IRT/IRT as a newborn cystic fibrosis screening method: optimal cutoff points for a mixed population.

The Brazilian Unified National Health System (SUS) has incorporated newborn screening for cystic fibrosis since 2001. The protocol involves two samples of immunoreactive trypsinogen (IRT1/IRT2). This study aims to analyze fixed and floating values at the first and second IRT (IRT1/IRT2) cutoff points and assess the accuracy of the IRT/IRT methodology in a population from Northeastern Brazil. Descriptive, individual-level data from the newborn screening reference service data system (2013-2017) were used in this observational population study. The sensitivity, specificity, and positive predictive values (PPV) for the protocol were calculated. The best cutoff point was determined using the Youden's index. The previous year's cut-off values for the IRT1 and IRT2 99.4-, 99.5-, 99.6-, and 99.7-percentiles were utilized for the floating cutoff. During the studied period, 840,832 newborns underwent screening for cystic fibrosis, obtaining 49 cystic fibrosis diagnoses: 39 by newborn screening (79.6%) and 10 (20.4%) by clinical suspicion (false negative). The sensitivity, specificity, and PPV of the protocol totaled 79.6%, 99.9%, and 6.1%, respectively. No proposed cutoff for IRT1 performed better than the current one. IRT2 performed similarly to the current protocol at a cutoff point of 90ng/mL, showing the appropriate sensitivity and specificity while reducing the frequency of false positives. The protocol to screen newborns for cystic fibrosis had low sensitivity, a predictive positive value, and a high number of false positives and negatives. A floating cut point for IRT1 or IRT2 seems to constitute no viable option. However, changing the IRT2 cut point from 70ng/mL to 90ng/mL seems to have advantages and should undergo consideration.

IRT/IRT as a newborn cystic fibrosis screening method: optimal cutoff points for a mixed population / Protocolo TIR/TIR como método de triagem neonatal para fibrose cística: pontos de corte ideais para populações com baixa incidência da doença e poucos recursos / Protocolo TIR/TIR como método de tamizaje neonatal de fibrosis quística: puntos de corte ideales para poblaciones con baja incidencia de la enfermedad y pocos recursos

Abstract: The Brazilian Unified National Health System (SUS) has incorporated newborn screening for cystic fibrosis since 2001. The protocol involves two samples of immunoreactive trypsinogen (IRT1/IRT2). This study aims to analyze fixed and floating values at the first and second IRT (IRT1/IRT2) cutoff points and assess the accuracy of the IRT/IRT methodology in a population from Northeastern Brazil. Descriptive, individual-level data from the newborn screening reference service data system (2013-2017) were used in this observational population study. The sensitivity, specificity, and positive predictive values (PPV) for the protocol were calculated. The best cutoff point was determined using the Youden's index. The previous year's cut-off values for the IRT1 and IRT2 99.4-, 99.5-, 99.6-, and 99.7-percentiles were utilized for the floating cutoff. During the studied period, 840,832 newborns underwent screening for cystic fibrosis, obtaining 49 cystic fibrosis diagnoses: 39 by newborn screening (79.6%) and 10 (20.4%) by clinical suspicion (false negative). The sensitivity, specificity, and PPV of the protocol totaled 79.6%, 99.9%, and 6.1%, respectively. No proposed cutoff for IRT1 performed better than the current one. IRT2 performed similarly to the current protocol at a cutoff point of 90ng/mL, showing the appropriate sensitivity and specificity while reducing the frequency of false positives. The protocol to screen newborns for cystic fibrosis had low sensitivity, a predictive positive value, and a high number of false positives and negatives. A floating cut point for IRT1 or IRT2 seems to constitute no viable option. However, changing the IRT2 cut point from 70ng/mL to 90ng/mL seems to have advantages and should undergo consideration.

