CD4 and hypersensitivity pneumonitis: Another characteristic of pulmonary disorders in patients with HTLV-1 is the presence of alveolitis (cryptogenic fibrosing alveolitis) and lymphocytosis (CD4+ and CD25+) (Matsuyama et al., 2003), in another study that evaluates the peripheral blood monocyte cells (PBMCs) and BALF from six patients (five HAM/TSP and one HTLV-1 carrier) who had pulmonary involvement, lymphocytosis and the presence of HTLV-1 provirus in the BALF of HTLV-1 patients was found (Kawabata et al., 2012).