidos; Inmunodeficiencia combinada grave; Círculos de escisión de receptores de células TSevere combined immunodeficiency (SCID), the most severe form of T-cell immunodeficiency, can be screened at birth by quantifying T-cell receptor excision circles (TRECs) in dried blood spot (DBS) samples. Early detection of this condition speeds up the establishment of appropriate treatment and increases the patient's life expectancy. Newborn screening for SCID started in January 2017 in Catalonia, the first Spanish and European region to universally include this testing. The results obtained in the first 2 years of experience are evaluated here. All babies born between January 2017 and December 2018 were screened. TREC quantification in DBS (1.5 mm diameter) was performed with the Enlite Neonatal TREC kit from PerkinElmer (Turku, Finland). In 2018, the retest cutoff in the detection algorithm was updated based on the experience gained in the first year, and changed from 34 to 24 copies/μL. This decreased the retest rate from 3.34 to 1.4% (global retest rate, 2.4%), with a requested second sample rate of 0.23% and a positive detection rate of 0.02%. Lymphocyte phenotype (T, B, NK populations), expression of CD45RA/RO isoforms, percentage and intensity of TCR αβ and TCR γδ, presence of HLA-DR+ T lymphocytes, and in vitro lymphocyte proliferation were studied in all patients by flow cytometry. Of 130,903 newborns screened, 30 tested positive, 15 of which were male. During the study period, one patient was diagnosed with SCID: incidence, 1 in 130,903 births in Catalonia. Thirteen patients had clinically significant T-cell lymphopenia (non-SCID) with an incidence of 1 in 10,069 newborns (43% of positive detections). Nine patients were considered false-positive cases because of an initially normal lymphocyte count with normalization of TRECs between 3 and 6 months of life, four infants had transient lymphopenia due to an initially low lymphocyte count with recovery in the following months, and three patients are still under study. The results obtained provide further evidence of the benefits of including this disease in newborn screening programs. Longer follow-up is needed to define the exact incidence of SCID in Catalonia

Evaluación de la relevancia clínica de diversas variantes de los genes CYP3A4, CYP3A5 y ABCB1 sobre ciclosporina y tacrolimus en trasplante hepático