Resumo: A triagem neonatal para fibrose cística oi incorporada ao Sistema Único de Saúde (SUS) em 2001. O protocolo envolve duas amostras de tripsinogênio imunorreativo (TIR/TIR). O objetivo foi analisar os valores fixos e flutuantes no primeiro e segundo pontos de corte da TIR (TIR1/TIR2) e avaliar a acurácia da metodologia TIR/TIR em uma população do nordeste brasileiro. Trata-se de um estudo observacional de base populacional que inclui dados descritivos em nível individual obtidos retrospectivamente do Serviço de Referência em Triagem Neonatal (2013-2017). Foram calculados a sensibilidade, a especificidade e o valor preditivo positivo (VPP) do protocolo. O melhor ponto de corte foi determinado pelo índice de Youden. Os pontos de corte do ano anterior para os percentis TIR1 e TIR2 de 99,4, 99,5, 99,6 e 99,7 foram utilizados para o ponto de corte flutuante. No período do estudo, 840.832 recém-nascidos foram submetidos à triagem neonatal para fibrose cística, com 49 diagnósticos de fibrose cística, sendo 39 pela triagem neonatal (79,6%) e 10 (20,4%) por suspeita clínica (falso-negativos). A sensibilidade, a especificidade e o VPP do protocolo de triagem neonatal para fibrose cística foram de 79,6%, 99,9% e 6,1%, respectivamente. Nenhum dos pontos de corte propostos para a TIR1 mostrou-se melhor do que o atual. A TIR2 teve desempenho semelhante ao atual no ponto de corte de 90ng/mL, demonstrando sensibilidade e especificidade adequadas, ao mesmo tempo que reduziu a frequência de falsos positivos. A triagem neonatal para fibrose cística apresentou valores baixos de sensibilidade e VPP, e número elevado de falso-positivos e negativos. Um ponto de corte flutuante para TIR1 ou TIR2 não parece ser uma opção viável. No entanto, a mudança do ponto de corte da TIR2 de 70ng/mL para 90ng/mL parece ter vantagens e deve ser considerada.

Resumen: El tamizaje neonatal de fibrosis quística fue incorporado al Sistema Único de Salud (SUS) en el 2001. El protocolo implica dos muestras de tripsinógeno inmunorreactivo (TIR/TIR). El objetivo fue analizar los valores fijos y flotantes en el primer y segundo puntos de corte de la TIR (TIR1/TIR2) y evaluar la precisión de la metodología TIR/TIR en una población del Nordeste brasileño. Se trata de un estudio observacional de base poblacional que incluye datos descriptivos a nivel individual obtenidos retrospectivamente del Servicio de Referencia en Tamizaje Neonatal (2013-2017). Se calcularon la sensibilidad, la especificidad y el valor predictivo positivo (VPP) del protocolo. El mejor punto de corte lo determinó el índice de Youden. Para el punto de corte flotante, se utilizaron los puntos de corte del año anterior para los percentiles TIR1 y TIR2 de 99,4, 99,5, 99,6 y 99,7. Durante el período de estudio, 840.832 recién nacidos fueron sometidos a tamizaje neonatal para fibrosis quística, con 49 diagnósticos de fibrosis quística, 39 de los cuales por la tamizaje neonatal (79,6%) y 10 (20,4%) por sospecha clínica (falsos negativos). La sensibilidad, la especificidad y el VPP del protocolo tamizaje neonatal para fibrosis quística fueron del 79,6%, 99,9% y 6,1%, respectivamente. Ninguno de los puntos de corte propuestos para la TIR1 resultó ser mejor que el actual. La TIR2 tuvo un desempeño similar al actual en el punto de corte de 90ng/mL, lo que demuestra sensibilidad y especificidad adecuadas, a la vez que redujo la frecuencia de falsos positivos. El tamizaje neonatal para fibrosis quística presentó valores bajos de sensibilidad y VPP, y un elevado número de falsos positivos y negativos. Un punto de corte flotante para TIR1 o TIR2 no parece ser una opción viable. Sin embargo, cambiar el punto de corte de la TIR2 de 70ng/mL a 90ng/mL parece tener ventajas y debe tenerse en cuenta.

Pilot study of newborn screening for six lysosomal diseases in Brazil.

BACKGROUND: Lysosomal diseases (LDs) are progressive life-threatening disorders that are usually asymptomatic at birth. Specific treatments are available for several LDs, and early intervention improves patient's outcomes. Thus, these diseases benefit from newborn screening (NBS). We have performed a pilot study for six LDs in Brazil by tandem mass spectrometry. METHODS: Dried blood spot (DBS) samples of unselected newborns were analyzed by the Neo-LSD™ kit (Perkin-Elmer) by MS/MS. Samples with low enzyme activity were submitted to the evaluation of specific biomarkers by ultra-performance liquid chromatography tandem-mass spectrometry as the second-tier, and were analyzed by a next-generation sequencing (NGS) multi-gene panel as the third-tier. All tests were performed in the same DBS sample. RESULTS: In 20,066 newborns analyzed, 15 samples showed activity of one enzyme below the cutoff. Two newborns had biochemical and molecular results compatible with Fabry disease, and five newborns had biochemical results and pathogenic variants or variants of unknown significance (VUS) in GAA. CONCLUSIONS: This study indicates that the use of enzyme assay as the first-tier test gives an acceptably low number of positive results that requires second/third tier testing. The possibility to run all tests in a DBS sample makes this protocol applicable to large-scale NBS programs.

