O vírus linfotrópico de células T humanos tipo 1 (HTLV-1): Quando suspeitar da infecção?

A infecção pelo vírus linfotrópico de células T humanas (HTLV) ocorre há milhares de anos. No entanto, o conhecimento sobre a sua patogênese é recente. Esse vírus é endêmico em várias regiões do mundo. No Brasil encontra-se presente em todos os estados, com prevalências variadas, sendo estimado cerca de 2,5 milhões de infectados. Fatores genéticos e imunológicos do hospedeiro são os principais responsáveis pelas manifestações clínicas associadas, que podem ser divididas em três categorias: neoplásicas, inflamatórias e infecciosas. Destacam-se a mielopatia associada ao HTLV (HAM/TSP) e a leucemia/linfoma de células T do adulto (ATLL) como as primeiras doenças associadas a esse retrovírus. Posteriormente, inúmeras outras doenças têm sido correlacionadas a esse vírus. Esta revisão atualiza conhecimentos epidemiológicos, fisiopatológicos, terapêuticos e principalmente diagnósticos do HTLV. O objetivo é permitir a suspeita etiológica do HTLV em suas diversas manifestações clínicas, hoje pouco correlacionadas com este agente.Human T Lymphotropic Virus (HTLV) infection has occurred for thousands of years. However, knowledge about this pathogenesis is recent. This virus is endemic worldwide. In Brazil it is present throughout the country , with different prevalence and about 2 5 million infected. Genetic and immunologic characteristics of the host are chiefly responsible for clinically associated manifestations which may be: neoplasic, inflammatory and infectious diseases. HTLV associated myelopathy (TSP/ HAM) and adult T cell leukemia/lymphoma (ATL) stand out as the first diseases associated to this retrovirus. Further, several diseases have been correlated to this virus. This review updates epidemiologic, physiopathologic, therapeutic and diagnostic knowledge of HTLV. The purose is to orient suspicion of HTLV etiology and several clinically associated manifestations, which currenty are seldom correlated with this virus

Avaliação de indivíduos infectados pelo Vírus Linfotrópico de Células T Humano Tipo 1 por tomografia por emissão de pósitrons, citocinas, quimiocinas e carga proviral

Exportado OPUSMade available in DSpace on 2019-08-09T22:07:47Z (GMT). No. of bitstreams: 1 tese_doutorado_luiz_romanelli.pdf: 5232831 bytes, checksum: 58804a6e5fb6028f8f49b1232c3176c8 (MD5) Previous issue date: 11O vírus linfotrópico de células T humana tipo 1 (HTLV-1) é um retrovírus endêmico em algumas regiões do planeta. A maior prevalência da infecção pelo HTLV1 em grupos populacionais distintos é atribuída principalmente às vias de transmissão, vertical e sexual, em associação a rotas migratórias transcontinentais ocorridas no decorrer de milhares de anos.1 É difícil estimar a real prevalência da infecção pelo HTLV-1 no mundo por existirem poucos estudos populacionais, sendo a maioria dos estudos baseados em populações específicas, como doadores de sangue, gestantes e outros grupos que podem sub ou superestimar a real prevalência desta infecção, estimada a comprometer 10 a 20 milhões de pessoas mundialmente.2 As rotas de origem do HTLV-1 ao Brasil ocorreram em três momentos distintos: durante a migração da Ásia para América do Norte pelo Estreito de Bering a milhares de anos atrás e consequentemente para América do Sul; em um segundo momento através do tráfico de escravos durante a colonização portuguesa; e na migração japonesa da primeira metade do século passado

Vestibular-evoked myogenic potential triggered by galvanic vestibular stimulation may reveal subclinical alterations in human T-cell lymphotropic virus type 1-associated myelopathy.

BACKGROUND:Vestibular-evoked myogenic potential triggered by galvanic vestibular stimulation (galvanic-VEMP) evaluates the motor spinal cord and identifies subclinical myelopathies. We used galvanic-VEMP to compare spinal cord function in individuals infected with human T-cell lymphotropic virus type 1 (HTLV-1) from asymptomatic status to HTLV-1-associated myelopathy (HAM). METHODOLOGY/PRINCIPAL FINDINGS:This cross-sectional study with 122 individuals included 26 HTLV-1-asymptomatic carriers, 26 individuals with possible HAM, 25 individuals with HAM, and 45 HTLV-1-seronegative individuals (controls). The groups were similar regarding gender, age, and height. Galvanic stimuli (duration: 400 ms; intensity: 2 mA) were applied bilaterally to the mastoid processes and VEMP was recorded from the gastrocnemius muscle. The electromyographic parameters investigated were the latency and amplitude of the short-latency (SL) and medium-latency (ML) responses. While SL and ML amplitudes were similar between groups, SL and ML latencies were delayed in the HTLV-1 groups compared to the control group (p<0.001). Using neurological examination as the gold standard, ROC curve showed an area under the curve of 0.83 (p<0.001) for SL and 0.86 (p<0.001) for ML to detect spinal cord injury. Sensibility and specificity were, respectively, 76% and 86% for SL and 79% and 85% for ML. Galvanic-VEMP disclosed alterations that were progressive in HTLV-1-neurological disease, ranging from SL delayed latency in HTLV-1-asymptomatic carriers, SL and ML delayed latency in possible HAM group, to absence of VEMP response in HAM group. CONCLUSIONS/SIGNIFICANCE:The worse the galvanic-VEMP response, the more severe the myelopathy. Galvanic-VEMP alteration followed a pattern of alteration and may be a prognostic marker of progression from HTLV-1-asymptomatic carrier to HAM

General characteristics of human T-cell lymphotropic virus type 1 (HTLV-1)-infected and -uninfected groups (n = 122).

<p>General characteristics of human T-cell lymphotropic virus type 1 (HTLV-1)-infected and -uninfected groups (n = 122).</p

Vestibular-evoked myogenic potential triggered by galvanic vestibular stimulation (galvanic-VEMP) tracings.

<p>(A) Delayed short-latency (SL) and medium-latency (ML) waves in an individual with asymptomatic human T-cell lymphotropic virus type 1 (HTLV-1) infection. (B) Absent SL response with delayed ML response latency in an individual with possible HTLV-1-associated myelopathy (HAM). (C) Absent SL and ML responses in an individual with HAM. These recordings were obtained from subjects with their heads rotated to the left and electromyographic (EMG) responses recorded from the right gastrocnemius muscle. The black line indicates the trace recorded with the cathode and anode on the right and left side respectively, whereas the gray line indicates the opposite stimulation polarity. SL, short-latency response onset; ML, medium-latency response onset.</p

Comparative analysis of the latency and amplitude of short-latency (SL) and medium-latency (ML) responses between human T-cell lymphotropic virus type 1 (HTLV-1)-infected and -uninfected groups.

<p>Comparative analysis of the latency and amplitude of short-latency (SL) and medium-latency (ML) responses between human T-cell lymphotropic virus type 1 (HTLV-1)-infected and -uninfected groups.</p

Frequency comparisons between normal and altered vestibular-evoked myogenic potential triggered by galvanic vestibular stimulation (galvanic-VEMP) for each group.

<p>The type of response (normal, delayed latency, or absent) and its frequency (%) is shown for each group. G1, uninfected control group; G2, human T-cell lymphotropic virus type 1 (HTLV-1)-asymptomatic group; G3, possible HTLV-1-associated myelopathy (HAM) group; G4, HAM group; n, number of participants. ^aDelayed latency of short-latency (SL), medium-latency (ML), or both responses. ^bAbsent SL, ML, or both responses. *p<0.001, chi-square or Fisher’s exact test.</p