[spa] Ciclosporina y tacrolimus son la base de la terapia inmunosupresora en el trasplante hepático, ya que son fármacos imprescindibles para la prevención del rechazo del órgano trasplantado. Sin embargo, todavía está pendiente de explicar una gran parte de su variabilidad farmacocinética y farmacodinámica. Existen estudios que ponen de manifiesto una relación entre las características farmacocinéticas y farmacodinámicas de estos fármacos con algunas variantes de genes que codifican para enzimas y proteínas clave relacionadas con su metabolismo y transporte. No obstante, los resultados publicados hasta el momento son controvertidos, cuya inconsistencia general puede estar relacionada con los siguientes factores: variabilidad étnica, pequeño número de pacientes incluidos en los estudios, inespecificidad de los sistemas de medida empleados para la determinación de la concentración de estos fármacos en sangre, variación en el punto del tiempo en el que se obtienen los resultados, e impacto del genotipo del donante. En el presente trabajo se han estudiado las variantes CYP3A4*1B (c.-392A>G), CYP3A4*22 (c.522-191C>T), CYP3A5*3 (c.6986A>G), y c.3435C>T y c.2677G>T del gen ABCB1. Se ha realizado minimizado las posibles variaciones debidas al diseño del estudio con el fin de ayudar a resolver parte de esta variabilidad y obtener resultados consistentes: incluyendo únicamente pacientes de la misma etnia y con un único inmunosupresor en monoterapia durante los tres primeros meses post-trasplante, realizando todas las medidas de la concentración de los fármacos inmunosupresores en sangre con el mismo sistema de medida, considerando el parámetro “ratio concentración dosis” en el estudio, empleando modelos estadísticos que tienen en cuenta la dependencia de los datos de un mismo individuo en el tiempo e incluyendo el genotipo tanto del receptor como del donante. Además se ha investigado el papel potencial de los genotipos, tanto a nivel individual como en combinación (haplotipos). También se ha evaluado la relevancia clínica de los hallazgos obtenidos, y se ha estudiado la influencia de dichas variantes genéticas sobre la eficacia clínica (incidencia de rechazo agudo) y sobre la seguridad (incidencia de aparición de los efectos adversos) en el paciente trasplantado hepático. En nuestra población en estudio, mediante los métodos descritos, se han identificado y/o al menos corroborado algunas observaciones interesantes que merecen estudios más detallados (como la de requerimientos de dosis más altos para los receptores de un injerto portador de la variante *1 del gen CYP3A5). En cuanto a la prevención de acontecimientos adversos, en ciclosporina parece interesante la influencia del alelo CYP3A4*1B en receptores sobre la neurotoxicidad, la combinación del alelo CYP3A4*1B en donantes con el genotipo 3435CC de ABCB1 en receptores sobre la hipertensión arterial. En tacrolimus el alelo CYP3A5*1 en receptores muestra relación con la nefrotoxicidad e hipertensión arterial, el alelo 3435T de ABCB1 en donantes con la diabetes mellitus y los alelos 2677A/T de ABCB1 en donantes con la neurotoxicidad. Podrían llevarse a cabo estudios prospectivos para verificar estos hallazgos, y corroborar la repercusión que tiene el conocimiento del genotipo. En general, se pone de manifiesto la relevancia del genotipo del donante. Aunque éste supone un inconveniente debido a que no puede ser elegido, recomendamos generar un Banco de ADN tanto de los receptores como de los donantes (incluyéndolo en el consentimiento informado) para permitir el acceso fácil y rápido a este tipo de muestras para la realización de futuros estudios farmacogenéticos. Posibles líneas de futuro serían: realizar este tipo de estudios pero midiendo la concentración de estos fármacos en el interior de los linfocitos; así como investigar la función que desempeña ABCB1 en linfocitos, en tejido hepático, tejido renal y en barrera hematoencefálica en relación a ciclosporina y tacrolimus, ya que parece tener un papel clave no sólo a nivel del intestino.[eng] Cyclosporine and tacrolimus are the basis for immunosuppressive therapy in liver transplantation: they are essential drugs for organ transplant rejection prevention. However, a large part of its pharmacokinetic and pharmacodynamic variability still needs to be explained. A number of studies show a relation between the pharmacokinetics and pharmacodynamics of these drugs with some variants of genes encoding key enzymes and proteins related to their metabolism and transport. Nevertheless, the results published so far are controversial. Their general inconsistency may be related to the following factors: ethnic variability, small number of patients included in the studies, lack of specificity measuring systems used for concentration determination of these drugs in blood, variation at the point in time where the results are obtained, and impact of donor genotype. In this work we have studied the following variants: CYP3A4*1B (C-392A>G), CYP3A4*22 (c.522-191C>T), CYP3A5*3 (c.6986A>G), and c.3435C>T and c.2677G>T from ABCB1 gene. We have minimized possible variations due to study design in order to help solve part of this variability and obtain consistent results. We have furthermore investigated the potential role of genotypes, both individually and in combination (haplotypes). Moreover, we have evaluated the clinical relevance of the findings, and we have also studied the influence of these genetic variants on clinical efficacy (incidence of acute rejection) and safety (incidence of occurrence of adverse effects) in the liver transplanted patient. In our study population, by the methods described, we have identified and/or at least confirmed some interesting observations that deserve more detailed studies (such as the requirement of higher doses for recipients of the CYP3A5*1 carriers graft). As regards the prevention of adverse events, in cyclosporine seems interesting the influence of CYP3A4*1B allele in receptors on neurotoxicity, the combination of CYP3A4*1B allele in donors with 3435CC ABCB1 recipients on hypertension. In tacrolimus the CYP3A5*1 allele in recipients shows relation to nephrotoxicity and hypertension, the 3435T ABCB1 allele in donors with diabetes mellitus and 2677A/T alleles of ABCB1 donors with neurotoxicity. Prospective studies could be conducted to verify these findings and corroborate the impact of the genotype knowledge. In general, it shows up the relevance of the donor genotype

Prevalence of self-reported food allergy among adolescents from Cuenca and Santa Isabel - Ecuador