Five-year performance analysis of a cystic fibrosis newborn screening program in northeastern Brazil

Abstract Objective: To analyze the performance of the cystic fibrosis (CF) newborn screening (NBS) program over its first five years in a Brazilian northeastern state. Methods: A population-based study using a screening algorithm based on immunoreactive trypsinogen (IRT)/IRT. Data were retrieved from the state referral screening center registry. The program performance was evaluated using descriptive indicators such as the results of an active search, coverage, newborn's age at the time of blood sampling, the time between sample collection and its arrival at the laboratory, and the child's age at diagnosis of disease. Results: The public CF screening program covered 82.6% of the 1,017,576 births that occurred, with an accumulated five-year incidence of 1:20,767 live births. The median (25th-75th) age at diagnosis was 3.5 (2.3-7.3) months. The sampling before 7 days of life for the first IRT (IRT1) increased between 2013 and 2017 from 42.2 to 48.3%. Around 5% of IRT1 samples and 30% of the second samples were collected after 30 days of life. In the first and second stages of screening, 23.6% and 19.9% of the infants, respectively, were lost to follow-up. In both stages of screening, the samples were retained at the health units for a median (25th-75th) of 9.0 (7.0-13.0) days. Conclusions: The coverage by the CF-NBS program was satisfactory as compared to other Brazilian state rates and the percentage of IRT1 samples collected within the first week of life increased progressively. However, time of samples retention at the health units, inappropriate sampling, inherent methodological problems, and loss of follow-up need to improve.

Five-year performance analysis of a cystic fibrosis newborn screening program in northeastern Brazil.

OBJECTIVE: To analyze the performance of the cystic fibrosis (CF) newborn screening (NBS) program over its first five years in a Brazilian northeastern state. METHOD: A population-based study using a screening algorithm based on immunoreactive trypsinogen (IRT)/IRT. Data were retrieved from the state referral screening center registry. The program performance was evaluated using descriptive indicators such as the results of an active search, coverage, newborn's age at the time of blood sampling, the time between sample collection and its arrival at the laboratory, and the child's age at diagnosis of disease. RESULTS: The public CF screening program covered 82.6% of the 1,017,576 births that occurred, with an accumulated five-year incidence of 1:20,767 live births. The median (25th-75th) age at diagnosis was 3.5 (2.3-7.3) months. The sampling before 7 days of life for the first IRT (IRT1) increased between 2013 and 2017 from 42.2 to 48.3%. Around 5% of IRT1 samples and 30% of the second samples were collected after 30 days of life. In the first and second stages of screening, 23.6% and 19.9% of the infants, respectively, were lost to follow-up. In both stages of screening, the samples were retained at the health units for a median (25th-75th) of 9.0 (7.0-13.0) days. CONCLUSIONS: The coverage by the CF-NBS program was satisfactory as compared to other Brazilian state rates and the percentage of IRT1 samples collected within the first week of life increased progressively. However, time of samples retention at the health units, inappropriate sampling, inherent methodological problems, and loss of follow-up need to improve.

Is there an association between prostate-specific antigen and androgen levels in 46, XX patients with congenital adrenal hyperplasia?

