Recruiting

Observational Study

Sponsor:

National Institute of Neurological Disorders and Stroke (NINDS)

Code:

NCT00001778

Conditions

HTLV-I Infection

Tropical Spastic Paraparesis

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Accepted

Study Details

Brief summary:

Objective:

Human T-lymphotropic virus type-I-associated myelopathy / tropical spastic paraparesis (HAM/TSP) is a rare neurologic disorder that affects less than 5% of patients infected with the HTLV-I virus. The purpose of this protocol is to study the natural history of HAM/TSP by monitoring clinical progression of patients longitudinally. Additionally, we will attempt to define the virological and immunological changes of HAM/TSP.

Study Population:

Patients with HAM/TSP who fulfill World Health Organization diagnostic criteria are eligible to participate in this protocol. Asymptomatic seropositive individuals and individuals with indeterminate HTLV-1 serology are also eligible to participate.

Design and Outcome Measures:

A longitudinal assessment of clinical, virological and immunological progression in HAM/TSP will be accomplished through periodic testing and evaluation. Asymptomatic seropositive individuals, those with seroindeterminate HTLV-I serology and normal volunteers may serve as controls. Longitudinal standardized neurological examinations will be performed. Longitudinal samples of serum, plasma, and lymphocytes may be obtained from participants. Lumbar punctures may be performed on all participants. These samples will be used virological and immunological assays. A focus is on the relationships between the characteristics of viral infection, the immune response, and the genetic makeup.

Conditions

HTLV-I Infection

Tropical Spastic Paraparesis

Study ID

NCT00001778

Start date

Apr 6, 1998

Status verified date

Sep 2, 2026

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Accepted

  • INCLUSION CRITERIA:

Participants that meet one of the following criteria:

  • Test positive for HTLV infection (positive HTLV-1 ELISA followed by a positive Western blot)
  • Positive HTLV ELISA but a Western Blot that only partially fulfills the above criteria (seroindeterminate)
  • Have a family member/significant other who is HTLV positive, and may have been exposed to the virus
  • Healthy volunteer AND
  • Willingness to participate in the protocol evaluations and procedures.

EXCLUSION CRITERIA:

  • Unwillingness or inability to participate in the protocol evaluations and procedures.
  • The presence of any medical, social, or psychiatric conditions that in the opinion of the investigator may affect the safety of the patients or compliance with the protocol.
  • Patients/healthy volunteers under the age of 18 are excluded.

Study Design

Enrollment

750 participants

Anticipated

Interventions and Outcome Measures

Arms

healthy volunteers

At least 18 years old and have no history of any medical illness that may confound study results or make participation in this protocol impossible

individuals seropositive for HTLV

Positive HTLV-1 ELISA followed by a positive Western Blot

individuals with indeterminate HTLV sero-status

Positive HTLV ELISA but a Western Blot that only partially fulfills criteria

Primary outcome measure

  • To characterize the baseline features of patients with HTLV infection with regards to clinical features, imaging studies, immunological markers, and viral studies. [ Time Frame: each study visit ]

Central Contacts and Locations

Central contacts

Locations

National Institutes of Health Clinical Center

Recruiting

Bethesda, Maryland, United States, 20892

More Information

Sponsor

National Institute of Neurological Disorders and Stroke (NINDS)

Last update posted

Sep 4, 2026

Last verified

Sep 2, 2026

Keywords

  • Immune Response
  • Sero-Indeterminant
  • Transmission
  • HTLV-1
  • HTLV-1 Associated Myelopathy
  • Natural History
  • HTLV-I
  • HAM/TSP

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by National Institute of Neurological Disorders and Stroke (NINDS) on 2026-09-04.