Prevalence and clinical features of HTLV neurologic disease in the HTLV Outcomes Study

JR Orland, J Engstrom, J Fridey, RA Sacher, JW Smith… - Neurology, 2003 - AAN Enterprises
JR Orland, J Engstrom, J Fridey, RA Sacher, JW Smith, C Nass, G Garratty, B Newman…
Neurology, 2003AAN Enterprises
Background: Almost 20 years after its discovery, the prevalence and clinical course of
human T-lymphotropic virus type I (HTLV-I)–associated myelopathy (HAM, also known as
tropical spastic paraparesis [TSP]) remain poorly defined. Whereas the causative
association of HTLV-I and HAM/TSP is generally recognized, controversy still surrounds the
relationship between HTLV-II and HAM/TSP. Methods: The HTLV Outcomes Study (HOST—
formerly Retrovirus Epidemiology Donor Study [REDS]) is a prospective cohort study …
Background: Almost 20 years after its discovery, the prevalence and clinical course of human T-lymphotropic virus type I (HTLV-I)–associated myelopathy (HAM, also known as tropical spastic paraparesis [TSP]) remain poorly defined. Whereas the causative association of HTLV-I and HAM/TSP is generally recognized, controversy still surrounds the relationship between HTLV-II and HAM/TSP.
Methods: The HTLV Outcomes Study (HOST—formerly Retrovirus Epidemiology Donor Study [REDS]) is a prospective cohort study including 160 patients with HTLV-I, 405 patients with HTLV-II, and 799 uninfected controls who have been followed every 2 years since 1990–1992. Clinical outcomes are measured by health interviews and examinations, and blood samples are obtained.
Results: Six cases of HTLV-I–associated myelopathy (3.7%, 95% CI 1.4 to 8.0) and four cases of HTLV-II myelopathy (1.0%, 95% CI 0.3 to 2.5) have been diagnosed since the formation of the cohort. There have been no cases of HAM/TSP diagnosed among HTLV-negative subjects (0.0%, 95% CI 0.0 to 0.5). Clinical features of the cases include lower extremity hyperreflexia, variably associated with weakness, spasticity, and bladder dysfunction.
Conclusions: Systematic screening of HTLV-infected blood donors reveals a high prevalence of HAM/TSP. The clinical course of HAM/TSP appears highly variable. HTLV-II–associated myelopathy generally presents with milder and more slowly progressive signs and symptoms.
American Academy of Neurology