Environmental risk factors associated with biliary atresia in Rio Grande do Sul, Brazil

Biliary atresia (BA) seems to be a multifactorial disorder in which environmental factors interact with the patient's genetic constitution. This study aimed to analyze information concerning environmental risk factors associated with BA in southern Brazil. A case-control study with mothers of patients with BA and mothers of patients with cystic fibrosis (CF) was conducted. Inquiry included questions related to exposition to environmental risk factors during the periconceptional and gestational (second and third trimesters) periods. Mothers of BA patients had smoked during pregnancy more frequently in comparison with the mothers of CF patients, but no significant difference was found in a multivariate analysis. There was no between group difference in terms of seasonality, but the multivariate analysis showed a significant difference within the BA group between date of conception in winter compared to other seasons. In conclusion, smoking during pregnancy seemed to increase the risk of BA while date of conception in winter decreased it (AU)

Atresia biliar: una enfermedad grave / Biliary atresia: a severe illness

La atresia biliar es una grave enfermedad que se manifiesta en los recién nacidos, y se desconoce su causa. La inflamación y destrucción progresiva de los conductos biliares conducen a la aparición de ictericia, coluria y acolia entre la segunda y sexta semana de vida. Como existen múltiples causas de colestasis neonatal en esta etapa de la vida, es necesario realizar un diagnóstico y derivación precoz para ofrecer un tratamiento quirúrgico, con el fin de restablecer el flujo biliar. Alrededor del 80% de los pacientes normalizan la bilirrubina luego de la portoenterostomía (operación de Kasai), realizada antes de los 45 días de vida. Si la operación fracasa, el trasplante hepático surge como única alternativa. La atresia biliar debe diagnosticarse durante el primer mes de vida y ser considerada una urgencia quirúrgica.

Biliary atresia is a serious disease of unknown cause, affecting newborns. An inflammation and progressive destruction of the bile ducts lead to jaundice, dark urines, and acholia, between the second and sixth weeks of life. Neonatal cholestasis could be due to several different diseases, thus a diagnosis of biliary atresia and early derivation for surgical treatment are necessary to allow a restoration of the bile flow. Eighty percent of the children normalize serum bilirubin after the portoenterostomy (Kasai operation), if they are operated before their 45 days of life. When Kasai operation fails, a liver transplantation is the only possibility. Biliary atresia must be diagnosed before the first month of life and must be considered as a surgical emergency.

Advances in biliary atresia: from patient care to research

Biliary atresia, the most common cause of liver transplantation in children, remains a challenge for clinicians and investigators. The development of new therapeutic options, besides the typical hepatoportoenterostomy, depends on a greater understanding of its pathogenesis and how it relates to the clinical phenotypes at diagnosis and the rate of disease progression. In this review, we present a perspective of how recent research has advanced the understanding of the disease and has improved clinical care protocols. Molecular and morphological analyses at diagnosis point to the potential contributions of polymorphism in the CFC1 and VEGF genes to the pathogenesis of the disease, and to an association between the degree of bile duct proliferation and long-term outcome. In experimental models, cholangiocytes do not appear to have antigen-presenting properties despite a substantial innate and adaptive immune response that targets the biliary epithelium and produces duct obstruction. Initial clinical trials assessing the efficacy of corticosteroids in decreasing the inflammation and improving outcome do not show a superior effect of corticosteroids as an adjuvant treatment following hepatoportoenterostomy. The best outcome still remains linked to an early diagnosis and surgical treatment. In this regard, the Yellow Alert campaign by the Sociedade Brasileira de Pediatria and the inclusion of the Stool Color Card in the health booklet given to every neonate in Brazil have the potential to decrease the age of diagnosis, shorten the time between diagnosis and surgical treatment, and improve the long-term outcome of children with this devastating disease.

Extrahepatic biliary atresia: current concepts and future directions

OBJETIVOS: Apresentar uma revisão atualizada sobre atresia das vias biliares extra-hepáticas, com ênfase em etiopatogenia, abordagens diagnósticas e terapêuticas e prognóstico. FONTES DOS DADOS: Foram selecionadas pelos sites de busca médica (MEDLINE e PubMed) pesquisas relacionadas à atresia biliar, utilizando as seguintes palavras-chave: biliary atresia,etiopathogenesis, diagnosis, treatment, prognosis, children. SíNTESE DOS DADOS A atresia das vias biliares extra-hepáticas é a principal indicação de transplante hepático na faixa etária pediátrica. Quanto à etiologia, o citomegalovírus, o reovírus e o rotavírus têm sido os agentes mais estudados como possíveis desencadeadores da obstrução imunomediada da árvore biliar. A resposta imune, especialmente o predomínio da resposta TH1 e do interferon gama, a susceptibilidade genética e as alterações do desenvolvimento embrionário da árvore biliar são aspectos que podem participar na etiopatogênese da obliteração das vias biliares extra-hepáticas. Ainda hoje, o único tratamento disponível é a portoenterostomia, cujos resultados são melhores quando realizada nos primeiros 2 meses de vida. Em relação ao prognóstico, as crianças não tratadas vão a óbito na totalidade, por complicações relacionadas à hipertensão portal e à cirrose hepática, e mesmo os casos tratados necessitam, em sua maioria, do transplante hepático. CONCLUSÃO: A atresia das vias biliares extra-hepáticas continua sendo a principal indicação de transplante hepático em crianças, e a mudança deste panorama depende de um melhor entendimento da etiopatogenia da obstrução biliar nos diferentes fenótipos da doença. Investigações futuras a respeito do papel do interferon gama e de outras citocinas são necessárias para avaliar se esses aspectos seriam potenciais alvos de intervenção terapêutica.

