ABSTRACT
ABSTRACT Background: Alpha 1-antitrypsin deficiency (AATD) is a hereditary codominant autosomal disease. This liver disease ranges from asymptomatic cases to terminal illness, which makes early recognition and diagnosis challenging. It is the main cause of pediatric liver transplantation after biliary atresia. Objective: To describe the clinical characteristics, as well as those of histologic and laboratory tests, phenotypic and/or genetic evaluation and evolution of a cohort of pediatric patients with AATD. Methods: This is a retrospective observational study of 39 patients with confirmed or probable AATD (without phenotyping or genotyping, but with suggestive clinical features, low serum alpha 1-antitrypsin (AAT) level and liver biopsy with PAS granules, resistant diastasis). Clinical, laboratory and histological variables, presence of portal hypertension (PH) and survival with native liver have been analyzed. Results: A total of 66.7% of 39 patients were male (26/39). The initial manifestation was cholestatic jaundice in 79.5% (31/39). Liver transplantation was performed in 28.2% (11/39) of patients. Diagnosis occurred at an average of 3.1 years old and liver transplantation at 4.1 years of age. 89.2% (25/28) of the patients with confirmed AATD were PI*ZZ or ZZ. The average AAT value on admission for PI*ZZ or ZZ patients was 41.6 mg/dL. All transplanted patients with phenotyping or genotyping were PI*ZZ (or ZZ). Those who were jaundiced on admission were earlier referred to the specialized service and had higher levels of GGT and platelets on admission. There was no significant difference in the survival curve when comparing cholestatic jaundiced to non-cholestatic jaundiced patients on admission. Comparing patients who did or did not progress to PH, higher levels of AST and APRI score at diagnosis (P=0.011 and P=0.026, respectively) were observed and in the survival curves patients with PH showed impairment, with 20.2% survival with native liver in 15 years. Conclusion: Jaundice is an important clinical sign that motivates referral to a specialist, but it does not seem to compromise survival with native liver. Patients progressing to PH had higher AST, APRi score on admission and significantly impaired survival with native liver. It is important to pay attention to these signs in the follow-up of patients with AATD.
RESUMO Contexto: Deficiência de alfa 1-antitripsina (DAAT) é uma doença hereditária, de caráter autossômico codominante. A apresentação da doença hepática varia desde casos assintomáticos até doença terminal, o que dificulta reconhecimento e diagnóstico precoces. É a principal causa de transplante hepático pediátrico após atresia de vias biliares. Objetivo: Descrever as características clínicas, de exames laboratoriais, histológicos, avaliação fenotípica e/ou genética e sobrevida de uma coorte de pacientes pediátricos com DAAT. Métodos: Estudo observacional retrospectivo de 39 pacientes com diagnóstico de DAAT confirmada ou provável (sem fenotipagem ou genotipagem, mas com clínica sugestiva, baixo nível sérico de alfa 1-antitripsina (A1AT) e biópsia hepática com grânulos PAS, diástase resistentes). Variáveis clínicas, laboratoriais, histológicas, presença de hipertensão portal (HP) e sobrevida com fígado nativo foram analisadas. Resultados: Dos 39 pacientes, 66,7% eram do sexo masculino (26/39). A manifestação inicial foi icterícia colestática em 79,5% (31/39). Em 28,2% (11/39) houve necessidade de transplante hepático. O diagnóstico ocorreu com uma idade média de 3,1 anos e, o transplante hepático, 4,1 anos. Dos pacientes com DAAT confirmada, 89,2% (25/28) eram PI*ZZ ou ZZ. O valor médio de A1AT na admissão de pacientes PI*ZZ ou ZZ foi 41,6 mg/dL. Todos os transplantados com fenotipagem ou genotipagem eram PI*ZZ (ou ZZ). Os ictéricos à admissão foram referenciados mais cedo ao serviço especializado e apresentaram níveis mais elevados de GGT e plaquetas à admissão. Não houve diferença significativa na curva de sobrevida ao compararmos icterícia colestática ou não à admissão. Ao comparar os pacientes que progrediram ou não para HP, observou-se níveis mais elevados de AST e APRI escore ao diagnóstico (P=0,011 e P=0,026, respectivamente) e, nas curvas de sobrevida, pacientes com HP apresentaram comprometimento, com 20,2% de sobrevida com fígado nativo em 15 anos. Conclusão: Icterícia é um sinal clínico importante que motiva o encaminhamento ao especialista, mas parece não comprometer a sobrevida com fígado nativo. Pacientes com evolução para HP tiveram AST e escore APRi mais elevados à admissão e comprometimento significativo da sobrevida com fígado nativo. Importante atentar a esses sinais no seguimento de pacientes com DAAT.
ABSTRACT
ABSTRACT Alpha-1 antitrypsin deficiency (AATD) is a rare genetic disorder caused by a mutation in the SERPINA1 gene, which encodes the protease inhibitor alpha-1 antitrypsin (AAT). Severe AATD predisposes individuals to COPD and liver disease. Early diagnosis is essential for implementing preventive measures and limiting the disease burden. Although national and international guidelines for the diagnosis and management of AATD have been available for 20 years, more than 85% of cases go undiagnosed and therefore untreated. In Brazil, reasons for the underdiagnosis of AATD include a lack of awareness of the condition among physicians, a racially diverse population, serum AAT levels being assessed in a limited number of individuals, and lack of convenient diagnostic tools. The diagnosis of AATD is based on laboratory test results. The standard diagnostic approach involves the assessment of serum AAT levels, followed by phenotyping, genotyping, gene sequencing, or combinations of those, to detect the specific mutation. Over the past 10 years, new techniques have been developed, offering a rapid, minimally invasive, reliable alternative to traditional testing methods. One such test available in Brazil is the A1AT Genotyping Test, which simultaneously analyzes the 14 most prevalent AATD mutations, using DNA extracted from a buccal swab or dried blood spot. Such advances may contribute to overcoming the problem of underdiagnosis in Brazil and elsewhere, as well as being likely to increase the rate detection of AATD and therefore mitigate the harmful effects of delayed diagnosis.
RESUMO A deficiência de alfa-1 antitripsina (DAAT) é um distúrbio genético raro causado por uma mutação no gene SERPINA1, que codifica o inibidor de protease alfa-1 antitripsina (AAT). A DAAT predispõe os indivíduos a DPOC e doença hepática. O diagnóstico precoce é essencial para a implementação de medidas preventivas e para limitar a carga da doença. Embora diretrizes nacionais e internacionais para o diagnóstico e manejo da DAAT estejam disponíveis há 20 anos, mais de 85% dos casos não são diagnosticados e, portanto, não são tratados. No Brasil, os motivos para o subdiagnóstico da DAAT incluem o desconhecimento dos médicos sobre a condição, a diversidade racial da população, o fato de os níveis séricos de AAT serem avaliados em um número limitado de indivíduos e a falta de ferramentas diagnósticas convenientes. O diagnóstico da DAAT baseia-se em resultados de exames laboratoriais. A abordagem diagnóstica padrão envolve a avaliação dos níveis séricos de AAT, seguida de fenotipagem, genotipagem, sequenciamento gênico ou suas combinações para detecção da mutação específica. Nos últimos 10 anos, novas técnicas foram desenvolvidas, oferecendo uma alternativa rápida, minimamente invasiva e confiável aos métodos tradicionais de teste. Um desses testes disponíveis no Brasil é o teste de genotipagem A1AT, que analisa simultaneamente as 14 mutações mais prevalentes da DAAT usando DNA extraído de swab bucal ou de sangue em papel-filtro. Esses avanços podem contribuir para a superação do problema do subdiagnóstico no Brasil e em outros países, bem como podem aumentar a taxa de detecção da DAAT e, portanto, mitigar os malefícios do diagnóstico tardio.