INTRODUCTION: Congenital adrenal hyperplasia (CAH), a genetic disease characterized by defective cortisol synthesis and excessive levels of sex hormones, can cause precocious puberty in both sexes in untreated individuals and virilization in female patients with a 46, XX karyotype. The female paraurethral (Skene's) gland has been reported as prostate analogous. Growth of prostate tissue is associated with androgen production; therefore, prostate-specific antigen (PSA) levels may represent a marker of virilization in 46, XX patients with CAH. OBJECTIVES: To describe PSA levels in 46, XX patients and evaluate whether higher PSA levels are associated with androgenization and the severity of the disease. STUDY DESIGN: Sixty-six patients with CAH and a 46, XX karyotype were included, irrespective of age. Serum PSA, testosterone, 17-hydroxyprogesterone (17-OHP) and androstenedione levels were measured. Patients' age, age at diagnosis, forms of the disease, Prader classification, bone age assessment, sex of rearing, surgery, and the presence of clinical complications were obtained from their medical records. RESULTS: The mean age of patients was 11.45 ± 10.74 years. Forty-three patients (65%) were diagnosed neonatally at a median of 0.08 years (mean 1.47 ± 2.34 years), with registers of 17-OHP measurements (Guthrie test) being available in 51%. Testosterone, 17-OHP and androstenedione were significantly high. PSA was detectable in 25% of cases (levels >0.01 ng/ml), with a mean of 0.03 ± 0.09 ng/ml, and only in patients over five years of age. A correlation was found between PSA and age (p < 0.001), age at diagnosis (p = 0.002), testosterone (p = 0.001) and androstenedione (p = 0.023). There was no correlation between PSA and the forms of CAH or Prader classification. A sub-analysis of the patients over five years of age in whom PSA was detectable also showed that there was a correlation between PSA (p < 0.05) and age at analysis, age at diagnosis, testosterone and androstenedione levels. DISCUSSION: Limitations of this study include the small sample size due to the rareness of the disease, its retrospective nature, the absence of a control group, the fact that the sample was selected at two referral centers, which could have resulted in a selection bias, and the use of different reference values in the different laboratories conducting the PSA tests. CONCLUSIONS: PSA is detectable in 25% of 46, XX patients with CAH, only after five years of age. PSA level increases significantly with age, age at diagnosis, and testosterone and androstenedione levels, confirming a correlation between PSA levels and elevated androgen levels.

Metabolic control and body composition of children and adolescents with phenylketonuria / Controle metabólico e composição corporal de crianças e adolescentes com diagnóstico neonatal de fenilcetonúria

ABSTRACT Objective: To characterize metabolic control and verify whether it has any relation with socioeconomic, demographic, and body composition variables in children and adolescents with phenylketonuria (PKU) diagnosed in the neonatal period. Methods: This cohort study collected retrospective data of 53 phenylketonuric children and adolescents. Data on family income, housing, and mother's age and schooling level were collected, and anthropometric measures of body composition and distribution were taken. All dosages of phenylalanine (Phe) from the last five years (2015-2019) were evaluated and classified regarding their adequacy (cutoffs: 0-12 years: 2-6 mg/dL; 12-19 years: 2-10 mg/dL). Adequate metabolic control was considered if ≥7%) of the dosages were within desired ranges. Results: The mean (±standard deviation) age in the last year was 10.1±4.6 years. Most of them were under 12 years old (33/53; 62.3%) and had the classic form of the disease (39/53; 73.6%). Better metabolic control was observed among adolescents (68.4 versus 51.4%; p=0.019). Overweight was found in 9/53 (17%) and higher serum Phe levels (p<0.001) were found in this group of patients. Metabolic control with 70% or more Phe level adequacy decreased along with the arm muscle area (AMA) (ptendency=0.042), being 70.0% among those with low reserve (low AMA), and 18.5% among those with excessive reserve (high AMA). Conclusions: Adequate metabolic control was observed in most patients. The findings suggest that, in this sample, the levels of phenylalanine may be related to changes in body composition.

RESUMO Objetivo: Caracterizar o controle metabólico e verificar se existe relação entre ele, variáveis socioeconômicas, demográficas e composição corporal de crianças e adolescentes com fenilcetonúria (FNC) diagnosticada no período neonatal. Métodos: Coorte com coleta retrospectiva de dados de 53 crianças e adolescentes fenilcetonúricos. Foram coletados dados de renda familiar, moradia, idade e escolaridade materna e realizaram-se medidas antropométricas de composição e distribuição corporal. Todas as dosagens de fenilalanina (Fal) dos últimos cinco anos (2015-2019) foram avaliadas e classificadas quanto à adequação (cortes: 0-12 anos: 2-6 mg/dL; 12-19 anos: 2-10 mg/dL). A proporção de dosagens adequadas ≥70% foi considerada como controle metabólico adequado. Resultados: A média (±desvio padrão) de idade, no último ano, foi de 10,1±4,6 anos. A maioria tinha menos de 12 anos (33/53; 62,3%) e apresentava a forma clássica da doença (39/53; 73,6%). Observou-se melhor controle metabólico entre os adolescentes (68,4 vs. 51,4%; p=0,019). Excesso de peso foi encontrado em 9/53 (17%) e maiores níveis séricos de Fal foram descritos nesse grupo (p<0,001). O percentual de controle metabólico com 70% ou mais de adequação dos níveis de Fal foi decrescente de acordo com a área muscular do braço (AMB; ptendência=0,042), sendo de 70% entre os de baixa reserva (AMB reduzida) e de 18,5% entre os com excesso (AMB elevada). Conclusões: Observou-se controle metabólico adequado na maioria dos avaliados e os achados sugerem que, nesta amostra, os níveis de fenilalanina podem estar relacionados com alterações da composição corporal.