La alergia alimentaria (AA) se asocia con el desarrollo de enfermedades atópicas y anafilaxia en adolescentes. Se determinó y comparó, entre adolescentes de Cuenca y Santa Isabel: i) la prevalencia de AA auto-reportada, ii) los alérgenos alimentarios comunes y iii) las enfermedades atópicas auto-reportadas. Se realizó un estudio de corte transversal en adolescentes de Cuenca (n=967) y Santa Isabel (n=498) entre julio de 2013 y julio de 2014. Se aplicaron cuestionarios de auto-reporte de AA. La prevalencia de AA auto-reportada fue del 27.8% (Cuenca 31.5% vs Santa Isabel 21.1 %; P<0.001). Los aditivos fueron los primeros alimentos reportados, seguidos de las frutas no cítricas. Se identificaron nuevos alimentos como la grosella y uvilla. El 20.4% de adolescentes que reportaron enfermedades atópicas reportaron también síntomas sugestivos de AA, mientras que, el 7.4% de adolescentes sin estas enfermedades reportaron síntomas sugestivos de AA (OR 3.39, IC 95 %: 2.6 a 4.4, P< 0.001). Se concluye que la AA auto-reportada a los aditivos y frutas no cítricas fueron las más prevalentes en los adolescentes de Cuenca y Santa Isabel. Se identificaron alimentos usualmente no reportados. Los adolescentes con enfermedades atópicas tuvieron tres veces más probabilidades de reportar AA que aquellos que no las presentaron.Food allergy (FA) is associated with the development of atopic diseases and anaphylaxis in adolescents. It was determined and compared among adolescents Cuenca and Santa Isabel: i) self-reported FA prevalence, ii) common food allergens and iii) self-reported atopic diseases. Crosssectional study was conducted in adolescents from Cuenca (n = 967) and Santa Isabel (n = 498) between July 2013 and July 2014. Data were collected through self-reported FA questionnaires. The prevalence of self-reported FA was 27.8% (Cuenca 31.5% vs. Santa Isabel 21.1 %; P <0.001). Additives were the major foods reported followed by the non-citrus fruits. 20.4% of adolescents who reported atopic diseases also reported suggestive symptoms of FA, while 7.4% of adolescents who reported suggestive symptoms of FA didn’t report atopic diseases (OR 3.39, 95% CI 2.6 to 4.4, P <0.001). In conclusion, self-reported additives and non-citrus fruits allergy were the most prevalent among adolescents in Cuenca and Santa Isabel. New foods usually not reported were identified. Adolescents with atopic disease were three times more likely to report FA than those who did not have atopic diseases.Cuenc

Foetal Haemoglobin as a Marker of Bone Marrow Suppression Secondary to Anti-Kell Alloimmunisation

Anti-Kell alloimmunisation is a potentially severe minor blood group type incompatibility, not only as a cause of haemolytic disease of the foetus and newborn, but also due to the destruction of red blood cells (RBC) and mature form in the bone marrow with the subsequent hyporegenerative anaemia. In severe cases and when the foetus shows signs of anaemia, an intrauterine transfusion (IUT) may be necessary. When repeated, this treatment can suppress erythropoiesis and worsen the anaemia. We report the case of a newborn who required four IUTs plus an additional RBC transfusion at one month of life due to late onset anaemia. The identification of an adult haemoglobin profile with a complete absence of foetal haemoglobin in the patient’s newborn screening samples at 2 and 10 days of life warned us of a possible late anaemia. The newborn was successfully treated with transfusion, oral supplements and subcutaneous erythropoietin. A blood sample taken at 4 months of life showed the expected haemoglobin profile for that age with a foetal haemoglobin of 17.7%. This case illustrates the importance of a close follow-up of these patients, as well as the usefulness of the haemoglobin profile screening as a tool for anaemia assessment

Impacto de la inclusión de pruebas de segundo nivel en el programa de cribado neonatal de Cataluña y en otros programas internacionales

