RESUMEN
Vertical transmission from mother to child, the main route of chronic hepatitis B virus (HBV) infection in the East Asia, is considered one of the most important predictors for the response to antiviral therapies as well as its complications such as cirrhosis and hepatocellular carcinoma. Therefore, it is critical in both etiologic and prognostic aspects to confirm whether or not chronic HBV infection is acquired vertically. This study investigated whether mother-to-child infection could be proved by the phylogenetic analyses of HBV pre-S/S genes ever since several decades have elapsed in mother-child pairs with presumed vertical transmission. The pre-S and S regions of HBVs were compared and analyzed phylogenetically in a total of 36 adults (18 mother-child pairs) with chronic HBV infection. All of the isolates of HBV were genotype C and serotype adr. The divergence between mothers and offsprings was 0 to 1.5%. Phylogenetic trees revealed that 17 of 18 pairs (94%) with presumed vertical transmission were grouped into the same cluster. Vertical transmission from mother to child could be strongly suggested even in adults with a history of several decades of HBV infection using the phylogenetic analyses of pre-S and S genes.
Asunto(s)
Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , ADN Viral/análisis , Genotipo , Antígenos de Superficie de la Hepatitis B/clasificación , Virus de la Hepatitis B/clasificación , Hepatitis B Crónica/diagnóstico , Transmisión Vertical de Enfermedad Infecciosa , Madres , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , SerotipificaciónRESUMEN
Foram analisadas 896 amostras de soros HBsAg positivos de cinco regiöes brasileiras. A presença de cinco diferentes subtipos (ayw2, ayw3, ayw4, adw2 e adw4) foi determinada. Na regiäo Norte, os subtipos adw4 (41,2%) e adw2 (37,2%) foram predominantes. No Nordeste somente o subtipo adw2 foi encontrado. No centro Oeste, Sudeste e Sul os subtipos ayw2, ayw3, adw4 estäo presentes, com predominância do adw2 no Centro Oeste e Sudeste (84,3% e 69,4% respectivamente), enquanto que no Sul o subtipo predominante foi ayw3 (41,9%) seguido pelo ayw2 (36,4%). Os subtipos ayw1 e ayr e adr näo foram encontrados entre amostras estudadas. Estes resultados mostram a diferença na incidência dos subtipos do HBsAg em diferentes regiöes do Brasil e seu significado em relaçäo à colonizaçäo e migraçöes neste país