Mutation screening in the genes PAX-8, NKX2-5, TSH-R, HES-1 in cohort of 63 Brazilian children with thyroid dysgenesis

ABSTRACT Objective: To evaluate the candidate genes PAX-8, NKX2-5, TSH-R and HES-1 in 63 confirmed cases of thyroid dysgenesis. Subjects and methods: Characterization of patients with congenital hypothyroidism into specific subtypes of thyroid dysgenesis with hormone levels (TT4 and TSH), thyroid ultrasound and scintigraphy. DNA was extracted from peripheral blood leukocytes and the genetic analysis was realized by investigating the presence of mutations in the transcription factor genes involved in thyroid development. Results: No mutations were detected in any of the candidate genes. In situ thyroid gland represented 71.1% of all cases of permanent primary congenital hypothyroidism, followed by hypoplasia (9.6%), ectopia (78%), hemiagenesis (6.0%) and agenesis (5.5%). The highest neonatal screening TSH levels were in the agenesis group (p < 0.001). Conclusions: Thyroid dysgenesis is possibly a polygenic disorder and epigenetic factors could to be implicated in these pathogeneses.

The c.63A>G polymorphism in the NKX2.5 gene is associated with thyroid hypoplasia in children with thyroid dysgenesis

Objective To search for genetic alteration in NKX2.5 gene in patients presenting both congenital heart disease (CHD) and TD. Subjects and methods Individual phenotypes were carefully analyzed in 86 children with thyroid dysgenesis (TD) using thyroid function tests, scintigraphy, ultrasound and echocardiography. DNA was extracted and NKX2.5 gene coding region was amplified by polymerase chain reaction (PCR) and sequenced. Results CHD were found in 8.1% of patients with TD. The mutation screening revealed two known polymorphisms in patients with isolated TD or TD associated with CHD. None of them are predicted to result in codon change in conserved domain. The c.63A>G polymorphism was detected in 54/86 patients (49 with isolated TD and 5 with TD combined with CHD). There was a significant association of c.63A>G polymorphism with hypoplasia (p < 0.036). The c.541G>A polymorphism was observed in only one patient with isolated thyroid hypoplasia. Conclusion NKX2.5 mutations were not found. The c.63A>G polymorphism might be associated with thyroid hypoplasia.

Hemoglobin A2 values in sickle cell disease patients quantified by high performance liquid chromatography and the influence of alpha thalassemia

BACKGROUND: In sickle cell disease, the quantification of Hb A2 is important for the differential diagnosis between sickle cell anemia (Hb SS) and Hb S/ß0-thalassemia.OBJECTIVE: To determine Hb A2 levels as quantified by high performance liquid chromatography in patients with sickle cell anemia (Hb SS) and with the SC hemoglobinopathy, with or without concomitant alpha thalassemia.METHODS: This is a retrospective study of 242 children aged between two and six years with diagnoses of Hb SS or Hb SC. The hemoglobin was evaluated using high performance liquid chromatography and alpha thalassemia [3.7 kb deletion (-a3.7)] was detected by polymerase chain reaction. Patients were classified as homozygous (-a3.7/-a3.7), heterozygous (-a3.7/a), or homozygous wild-type. Analysis of variance was used to compare the mean Hb A2 values between the alpha thalassemia groups.RESULTS: The mean (± standard deviation) Hb A2 concentrations in the Hb SS group (n = 135) was 3.68 ± 0.65%. The mean values for individuals with Hb SS and heterozygous (n = 28) or homozygous for alpha thalassemia (n = 3) were 3.98 ± 0.64% and 4.73 ± 0.25%, respectively. The mean Hb A2 of all the Hb SC patients (n = 107) was 4.01 ± 0.507 with 4.29 ± 0.41% and 4.91 ± 0.22% in individuals heterozygous (n = 23) and homozygous for alpha thalassemia (n = 7), respectively. All patients homozygous for alpha thalassemia had Hb A2 levels above 3.5%. However, Hb A2 values above 5.2% were seen in patients with Hb SS and Hb SC, independently of alpha thalassemia.CONCLUSION: Hb A2 levels are elevated in patients with Hb S or Hb C, and are directly influenced by the alpha thalassemia genotypes.

