title: Helminthic infection and the risk of neurologic disease progression in HTLV-1.
abstract: BACKGROUND
  Infection with the human T-cell lymphotropic virus, type 1 (HTLV-1) has been associated with an increased Th1 response. Interestingly, a higher prevalence of helminthic coinfection has been observed among infected individuals, and subsequent modulation of the immune response typically associated with helminths may influence clinical outcomes among HTLV-1 coinfected individuals.
  
  
  OBJECTIVE
  This study was conducted to elucidate the association between helminthic coinfection and the development of clinically characterized neurologic disease that occurs in HTLV-1 infection.
  
  
  METHODS
  In a cohort analysis, incidence of HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) was recorded. Incidence of clinical outcomes and disease-free survival of several neurologic outcomes associated with HTLV-1 were estimated using the Kaplan-Meier method with log-rank tests. The relationships between helminthic infection and risk of HTLV-1 neurologic outcomes were assessed by Cox proportional hazard modeling.
  
  
  RESULTS
  Seventy-four coinfected and 79 non-coinfected patients were followed, with 92 helminthic infections observed in the coinfected group. One patient per group developed HAM/TSP and the risk of progression to neurologic disease outcomes did not differ among those with and without helminthic coinfection (p>0.45). A significant difference was noted in the prevalence of neurologic disease outcomes among all patients at the conclusion of the study (p<0.01).
  
  
  CONCLUSIONS
  These data suggest that treated helminthic infection does not affect risk of development of neurologic disease in HTLV-1 infection, and reinforce that treatment of helminths does not adversely affect patients with HTLV-1. Importantly, among all patients, an overall progression of neurologic disease was observed.
authors.affiliation: Stanford University School of Medicine, Medical School Office Building Room 323, Stanford, CA 94305-5404, USA. msundber@stanford.edu
authors.forename: Michael A
authors.initials: MA
authors.lastname: Sundberg
authors.forename: Davi
authors.initials: D
authors.lastname: Costa
authors.forename: Gloria
authors.initials: G
authors.lastname: Orge
authors.forename: Néviton M
authors.initials: NM
authors.lastname: Castro
authors.forename: André
authors.initials: A
authors.lastname: Muniz
authors.forename: Marshall J
authors.initials: MJ
authors.lastname: Glesby
authors.forename: Edgar M
authors.initials: EM
authors.lastname: Carvalho
mesh_terms: D000328:Adult; D015331:Cohort Studies; D060085:Coinfection; D018450:Disease Progression; D018572:Disease-Free Survival; D005243:Feces / Q000821:virology; D005260:Female; D015490:HTLV-I Infections / Q000469:parasitology* / Q000473:pathology; D006373:Helminthiasis / Q000473:pathology / Q000821:virology*; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015493:Paraparesis, Tropical Spastic / Q000469:parasitology* / Q000821:virology*; D015995:Prevalence