OBJECTIVE: To provide an updated review on extrahepatic biliary atresia, focusing mainly on its etiopathogenesis, diagnosis, treatment and prognosis. SOURCES: MEDLINE and PubMed databases were searched using the following keywords: biliary atresia,etiopathogenesis, diagnosis, treatment, prognosis, children. SUMMARY OF THE FINDINGS: Extrahepatic biliary atresia is the main indication for liver transplantation among pediatric patients. As to its etiology, cytomegalovirus, reovirus and rotavirus have been widely investigated as possible triggers of the immunomediated obstruction of the biliary tree. The immune response, especially the predominant TH1 and interferon-gamma responses, genetic susceptibility and disorders related to the embryonic development of the biliary tree can play a role in the etiopathogenesis of extrahepatic biliary atresia. Yet today, portoenterostomy is the only available treatment, with better results when performed in the first 2 months of life. As to prognosis, all untreated children eventually die due to complications resulting from portal hypertension and liver cirrhosis, and most treated children have to undergo liver transplantation. CONCLUSIONS: Extrahepatic biliary atresia is still the major indication for pediatric liver transplantation, and to change this scenario some more light should be shed upon the etiopathogenesis of biliary atresia in different disease phenotypes. Future research into the role of interferon-gamma and of other cytokines is necessary in order to assess whether these aspects should be potential targets for therapeutic intervention.

A placa ductal e a organização do sistema biliar intra-hepático / The ductal plate and the organization of the intra-hepatic biliary system

Os autores estudam a placa ductal e a sua relação com o desenvolvimento do sistema biliar intra-hepático. Alguns aspectos deste processo são destacados, como a formação e a relação temporal da placa ductal com os diversos estágios de formação do sistema biliar. É salientado o papel de marcadores imunohistoquímicos, como as citoqueratinas, no estudo e compreensão do desenvolvimento embriológico hepato-biliar. A compreensão destes aspectos é importante para entender a gênese de algumas entidades patológicas que acometem a via biliar, como a atresia biliar e a fibrose hepática congênita

Virus papiloma humano, hepatitis gigantocelular neonatal y atresia de vias biliares / Human papillomavirus, neonatal giant cell hepatitis and biliary duct atresia

En trabajos previos hemos relatado el reconocimiento de la presencia de ADN del HPV en casos de hepatitis gigantocelular neonatal idiopática (HGNI) y atresia de vías biliares (AVB) en material de archivo usando la técnica de PCR. A fin de investigar una posible transmisión vertical estudiamos la presencia de ADN del HPV en hisopados cervicales de madres así como un tejido hepático fijado en formol e incluído en parafina, de 3 lactantes con HGNI y 4 con AVB mediante la técnica de nested-PCR. En dos casos los extendidos cervicales presentaron coilocitos, compatibles con infección por HPV. Excepto en uno el parto fué por vía vaginal en todos. Todos los lactantes eran del sexo masculino. En todos los casos se demostró amplificación del ADN del HPV, siendo concordante los tipos en los lactantes y sus madres. Aunque este es un grupo pequeño los hallazgos están de acuerdo con nuestros datos previos. La presencia del mismo tipo de HPV en el hígado de los lactantes y en hisopados de sus madres es otro argumento que apoya la posibilidad de una transmisión vertical del virus.

The relative importance of familial, reproductive and environmental factors in biliary atresia: etiological implications and effect on patient survival

The clinical records of 237 patients with extrahepatic biliary atresia (EHBA) attendi9ng King's College Hospital, London, between March 1973 and October 1985 were analyzed in terms of familial and reproductive factors, as well as of their possible effect on patient survival. The male: female ratio was 0.93, and the ages of the patients'mothers and fathers were significantly higher than would have been expected from sibship data. Similarly, the number of first-born children having EHBA was less than expected. In a subsample of 189 mothers, the obstetrical histories of women who had children with associated EHBA (20% of the total) showed: 1) a higher frequency of illness before and during pregnancy; 2) a higher level of pharmaceutical drug consumption during pregnancy, and 3) more fetal losses, especially in the gestation immediately preceding the patient's birth. Age at death (average 15.1 ñ 13.2 monthjs) and survival rates depend critically on surgical intervention and were not related to the presence or absence of extrahepatic malformations or to the type of atresia. The present observations, taken together with those of others, indicate that problems in the reproductive process or exposure to noxious environmental agents may be etiological factors in associated EHBA