[Clinical diversity of HAM/TSP]

Area of Science:

• Virology
• Immunology
• Neurology

Context:

• Human T-lymphotropic virus type I (HTLV-I) is a retrovirus linked to adult T-cell leukemia and inflammatory conditions such as HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP).
• Transmission primarily occurs from mother to child via breastfeeding, with significant carrier and patient populations in Japan.
• Inflammation in HAM/TSP extends throughout the central nervous system (CNS), not limited to the thoracic cord.

Purpose:

• To summarize the pathology and transmission of HTLV-I.
• To highlight the clinical manifestations and epidemiological status of HTLV-I infection.
• To emphasize the need for preventative measures and therapeutic strategies.

Summary:

• HTLV-I infection leads to adult T-cell leukemia and various inflammatory diseases, including HAM/TSP, affecting the CNS.
• Pathology involves infiltration of HTLV-I-infected lymphocytes and cytotoxic T lymphocytes into the CNS, causing bystander damage.
• Patients with HAM/TSP exhibit higher proviral loads and may develop complications in other organs.

Impact:

• Effective prevention of mother-to-child transmission through breastfeeding cessation is critical for controlling HTLV-I spread.
• Urgent development of treatments to eliminate HTLV-I-infected cells is necessary to manage the disease and its complications.