IL18 and tropical spastic paraparesis: HTLV-1 AC and HAM/TSP patients displayed similar CSF levels of VILIP-1, sRAGE, sTREM-1, sTREM-2, BDNF, VEGF, β-NGF, IL-6, IL-18, TNF-α, and fractalkine/CX3CL1 (Figure 4).