title: Proviral load and the balance of serum cytokines in HTLV-1-asymptomatic infection and in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP).
abstract: This study compared the proviral load and the plasma cytokine profiles (interleukin-IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ) in 87 HTLV-1-infected individuals, including 28 with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), 32 with possible pHAM/TSP and 27 asymptomatic carriers (AC). The control group was composed by 21 HTLV-1-seronegative individuals. Our finding demonstrated that HAM/TSP group presented higher proviral load as compared to all other HTLV-1 groups (p<0.0001). The HAM/TSP group showed higher serum concentration of IL-6 (p=0.0009) as compared to all other groups. Moreover, higher serum concentration of IFN-γ (p=0.0118) and IL-4 (p=0.0166) were observed in HAM/TSP group as compared to the healthy controls. Additionally, the HAM/TSP group also showed higher serum concentration of TNF-α (p=0.0239) and IFN-γ (p=0.0118) as compared to AC. No differences in the serum concentration of IL-2 and IL-10 were observed among the groups. The analysis of cytokine balance demonstrated that HAM/TSP presented higher pro-inflammatory profile with enhanced IFN-γ/IL-10 and IFN-γ/IL-4 ratio as compared to AC and pHAM/TSP. Further analysis pointed out to a positive correlation between the IFN-γ response and the proviral load in AC. Conversely, a negative association between TNF-α and IL-2 with the proviral load was the hallmark of HAM/TSP group. These findings suggested that the proviral load and the pro-inflammatory cytokine profile may be independent events in the peripheral blood of HAM/TSP individuals. The knowledge about the existence of individual virological/immunological behavior upon HTLV-1 infection, may guide to the establishment of more effective therapeutic interventions.
authors.affiliation: Programa de Pós-Graduação em Infectologia e Medicina Tropical - Faculdade de Medicina da Universidade Federal de Minas Gerais, Minas Gerais, Av. Prof. Alfredo Balena, 190 - sala 533, CEP: 30.130-100, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Ana Lúcia Borges
authors.initials: AL
authors.lastname: Starling
authors.forename: Olindo Assis
authors.initials: OA
authors.lastname: Martins-Filho
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Lambertucci
authors.forename: Ludimila
authors.initials: L
authors.lastname: Labanca
authors.forename: Silvio Roberto
authors.initials: SR
authors.lastname: de Souza Pereira
authors.forename: Andréa
authors.initials: A
authors.lastname: Teixeira-Carvalho
authors.forename: Marina Lobato
authors.initials: ML
authors.lastname: Martins
authors.forename: João Gabriel
authors.initials: JG
authors.lastname: Ribas
authors.forename: Anna Bárbara F
authors.initials: AB
authors.lastname: Carneiro-Proietti
authors.forename: Denise Utsch
authors.initials: DU
authors.lastname: Gonçalves
mesh_terms: D000328:Adult; D000368:Aged; D058345:Asymptomatic Infections; D016207:Cytokines / Q000097:blood*; D005260:Female; D015490:HTLV-I Infections / Q000276:immunology* / Q000473:pathology / Q000821:virology*; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011533:Proviruses / Q000302:isolation & purification*; D044967:Serum / Q000737:chemistry / Q000821:virology; D019562:Viral Load; D055815:Young Adult
chemical_list: D016207:Cytokines