HTLV-associated myelopathy in a cohort of HTLV-I and HTLV-II-infected blood donors. The REDS investigators.
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.
Murphy
E L
EL
Department of Laboratory Medicine, University of California, San Francisco 94143-0884, USA.
Fridey
J
J
Smith
J W
JW
Engstrom
J
J
Sacher
R A
RA
Miller
K
K
Gibble
J
J
Stevens
J
J
Thomson
R
R
Hansma
D
D
Kaplan
J
J
Khabbaz
R
R
Nemo
G
G
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