Breastfeeding and the anthropometric profile of children with sickle cell anemia receiving follow-up in a newborn screening reference service / Aleitamento materno e perfil antropométrico de crianças com doença falciforme acompanhadas em serviço de referência em triagem neonatal

OBJECTIVE: To study the breastfeeding history (BF) and the anthropometric status of children with Sickle Cell Disease (SCD). METHODS: A cross-sectional study of 357 children with SCD aged between 2 and 6 years, regularly followed at a Newborn Screening Reference Service (NSRS) between November 2007 and January 2009. The outcome was anthropometric status and the exposures were: BF pattern, type of hemoglobinopathy and child's age and gender. RESULTS: The mean (SD) age was 3.7 (1.1) years, 52.9% were boys and 53.5% had SCA (hemoglobin SS). The prevalence of exclusive breastfeeding (EBR) up to six months of age was 31.5%, the median EBR times (p25-p75) was 90.0 (24.0-180.0) days and the median weaning ages (p25-p75) was 360.0 (90.0-720.0) days respectively. Normal W/H children experienced EBR for a mean duration almost four times longer than malnourished children (p=0.01), and were weaned later (p<0.05). Height deficit was found in 5.0% of children, while all the children with severe short stature had had SCA (hemoglobin SS) and were older than 4 years of age. CONCLUSIONS: EBF time and weaning age were greater than that found in the literature, which is a possible effect of the multidisciplinary follow-up. Duration of EBF and later weaning were associated with improved anthropometric indicators.

OBJETIVO: Descrever a história de aleitamento materno (AM) e estado antropométrico de crianças com doença falciforme (DF). MÉTODOS: Estudo transversal com 357 crianças com hemoglobinopatias SS e SC de dois e seis anos, acompanhadas regularmente num Serviço de Referência em Triagem Neonatal (SRTN) entre novembro de 2007 e janeiro de 2009. O desfecho correspondeu ao estado antropométrico e as exposições foram: padrão do AM, tipo de hemoglobinopatia, faixa etária e sexo da criança. RESULTADOS: A média (DP) de idade observada foi de 3,7 (1,1) anos, 52,9% meninos e 53,5% com hemoglobinopatia SS. A prevalência de aleitamento materno exclusivo (AME) até o sexto mês foi de 31,5%, a mediana (p25-p75) do tempo de AME foi de 90 (24-180) dias e a mediana (p25-p75) da idade de desmame foi de 360 (90-720) dias. Crianças eutróficas em relação ao P/A tiveram o tempo de AME, em média, quase quatro vezes maior do que os desnutridos (p < 0,01), bem como foram desmamadas mais tarde (p < 0,05). O déficit de altura foi encontrado em 5% das crianças e todas as crianças com baixa estatura grave tinham hemoglobinopatia SS e mais de quatro anos. CONCLUSÕES: O tempo de AME e a idade de desmame foram superiores aos encontrados na literatura, possível efeito do acompanhamento multidisciplinar. A duração do AME e a idade mais tardia de desmame foram associadas a melhores indicadores antropométricos.

Dried blood spot testing for the antenatal screening of HTLV, HIV, syphilis, toxoplasmosis and hepatitis B and C: prevalence, accuracy and operational aspects

Introduction: Screening for vertically transmitted infection is mandatory and must be conducted at the first prenatal consultation. The most vulnerable women's groups are those at the lowest socio-economic level. Dried blood spot testing on filter paper could represent a secure way to screen pregnant women in the prenatal period. Methods: A cross-sectional study was conducted between November 2009 and March 2010, in the Metropolitan Region of Salvador, Bahia, Brazil, to compare the accuracy of the dried blood spot in filter paper and venipuncture serological as screening methods for HIV, HTLV, VHB, VHC, Treponema pallidum, and Toxoplasma gondii during prenatal period. Results of the venous blood sample collected in tubes were considered the gold standard. Results: Serum samples and dried blood spot were obtained from 692 pregnant women aged between 14 and 42 years, with a median age of 26. Thirteen women were seropositive for T. gondii (1.88%; 95% CI: 0.60–2.71%), five for T. pallidum (0.72%; 95% CI: 0.15–1.61%), two for HBV (0.29%; 95% CI: 0.050.95%) and one for HTLV-1 (0.14%; 95% CI: 0.01–0.71%). No one was positive for HCV and HIV. The dried blood spot accuracy for syphilis and HTLV were 100% (95% CI: 99.25–100) and 100% (95% CI: 99.45–100%), respectively. The average time between blood collection and recording of the sample in the reference laboratory was 4.93 (3.82) days and between dried blood spot processing and active search for pregnant women was 3.44 (4.27) days. Conclusions: The use of dried blood spot may represent a secure way to expedite access to results of vertically transmitted diseases in the prenatal period, particularly in regions with scarce healthcare resources. .

