Neurodegenerative disease in association with sexual transmission of human T-cell lymphotropic virus type 2 subtype b in Argentina

Abstract

Background: The aim of this study is to show that human T-cell lymphotropic virus type 2 (HTLV-2) infection produces symptoms resembling those described for HTLV-1-associated myeloneuropathy and to highlight the role of sexual transmission in the silent dissemination of HTLV-2. Methods: Patient samples were tested by particle agglutination and indirect immunofluorescence assay. The HTLV type was defined by molecular techniques. Nucleotide sequence analysis of HTLV-2 long terminal repeat region, T cell CD3/CD4 and T cell CD3/CD8 counts and typing of human leucocyte antigen (HLA) alleles A, B, C and DRB1 were also performed. Results: HTLV-2 subtype b infection was confirmed in two blood donors and their sexual partners. Two patients exhibited distinctive signs and symptoms of progressive neurological disease. Three infected patients carried HLA-C∗04. Both patients with neurological disease also carried HLA-A∗31 and HLA-DRB1∗07 alleles. Conclusions: Herein we describe for the first time sexual transmission of HTLV-2 in a non-endemic region of Argentina, highlighting the relevance of this transmission route in HTLV-2 silent dissemination out of the clusters of endemicity. We also provide evidence that HTLV-2 infection causes symptoms resembling those described for HTLV-1-associated myeloneuropathy. The evidence presented herein points to the critical need for public health strategies to reduce the spread of this neglected infection.