RESUMO
Partindo de dois oligonucleotídeos degenerados derivados de uma fração conservada da região pol de retrovírus conhecidos, foi pesquisada a presença de agente viral exógeno ou de uma seqüência endógena similar as retrovirais (ERV). A partir da amplificação do DNA pela técnica de PCR, foram testadas células mononucleares periféricas de 33 portadores de paraparesia crural espática de evolução crônica sem agente etiológico conhecido, produzindo um fragmento de aproximadamente 500 bp em 8 destas amostras...
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Doenças da Medula Espinal/virologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/sangue , Leucemia-Linfoma Linfoblástico de Células T Precursoras/terapia , Linfoma não Hodgkin/diagnóstico , Linfoma não Hodgkin/imunologia , Linfoma não Hodgkin/sangue , Paraparesia Espástica/metabolismo , Paraparesia Espástica/virologia , Paraparesia Espástica Tropical/metabolismo , Paraparesia Espástica Tropical/virologia , Retroviridae , Western Blotting , Diagnóstico Clínico , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase , Sorologia , Sorodiagnóstico da AIDS/classificação , Sorodiagnóstico da AIDS/métodos , Sorodiagnóstico da AIDS , Testes Sorológicos/métodos , Testes SorológicosRESUMO
BACKGROUND: Tropical spastic paraparesis (TSP) is an endemic disease in Chile. In most countries, only 50% of patients are seropositive to HTLV-I. However, new studies suggest that seronegative TSP is also associated with HTLV-I. AIM: To describe clinical and virological features of seronegative patients with TSP. PATIENTS AND METHODS: Seventy two Chilean patients with TSP, studied by clinical, radiological and laboratory methods during 1998, are reported. The determination of antibodies to HTLV-I was accomplished by ELISA, immunofluorescence and Western-blot analysis. Polymerase chain reaction for tax and 5'Ltr genes was made using primers SK 43-44, LTR1 and LTR6. RESULTS: Thirty one patients were HTLV-I positive and 41 were negative. No clinical, radiological or laboratory differences were observed between both groups. In seropositive patients, tax and 5'ltr viral gene sequences of the HTLV-I provirus were detected in DNA of peripheral blood mononuclear cells. In seronegative cases, sequences of tax gene were detected, exclusively, in 18 of 41 patients. CONCLUSIONS: These results confirm an association with HTLV-I infection in 43.9% of the TSP seronegative patients. These findings support the hypothesis that a defective provirus infects peripheral blood mononuclear cells in seronegative cases of TSP. The importance tax gene in the diagnosis of the TSP is also emphasized.