Human T-lymphotropic virus 1

HTLV-1 and HIV-1 EM 8241 lores

Human T-lymphotropic virus 1 (HTLV-1) is a retrovirus that infects T-lymphocytes, a type of white blood cell that plays a central role in the immune system. HTLV-1 is associated with several diseases, including adult T-cell leukemia/lymphoma (ATLL) and HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP).

Virology

HTLV-1 is a member of the Deltaretrovirus genus within the Retroviridae family. The virus has a single-stranded RNA genome that is reverse transcribed into DNA and integrated into the host cell's genome. The viral genome encodes several proteins, including gag, pol, and env, which are essential for viral replication and assembly.

Transmission

HTLV-1 is transmitted through several routes:

• Mother-to-child transmission (primarily through breastfeeding)
• Sexual transmission
• Blood transfusion
• Intravenous drug use

Epidemiology

HTLV-1 is endemic in certain regions, including Japan, the Caribbean, parts of Africa, and South America. The prevalence of HTLV-1 infection varies widely, with some areas having infection rates as high as 10%.

Clinical Manifestations

HTLV-1 infection can lead to several clinical conditions:

• Adult T-cell leukemia/lymphoma (ATLL): A rare and aggressive form of cancer that affects T-lymphocytes.
• HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP): A chronic and progressive disease of the spinal cord.
• Infective dermatitis: A chronic skin condition seen primarily in children.

Diagnosis

Diagnosis of HTLV-1 infection is typically made through serological testing to detect antibodies against the virus. Polymerase chain reaction (PCR) can also be used to detect viral DNA in infected cells.

Treatment

There is currently no cure for HTLV-1 infection. Treatment focuses on managing symptoms and complications. Antiretroviral therapy has limited efficacy in HTLV-1 infection, and treatment for ATLL may include chemotherapy and antiviral drugs.

Prevention

Preventive measures include:

• Screening of blood products for HTLV-1
• Encouraging safe sex practices
• Avoiding breastfeeding by HTLV-1 infected mothers

See Also

• Retrovirus
• Adult T-cell leukemia/lymphoma
• HTLV-1 associated myelopathy/tropical spastic paraparesis
• Infective dermatitis
• Serological testing
• Polymerase chain reaction