title: Human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis: viral load and muscle tone are correlated.
abstract: Human T-lymphotropic virus type 1 (HTLV-1) infections are associated with varying degrees of HTLV-1 viral load and spasticity. Increased viral load is associated with higher risk of developing HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The authors performed a cross-sectional study of 24 people with HAM/TSP in Lima, Perú, to determine if higher HTLV-1 viral load was correlated with increased muscle tone, measured with a device providing quantitative spasticity assessment (QSA). Median HTLV-1 viral load was 17.0 copies/100 peripheral blood mononuclear cells and QSA value was 39.9 Newton-meters/radian. HTLV-1 viral load was significantly correlated with QSA value (Spearman rho = .48, P = .02), suggesting viral load may play a role in expression of symptomatic neurologic disease. Longitudinal studies are needed to determine if treatments that reduce viral load will reduce muscle tone.
authors.affiliation: Department of Neurology, University of Washington School of Medicine, Seattle, Washington, USA. jzunt@u.washington.edu
authors.forename: J R
authors.initials: JR
authors.lastname: Zunt
authors.forename: S M
authors.initials: SM
authors.lastname: Montano
authors.forename: I
authors.initials: I
authors.lastname: Beck
authors.forename: J Ov
authors.initials: JO
authors.lastname: Alarcón
authors.forename: L M
authors.initials: LM
authors.lastname: Frenkel
authors.forename: C T
authors.initials: CT
authors.lastname: Bautista
authors.forename: R
authors.initials: R
authors.lastname: Price
authors.forename: W T
authors.initials: WT
authors.lastname: Longstreth
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D008297:Male; D009129:Muscle Tonus / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D015493:Paraparesis, Tropical Spastic / Q000503:physiopathology / Q000821:virology*; D010568:Peru; D016133:Polymerase Chain Reaction; D019562:Viral Load