Detection of human T-cell lymphotropic virus type 1 in plasma samples

• Published in: Virus research Vol. 163; no. 1; pp. 87 - 90
• Main Authors: Cabral, Fabio, Arruda, Liã Barbara, de Araújo, Marilia Ladeira, Montanheiro, Patricia, Smid, Jerusa, de Oliveira, Augusto César Penalva, Duarte, Alberto J.S., Casseb, Jorge
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2012
• Subjects: Adult; adults; Carrier State - virology; deoxyribonucleases; disease surveillance; DNA; Female; HTLV-1; HTLV-1 plasma viral load; HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP); HTLV-I Infections - virology; Human T-lymphotropic virus; Human T-lymphotropic virus 1; Human T-lymphotropic virus 1 - isolation & purification; Humans; leukemia; lymphoma; Male; Middle Aged; Nested PCR; patients; Plasma - virology; Polymerase Chain Reaction; Primate T-lymphotropic virus 1; quantitative polymerase chain reaction; Real-time PCR; Real-Time Polymerase Chain Reaction; RNA; RNA, Viral - blood; T-lymphocytes; virus replication; viruses; HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP); Nested PCR; HTLV-1 plasma viral load; HTLV-1; Real-time PCR
• ISSN: 0168-1702; 1872-7492
• DOI: 10.1016/j.virusres.2011.08.014

► HTLV-1 is usually spreading by cell-to-cell contact. ► No studies have observed virions in the plasma. ► Our results showed the presence of HTLV-1 virions in the plasma. 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.