title: Detection of human T-cell lymphotropic virus type 1 in plasma samples.
abstract: Human T-cell lymphotropic virus type 1 (HTLV-1) is an RNA virus responsible for diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T-cell leukemia/lymphoma (ATL). Cell-to-cell contact and Tax-induced clonal expansion of infected cells are the main modes of virus replication, making virus detection during the viremic stage difficult. Consequently, the proviral load is the current virologic marker for disease monitoring, but the mechanisms of progression have not been established yet. Thus, this study investigated the presence of virus in plasma from asymptomatic HTLV-1 carriers and from HAM/TSP patients. Real-time PCR was performed on DNA from 150 plasma samples; 12 (8%) had detectable DNA amplification, including 6 (4%) asymptomatic HTLV-1 carriers and 14 (26%) HAM/TSP patients (p<0.005). Of the 33 samples submitted for nested PCR, six (18%, p=0.02) were positive for HTLV-1 RNA in the plasma. Additionally, 26 plasma samples were treated with DNAse enzyme to eliminate any DNA contamination before RNA extraction. Two of them (8%) showed amplification for HTLV-1 (p=0.5). Therefore, this study described for the first time the detection of free HTLV-1 RNA in plasma from HTLV-1-infected subjects, regardless of their clinical status. Thus, HTLV-1 viral replication does occur in plasma, and other transmission pathways for HTLV-1 should be investigated further.
authors.affiliation: Laboratory of Immunodeficiencies and Dermatology, Sao Paulo University Medical School, Sao Paulo, Brazil. fabioabcabral@yahoo.com.br
authors.forename: Fabio
authors.initials: F
authors.lastname: Cabral
authors.forename: Liã Barbara
authors.initials: LB
authors.lastname: Arruda
authors.forename: Marilia Ladeira
authors.initials: ML
authors.lastname: de Araújo
authors.forename: Patricia
authors.initials: P
authors.lastname: Montanheiro
authors.forename: Jerusa
authors.initials: J
authors.lastname: Smid
authors.forename: Augusto César Penalva
authors.initials: AC
authors.lastname: de Oliveira
authors.forename: Alberto J S
authors.initials: AJ
authors.lastname: Duarte
authors.forename: Jorge
authors.initials: J
authors.lastname: Casseb
mesh_terms: D000328:Adult; D002353:Carrier State / Q000821:virology*; D005260:Female; D015490:HTLV-I Infections / Q000821:virology*; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010949:Plasma / Q000821:virology*; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000097:blood*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D012367:RNA, Viral