title: HTLV-associated myelopathy in a cohort of HTLV-I and HTLV-II-infected blood donors. The REDS investigators.
abstract: OBJECTIVE
  HTLV-I-associated myelopathy (HAM) is a slowly progressive spastic paraparesis caused by infection with human T-lymphotropic virus type I (HTLV-I). The prevalence of HAM among those infected with HTLV-I is poorly defined, and the association of a similar myelopathy with HTLV-II infection has not been confirmed.
  
  
  METHODS
  Cross-sectional examination of HTLV-I, HTLV-II, and control subjects from the baseline visit of a cohort study. SETTING/ SUBJECTS: Persons testing HTLV seropositive at the time of blood donation at five U.S. blood centers, their seropositive sex partners, and a matched control group of HTLV seronegative blood donors.
  
  
  METHODS
  HTLV-I and HTLV-II were differentiated by serology and/or polymerase chain reaction. All subjects received systematic neurologic screening examinations.
  
  
  RESULTS
  A diagnosis of myelopathy was confirmed in four of 166 HTLV-I subjects (2.4%, 95% confidence interval 0.7%, 6.1%) and in one of 404 HTLV-II subjects (0.25%, 95% confidence interval 0.0%, 0.6%). None of the 798 controls had a similar myelopathy, although one had longstanding typical multiple sclerosis.
  
  
  CONCLUSIONS
  Our data also suggest that HAM occurs more frequently among HTLV-I-infected subjects than reported by previous studies. The HTLV-II infected myelopathy patient identified in this cohort, together with three other case reports in the literature, implies a pathogenic role for this human retrovirus. The diagnosis of HTLV-associated myelopathy should be considered in cases of spastic paraparesis or neurogenic bladder when risk factors for HTLV-I or HTLV-II infection are present.
authors.affiliation: Department of Laboratory Medicine, University of California, San Francisco 94143-0884, USA.
authors.forename: E L
authors.initials: EL
authors.lastname: Murphy
authors.forename: J
authors.initials: J
authors.lastname: Fridey
authors.forename: J W
authors.initials: JW
authors.lastname: Smith
authors.forename: J
authors.initials: J
authors.lastname: Engstrom
authors.forename: R A
authors.initials: RA
authors.lastname: Sacher
authors.forename: K
authors.initials: K
authors.lastname: Miller
authors.forename: J
authors.initials: J
authors.lastname: Gibble
authors.forename: J
authors.initials: J
authors.lastname: Stevens
authors.forename: R
authors.initials: R
authors.lastname: Thomson
authors.forename: D
authors.initials: D
authors.lastname: Hansma
authors.forename: J
authors.initials: J
authors.lastname: Kaplan
authors.forename: R
authors.initials: R
authors.lastname: Khabbaz
authors.forename: G
authors.initials: G
authors.lastname: Nemo
mesh_terms: D015492:AIDS Serodiagnosis; D000328:Adult; D001782:Blood Donors; D015331:Cohort Studies; D004812:Epidemiologic Methods; D005260:Female; D015490:HTLV-I Infections / Q000150:complications* / Q000453:epidemiology*; D015491:HTLV-II Infections / Q000150:complications* / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D015493:Paraparesis, Tropical Spastic / Q000175:diagnosis / Q000453:epidemiology*; D012307:Risk Factors; D012747:Sexual Partners; D014549:Urinary Incontinence / Q000150:complications