Subject(s)
Humans , alpha 1-Antitrypsin Deficiency/diagnosis , alpha 1-Antitrypsin Deficiency/genetics , Brazil , alpha 1-Antitrypsin/genetics , MutationABSTRACT
Resumen La deficiencia de alfa-1 antitripsina (AAT) es uno de los trastornos hereditarios más frecuentes y con mayor incidencia en pacientes con enfermedad pulmonar obstructiva crónica (EPOC). Se desconoce su prevalencia en aquellos con neumotórax espontáneo. El objetivo fue estimar la prevalencia de deficiencia de AAT en sujetos con neumotórax espontáneo. El estudio fue prospectivo y de corte transversal en pacientes con neumotórax espontáneo primario. Se excluyeron aquellos con neumotórax secundario. Se realizó cuantificación de AAT en suero por nefelometría y posterior genotipificación rápida (PCR en tiempo real) para detectar los alelos de deficiencia más prevalentes (Z y S) en aquellos con concentraciones séricas ≤ 120 mg/dl. Se incluyeron 58 pacientes con neumotórax espontáneo primario. La edad promedio fue de 34 ± 13 años con predominio de sexo masculino (72%) y alta prevalencia de tabaquismo actual y pasado (60%). Del total, el 26% (IC95%: 15-39) presentó concentraciones de AAT ≤ 120mg/dl. Encontramos 7 formas deficitarias (12%; IC 95%: 5-23%). Un paciente presentó una forma grave Pi*ZZ (1.7%), 3 fueron heterocigotos Z (5.2%) y 3 heterocigotos S (5.2%). La prevalencia de variantes deficitarias de AAT fue alta en este grupo con neumotórax espontáneo.
Abstract Alpha-1 antitrypsin (AAT) deficiency is one of the most common inherited disorders with a higher incidence in patients with chronic obstructive pulmonary disease (COPD). Its prevalence in patients with spontaneous pneumothorax is unknown. The objective was to estimate the prevalence of AAT deficiency in patients with spontaneous pneumothorax. This was a prospective cross-sectional study, in patients with spontaneous pneumothorax, where those with secondary pneumothorax were excluded. Quantification of serum AAT by nephelometry and subsequent rapid genotyping (real time PCR) was performed, in order to detect the most prevalent deficiency alleles (Z and S) in those subjects with serum AAT concentrations ≤ 120 mg/dl. Fifty-eight patients with primary spontaneous pneumothorax were included. The average age was 34 ± 13 years with male predominance (72%) and high prevalence of current and past smoking (60%). Twenty six percent of them (95% CI: 15-39) presented AAT serum concentrations ≤ 120mg/dl. We found 7 deficiency variants (12%; IC 95%: 5-23%). One patient presented a severe Pi*ZZ form (1.7%), 3 were heterozygotes Z (5.2%) and 3 heterozygotes S (5.2%). The prevalence of AAT deficient variants was high in patients with spontaneous pneumothorax.
Subject(s)
Humans , Pneumothorax/epidemiology , alpha 1-Antitrypsin Deficiency/epidemiology , Pneumothorax/genetics , Cross-Sectional Studies , Prospective Studies , alpha 1-Antitrypsin Deficiency/complications , alpha 1-Antitrypsin Deficiency/genetics , Pulmonary Disease, Chronic ObstructiveABSTRACT
INTRODUCTION: Alpha-1 antitrypsin deficiency (AATD) is still underdiagnosed, despite the recommendation to determine AAT in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVE: To estimate the prevalence of AATD in COPD patients adjusted according to the population of the COPD prevalence study in Argentina (EPOC.AR). MATERIAL AND METHODS: This was a multicenter prospective cross-sectional study of a population aged≥30 years of age diagnosed with COPD, involving AAT quantification in dry blood spot and subsequent genotyping in subjects with<1.5mg/dL AAT in dry blood spot (<80mg/dL in serum). AAT was defined as the detection of variants ZZ or SZ on genotyping. The EPOC.AR study population was used to calculate local adjusted prevalence. RESULTS: We included 3,254 patients (544 with AAT<80mg/dL) with a spirometric diagnosis of COPD. The prevalence of AATD in the total study population was 1.29% (95% CI 0.93-1.74), of which 0.92% (95% CI 0.62-1.31) were Pi*ZZ and 0.37% (95% CI 0.19-0.64) Pi*SZ. The adjusted prevalence of AATD in COPD patients≥40 years of age was 0.83% (95% CI 0.23-2.08). We found that AATD was negatively associated with age (OR 0.94; 95% CI 0.90-0.98; P=.006), smoking habit (OR 0.98; 95% CI 0.96-0.99; P=.009), and FEV1% (OR 0.95; 95% CI 0.91-0.99; P=.015). CONCLUSIONS: The prevalence of AATD in the adult population with COPD in Argentina is estimated to be 0.83%, which could represent 17,000 cases in our country.
Subject(s)
Pulmonary Disease, Chronic Obstructive , alpha 1-Antitrypsin Deficiency , Adult , Argentina/epidemiology , Cross-Sectional Studies , Humans , Prevalence , Prospective Studies , Pulmonary Disease, Chronic Obstructive/epidemiology , alpha 1-Antitrypsin Deficiency/complicationsABSTRACT
ABSTRACT Objective: The clinical, functional, radiological and genotypic descriptions of patients with an alpha-1 antitrypsin (A1AT) gene mutation in a referral center for COPD in Brazil. Methods: A cross-sectional study of patients with an A1AT gene mutation compatible with deficiency. We evaluated the A1AT dosage and genotypic, demographic, clinical, tomographic, and functional characteristics of these patients. Results: Among the 43 patients suspected of A1AT deficiency (A1ATD), the disease was confirmed by genotyping in 27 of them. The A1AT median dosage was 45 mg/dL, and 4 patients (15%) had a normal dosage. Median age was 54, 63% of the patients were male, and the respiratory symptoms started at the age of 40. The median FEV1 was 1.37L (43% predicted). Tomographic emphysema was found in 77.8% of the individuals. The emphysema was panlobular in 76% of them and 48% had lower lobe predominance. The frequency of bronchiectasis was 52% and the frequency of bronchial thickening was 81.5%. The most common genotype was Pi*ZZ in 40.7% of participants. The other genotypes found were: Pi*SZ (18.5%), PiM1Z (14.8%), Pi*M1S (7.4%), Pi*M2Z (3.7%), Pi*M1I (3.7%), Pi*ZMnichinan (3.7%), Pi*M3Plowell (3.7%), and Pi*SF (3.7%). We did not find any significant difference in age, smoking load, FEV1, or the presence of bronchiectasis between the groups with a normal and a reduced A1AT dosage, neither for 1 nor 2-allele mutation for A1ATD. Conclusions: Our patients presented a high frequency of emphysema, bronchiectasis and bronchial thickening, and early-beginning respiratory symptoms. The most frequent genotype was Pi*ZZ. Heterozygous genotypes and normal levels of A1AT also manifested significant lung disease.
