The Native Antigen Company is part of LGC Clinical Diagnostics - Learn More

0 Items
Select Page

Human T-Cell Lymphotropic Virus

Human T-cell lymphotropic virus (HTLV) are retroviruses which can cause an uncommon type of T-cell lymphocytic leukemia and non-Hodgkin lymphoma in adults called adult T-cell leukemia/lymphoma (ATLL). There are four known types of HTLV (HTLV-1, HTLV-2, HTLV-3, and HTLV-4); HTLV-1 is the most pathogenic for humans while HTLV-2 usually produces mild neurological disease. Both are prevalent worldwide. HTLV-3 and HTLV-4 have only been identified in Central Africa and usually affect non-human hominids. Despite infecting at least 10 million people worldwide, HTLV is still considered a neglected disease.

Human T-Cell Lymphotropic Virus

The human T-cell lymphotropic virus, human T-lymphotropic virus, or human T-cell leukemia-lymphoma virus (HTLV) family of viruses are human retroviruses that cause a type of cancer called adult T-cell leukemia/lymphoma and a demyelinating disease called HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). They were discovered by Robert Gallo and colleagues in 1980 and belong to a larger group of primate T-lymphotropic viruses (PTLVs). Members of this family that infect humans are called HTLVs, and those that infect Old World monkeys are called Simian T-lymphotropic viruses (STLVs). Four types of HTLVs (HTLV-1, HTLV-2, HTLV-3, and HTLV-4) have been identified. The original name for HIV, the virus that causes AIDS, was HTLV-3. A closely related virus is bovine leukemia virus BLV (Martinez et al., 2019).
HTLV-1 is a retrovirus belonging to the family retroviridae and the genus deltaretrovirus which predominately infects CD4+ T cells. It can be transmitted from mother to child, through sexual contact, and through contaminated blood products. The virus affects up to 10 million people worldwide with endemic regions of infection in Southwest Japan, sub-Saharan Africa, South America, the Caribbean, and regions of the Middle East and Australo-Melanesia. The major geographic subtypes are Cosmopolitan subtype A, Central African subtype B, Australo-Melanesian subtype C, and Central African/Pygmies subtype D. Cosmopolitan subtype A is the most widespread subtype (endemic subgroups in Japan, Central and South America, the Caribbean, North and West Africa, and regions of the Middle East). It is directly associated to one of the most aggressive T cell malignancies; Adult T Cell Leukemia-Lymphoma (ATLL) and a progressive neurological disorder, Tropical Spastic Paraparesis/ HTLV-1 Associated Myelopathy (TSP/HAM). Between 1 in 20 and 1 in 25 infected people are thought to develop cancer as a result of the virus (Verdonck et al., 2007).
HTLV-2 closely related to HTLV-1 and may be linked to cutaneous T-cell lymphoma (CTCL). HTLV-2 is far less prevalent than HTLV-1 with an estimated 800,000 infected individuals worldwide. Most documented HTLV-2 infected individuals are found in the United States highly concentrated in the Native American and intravenous drug user populations. A similar epidemiologic pattern is found in the second most HTLV-2 infected region, Brazil. HTLV-2 is divided into four molecular subtypes; a, b, c, and d. HTLV-2a and HTLV-2b are commonly found in the Americas and Europe whereas HTLV-2c and HTLV-2d are found predominantly in Brazil and Central Africa. HTLV-2 is associated with milder neurologic disorders and chronic pulmonary infections. No specific illnesses have yet been associated with HTLV-3 and HTLV-4 (Eusebio-Ponce et al., 2019).


  • Eusebio-Ponce E, Anguita E, Paulino-Ramirez R, Candel FJ. HTLV-1 infection: An emerging risk. Pathogenesis, epidemiology, diagnosis and associated diseases. Rev Esp Quimioter. 2019 Dec;32(6):485-496.
  • Martinez MP, Al-Saleem J, Green PL. Comparative virology of HTLV-1 and HTLV-2. Retrovirology. 2019 Aug 7;16(1):21.
  • Verdonck K, González E, Van Dooren S, Vandamme AM, Vanham G, Gotuzzo E. Human T-lymphotropic virus 1: recent knowledge about an ancient infection. Lancet Infect Dis. 2007 Apr;7(4):266-81.


Check out our FAQ section for answers to the most frequently asked questions about our website and company.

Monkeypox; 3 months on

It has been 3 months since a new, unusually widespread outbreak of Monkeypox was first identified. What was normally a virus confined to limited infections in the West African continent is becoming a global health concern.   What have we learned about this virus...

COVID-19 Underlines the Need for Universal Vaccines

This article was originally published on Clinical Lab Manager. In recent history, humanity has witnessed numerous emerging viral diseases, including the SARS, MERS, and SARS-2 coronaviruses, as well as HIV, Zika, Ebola, and H1N1 and H3N2 influenza. None have tested...

Tick-Borne Diseases: The Need for Integrated Approaches to Human-Animal Diagnosis

This article has been published in Volume 8, Issue 3 of International Animal Health Journal. Ticks are responsible for a diverse group of neglected, and rapidly expanding diseases, affecting humans, companion animals and livestock. A growing understanding of tick-host...

The Continued Challenges of Flavivirus Serology

This article was originally published on the Science Advisory Board. Flaviviruses are a genus of positive-sense RNA viruses, largely transmitted by mosquito and tick vectors that cause infections, including yellow fever, dengue, the Zika virus, West Nile virus,...

The Role of Serology in Tracking COVID-19 Mutations

This article was originally published on Clinical Lab Products. As SARS-CoV-2 began its global proliferation in early 2020, scientists hastened to investigate its biology, develop diagnostic tests, and design candidate vaccines, marking one of the most...

Get in Touch

We sometimes send exclusive information and offers to our customers - please let us know if you are happy to receive these

12 + 10 =