Article
Distribution of human T cell lymphotropic virus type 1 (HTLV-1) subtypes in Brazil: genetic characterization of LTR and tax region.
Registro en:
KASHIMA, S. et al. Distribution of human T cell lymphotropic virus type 1 (HTLV-1) subtypes in Brazil: genetic characterization of LTR and tax region. AIDS Reserach Human and Retroviruses, v. 22, n. 10, p. 953-599, 2006.
0889-2229
Autor
Kashima, Simone G
Alcantara, Luiz Carlos Júnior
Takayanagui, Osvaldo Massaiti
Cunha, Marco Aurelio Valtas
Castro Filho, Bernardo Galvão
Oliveira, Maria Socorro Pombo de
Zago, Marco Antonio
Covas, Dimas Tadeu
Resumen
We report the molecular and epidemiological characterization of 128 human T cell lymphotropic virus type
1 (HTLV-1) isolates from Brazilian patients with different clinical manifestations of the infection. Thirty-two
percent of the patients were asymptomatic, 44% had HTLV-1-associated myelopathy/tropical spastic paraparesis
(HAM/TSP), and 23% had adult T cell leukemia/lymphoma (ATLL). Phylogenetic analysis performed
using part of the LTR region of the viral genome revealed that all Brazilian isolates belonged to the Cosmopolitan
subtype, with the following distribution within the Transcontinental subgroup: 81.6% within the
Latin American cluster and 15.8% outside the Latin American cluster. Two isolates belonged to the Japanese
subgroup. Molecular analysis of the tax region showed a high nucleotide similarity ( 99%) with 41 prototype
sequences, including the ATK-1 isolate. The mean number of nucleotide substitutions ranged from 1
to 8. Five specific nucleotide substitutions, C7401T, T7914C, C7920T, C7982T, and G8231A, were highly conserved
among the Brazilian isolates (79.6%), with a frequency ranging from 81.6% to 100% in the sample
group and from 18.4% to 24.1% in the prototypes used, suggesting the existence of a molecular signature.
These changes were not correlated with a specific clinical status of the patients and could be a molecular characteristic
of the HTLV-1 strains that circulate in Brazil.