Although the effects of IFN-α and high-dose AA on cytokine levels of HAM/TSP PBMCs were not significantly different, we suggest that high-dose AA has differential and superior immunomodulatory effects over IFN-α in HAM/TSP PBMCs, given the exacerbated in vitro production of primarily IFN-γ and TNF-α by PBMCs from HAM/TSP patients and their high in vivo levels in cerebrospinal fluid and spinal cord lesions of HAM/TSP patients [22], [35]–[39]. Here, TNF is linked to tropical spastic paraparesis.