RESUMO Objetivo: Caracterização clínica, funcional, radiológica e genotípica dos pacientes portadores de mutações do gene da alfa-1 antitripsina (A1AT) em um centro de referência em doença pulmonar obstrutiva crônica (DPOC) no Brasil. Métodos: Estudo transversal de pacientes com mutação no gene da A1AT compatível com deficiência. Foram avaliadas características genotípicas, demográficas, clínicas, tomográficas, de função pulmonar, e dosagem de A1AT. Resultados: De 43 pacientes suspeitos para deficiência de alfa-1 antitripsina (DA1AT), a doença foi confirmada por genotipagem em 27. A mediana da dosagem de A1AT foi de 45 mg/dL, e 4 pacientes (15%) apresentavam dosagens normais. A idade mediana foi de 54 anos, 63% dos participantes eram do sexo masculino e a idade do início dos sintomas prevalente foi aos 40 anos. A mediana do volume expiratório forçado no primeiro segundo (VEF1) foi de 1,37 L (43% do previsto). Enfisema tomográfico foi encontrado em 77,8% dos indivíduos, sendo panlobular em 76% e de predomínio em lobos inferiores em 48%. A frequência de bronquiectasias foi de 52%, e a de espessamento brônquico, de 81,5%. O genótipo mais encontrado foi Pi*ZZ (40,7%). Os demais genótipos foram: Pi*SZ (18,5%), Pi*M1Z (14,8%), Pi*M1S (7,4%), Pi*M2Z (3,7%), Pi*M1I (3,7%), Pi*ZMnichinan (3,7%), Pi*M3Plowell (3,7%) e Pi*SF (3,7%). Não encontramos diferença significativa para idade, carga tabágica, VEF1 e presença de bronquiectasias entre os grupos com dosagem de A1AT normal versus alterada, nem entre 1 alelo versus 2 alelos com mutação para DA1AT. Conclusões: Nossos pacientes apresentaram alta frequência de enfisema, bronquiectasias e espessamento brônquico, com início precoce dos sintomas respiratórios. O genótipo mais frequente foi Pi*ZZ, embora genótipos heterozigotos e níveis normais de A1AT também tenham se manifestado com doença pulmonar significativa.
Subject(s)
Humans , Male , Female , Middle Aged , alpha 1-Antitrypsin/genetics , Mutation/genetics , Phenotype , Respiratory Function Tests , Tomography, X-Ray Computed , Cross-Sectional Studies , alpha 1-Antitrypsin Deficiency/diagnosis , alpha 1-Antitrypsin Deficiency/genetics , GenotypeABSTRACT
El déficit de alfa -1 Antitripsina (DAAT) es una enfermedad genética rara, asociada a un incremento a padecer enfisema pulmonar y hepatopatía crónicas en niños y adultos, frecuentemente subdiagnosticada, con largos retrasos entre el inicio de los síntomas y el diagnóstico definitivo. La alfa 1-antitripsina (AAT) es el inhibidor de proteasas más abundante en el organismo humano. Se considera déficit grave y es a lo que habitualmente se refiere la literatura científica a los siguientes fenotipos: SZ, ZZ y Null. Es necesario programas de cribado para su detección precoz, por lo que se ha descripto y validado un método sencillo y específico, mediante el cual se cuantifica el valor de AAT por nefelometría en muestras de gota de sangre en papel secante y se realiza genotipificación rápida de las variantes Z y S. Objetivos: Determinar la proporción de individuos con DAAT en una población de pacientes con enfermedades respiratorias crónicas. Identificar y caracterizar a aquellos con déficit de AAT. Materiales y Método: Estudio Observacional, Descriptivo de corte Transversal de cribado de déficit de AAT, entre el 2 de enero de 2014 a 30 de marzo de 2015. De 80 personas que cumplieron con los criterios de inclusión y que concurrieron de forma espontánea o por derivación al Servicio de Neumonología del Hospital Tránsito Cáceres de Allende, Córdoba, Argentina, se analizaron 62 pacientes que aceptaron realizarse el estudio. Se realizó dosaje de alfa1-antitripsina mediante gota de sangre en papel secante a los pacientes que cumplieron los criterios de inclusión. Se solicitó espirometría, Tomografía Computada de Tórax de Alta Resolución y genotipificación rápida solo a aquellos pacientes con valores de alfa 1-antitripsina < 1,8 mg/dL. Resultados: En el presente trabajo se estudió un total de 62 pacientes, 28 (45,2%) fueron de sexo femenino y 34 (54,8%) de sexo masculino, 37 (59,7%) tuvieron valores de alfa 1-antitripsina ≥ 1,8 mg/dL y 25 (40,3%) < 1,8 mg/dL. La obtención del genotipo por la técnica de gota seca a 25 (40,3%; 25:62) pacientes con valores < 1,8 mg/dL mostró que: 22 (88%; 22:25) fueron NoS NoZ, 2 (8%; 2:25) Heterocigoto para Z y 1 (4%; 1:25) Heterocigoto para S. El patrón espirométrico predominante según criterio de ATS/ERS fue el obstructivo (88%). El patrón en TCAR fue de enfisema en 22 pacientes (88%): 7 (31,8%) centrolobulillar, 8 (36,4%) paraseptal, 7 (31,8%) panlobulillar. Hubo 2 pacientes (8%) con bronquiectasias, y 1 (4%) fue normal. Conclusión: En una población seleccionada por síntomas y/o antecedentes se pueden identificar con el cribado con técnica de gota seca a pacientes con DAAT, que en su expresión grave es poco frecuente en la Argentina, probablemente subdiagnosticado, siendo superior el número de portadores heterocigotos PIS y PIZ. El diagnóstico precoz de DAAT es poco frecuente. Es difícil establecer conclusiones sobre el grupo de alfa 1-antitripsina <1,8 mg/dL sin ser deficiencias graves, en relación a las variables estudiadas en la muestra debido a la escases de estudios y bibliografía encontradas sobre el tema. Consideramos que los pacientes que presentan un genotipo No S No Z y los que presentan discordancia deben ser confirmados cuantitativamente y tener una caracterización del fenotipo en muestras de suero por Isoelectoenfoque y ocasionalmente el análisis molecular del gen para variantes alélicas poco frecuentes, nuevas o nulas.
Subject(s)
Straining of Liquids , alpha 1-Antitrypsin DeficiencyABSTRACT
A deficiência de alfa-1-antitripsina (AAT) é associada ao desenvolvimento de doenças hepáticas graves e enfisema pulmonar precoce. Em todo o mundo, considera-se que apenas 2% dos casos estimados da deficiência de AAT tenham sido diagnosticados. A disciplina de Pneumologia da Universidade do Estado do Rio de Janeiro vem realizando testes de varredura para deficiência de AAT através da técnica de nefelometria em papel filtro em todos os pacientes com diagnóstico de DPOC. A prevalência de mutações graves encontradas nos genes da AAT em pacientes com DPOC foi de 2,4% e não difere dos dados existentes previamente na literatura, mas o número de outros pacientes com mutações leves é bastante elevado (4%). As autoras sugerem que a dosagem sistemática de AAT em todos os pacientes com DPOC possa ser uma estratégia eficiente para captura dos pacientes com deficiência enzimática, permitindo que medidas preventivas como a suspensão do fumo e o aconselhamento genético seja efetivadas.
