CD4 and tropical spastic paraparesis: Patients with HTLV-1-associated inflammatory diseases (e.g., HAM/TSP and uveitis) exhibit more substantial lung tissue injury, as evidenced by the significantly increased levels of lymphocytes (CD4+ and CD25+), cytokines (IL-2, IL-12, and IFN-γ), and inflammatory chemokines (MIP-1α and IP-10) as well as cell adhesion molecules (ICAM-1) in the BALF compared to the levels observed in asymptomatic carriers (Yamazato et al., 2003; Nakayama et al., 2011, 2013).