title: SYBR Green-based quantitation of human T-lymphotropic virus type 1 proviral load in Peruvian patients with neurological disease and asymptomatic carriers: influence of clinical status, sex, and familial relatedness.
abstract: To evaluate the human T-lymphotropic virus type 1 (HTLV-1) proviral DNA load in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and asymptomatic HTLV-1 carriers, a SYBR Green-based real-time quantitative polymerase chain reaction (qPCR) assay was developed. HTLV-1 proviral DNA in peripheral blood mononuclear cells (PBMCs) was quantified using primers targeting the pX region and the HTLV-1 copy number normalized to the amount of ERV-3 (Endogenous Retrovirus 3) cellular DNA. Thirty-three asymptomatic HTLV-1 carriers (ACs) and 39 patients with HAM/TSP were enrolled. Some participants were relatives of HAM/TSP cases (16 ACs and 7 patients with HAM/TSP). On multiple linear regression analysis, the authors found a significant association between clinical status and HTLV-1 proviral load (P < .01), but only among women. ACs showed a median proviral load of 561 copies per 104 PBMCs (interquartile range: 251-1623). In HAM/TSP patients, the median proviral load was 1783 (1385-2914). ACs related to HAM/TSP patients presented a relatively high proviral load (median 1152); however, the association between relatedness to a HAM/TSP patient and proviral load was not significant (P = .1). In HAM/TSP patients, no association was found between proviral load and disease duration, progression or severity. The fact that the effect of HAM/TSP upon the HTLV-1 proviral load differed between sexes and the finding of a high proviral load among asymptomatic relatives of HAM/TSP patients suggest that not yet identified genetic or environmental factors influence the pathogenesis of HTLV-1 infection.
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. 05865@upch.edu.pe
authors.forename: Vanessa
authors.initials: V
authors.lastname: Adaui
authors.forename: Kristien
authors.initials: K
authors.lastname: Verdonck
authors.forename: Iván
authors.initials: I
authors.lastname: Best
authors.forename: Elsa
authors.initials: E
authors.lastname: González
authors.forename: Martín
authors.initials: M
authors.lastname: Tipismana
authors.forename: Jorge
authors.initials: J
authors.lastname: Arévalo
authors.forename: Guido
authors.initials: G
authors.lastname: Vanham
authors.forename: Miguel
authors.initials: M
authors.lastname: Campos
authors.forename: Mirko
authors.initials: M
authors.lastname: Zimic
authors.forename: Eduardo
authors.initials: E
authors.lastname: Gotuzzo
mesh_terms: D052160:Benzothiazoles; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000302:isolation & purification*; D003959:Diamines; D018450:Disease Progression; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D009930:Organic Chemicals; D015493:Paraparesis, Tropical Spastic / Q000821:virology*; D010568:Peru; D011533:Proviruses / Q000302:isolation & purification*; D011804:Quinolines; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D012737:Sex Factors; D019562:Viral Load / Q000379:methods*
chemical_list: D052160:Benzothiazoles; D004279:DNA, Viral; D003959:Diamines; D009930:Organic Chemicals; D011804:Quinolines; C098022:SYBR Green I