Alpha-1-antitrypsin deficiency (AAT) is associated with the development of severe liver disease and early pulmonary emphysema. Around the world, only 2% of the estimated cases of AAT deficiency are believed to have been diagnosed. The discipline of Pulmonology of the University of the State of Rio de Janeiro has been conducting tests for AAT deficiency by filter nephelometry technique in all patients diagnosed with COPD. The prevalence of severe mutations found in AAT genes in patients with COPD was 2.4% and does not differ from previous data in the literature, but the number of other patients with mild mutations is quite high (4%). The authors suggest that the systematic dosing of AAT in all patients with COPD may be an effective strategy to capture patients with enzyme deficiency, allowing preventive measures such as smoking cessation and genetic counseling to be effective.
Subject(s)
Humans , Male , Female , Pulmonary Emphysema , alpha 1-Antitrypsin Deficiency , Pulmonary Disease, Chronic ObstructiveABSTRACT
El hígado humano, órgano unitario con múltiples funciones vitales, ocupa una posición anatómica privilegiada y estratégica, que le permite recibir información del resto de los órganos y sistemas de la economía. Es posible estar ante una enfermedad hepática con probables complicaciones sistémicas o frente a trastornos extrahepáticos que pueden afectar el hígado. Tal es el caso de las alteraciones en el metabolismo de determinados sustratos que tienen un impacto directo en este órgano y que ocasionan enfermedades hepáticas diversas. Así, se mencionan entre otras: la deficiencia de alfa 1 antitripsina (glicoproteína) que produce colestasis neonatal y cirrosis hepática en adolescentes y adultos con potencial desarrollo de hepatocarcinoma, y la alteración del metabolismo de ciertos metales como el cobre y el hierro, los que al acumularse en el hígado (sobrecarga hepática), dan por resultado las enfermedades de Wilson y hemocromatosis, respectivamente. Estas enfermedades metabólicas, si bien son de baja frecuencia en Argentina, y algunas de ellas difícilmente diagnosticadas en todo el mundo, pueden derivar en una muerte temprana. Esta breve revisión tiene como objetivo enfatizar que las enfermedades metabólicas que afectan al hígado no son una rareza y que pueden presentarse en diversas formas, y así mimetizarse con otras hepatopatías. Lo importante es tenerlas siempre presente.
Human liver, an extraordinary organ with multiple vital functions, takes up a privileged anatomic position, whose strategic site enables it to receive information from the rest of the organism. It is possible to observe liver disease with probable systemic complications, or extrahepatic manifestations that can affect the liver.They could be overthrow metabolisms because of some substances with a direct impact on the gland leading to different liver diseases. Such is the case of Alpha 1 antitrypsin deficiency (a glycoprotein deficiency) which leads to neonatal colestasis and cirrhosis in young and adults, and potentially develop hepatocellular carcinoma. Copper and ironmetabolisms and their accumulation load the hepatocites as a result give rise to Wilson disease and hemochromatosis, respectively. These metabolic diseases, of less frequency in Argentina, are hard to be diagnosed world wide and can lead to premature death. This short revision is aimed at emphasizing that metabolic diseases are not rare and can mimicry different liver diseases.
O fígado humano, órgão unitário com múltiplas funções vitais, ocupa uma posição anatômica privilegiada e estratégica, o que lhe permite receber informações do resto dos órgãos e sistemas da economia. É possível estar diante de uma doença hepática com prováveis complicações sistêmicas ou perante distúrbios extra hepáticos que podem afetar o fígado. Tal é o caso das alterações no metabolismo de certos substratos que têm um impacto direto neste órgão, causando diversas doenças hepáticas. Deste modo, são mencionadas, dentre outras: a deficiência de alfa 1 antitripsina (glicoproteína) que produz colestase neonatal e cirrose hepática nos adolescentes e adultos com potencial desenvolvimento de hepatocarcinoma e a alteração do metabolismo de certos metais como o cobre e o ferro, os quais ao se acumularem no fígado (sobrecarga hepática), resultam nas doenças de Wilson e Hemocromatose, respectivamente. Estas doenças metabólicas, apesar de serem de baixa frequência na Argentina, e algumas delas dificilmente diagnosticadas em todo o mundo, podem levar à morte precoce. Esta breve revisão visa enfatizar que as doenças metabólicas que afetam o fígado não são uma raridade e podem se apresentar de várias formas, mimetizando-se com outras hepatopatias. O importante é que estejam sempre presentes.
Subject(s)
Humans , Hemochromatosis , Hepatolenticular Degeneration , Liver/metabolism , Metabolic Diseases/classification , alpha 1-Antichymotrypsin , Copper , IronABSTRACT
ABSTRACT Objective: To determine the prevalence of alpha 1-antitrypsin (AAT) deficiency (AATD), as well as allele frequency, in COPD patients in Brazil. Methods: This was a cross-sectional study involving 926 COPD patients 40 years of age or older, from five Brazilian states. All patients underwent determination of AAT levels in dried blood spot (DBS) samples by nephelometry. Those with DBS AAT levels ≤ 2.64 mg/dL underwent determination of serum AAT levels. Those with serum AAT levels of < 113 mg/dL underwent genotyping. In case of conflicting results, SERPINA1 gene sequencing was performed. Results: Of the 926 COPD patients studied, 85 had DBS AAT levels ≤ 2.64 mg/dL, and 24 (2.6% of the study sample) had serum AAT levels of < 113 mg/dL. Genotype distribution in this subset of 24 patients was as follows: PI*MS, in 3 (12.5%); PI*MZ, in 13 (54.2%); PI*SZ, in 1 (4.2%); PI*SS, in 1 (4.2%); and PI*ZZ, in 6 (25.0%). In the sample as a whole, the overall prevalence of AATD was 2.8% and the prevalence of the PI*ZZ genotype (severe AATD) was 0.8% Conclusions: The prevalence of AATD in COPD patients in Brazil is similar to that found in most countries and reinforces the recommendation that AAT levels be measured in all COPD patients.
RESUMO Objetivo: Determinar a prevalência da deficiência de alfa 1-antitripsina (AAT), bem como a frequência alélica, em pacientes com DPOC no Brasil. Métodos: Estudo transversal com 926 pacientes com DPOC, com 40 anos ou mais, oriundos de cinco estados brasileiros. Todos os pacientes foram submetidos a dosagem de AAT em amostras de sangue seco por meio de nefelometria. Aqueles em que a concentração de AAT no sangue seco foi ≤ 2,64 mg/dl foram submetidos a dosagem sérica de AAT. Aqueles em que a concentração sérica de AAT foi < 113 mg/dl foram submetidos a genotipagem. Quando os resultados foram discrepantes, foi realizado o sequenciamento do gene SERPINA1. Dos 926 pacientes com DPOC estudados, 85 apresentaram concentração de AAT em sangue seco ≤ 2,64 mg/dl, e 24 (2,6% da amostra) apresentaram concentração sérica de AAT < 113 mg/dl. A distribuição genotípica nesse subgrupo de 24 pacientes foi a seguinte: PI*MS, em 3 (12,5%); PI*MZ, em 13 (54,2%); PI*SZ, em 1 (4,2%); PI*SS, em 1 (4,2%); e PI*ZZ, em 6 (25,0%). Na amostra estudada, a prevalência global da deficiência de AAT foi de 2,8% e a prevalência do genótipo PI*ZZ (deficiência grave de AAT) foi de 0,8%. Conclusões: A prevalência da deficiência de AAT em pacientes com DPOC no Brasil é semelhante àquela encontrada na maioria dos países e reforça a recomendação de que se deve medir a concentração de AAT em todos pacientes com DPOC.