Background: Newborn screening programmes (NBSP) have experienced a qualitative breakthrough due to the implementation of tandem mass spectrometry. However, the tests used give rise to false positives (FP) generating an excessive request for second samples with the consequent anxiety of the families. In order to avoid this problem several programmes have developed second-tier tests (2TT). Methods: This article presents our experience in the implementation of 2TT in the NBSP of Catalonia, as well as in other international programmes. Results: From 2004 to the present, 2TT tests have been developed for more than 30 diseases. The use of 2TT helps to decrease the FP rate and increase the positive predictive value (PPV). In the NBSP of Catalonia, the implementation of 2TT for the detection of methylmalonic and propionic acidemias, homocystinurias, maple syrup disease and citrulinaemia, has managed to increase the PPV to 95% and decrease the PF rate to less than 0.01%. In cystic fibrosis, the application of 2TT slightly increases PPV but with a significant decrease in the request for second samples and in the number of cases referred to clinical units. Conclusions: The introduction of 2TT in the NBSP allows to reduce considerably the FP, decreases the number of requested samples, as well as both anxiety and stress of the families, at the same time that the hospital costs are reduced and the PPV is increased, improving notably the efficiency of the NBSP.Fundamentos: Los programas de cribado neonatal (PCN) han experimentado un gran avance cualitativo debido a la implementación de la espectrometría de masas en tándem. Sin embargo, las pruebas utilizadas dan lugar a falsos positivos (FP) generando una excesiva solicitud de segundas muestras con la consiguiente ansiedad de las familias. Con el fin de evitar este problema diversos programas han desarrollado pruebas de segundo nivel (2TT). Métodos: En este artículo se presenta nuestra experiencia en la implementación de 2TT en el PCN de Cataluña, así como en otros programas internacionales. Resultados: Desde el año 2004 hasta la actualidad se han desarrollado pruebas de 2TT para más de 30 enfermedades. La utilización de 2TT ayuda a disminuir la tasa de FP y aumentar el valor predictivo positivo (VPP). En el PCN de Cataluña, la implementación de 2TT para la detección de acidemias metilmalónicas y propiónica, homocistinurias, jarabe de arce y citrulinemia, ha conseguido aumentar el VPP a un 95% y disminuir la tasa de FP a menos del 0,01%. En la fibrosis quística la aplicación de 2TT aumenta ligeramente el VPP pero con disminución significativa de la solicitud de segundas muestras y de los casos referidos a las unidades clínicas. Conclusiones: La introducción de los 2TT en los PCN permite reducir considerablemente los FP, disminuye el número de muestras solicitadas, así como la ansiedad y el estrés de las familias, a la vez que se reducen los costes hospitalarios y se aumenta el VPP, mejorando notablemente la eficiencia de los PCN

Análisis de la implementación de un sistema de transporte unificado de las muestras de cribado neonatal en Cataluña

The Neonatal Screening Program in Catalonia from its inception fifty years ago until today, has enabled the early diagnosis and treatment of more than 2,000 newborns. In the last decade, the Program has undergone various extensions regarding its panel of diseases and has improved its evaluation with the inclusion of quality indicators in all its stages. One of the pending subjects of the screening program has been the improvement of the quality indexes related to the sample’s arrival time to the laboratory after their extraction. The extension of the territory, the dispersion of numerous maternal centers, as well as the diversity and heterogeneity of the sample transport systems, have been an obstacle to quality compliance of these indexes. With the aim of reducing the period of samples arrival to the laboratory and continue to move towards meeting the standards established by the Ministry of Health, in 2020 a unified sample transport system has been implemented for the entire Catalan territory. The times obtained during the first months with the new system, have shown a notable improvement in the results, achieving a reduction of 50% of the days between the extraction of the sample and its arrival at the laboratory.El Programa de Cribado Neonatal (PCN) de Cataluña ha permitido el diagnóstico y tratamiento precoz de más de 2.000 recién nacidos desde su inicio hace cincuenta años hasta la actualidad. En la última década, el PCN ha experimentado diversas ampliaciones en cuanto a su panel de enfermedades y ha mejorado su evaluación con la inclusión de indicadores de calidad en todas sus etapas. Una de las asignaturas pendientes del programa de cribado ha sido la mejora de los indicadores relativos al tiempo de llegada de las muestras al laboratorio desde su extracción. La extensión territorial, la dispersión de los sesenta y seis centros maternales, así como la diversidad y heterogeneidad de los sistemas de transporte de muestras, han supuesto un obstáculo para el cumplimiento de la calidad de este indicador. Con el objetivo de reducir el período de llegada de las muestras al laboratorio y seguir avanzando en el cumplimiento de los estándares establecidos por el Ministerio de Sanidad, en 2020 se ha implementado un sistema de transporte de muestras unificado para todo el territorio catalán. Los tiempos obtenidos durante los primeros meses con el nuevo sistema muestran una mejora notable de los resultados, consiguiendo una reducción del 50% de los días transcurridos desde la extracción de la muestra hasta su llegada al laboratorio