Caracterização genético-clínica de pacientes com fenilcetonúriano Estado de Alagoas / Genetic and clinical characterization of patients with phenylketonuria in Alagoas state, Brazil

Objetivos: Caracterizar o perfil genético-clínico de pacientes com fenilcetonúria em Alagoas, diagnosticados e acompanhados pelo Programa Nacional de Triagem Neonatal.Métodos: Pacientes com fenilcetonúria, assistidos pelo Serviço de Referência em Triagem Neonatal de Alagoas, foram submetidos a coleta de sangue para rastrear mutações genéticas determinantes da variação fenotípica da doença. Concomitantemente, os pacientes ou seus responsáveis responderam a um questionário padronizado para coleta de dados clínicos e epidemiológicos.Resultados: Foram acompanhados 20 pacientes, sendo 14 do sexo masculino e seis do sexo feminino, pertencentes a 18 famílias. A idade dos pacientes estudados variou de 3 a 31 anos. Houve consanguinidade parental em 3/18 famílias; recorrência familial 3/18; 3/20 tiveram diagnóstico tardio; 2/20 interromperam temporariamente o tratamento; 1/20 não aderiu ao tratamento; e 6/20 apresentam manifestações clínicas. A análise das mutações foi concluída em 15/20 pacientes. As mutações encontradas no gene da fenilalanina hidroxilase foram: R261Q-homozigose (2 pacientes); V388M/I65T (1); R270K/V388M (1); I65T/L348V (1); IVS10nt11G>A-homozigose (2); V388M/R252W (1); R261Q/I65T (1); IVS10nt11G>A/R252W (1); V388M/IVS10nt11G>A (3); R261Q/R252W (1); R261Q/V388M (1).Conclusões: O genótipo V388M/IVS10nt11G>A foi o mais prevalente. Trinta por cento dos pacientes foram sintomáticos, provavelmente pela natureza das mutações, não adesão ao tratamento, tratamento inadequado e/ou diagnóstico tardio.

Aims: Characterizing the genetic/clinical profile of patients diagnosed with Phenylketonuria in Alagoas, monitored by the National Program of Newborn Screening. Methods: Patients with phenylketonuria, assisted by the Reference Center for Neonatal Screening of Alagoas , underwent blood sampling for detecting genetic determinants for the phenotypic variability of the disease. Concomitantly, patients or their guardians answered a standardized questionnaire for collection of clinical and epidemiological data. Results: Twenty patients (14 males and 6 females), belonging to 18 families, were monitored. Age ranged from 3-31 (mean age 10.35).We found parental consanguinity in 3/18 families; familial recurrence was 3/18; 3/20 had late diagnosis; 2/20 interrupted treatment for some time; 1/20 did not adhere to treatment; and 6/20 had clinical manifestations. Analysis of mutations was concluded in 15/20 patients. Mutations found in the phenylalanine hydroxylase gene were: R261Q-homozygous (2 patients); V388M/I65T (1); R270K/V388M (1); I65T/L348V (1); IVS10nt11G>A-homozygous(2); V388M/R252W (1); R261Q/I65T (1); IVS10nt11G>A/R252W (1); V388M/IVS10nt11G>A (3); R261Q/R252W (1); R261Q/V388M (1).