Subject(s)
Humans , Male , Female , Middle Aged , Aged , alpha 1-Antitrypsin Deficiency/epidemiology , Gene Frequency/genetics , Pulmonary Disease, Chronic Obstructive/epidemiology , alpha 1-Antitrypsin Deficiency/blood , alpha 1-Antitrypsin Deficiency/diagnosis , alpha 1-Antitrypsin Deficiency/genetics , alpha 1-Antitrypsin/genetics , Brazil/epidemiology , Cross-Sectional Studies , Genotype , Prevalence , Pulmonary Disease, Chronic Obstructive/blood , Pulmonary Disease, Chronic Obstructive/genetics , Sequence Analysis, DNAABSTRACT
Immunochemistry with anti-vimentin, anti-lysozyme, anti-alpha 1 antitrypsin, anti-CD3 and anti-CD79α antibodies has been used for characterization of primary cell culture in the transmissible venereal tumor (TVT). Samples for primary cell culture and immunohistochemistry assays were taken from eight dogs with cytological and clinical diagnosis of TVT. To validate the immunochemical results in the primary cell culture of TVT, a chromosome count was performed. For the statistical analysis, the Mann-Whitney test with p<0.05 was used. TVT tissues and culture cells showed intense anti-vimentin immunoreactivity, lightly to moderate immunoreactivity for anti-lysozyme, and mild for anti-alpha-antitrypsin. No marking was achieved for CD3 and CD79α. All culture cells showed chromosomes variable number of 56 to 68. This is the first report on the use of immunocytochemical characterization in cell culture of TVT. Significant statistic difference between immunochemistry in tissue and culture cell was not established, what suggests that the use of this technique may provide greater certainty for the confirmation of tumors in the primary culture. This fact is particularly important because in vitro culture of tumor tissues has been increasingly used to provide quick access to drug efficacy and presents relevant information to identify potential response to anticancer medicine; so it is possible to understand the behavior of the tumor.(AU)
Os anticorpos anti-vimentina, anti-lisozima, anti-alfa 1 antitripsina, anti-CD3 e anti-CD79α foram empregados para a caracterização de culturas primárias de tumor venéreo transmissível canino (TVT). Amostras para cultura primária e imuno-histoquímica foram coletadas de oito cães com diagnóstico clínico e citológico de TVT. Para validar o resultado inmunocitoquímico nas culturas de TVT foi realizada a contagem de cromossomos. Para a análise estatística o teste de Mann-Whitney foi empregado a um nível de significância de p<0.05. As culturas e os tecidos de TVT apresentaram intensa reatividade para vimentina, moderada a leve para Lisozima, moderada para alfa-antitripsina e não houve marcação para CD3 e CD79α. Finalmente, todas as culturas apresentaram números de cromossomos que variaram de 56 a 68. Este é o primeiro relato que apresenta o uso da immunocitoquímica para a caracterização de culturas de TVT. Assim, e devido ao fato de se observar semelhança entre a imunomarcação em células e tecidos, sugere-se que o uso desta técnica possa auxiliar na confirmação de culturas primárias do tumor, fato muito importante porque a utilização da cultura do tumor pode permitir o acesso a informação relevante sobre resposta potencial a um tratamento e conhecimento do comportamento biológico do tumor.(AU)
Subject(s)
Animals , Dogs , alpha 1-Antitrypsin/analysis , Venereal Tumors, Veterinary , Cytogenetic Analysis/veterinary , Immunohistochemistry/veterinary , Muramidase/analysis , Statistics, Nonparametric , Vimentin/analysisABSTRACT
Introducción: debido a la alta frecuencia de las mutaciones C282Y y H63D del gen HFE, promotor de la hemocromatosis tipo 1 y de las mutaciones S o Z, causantes de la deficiencia de alfa-1-antitripsina (def-A1AT), se han reportado su coexistencia en varios pacientes, por lo que algunos autores han mencionado a las mutaciones en el gen HFE como posible contribuyente al desarrollo de las manifestaciones hepáticas en pacientes con def-A1AT.Objetivo: determinar la frecuencia de las mutaciones C268Y y H63D en pacientes con hepatopatías y diagnóstico presuntivo de def-A1AT.Materiales y métodos: se realizó un estudio descriptivo, conformado por 65 pacientes con hepatopatías, remitidos al laboratorio de biología molecular del Centro Nacional de Genética Médica, para el diagnóstico molecular de las mutaciones S y Z del gen de la alfa-1-antitripsina. Para la amplificación de las mutaciones C282Y y H63D se empleó el método de reacción en cadena de la polimerasa, con polimorfismos en los tamaños de los fragmentos de restricción (PCR-RFLP). Resultados: la frecuencia de las mutaciones C282Y y H63D del gen HFE en los pacientes con diagnostico presuntivo de deficiencia de alfa-1-antitripsina fue de 5,3 por ciento y 17 por ciento, respectivamente. Conclusiones: este estudio mostró que la frecuencia de estas dos mutaciones en la población cubana es alta. Igualmente, se pudo apreciar que ambas mutaciones, aun en estado heterocigoto, parecen jugar un papel fundamental en el desarrollo de diferentes patologías(AU)
Introduction: Due to the high frequency of C282Y and H63D mutations in the HFE gene, promoter type 1 hemochromatosis, and mutations S or Z causing the deficiency of alpha-1-antitrypsin (def-A1AT), studies have shown their coexistence in several patients. As a result, many scientists consider mutations in the HFE gene as a possible contributor to the development of hepatic events in patients with A1AT-def. Aim: To determine the frequency of C268Y and H63D mutations in patients with liver disease and presumptive diagnosis of A1AT-def. Materials and methods: We conducted a descriptive study that involved 65 patients with liver disease who were referred to the Molecular Biology Laboratory of the National Center of Medical Genetics for the molecular diagnosis of S and Z mutations of the gene for alpha-1 antitrypsin. We used the polymerase chain reaction method with polymorphisms in the sizes of the restriction fragments (PCR-RFLP).Results: The frequency of C282Y and H63D mutations of the HFE gene in patients with presumptive diagnosis of deficiency of alpha-1 antitrypsin was 5,3 percent and 17 percent respectively. Conclusions: this study showed that the frequency of these two mutations in Cuban population is high. We also observed that both of them, even in heterozygous state, seem to play a main role in the development of different diseases(AU)
Subject(s)
Humans , Male , Female , Genetic Association Studies , Liver Diseases/genetics , Hemochromatosis/genetics , alpha 1-Antitrypsin Deficiency/genetics , Pathology, Molecular , Mutation/genetics , Epidemiology, DescriptiveABSTRACT
Introducción: debido a la alta frecuencia de las mutaciones C282Y y H63D del gen HFE, promotor de la hemocromatosis tipo 1 y de las mutaciones S o Z, causantes de la deficiencia de alfa-1-antitripsina (def-A1AT), se han reportado su coexistencia en varios pacientes, por lo que algunos autores han mencionado a las mutaciones en el gen HFE como posible contribuyente al desarrollo de las manifestaciones hepáticas en pacientes con def-A1AT. Objetivo: determinar la frecuencia de las mutaciones C268Y y H63D en pacientes con hepatopatías y diagnóstico presuntivo de def-A1AT. Materiales y métodos: se realizó un estudio descriptivo, conformado por 65 pacientes con hepatopatías, remitidos al laboratorio de biología molecular del Centro Nacional de Genética Médica, para el diagnóstico molecular de las mutaciones S y Z del gen de la alfa-1-antitripsina. Para la amplificación de las mutaciones C282Y y H63D se empleó el método de reacción en cadena de la polimerasa, con polimorfismos en los tamaños de los fragmentos de restricción (PCR-RFLP). Resultados: la frecuencia de las mutaciones C282Y y H63D del gen HFE en los pacientes con diagnostico presuntivo de deficiencia de alfa-1-antitripsina fue de 5,3 % y 17 %, respectivamente. Conclusiones: este estudio mostró que la frecuencia de estas dos mutaciones en la población cubana es alta. Igualmente, se pudo apreciar que ambas mutaciones, aun en estado heterocigoto, parecen jugar un papel fundamental en el desarrollo de diferentes patologías.
