Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 32-03: Other Neurotropic Viruses + Key Features Download Section PDF Listen +++ ++ Retroviruses, types 1 and 2, that infect CD4 and CD8 T cells, respectively HTLV-1 infection Associated with HTLV-1 adult T cell lymphoma/leukemia (ATL) and HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) Infects approximately 20 million individuals worldwide Endemic in southern Japan, Caribbean, much of the sub-Saharan Africa, South America, Eastern Europe, Oceania HTLV-2 is mainly found in native populations of South (1–58%), Central (8–10%) and North America (2–13%), as well as African pygmies tribes Virus is transmitted horizontally (sex), vertically (intrauterine, peripartum, and prolonged breast-feeding), and parenterally (injection drug use and blood transfusion) Transmission via organ transplant has been reported Disease may flare when biologic agents are used for rheumatoid conditions + Clinical Findings Download Section PDF Listen +++ ++ ATL presents with Diffuse lymphadenopathy Maculopapular skin lesions Periodontitis Bronchoalveolar disorder Organomegaly Lytic bone lesions Hypercalcemia Opportunistic infections, such as Pneumocystis jirovecii pneumonia and cryptococcal meningitis, are common HTLV-1 seropositivity is associated with Increased risk of tuberculosis and Strongyloides stercoralis hyperinfection Crusted scabies Infective dermatitis HTLV positivity is associated with erythrocytosis, lymphocytosis (HTLV-2) and with thrombocytosis (HTLV-1). HTLV-2 appears to cause a myelopathy that is milder and slower to progress than HAM HTLV-1/HIV coinfection is associated both with higher CD4 counts and a higher risk of HAM Inflammatory states associated with HTLV-1 infection include Arthropathy Recurrent facial palsies Polymyositis Uveitis Sicca Sjögren syndrome Vasculitis Cryoglobulinemia Infiltrative pneumonitis Ichthyosis Studies from Brazil show that a subset of patients with chronic inflammation and HTLV-1 infections May be asymptomatic Are recognized as having an "intermediate syndrome" that may progress to full blown myelopathy Bronchioloalveolar carcinoma is increased in frequency in the presence of HTLV-1 HAM characterized by Progressive motor weakness Symmetric spastic paraparesis Bilateral facial palsies Falls Nociceptive low back pain Paraplegia with hyperreflexia Bladder and sexual disorders (eg, dyspareunia, erectile dysfunction), sensory disturbances, constipation + Diagnosis Download Section PDF Listen +++ ++ The peripheral smear can show atypical lymphoid cells with basophilic cytoplasm and convoluted nuclei (flower cells) The diagnostic standard is evidence of clonal integration of the proviral DNA genome into tumor cell Identification of HTLV-1 antibodies supports the diagnosis An HTLV-1 provirus load in peripheral blood mononuclear cells and CSF cells, and an HTLV-1 mRNA load are proposed as markers of HAM risk and progression Serum neopterin levels may indicate disease activity + Treatment Download Section PDF Listen +++ ++ No vaccine or antiviral therapy currently exists for the prevention and treatment of HTLV infections, although considerable research in Japan on the use of the viral product tax in immunotherapy remains underway ATL managed with chemotherapy, with allogeneic stem cell transplantation and use of monoclonal antibodies Mogamulizumab, an anti-CCR4 inhibitor Anti-CD25 agents Cerdulatinib, a dual SYK/JAK [spleen tyrosine kinase/Janus kinase] inhibitor A chemotherapy regimen in Japan using eight different agents shows a higher response rate than traditional biweekly CHOP (40% vs 25%) Combination therapy with interferon-alpha has been used with success. A therapeutic vaccine is in early clinical trials Prophylaxis against infections is needed in ATL because patients show a profound immunodeficiency HAM Treated with a variety of immune-modulating agents (including corticosteroids) without consistent results Combination therapies being studied include Raltegravir alone or in combination with zidovudine Prednisolone, pegylated interferon, and sodium valproate Pentoxifylline, cyclosporine, and tamibarotene Plasmapheresis may improve gait and sensory disturbance among some patients Pulsed methylprednisolone may improve muscle pain Interferon-alpha may be of some efficacy Blood supply is now screened for HTLV-1 because transfusion is a recognized mode of transmission Patients who are coinfected with HIV-1 and HTLV reportedly do respond to antiretroviral therapy for HIV