title: Defective human T-cell lymphotropic virus type I (HTLV-I) provirus in seronegative tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM) patients.
abstract: Infection with human T-cell lymphotropic virus type I (HTLV-I) have been associated with the development of the tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM). We studied the presence of HTLV-I provirus in peripheral blood mononuclear cells (PBMC) from 72 Chilean patients with progressive spastic paraparesis by polymerase chain reaction: 32 seropositive and 40 seronegative cases. We amplified different genomic regions of HTLV-I using primers of 5' ltr, tax, env/tax, pX, pol and env genes. These genes were detected from all seropositive patients. The seronegative patients were negative with 5' ltr, pol, env, and pX primers. However, amplified product of tax and env/tax genes was detected from 16 and four seronegative patients, respectively. Three of them were positive with both genetic regions. The results of this study show that the complete HTLV-I provirus is found in 100% of seropositive cases. In seronegative cases, clinically very similar of seropositive cases, was found only tax gene in 42.5% (17/40) of patients. These results suggest the presence of a defective HTLV-I provirus in some seronegative patients with progressive spastic paraparesis, and suggest a pathogenic role of this truncate provirus for a group of TSP/HAM.
authors.affiliation: Section of Virology, Public Health Institute of Chile, Avenida Marathon 1000, Santiago, Chile. eramirez@ispch.cl
authors.forename: E
authors.initials: E
authors.lastname: Ramirez
authors.forename: J
authors.initials: J
authors.lastname: Fernandez
authors.forename: L
authors.initials: L
authors.lastname: Cartier
authors.forename: C
authors.initials: C
authors.lastname: Villota
authors.forename: M
authors.initials: M
authors.lastname: Rios
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D002677:Chile; D004279:DNA, Viral / Q000097:blood; D003673:Defective Viruses / Q000235:genetics* / Q000302:isolation & purification; D005260:Female; D016356:Gene Products, tax / Q000737:chemistry / Q000235:genetics; D015481:HTLV-I Antibodies / Q000097:blood*; D015490:HTLV-I Infections / Q000821:virology*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D015493:Paraparesis, Tropical Spastic / Q000821:virology*; D011533:Proviruses / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D004279:DNA, Viral; D016356:Gene Products, tax; D015481:HTLV-I Antibodies; D014764:Viral Proteins