title: Identification of human T-lymphotropic virus type I (HTLV-I) subtypes using restricted fragment length polymorphism in a cohort of asymptomatic carriers and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis from São Paulo, Brazil.
abstract: Although human T-lymphotropic virus type I (HTLV-I) exhibits high genetic stability, as compared to other RNA viruses and particularly to human immunodeficiency virus (HIV), genotypic subtypes of this human retrovirus have been characterized in isolates from diverse geographical areas. These are currently believed not to be associated with different pathogenetic outcomes of infection. The present study aimed at characterizing genotypic subtypes of viral isolates from 70 HTLV-I-infected individuals from São Paulo, Brazil, including 42 asymptomatic carriers and 28 patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), using restricted fragment length polymorphism (RFLP) analysis of long terminal repeat (LTR) HTLV-I proviral DNA sequences. Peripheral blood mononuclear cell lysates were amplified by nested polymerase chain reaction (PCR) and amplicons submitted to enzymatic digestion using a panel of endonucleases. Among HTLV-I asymptomatic carriers, viral cosmopolitan subtypes A, B, C and E were identified in 73.8%, 7.1%, 7.1% and 12% of tested samples, respectively, whereas among HAM/TSP patients, cosmopolitan A (89.3%), cosmopolitan C (7.1%) and cosmopolitan E (3.6%) subtypes were detected. HTLV-I subtypes were not statistically significant associated with patients' clinical status. We also conclude that RFLP analysis is a suitable tool for descriptive studies on the molecular epidemiology of HTLV-I infections in our environment.
authors.affiliation: Laboratório de Virologia (LIM-52), Departamento de Doenças Infecciosas e Parasitárias, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, 05403-000, Brasil. segurado@usp.br
authors.forename: Aluisio A C
authors.initials: AA
authors.lastname: Segurado
authors.forename: Cláudia
authors.initials: C
authors.lastname: Biasutti
authors.forename: Rogério
authors.initials: R
authors.lastname: Zeigler
authors.forename: Cristhieni
authors.initials: C
authors.lastname: Rodrigues
authors.forename: Cristine D
authors.initials: CD
authors.lastname: Damas
authors.forename: Maria Lúcia S G
authors.initials: ML
authors.lastname: Jorge
authors.forename: Paulo E
authors.initials: PE
authors.lastname: Marchiori
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil; D002353:Carrier State / Q000821:virology*; D015331:Cohort Studies; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D015368:Human T-lymphotropic virus 1 / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D015493:Paraparesis, Tropical Spastic / Q000453:epidemiology / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D004279:DNA, Viral