CD8A and tropical spastic paraparesis: Brito-Melo (2002 and 2006) and Coelho-dos-Reis (2007) and collaborators proposed that, among the many altered subset of cells on HTLV-1 carriers from Brazil, the decreased frequency of B cells, the increased frequency of activated CD8+ T cells and the T/B cell ratio are characteristic of HAM/TSP patients [13], [22], [39].