Introduction: Due to the high frequency of C282Y and H63D mutations in the HFE gene, promoter type 1 hemochromatosis, and mutations S or Z causing the deficiency of alpha-1-antitrypsin (def-A1AT), studies have shown their coexistence in several patients. As a result, many scientists consider mutations in the HFE gene as a possible contributor to the development of hepatic events in patients with A1AT-def. Aim: To determine the frequency of C268Y and H63D mutations in patients with liver disease and presumptive diagnosis of A1AT-def. Materials and methods: We conducted a descriptive study that involved 65 patients with liver disease who were referred to the Molecular Biology Laboratory of the National Center of Medical Genetics for the molecular diagnosis of S and Z mutations of the gene for alpha-1 antitrypsin. We used the polymerase chain reaction method with polymorphisms in the sizes of the restriction fragments (PCR-RFLP). Results: The frequency of C282Y and H63D mutations of the HFE gene in patients with presumptive diagnosis of deficiency of alpha-1 antitrypsin was 5.3% and 17% respectively. Conclusions: this study showed that the frequency of these two mutations in Cuban population is high. We also observed that both of them, even in heterozygous state, seem to play a main role in the development of different diseases.
ABSTRACT
Immunochemistry with anti-vimentin, anti-lysozyme, anti-alpha 1 antitrypsin, anti-CD3 and anti-CD79 antibodies has been used for characterization of primary cell culture in the transmissible venereal tumor (TVT). Samples for primary cell culture and immunohistochemistry assays were taken from eight dogs with cytological and clinical diagnosis of TVT. To validate the immunochemical results in the primary cell culture of TVT, a chromosome count was performed. For the statistical analysis, the Mann-Whitney test with p 0.05 was used. TVT tissues and culture cells showed intense anti-vimentin immunoreactivity, lightly to moderate immunoreactivity for anti-lysozyme, and mild for anti-alpha-antitrypsin. No marking was achieved for CD3 and CD79. All culture cells showed chromosomes variable number of 56 to 68. This is the first report on the use of immunocytochemical characterization in cell culture of TVT. Significant statistic difference between immunochemistry in tissue and culture cell was not established, what suggests that the use of this technique may provide greater certainty for the confirmation of tumors in the primary culture. This fact is particularly important because in vitro culture of tumor tissues has been increasingly used to provide quick access to drug efficacy and presents relevant information to identify potential response to anticancer medicine; so it is possible to understand the behavior of the tumor.(AU)
Os anticorpos anti-vimentina, anti-lisozima, anti-alfa 1 antitripsina, anti-CD3 e anti-CD79 foram empregados para a caracterização de culturas primárias de tumor venéreo transmissível canino (TVT). Amostras para cultura primária e imuno-histoquímica foram coletadas de oito cães com diagnóstico clínico e citológico de TVT. Para validar o resultado inmunocitoquímico nas culturas de TVT foi realizada a contagem de cromossomos. Para a análise estatística o teste de Mann-Whitney foi empregado a um nível de significância de p 0.05. As culturas e os tecidos de TVT apresentaram intensa reatividade para vimentina, moderada a leve para Lisozima, moderada para alfa-antitripsina e não houve marcação para CD3 e CD79. Finalmente, todas as culturas apresentaram números de cromossomos que variaram de 56 a 68. Este é o primeiro relato que apresenta o uso da immunocitoquímica para a caracterização de culturas de TVT. Assim, e devido ao fato de se observar semelhança entre a imunomarcação em células e tecidos, sugere-se que o uso desta técnica possa auxiliar na confirmação de culturas primárias do tumor, fato muito importante porque a utilização da cultura do tumor pode permitir o acesso a informação relevante sobre resposta potencial a um tratamento e conhecimento do comportamento biológico do tumor.(AU)
Subject(s)
Animals , Dogs , Venereal Tumors, Veterinary , alpha 1-Antitrypsin/analysis , Cytogenetic Analysis/veterinary , Muramidase/analysis , Vimentin/analysis , Immunohistochemistry/veterinary , Statistics, NonparametricABSTRACT
Este relato alerta para a deficiência de alfa1antitripsina em neonato, que se apresentou como síndrome colestática. Seu subdiagnóstico constitui-se em importante limitação para o seu reconhecimento e tratamento adequado. A boa evolução ocorre em cerca de 50% dos pacientes. Associa-se, na maioria das vezes, a acometimento extra e intra-hepático e ausência de manifestações clínicas que indiquem o seu diagnóstico. A deficiência de alfa1antitripsina está entre as doenças que precisam ser excluídas frente à colestase neonatal.
This report draws attention to the alpha 1 antitrypsin deficiency in newborns presented as a cholestatic syndrome. Its sub-diagnosis constitutes a major constraint for recognition and appropriate treatment. Good outcomes occur in approximately 50% of patients.It is associated in most cases, to extra and intra-hepatic involvement and the absence of clinical signs that indicate its diagnosis. The alpha 1 antitrypsin deficiency is among the diseases that need to be excluded when facing neonatal cholestasis.
ABSTRACT
INTRODUCTION: Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder associated with early onset chronic obstructive pulmonary disease (COPD) and liver disease. It is also a highly under-diagnosed condition. As early diagnosis could prompt specific interventions such as smoking cessation, testing of family members, genetic counselling and use of replacement therapy, screening programs are needed to identify affected patients. OBJECTIVE: To estimate the prevalence of severe AATD in COPD patients by routine dried blood spot testing and subsequent genotyping in patients with alpha-1 antitrypsin (AAT) levels below an established threshold. MATERIALS AND METHODS: Cross-sectional study of adult COPD patients attending the Hospital Dr. Antonio Cetrángolo (Buenos Aires, Argentina) between 2009 and 2012. The study consisted of capillary blood collection via finger stick to determine AAT levels, clinical evaluation and lung function tests. Genotype was determined in AAT-deficient patients. RESULTS: A total of 1,002 patients were evaluated, of whom 785 (78.34%) had normal AAT levels, while low AAT levels were found in 217 (21.66%). Subsequent genotyping of the latter sub-group found: 15 (1.5%, 95% CI 0.75-2.25) patients with a genotype associated with severe AATD, of whom 12 were ZZ (1.2%, 95% CI 0.52-1.87) and 3 SZ (0.3%, 95% CI 0-0.64). The remaining 202 patients were classified as: 29 Z heterozygotes (2.89%, 95% CI 1.86-3.93), 25 S heterozygotes (2.5%, 95% CI 1.53-3.46) and 4 SS (0.4%, 95% CI 0.01-0.79). A definitive diagnosis could not be reached in 144 patients (14.37%, 95% CI 12.2-16.54). CONCLUSION: The strategy using an initial serum AAT level obtained by dried blood spot testing and subsequent genotyping was a satisfactory initial approach to a screening program for severe AAT, as a definitive diagnosis was achieved in 87% of patients. However, results were not obtained for logistical reasons in the remaining 13%. This major obstacle may be overcome by the use of dried blood spot phenotyping techniques. We believe this approach for detecting AATD in COPD patients, in compliance with national and international guidelines, is supported by our results.
