This study aimed to describe the epidemiological, immunological and molecular features of infection by the human T-lymphotropic virus-1/2 (HTLV-1/2) in individuals with HIV-1 in an urban area of Piaui State, Brazil. Exclusion criteria included patients under 18 years of age, pregnant women or Amerindians. Of 805 individuals analyzed by the serological method (ELISA) for the detection of anti-HTLV-1/2, 18 (2.24%) were positive, but only 13 (1.61%) were confirmed by PCR. The RFLP analysis revealed that nine (1.12%) of these subjects were positive for HTLV-1 and four (0.5%) for HTLV-2. The mean age of these co-infected individuals was 50.9±9.1 years, and a significant association was found with age (above 40 years: p = 0.002), minor surgeries (p = 0.004) and blood transfusion (p = 0.031). Quantification of the T CD4+/CD8+ lymphocytes and the HIV-1 viral load showed no significant association of T CD8 + lymphocyte levels with co-infection in the patients with HIV-1/HTLV-1. The sequencing of the LTR region and phylogenetic analysis indicated that the nine HTLV-1 strains belong to the Transcontinental subgroup of the Cosmopolitan group (1a), with a 83% (neighbor-joining) bootstrap value. The HTLV-2 strains were identified as subtype HTLV-2c, supported by a bootstrap value of 79%. Further studies in other population subgroups, such as blood donors and drug users, will be necessary to clarify the dissemination of HTLV-1/2 in Piau and elucidate the developmental profile of the virus in the region.

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O vírus linfotrópico de células T humanas 1 (HTLV-1) é um retrovírus associado a patologias humanas como leucemia/linfoma de células T do adulto (LLcTA) e paraparesia espástica tropical/mielopatia associada ao HTLV (PET/MAH) 17 . O HTLV-1 tem sido também associado a casos de polimiosite, poliartrite e uveíte 12 13 14 15 .A paraparesia espástica tropical/mielopatia associada ao HTLV (PET/MAH) é uma doença desmielinizante crônica e progressiva associada à infecção pelo HTLV-1 e que afeta predominantemente a coluna vertebral. Relata-se que esta doença afeta entre 0,2 e 5% dos indivíduos infectados na quarta década de vida 7 25 .Caracterização molecular do HTLV-1 em pacientes com paraparesia espástica tropical/mielopatia associada ao HTLV-1 em Belém, Pará ABSTRACTThe present study evaluated the occurrence of HTLV-1 and its subtypes in blood samples of patients presenting symptoms of tropical spastic paraparesis/HTLV-1 associated myelopathy. The detection of HTLV infection was performed by serological and molecular assays. Além disso, uma síndrome neurológica similar a PET/MAH tem sido descrita em raros pacientes portadores da coinfecção HIV-1/HTLV-2 19 e pelo menos um paciente infectado com HTLV-2 já foi identificado com uma doença neurodegenerativa progressiva crônica clinicamente indistinguível de PET/MAH 6 21 .Embora a ocorrência de PET/MAH seja elevada em algumas áreas geográficas, até o presente momento são raras as informações acerca das características moleculares do HTLV-1 que possam justificar a ocorrência de apenas 1 a 5% dos indivíduos infectados apresentarem PET/MAH. Assim, o presente estudo teve como objetivo investigar o perfil