Aspectos clínicos e demográficos da fenilcetonúria no Estado da Bahia / Clinical and demographic aspects of phenylketonuria in Bahia State, Brazil

OBJETIVO:Descrever as características clínicas e demográficas dos pacientes com diagnóstico de hiperfenilalaninemia acompanhados no Serviço de Referência em Triagem Neonatal da Bahia. MÉTODOS: Estudo transversal de 99 famílias (111 afetados) com fenótipo bioquímico de hiperfenilalaninemia, com coleta de dados em prontuários e em banco de dados laboratorial, incluindo aspectos demográficos e clínicos. RESULTADOS: A incidência de hiperfenilalaninemia na Bahia foi de um caso a cada 16.334 nascidos vivos, com cobertura de 91 por cento. Dentre os pacientes acompanhados, 82 por cento foram diagnosticados pela triagem neonatal e, em 11 famílias, havia mais de um caso. O fenótipo clássico da fenilcetonúria foi diagnosticado em 63 (57 por cento) pacientes. Entre os triados, a mediana de idade na primeira consulta foi 39,5 dias e, deles, 34 por cento apresentavam sintomatologia nesse momento; nenhum com atraso no desenvolvimento neuropsicomotor. A consanguinidade foi descrita em 32 por cento dos casos e houve predomínio de pacientes classificados como brancos (63 por cento). Os pais tinham baixa escolaridade e baixa renda. Dos 417 municípios da Bahia, 15 por cento apresentavam pelo menos um caso, com concentração na região nordeste (10 por cento) e na capital do Estado (14 por cento). CONCLUSÕES: Os resultados evidenciaram idade tardia ao início do tratamento, o que pode comprometer os resultados do programa. Observou-se também presença de consanguinidade e recorrência familiar, reforçando a importância da investigação familiar para diagnosticar indivíduos com deficiência mental de etiologia não esclarecida que podem se beneficiar de tratamento.

OBJECTIVE:To describe demographic and clinical characteristics of patients with hyperphenylalaninemia followed at the Neonatal Screening Reference Service of Bahia, Brazil. METHOD:Cross-sectional study including 99 families (111 affected individuals) with biochemical phenotype of hyperphenylalaninemia by chart review and laboratory database that include demographic and clinical features. RESULTS: The incidence of hyperphenylalaninemia in Bahia was one case per 16,334 live births, covering 91 percent of them. Among patients followed, 82 percent were diagnosed by newborn screening and, in 11 families, there were more than one case. The classic phenotype of phenylketonuria was diagnosed in 63 (57 percent) patients. Among those screened, the median age at first consultation was 39.5 days. Among the patients, 34 percent had symptoms at the first medical consultation, none of them with delayed neurodevelopment. Consanguinity was reported in 32 percent of patients. Affected individuals were predominantly classified as white (63 percent). The parents had low education and low income. Among the 417 municipalities of Bahia, 15 percent had at least one case, with a concentration in the Northeast (10 percent) and in the capital of the State (14 percent). CONCLUSIONS: The results showed elevated age at the beginning of the treatment, which may compromise the program results. Presence of consanguinity and familial recurrence were also noted. Careful investigation of families searching for individuals with mental retardation of unknown etiology that would benefit from the treatment is important.

Aspectos clínicos da fenilcetonúria em serviço de referência em triagem neonatal da Bahia / Clinical aspects of phenylketonuria in a reference service for neonatal screening in Bahia

OBJETIVOS: descrever as características clínicas dos pacientes com hiperfenilalaninemia acompanhados no Serviço de Referência em Triagem Neonatal (SRTN) do estado da Bahia. MÉTODOS: estudo descritivo transversal, tendo como amostra todos os pacientes com diagnóstico conhecido de Hiperfenilalaninemia residentes no estado da Bahia e acompanhados no SRTN até setembro de 2005. Tal população é composta de 46 famílias, num total de 51 pacientes. A análise dos dados foi descritiva, incluindo medidas de tendência central e dispersão. RESULTADOS: houve discreto predomínio do gênero feminino (52,9 por cento). A maioria dos pacientes (78,4 por cento) teve seu diagnóstico estabelecido através da triagem neonatal, tendo, portanto, tratamento precoce. Consangüinidade foi registrada em 32,6 por cento das famílias. A média de início do tratamento entre os pacientes diagnosticados pela triagem neonatal foi de 56,6 37,8 dias, enquanto que entre os pacientes com diagnóstico tardio, foi de 7,1 anos. CONCLUSÕES: o estudo descreve um grupo de pacientes representativo de uma patologia incluída no Programa Nacional de Triagem Neonatal (PNTN), sendo, portanto, de relevância para a saúde pública. Entre os dados clínicos, chama a atenção a média de idade do início do tratamento, superior ao recomendado na literatura, alertando para a necessidade de um maior enfoque no diagnóstico precoce.