Subject(s)
Pulmonary Disease, Chronic Obstructive/epidemiology , alpha 1-Antitrypsin Deficiency/epidemiology , Adult , Aged , Algorithms , Argentina/epidemiology , Comorbidity , Cross-Sectional Studies , Female , Genotype , Humans , Isoelectric Focusing , Male , Mass Screening , Middle Aged , Nephelometry and Turbidimetry , Phenotype , Prevalence , Real-Time Polymerase Chain Reaction , Smoking/epidemiology , Spirometry , alpha 1-Antitrypsin/blood , alpha 1-Antitrypsin Deficiency/diagnosis , alpha 1-Antitrypsin Deficiency/geneticsABSTRACT
Tracheal diverticulum, defined as a benign outpouching of the tracheal wall, is rarely diagnosed in clinical practice. It can be congenital or acquired in origin, and most cases are asymptomatic, typically being diagnosed postmortem. We report a case of a 69-year-old woman who was hospitalized after presenting with fever, fatigue, pleuritic chest pain, and a right neck mass complicated by dysphagia. Her medical history was significant: pulmonary emphysema (alpha-1 antitrypsin deficiency); bronchiectasis; and thyroidectomy. On physical examination, she presented diminished breath sounds and muffled heart sounds, with a systolic murmur. Laboratory tests revealed elevated inflammatory markers, a CT scan showed an air-filled, multilocular mass in the right tracheal wall, and magnetic resonance imaging confirmed the CT findings. Fiberoptic bronchoscopy failed to reveal any abnormalities. Nevertheless, the patient was diagnosed with tracheal diverticulum. The treatment approach was conservative, consisting mainly of antibiotics. After showing clinical improvement, the patient was discharged.
Divertículos da traqueia são evaginações benignas da parede traqueal e raramente diagnosticados na prática clínica. Podem ser congênitos ou adquiridos, e na maioria dos casos são assintomáticos, sendo tipicamente diagnosticados em estudos post-mortem. Relatamos o caso de uma mulher de 69 anos que foi hospitalizada após apresentar febre, fadiga, dor torácica pleurítica e uma massa cervical à direita complicada por disfagia. Tinha antecedentes pessoais de enfisema pulmonar (deficiência de alfa-1 antitripsina), bronquiectasias e tireoidectomia. Ao exame físico apresentava murmúrio vesicular diminuído, hipofonese cardíaca e um sopro sistólico. Laboratorialmente apresentava marcadores inflamatórios elevados, e uma TC mostrou uma massa aérea, multiloculada na parede direita da traqueia, achados confirmados por ressonância magnética nuclear. Realizou ainda uma fibrobroncoscopia que se revelou normal. Assumiu-se o diagnóstico de divertículo da traqueia. O tratamento proposto foi conservador, consistindo principalmente de antibioticoterapia. Após melhora clínica, a paciente recebeu alta.
Subject(s)
Aged , Female , Humans , Anti-Bacterial Agents/therapeutic use , Diverticulum/complications , Tracheal Diseases/complications , alpha 1-Antitrypsin Deficiency/complications , Diverticulum/drug therapy , Magnetic Resonance Imaging , Pulmonary Emphysema , Tomography, X-Ray Computed , Thienamycins/therapeutic use , Tracheal Diseases/drug therapy , Vancomycin/therapeutic use , alpha 1-Antitrypsin Deficiency/drug therapyABSTRACT
Aun cuando el papel de la biopsia hepática está cambiando con el desarrollo de nuevos métodos de diagnóstico y del avance de las técnicas de imagen, de biomarcadores no invasivos, estudios proteómicos y genómicos, la biopsia hepática realizada en el momento y con la indicación adecuadas continúa siendo una importante herramienta para la evaluación y diagnóstico de los niños con colestasis tanto en el periodo neonatal como durante la infancia temprana o tardía, no solo para determinar una etiología o establecer un pronóstico sino para guiar una terapia (1). Son múltiples las causas y varios los patrones morfológicos observados, puede estar relacionada a un defecto genético del metabolismo hepático incluyendo la síntesis de ácidos biliares, la formación y función de transportadores de membrana o a alteraciones en el desarrollo de las vías biliares, muchos de los cuales pueden sobreponerse y deben interpretarse en conjunto con los hallazgos clínicos, genéticos y de laboratorio. Los síndromes heredados que producen colestasis intrahepática y la atresia biliar son las causas más comunes de enfermedad hepática crónica y la indicación principal para el trasplante hepático en niños. El enfoque que aquí daremos hace hincapié en la estrecha colaboración que debe existir entre pediatras, gastroenterólogos, cirujanos pediátricos y los patólogos para la correcta identificación y posterior manejo sea médico o quirúrgico incluyendo el trasplante hepático, de muchas de las patologías colestásicas que afectan este grupo etario (2, 3).
Although the role of liver biopsies is changing with the development of new diagnostic methods and advances in imaging techniques, non-invasive biomarkers, proteomic and genomic studies, a liver biopsy performed at the right time and with appropriate indications continues to be an important tool for assessment and diagnosis of children with cholestasis. This is equally true in the neonatal period, in early childhood, and in late childhood not only for determination of an etiology and establishing a prognosis, but also for guiding treatment of the patient (1). There are multiple causes and morphological patterns that may be related to a genetic defect in aspects of hepatic metabolism including synthesis of bile acids, formation and function of membrane transporters, and alterations in the development of the bile ducts. Many of these may overlap and should be interpreted in conjunction with clinical, genetic and laboratory findings. Inherited syndromes that produce intrahepatic cholestasis and biliary atresia are the most common causes of chronic liver disease and the leading indication for liver transplantation in children. The approach we present here emphasizes the close cooperation that should exist between pediatricians, gastroenterologists, pediatric surgeons and pathologists for proper identification of many of the cholestatic diseases that can affect this age group. Subsequent surgical or medical management may include liver transplantation (2, 3).
