RESUMEN
Human T cell lymphotropic virus type 2 (HTLV-2) has been shown to be endemic in Brazilian Indians and among intravenous drug users in urban areas, but transmission of this infection seems to be infrequent in the general population living in urban areas in Brazil. Six persons in three generations of a Brazilian family were evaluated to assess HTLV-2 transmission and its molecular features in the positive cases. The index was detected during screening (HTLV EIA) of donated blood in Fundação Hemominas, Belo Horizonte, Brazil. Confirmatory serological test and viral typing were performed by Western blotting and polymerase chain reaction. The family consisted of husband, wife (index case), three daughters, and the mother of the index case. The husband and one daughter were found positive, thus pointing to horizontal and vertical transmission. The husband was a truck driver, who reported casual sex during frequent traveling. The positive daughter was breast-fed for 3 months, as opposed to the remaining two (seronegative), who breast-fed for 1 month. The index case's mother was negative. To identify HTLV-2 subtype(s), phylogenetic analysis of the noncoding long terminal repeat region and part of the env and tax coding regions was performed. These new isolates from Belo Horizonte are related to subtype IIa but present a molecular variant with extended tax, previously reported in subtype IIc. Analyzing both LTR and env regions, the family's sequences clustered with isolates of Brazilian intravenous drug users and transfusion transmitted virus.
Asunto(s)
Transmisión de Enfermedad Infecciosa , Infecciones por HTLV-II/transmisión , Virus Linfotrópico T Tipo 2 Humano/inmunología , Transmisión Vertical de Enfermedad Infecciosa , Adulto , Brasil/epidemiología , Familia , Femenino , Anticuerpos Anti-HTLV-II/sangre , Infecciones por HTLV-II/epidemiología , Infecciones por HTLV-II/virología , Virus Linfotrópico T Tipo 2 Humano/clasificación , Virus Linfotrópico T Tipo 2 Humano/genética , Humanos , Lactante , Masculino , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Estudios Seroepidemiológicos , Población UrbanaRESUMEN
O Vírus Linfotrópico de células T humanas tipo 1 (HTLV-1) está associado a uma mielopatia (chamada mielopatia associada ao HTLV - HAM/TSP). A trombospondina-1 (TSP-1) é uma proteína da matriz que interfere com a adesão, a motilidade, e a proliferação celular. Níveis deexpressão de RNA mensageiro (mRNA) da trombospondina-1 foram avaliados em indivíduos infectados por HTLV-1: 11 pacientes assintomáticos, 18 com mielopatia ou oligossintomáticos, e 13participantes não-infectados. O RNA de células mononucleares do sangue periférico foi submetido à análise de RT-PCR para trombospondina-1. O número de indivíduos que expressaram esta proteína foi maior no grupo com mielopatia/sintomas (14/18, p igual 0,007). Em geral, a tendência para valores mais elevados de mRNA de trombospondina-1 foi observada no grupo de infectados pelo vírus (p igual 0,062). Os níveis mais elevados de expressão do mRNA foram detectados no início dos sintomas clínicos da HAM/TSP. Estudos adicionais com maior número de amostras são necessários para elucidar melhor o papel desta proteína da matriz na rede inflamatória relacionada à HAM/TSP.