RESUMO
Human T cell lymphotropic virus (HTLV) is the caustive agent of two main conditions i. e., the HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and the adult T-cell leukemia/lymphoma (ATLL). HTLV diagnosis is based on serological and molecular approaches; however, an accurate and validated method is still needed. The objective of this study was to establish a rapid and sensitive molecular test to confirm and discriminate HTLV 1/2 types. The test validation was performed as a multicentric study involving HTLV confirmation centers throughout Brazil. Proviral DNA was extracted from whole blood and the amplification was performed using in-house designed primer and probe sets targeting the pol genomic region. An internal control to validate the extraction and amplification was also included. The limit of detection (LoD) of the assay was four copies/reaction for HTLV-1 and 10.9 copies/reaction for HTLV-2. The diagnostic sensitivity of the platform was 94.6% for HTLV-1, 78.6% for HTLV-2, and the specificity was 100% for both viruses. Cross-reactions of the test with human viruses including HAV, HBV, HCV, HIV-1/2, and parvovirus B19 were not observed. During the multicentric validation, the test was used to screen a total of 692 blood samples obtained from previously confirmed HTLV-positive individuals. From these, 91.1% tested positive being concordant with the previously obtained results. In conclusion, our duoplex-RT-PCR-HTLV1 /2 presented adequate efficiency for HTLV-1/2 differentiation showing high sensitivity and specificity. Therefore, it can be a suitable tool for confirmation of suspected and inconclusive HTLV cases, prenatal and pre-transplant diagnosis, in Brazil and in other countries HTLV-endemic countries.
RESUMO
About 95% of HTLV-1 infected patients remain asymptomatic throughout life, and the risk factors associated with the development of related diseases, such as HAM/TSP and ATL, are not fully understood. The human leukocyte antigen-G molecule (HLA-G), a nonclassical HLA class I molecule encoded by MHC, is expressed in several pathological conditions, including viral infection, and is related to immunosuppressive effects that allow the virus-infected cells to escape the antiviral defense of the host. The 14-bp insertion/deletion polymorphism of exon 8 HLA-G gene influences the stability of the transcripts and could be related to HTLV-1-infected cell protection and to the increase of proviral load. The present study analyzed by conventional PCR the 14-bp insertion/deletion polymorphism of exon 8 HLA-G gene in 150 unrelated healthy subjects, 82 HTLV-1 infected patients with symptoms (33 ATL and 49 HAM), and 56 asymptomatic HTLV-1 infected patients (HAC). In addition, the proviral load was determined by quantitative real-time PCR in all infected groups and correlated with 14-bp insertion/deletion genotypes. The heterozygote genotype frequencies were significantly higher in HAM, in the symptomatic group, and in infected patients compared to control (p < 0.05). The proviral load was higher in the symptomatic group than the HAC group (p < 0.0005). The comparison of proviral load and genotypes showed that -14-bp/-14-bp genotype had a higher proviral load than +14-bp/-14-bp and +14-bp/+14-bp genotypes. Although HLA-G 14-bp polymorphism does not appear to be associated with HTLV-1 related disease development, it could be a genetic risk factor for susceptibility to infection.
Assuntos
Infecções por Deltaretrovirus/genética , Antígenos HLA/genética , Antígenos de Histocompatibilidade Classe I/genética , Mutação INDEL , Polimorfismo Genético , Adolescente , Adulto , Idoso , DNA Viral/genética , Suscetibilidade a Doenças , Feminino , Genótipo , Antígenos HLA-G , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Fatores de Risco , Carga Viral/genéticaRESUMO
O Departamento Científico de LCR (DC-LCR) da Academia Brasileira de Neurologia (ABN) recomenda a adoçäo do Termo de Consentimento Livre e Esclarecido (TCLE) como procedimento prévio à punçäo para coleta de LCR, tendo como finalidade o adequado esclarecimento dos pacientes quanto aos riscos do procedimento e às medidas de prevençäo de complicaçöes do exame. O documento final do TCLE foi resultado de consenso entre os membros de DC-LCR. O DC-LCR da ABN considerou também pertinente e importante a divulgaçäo das normas legais relacionadas à pesquisas em seres humanos em nosso país
Assuntos
Humanos , Líquido Cefalorraquidiano , Ética Médica , Consentimento Livre e Esclarecido , Manejo de Espécimes , Punção Espinal , Brasil , Comissão de Ética , Pesquisa , Punção EspinalRESUMO
O presente volume é uma atualizaçäo sobre os vírus linfotrópicos humanos I e II (HTLV-I/II) e aborda aspectos da biologia, epidemiologia, diagnóstico e aconselhamento de doadores positivos.
Assuntos
Humanos , Vírus Linfotrópico T Tipo 1 Humano/crescimento & desenvolvimento , Vírus Linfotrópico T Tipo 2 Humano/crescimento & desenvolvimento , Infecções por HTLV-I/diagnóstico , Infecções por HTLV-II/diagnóstico , Brasil , Infecções por HTLV-I/epidemiologia , Infecções por HTLV-II/epidemiologia , Educação de Pacientes como AssuntoRESUMO
O volume de número III é sobre os vírus linfotrópicos humanos I e II (HTLV-I/II) e aborda aspectos relevantes da biologia, epidemiologia, diagnóstico e aconselhamento de doadores positivos.