Subject(s)
Humans , Biliary Atresia , Biopsy , CholestasisABSTRACT
El déficit de alfa-1 antitripsina (AAT) es una condición hereditaria rara y raramente diagnosticada en todo el mundo, incluida Argentina. El infradiagnóstico es fundamentalmente debido a que muchos médicos desconocen su existencia, diagnóstico y tratamiento. Por ello, la Asociación Argentina de Medicina Respiratoria encomendó a un grupo de expertos la elaboración de la presente normativa. La AAT es una glicoproteína secretada por el hígado, muy abundante en sangre, tejidos y fluidos corporales, cuya función principal consiste en inhibir la elastasa del neutrófilo y otras serin proteasas, confiriendo al suero humano más del 90% de su capacidad antiproteasa. El déficit de AAT deriva de mutaciones del gen de la SERPINA1, y se manifiesta clínicamente por enfisema pulmonar, cirrosis hepática y, con menor frecuencia, por paniculitis, vasculitis sistémicas y posiblemente otras enfermedades. El déficit grave de AAT afecta mayoritariamente a individuos de raza caucasiana y tiene su máxima prevalencia (1:2.000-1:5.000 individuos) en el norte, oeste y centro de Europa. En EEUU y Canadá, la prevalencia es de 1: 5.000-10.000, y es 5 veces menor en países latinoamericanos, incluida Argentina, donde se estima que puede haber unos 18.000 individuos con genotipos deficientes graves SZ y ZZ, la inmensa mayoría sin diagnosticar. Sospechar la enfermedad resulta clave para medir la concentración sérica de AAT y completar el diagnóstico con la determinación del fenotipo o genotipo ante concentraciones bajas. La detección de casos permite la puesta en práctica del consejo genético, el chequeo de familiares consanguíneos y, en casos seleccionados, la aplicación de terapia sustitutiva.(AU)
The alpha-1 antitrypsin (AAT) deficiency is a rare hereditary condition which is rarely diagnosed in the world, including Argentina. Underdiagnosis is mainly due to lack of knowledge of its diagnosis and treatment by many physicians. For this reason, the Argentine Association of Respiratory Medicine convened a group of experts to develop the present guidelines. AAT is a glycoprotein secreted by the liver; it reaches high levels in blood, body tissues and fluids. Its main function is to inhibit the neutrophil elastase and other serum proteases providing 90% of human serine antiprotease activity. The AAT deficiency is produced by mutations of the SERPINA1 gene. Its clinical manifestations are pulmonary emphysema, liver cirrhosis, and less often panniculitis, systemic vasculitis and possibly other conditions. The severe AAT deficiency affects mainly Caucasian individuals. The highest prevalence, ranging from 1 in 2000 to 1 in 5000 population is observed in northern, western and central Europe. In the USA and Canada, the prevalence varies from 1 in 5000 to 1 in 10000 population. It is 5 times less frequent in Latin American countries. It is estimated that in Argentina there may be 18000 cases with severe deficiency of SZ y ZZ genotypes, most of them undiagnosed. It is crucial to suspect the disease in order to measure the serum AAT concentration, and, if the concentrations are low, to confirm the diagnosis with the phenotype or genotype determinations. Case detection allows genetic advice, control of blood-related relatives and in selected cases, replacement therapy.(AU)
ABSTRACT
El déficit de alfa-1 antitripsina (AAT) es una condición hereditaria rara y raramente diagnosticada en todo el mundo, incluida Argentina. El infradiagnóstico es fundamentalmente debido a que muchos médicos desconocen su existencia, diagnóstico y tratamiento. Por ello, la Asociación Argentina de Medicina Respiratoria encomendó a un grupo de expertos la elaboración de la presente normativa. La AAT es una glicoproteína secretada por el hígado, muy abundante en sangre, tejidos y fluidos corporales, cuya función principal consiste en inhibir la elastasa del neutrófilo y otras serin proteasas, confiriendo al suero humano más del 90% de su capacidad antiproteasa. El déficit de AAT deriva de mutaciones del gen de la SERPINA1, y se manifiesta clínicamente por enfisema pulmonar, cirrosis hepática y, con menor frecuencia, por paniculitis, vasculitis sistémicas y posiblemente otras enfermedades. El déficit grave de AAT afecta mayoritariamente a individuos de raza caucasiana y tiene su máxima prevalencia (1:2.000-1:5.000 individuos) en el norte, oeste y centro de Europa. En EEUU y Canadá, la prevalencia es de 1: 5.000-10.000, y es 5 veces menor en países latinoamericanos, incluida Argentina, donde se estima que puede haber unos 18.000 individuos con genotipos deficientes graves SZ y ZZ, la inmensa mayoría sin diagnosticar. Sospechar la enfermedad resulta clave para medir la concentración sérica de AAT y completar el diagnóstico con la determinación del fenotipo o genotipo ante concentraciones bajas. La detección de casos permite la puesta en práctica del consejo genético, el chequeo de familiares consanguíneos y, en casos seleccionados, la aplicación de terapia sustitutiva.
The alpha-1 antitrypsin (AAT) deficiency is a rare hereditary condition which is rarely diagnosed in the world, including Argentina. Underdiagnosis is mainly due to lack of knowledge of its diagnosis and treatment by many physicians. For this reason, the Argentine Association of Respiratory Medicine convened a group of experts to develop the present guidelines. AAT is a glycoprotein secreted by the liver; it reaches high levels in blood, body tissues and fluids. Its main function is to inhibit the neutrophil elastase and other serum proteases providing 90% of human serine antiprotease activity. The AAT deficiency is produced by mutations of the SERPINA1 gene. Its clinical manifestations are pulmonary emphysema, liver cirrhosis, and less often panniculitis, systemic vasculitis and possibly other conditions. The severe AAT deficiency affects mainly Caucasian individuals. The highest prevalence, ranging from 1 in 2000 to 1 in 5000 population is observed in northern, western and central Europe. In the USA and Canada, the prevalence varies from 1 in 5000 to 1 in 10000 population. It is 5 times less frequent in Latin American countries. It is estimated that in Argentina there may be 18000 cases with severe deficiency of SZ y ZZ genotypes, most of them undiagnosed. It is crucial to suspect the disease in order to measure the serum AAT concentration, and, if the concentrations are low, to confirm the diagnosis with the phenotype or genotype determinations. Case detection allows genetic advice, control of blood-related relatives and in selected cases, replacement therapy.
Subject(s)
Therapeutics , alpha 1-Antitrypsin , GeneticsABSTRACT
OBJECTIVE: To validate and develop an immunonephelometric assay for the determination of alpha-1 antitrypsin (AAT) levels in dried blood spots from COPD patients in Brazil. METHODS: We determined AAT levels in serum samples and dried blood spots from 192 COPD patients. For the preparation of dried blood spots, a disk (diameter, 6 mm) was placed into a tube, eluted with 200 µL of PBS, and stored overnight at 4ºC. All of the samples were analyzed by immunonephelometry in duplicate. We used the bootstrap resampling method in order to determine a cut-off point for AAT levels in dried blood spots. RESULTS: The correlation coefficient between the AAT levels in serum samples and those in dried blood spots was r = 0.45. For dried blood spots, the cut-off value was 2.02 mg/dL (97% CI: 1.45-2.64 mg/dL), with a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 95.7%, 27.2%, and 100%, respectively. CONCLUSIONS: This method for the determination of AAT levels in dried blood spots appears to be a reliable screening tool for patients with AAT deficiency. .
OBJETIVO: Validar e desenvolver um método de dosagem de alfa-1 antitripsina (AAT) por imunonefelometria em amostras de sangue em papel-filtro em pacientes com DPOC no Brasil. MÉTODOS: Amostras de soro e de sangue em papel-filtro de 192 pacientes com DPOC foram utilizadas para a dosagem de AAT. Para a preparação das amostras de sangue em papel-filtro, um disco do papel com diâmetro de 6 mm foi colocado em um tubo e eluído com 200 µL de PBS, permanecendo por toda a noite a 4ºC. Todas as amostras foram analisadas em duplicata por imunonefelometria. O método de reamostragem bootstrap foi utilizado para a determinação de um ponto de corte para o nível de AAT nas amostras de sangue em papel-filtro. RESULTADOS: O coeficiente de correlação entre os níveis de AAT em soro e em sangue em papel-filtro foi de r = 0,45. Para as amostras em papel-filtro, o ponto de corte foi de 2,02 mg/dL (IC97%: 1,45-2,64 mg/dL), com sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo de 100%, 95,7%, 27,2% e 100%, respectivamente. CONCLUSÕES: Este método de determinação dos níveis de AAT em sangue em papel-filtro se mostrou uma ferramenta confiável para o rastreamento de pacientes com deficiência de AAT. .