Human T lymphotropic virus types 1 and 2: a point of view

Reported at the beginning of the 1980s, Human T lymphotropic viruses type 1 and 2 (HTLV1, HTLV 2) were the first retroviruses to have been detected in human beings. HTLV 1 was isolated from adult T-cell leukemia (ATL) and first described by Takatsuki et al. in Japan in 1976, as a malignancy that only affects T cells and only in adults (1, 2). Albeit infrequent, HTLV-1 infection may lead to severe morbidity when it causes malignancy or degenerative conditions. The virus can also cause mild immune deficiency even in the absence of any malignancy. Fatal neurologic diseases, such as HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), uveitis, iritis, peripheral neuropathies, and arthritis can also be caused by HTLV-1. All these diseases can be autoimmune, but their exact mechanisms are not yet known (3). Human T lymphotropic virus type 2 (HTLV-2) was discovered in a patient with a T-cell variant of hairy cell leukemia. The virus has been associated with increased mortality and morbidity, risk for pneumonia and bronchitis, urinary tract infections, and rare neurologic manifestations. HTLV infection is lifelong and disease symptoms can manifest some 20-40 years post-infection